Catechol-Functionalized Chitosan/Iron Oxide Nanoparticle Composite Inspired by Mussel Thread Coating and Squid Beak Interfacial Chemistry

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "Catechol-Functionalized Chitosan/Iron Oxide Nanoparticle Composite Inspired by Mussel Thread Coating and Squid Beak Interfacial Chemistry"

Transcription

1 pubs.acs.org/langmuir Catechol-Functionalized Chitosan/Iron Oxide Nanoparticle Composite Inspired by Mussel Thread Coating and Squid Beak Interfacial Chemistry Ondrej Zvarec,, Sreekanth Purushotham, Admir Masic, Raju V. Ramanujan, and Ali Miserez,,, * School of Materials Science and Engineering, Nanyang Technological University, Singapore ; Centre for Biomimetic Sensor Science, Nanyang Technological University, Singapore ; Energy Research Institute at NTU, Nanyang Technological University, Singapore ; Max-Planck Institute of Colloids and Interfaces, Department of Biomaterials, Science Campus Golm, Potsdam, Germany; School of Biological Sciences, Nanyang Technological University, Singapore *S Supporting Information ABSTRACT: Biological materials offer a wide range of multifunctional and structural properties that are currently not achieved in synthetic materials. Herein we report on the synthesis and preparation of bioinspired organic/inorganic composites that mimic the key physicochemical features associated with the mechanical strengthening of both squid beaks and mussel thread coatings using chitosan as an initial template. While chitosan is a well-known biocompatible material, it suffers from key drawbacks that have limited its usage in a wider range of structural biomedical applications. First, its load-bearing capability in hydrated conditions remains poor, and second it completely dissolves at ph < 6, preventing its use in mild acidic microenvironments. In order to overcome these intrinsic limitations, a chitosan-based organic/inorganic biocomposite is prepared that mimics the interfacial chemistry of squid beaks and mussel thread coating. Chitosan was functionalized with catechol moieties in a highly controlled fashion and combined with superparamagnetic iron oxide (γ-fe 2 O 3 ) nanoparticles to give composites that represent a significant improvement in functionality of chitosan-based biomaterials. The inorganic/organic (γ-fe 2 O 3 /catechol) interfaces are stabilized and strengthened by coordination bonding, resulting in hybrid composites with improved stability at high temperatures, physiological ph conditions, and acid/base conditions. The inclusion of superparamagnetic particles also makes the composites stimuli-responsive. INTRODUCTION Synthetic materials that mimic the chemical and structural complexity of biological systems are the holy grail of bioinspired composite formulation. With increasing understanding of structure property relationships of many natural materials at various length scales, from the molecular level up to the micro- and macro-scale, an increasing number of bioinspired synthetic strategies are emerging. 1 Among the various length scales probed in biological materials, the molecular scale, which particularly includes the elucidation of primary sequence in protein-based materials, their posttranslational modifications, or their interfacial chemistry, perhaps remains the most elusive. However, there are notable exceptions of biological materials whose molecular-scale designs have been elucidated, and those represent unique source of bioinspired synthesis strategies. Two such materials include squid beaks and mussel thread cuticle coatings, whose strengthening mechanisms at the molecular scale have recently been revealed. Squid beaks are highly sclerotized chitin-proteinwater composites with graded structural properties that correlate with molecular gradients. 2 The compliant region attached to the jaw muscular tissue is mostly composed of hydrated chitin ( 80 wt. pct water) with a small amount of hydrophilic proteins. Moving toward the hard rostrum, the water is gradually exchanged by Gly- and His-rich proteins. These proteins impregnate the chitinous nanofibrillar network, and are subsequently stabilized by covalent cross-linking between His and catecholic residues, the latter originating either from post-translational modification of Tyr into dihydroxylphenylalanine (DOPA), or from secretion of lowmolecular weight catecholic compounds. This curing mechanism has a dual role in squid beak maturation. First, it results in a dense cross-linked network of proteins that enclose the chitin nanofibrous network. Second, it drives water molecules out of the chitin network, stiffening the chitin fiber by localized dehydration. 3 Hence, a key physicochemical characteristic is the controlled desolvation of molecular-bound water from the chitin polymer. In mussel thread coatings, a central and unusual Received: May 20, 2013 Revised: July 16, 2013 Published: July 18, American Chemical Society 10899

2 characteristic that hardens the protective layer (known as the cuticle) is the presence of DOPA-Fe 3+ coordination bonds, which cross-link the cuticle proteins into dense micro- and nanoscale globular particles. 4,5 Under mechanical stress, the load is transferred onto the dense DOPA-Fe 3+ globular regions, circumventing cuticle failure through formation of microfractures, highlighting the role of the DOPA-Fe 3+ coordination as a sacrificial bond. 6 In the first stage of our composite strategy, we functionalized chitosan fibers (CS) with catecholic moieties (CAT) in a controlled manner, with the dual goals of (i) reducing the number of hydrophilic amine motifs along the backbone, and (ii) providing the polymer with side-chain functionality that triggers subsequent cross-linking (Scheme 1). Catecholic Scheme 1. Synthetic Strategy of Chitosan Derived Bio- Inspired Organic/Inorganic Composites functional groups were chosen because of their versatile characteristics, 7 including covalent cross-linking 8 and coordination bonding. 6,9 This is followed by induced coordination of functionalized chitosan with superparamagnetic iron oxide (γ- Fe 2 O 3 ) nanoparticles, allowing catecholic side groups to form a robust coordinated-bonded network with the surface of iron oxide nanoparticles, similar to the catechol-fe 3+ coordination cross-linked network observed in mussel thread coatings. 6 The addition of superparamagnetic γ-fe 2 O 3 nanoparticles (MNP) enables magnetic functionality, 10 making these hybrid composites multifunctional, robust, and stimuli-active materials that could be employed in various biomedical devices. EXPERIMENTAL SECTION Synthesis of Iron(III) Oxide (Fe 2 O 3 ) Nanoparticles. FeCl 3 6H 2 O (27g, 0.1 M) and FeCl 2 4H 2 O (10g, 0.05M) were dissolved in ultrapure Milli-Q water (200 ml) and heated to 80 C under nitrogen. To the solution was added 0.14 M NaOH dropwise over 20 min and the solution was stirred at 80 C for 30 min. The solution was then cooled, centrifuged at 8000 rpm for 15 min, and the precipitate was collected. The precipitate was washed with water (5 200 ml) and magnetically separated to give magnetite nanoparticles (Fe 3 O 4 ), which were stored under an inert atmosphere. Magnetite nanoparticles (Fe 3 O 4 ) were converted to maghemite (γ-fe 2 O 3 ) by oxidation in air at 150 C for 1 h, yielding particles with an average size of 11.6 nm (SD = 3). Synthesis of Catechol-Functionalized Chitosan (CAT CS ). To a solution of 92% deacetylated chitosan (1 equiv) in water ( ml) was added at ambient temperature 1-hydroxybenzotriazole hydrate (HOBT) (2 equiv) and stirred for 1 h. Respective Catechol ( equiv) and N-ethyl-N -(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI) (2 equiv) in ethanol (100 ml) was added and the solution stirred for 7 days. The solution was dialyzed with water until the dialysate tested negative to the Arnow assay (typically 6 4 ltr changes). The resulting solution was then lyophilized to give the required functionalized chitosan polymer. L-DOPA ; 1 H NMR (400 MHz; D 6 -DMSO-d 6, δ) (s, 1H), 8.71 (s, 2H), 6.94 (d, 1H, J = 6.0 Hz), 6.92 (t, 1H, J = 4 Hz), 6.47 (d, 1H, J = 4 Hz), (m, 1H), (m, 2H), 1.34 (s, 9H). 11 Chitosan; 1 H NMR (400 MHz; D 2 O, δ) 3.83 (s, 1H) 3.65 (s, 2H), 3.09 (3H). 12 DOPA CS (2), 1 H NMR (400 MHz; D 2 O, δ) (m, 3H, DOPA) 3.82 (s, 1H, chitosan), 3.63 (s, 2H, chitosan) (s, 3H, chitosan), (m, 2H, DOPA). DHA CS (3), 1 H NMR (400 MHz; D 2 O, δ) (m, 3H, DHA), 3.81 (s, 1H, chitosan), 3.63 (s, 2H, Chitosan), 3.07 (s, 3H, chitosan), (m, 2H, DHA), (m, 1H, DHA), (m, 1H, DHA). Chitosan Polymer-Fe 2 O 3 Nanoparticle Incorporation Preparation (mnp-cat CS ). To a solution of requisite chitosan polymer (100 mg) in 15% acetic acid (20 ml) was added Fe 2 O 3 nanoparticle (1 equiv or 0.1 equiv respective to CAT CS monomer unit) in 1 ml in a single portion and allowed to stir for 72 h. The solution was dialyzed with water (3 4 ltr changes), and the solution decanted from unreacted nanoparticles into glass molds ( 5 cm diameter) and cured under atmospheric conditions. The resulting cured film was washed with water to give the desired composites. Surface Chemistry Analysis. 1H NMR spectra were obtained using a Bruker AVANCE I 400 MHz spectrometer in either deuterated dimethyl sulfoxide, chloroform, or water. Dimethyl sulfoxide (1H = 2.50 ppm, 13C = 39.5 ppm), chloroform (1H = 7.26 ppm, 13C = 77.0 ppm) and water (1H = 4.79 ppm) were used as internal standards for NMR analysis. Arnows assay was performed as per literature for each polymer to identify the presence of catechol. 13,14 UV vis spectra were obtained using a Thermo Scientific NanoDrop 2000c spectrophotometer for all modified chitosan polymers. Fourier transform infrared (FTIR) spectra were recorded for all polymers using a Bruker Vertex 70. For Raman spectroscopy, a continuous laser beam was focused on the sample through a confocal Raman microscope (CRM200, WITec) equipped with a piezo-scanner (P-500, Physik Instrumente). The diode-pumped 785 nm laser excitation (Toptica Photonics AG) was used in combination with a 20 objective lens (Nikon, NA = 0.4). The spectra were acquired using a CCD camera (DU401A-DR-DD, Andor) behind a grating (300 g mm 1 ) spectrograph (Acton, Princeton Instruments Inc.) (for each spectrum a total of 30 s integration time was applied). The ScanCtrlSpectroscopyPlus software (version 2.08, Witec) was used for spectra processing. Physical and Magnetic Properties Analysis. Transmission electron microscopy samples of the nanoparticles were prepared by drying a drop of the aqueous colloidal suspension on a copper grid. A JEOL 2010F transmission electron microscope operating at 200 kv was used for bright field imaging and particle size measurements were made using ImageJ software (see Figure S1a of the Supporting Information, SI). X-ray diffraction scans were performed on the iron oxide nanoparticle powder using a Shimadzu 6000 X-ray diffractometer with Cu Kα radiation of wavelength 1.54 Å at a scan rate of 0.5 min 1 through the 2Θ range of The Intensity vs 2Θ plot was matched to reference JCPDS files to indentify the phase and index the peaks (see Figure S1b of the SI). Magnetic measurements of the iron oxide nanoparticles as well as composite films were performed at room temperature up to an applied field strength of 20 koe with a vibrating sample magnetometer attached to a Quantum Design PPMS physical property measurement system. Mechanical Properties Analysis. Nanoindentation studies of composites were completed using a Hysitron TI950 triboindenter. Samples were mounted in epoxy resin before analysis. Dehydrated conditions: Using a 20 μm conical diamond probe with a load of 300 μn a series indentations across a 200 μm grid were 10900

3 Figure 1. FTIR analysis (A) of functional chitosan and composites, ph 3 and Raman spectra (B) of (1:1) mnp-dopa CS and mnp-dha CS composites. performed for each composite. Hydrated conditions: Samples were presoaked before analysis in ultrapure milli-q water. With a 20 μm conical diamond probe a series of indentations at a controlled load of 100 μn across a 200 μm grid were acquired for each composite. Thermal gravimetric analysis of the composite films was performed using a TA Instruments Q500 TGA system. Weight loss of bare iron oxide nanoparticles as well as pure chitosan was measured for reference. Samples ( 5 mg) were heated in the temperature range C at a ramp rate of 10 C min 1 in air and N 2. RESULTS AND DISCUSSION Using water-soluble EDCI/HOBT carbodiimide chemistry, a series of CAT CS polymers were prepared with a catecholic content in the range of 20 82%, representing the highest reported example of covalently bonded catechol into a polysaccharide backbone (see Table S1 of the SI). In tandem, recent developments in catechol functionalization of the chitosan backbone have emerged. 15 A similar level of catecholic functionalization was recently reported on polysiloxane elastomers by Heo et al., 16 with the goal of providing high affinity toward oxides. By limiting the addition of catechol, amidation could be achieved with highly controlled monomeric ratios. Typically, 1D HNMR (see Figures S2 S5 of the SI) spectrum showed resonances in the region of ppm, attributed to the aryl motif of the catechol with reduction of the amine peak at 3.08 ppm, all of which confirmed the amidation of chitosan s backbone. The active phenolic motifs were established through Arnow s staining, an effective assay in identifying the presence of catecholic motifs. 17 Iron oxide nanoparticles were incorporated into CAT CS polymers, and the impregnation process was controlled such that molar ratios of 1:1 and 1:0.1 (CAT CS : MNP) were obtained and cast into thin films. With 82% catechol functionalization (4a), the composites yielded a clustered microstructure, while with 47% functionalization, the composites (4b/d) were brittle. During thin film deposition, appropriate films of uniform thickness ( μm) were only obtained when the composites catecholic content was below 50% (4c/e), presumably due to the intrinsic hydrophobic interactions with the high catecholic content. These composites were subsequently characterized in more detail. In order to probe the nature of the functionalized chitosan/ Fe 2 O 3 interfaces, the composites were investigated by FTIR and Raman spectroscopy at various stages of processing. FTIR spectroscopy (Figure 1a) of CAT CS polymers showed the expected signals associated with the polysaccharide backbone and the presence of the catecholic motif including the aryl 6 (1405 cm 1 ) and phenolic alcohol bands (1267 cm 1 ). 22 Physical attachment of the catechol was confirmed with the presence of the amide I/II and carbonyl bands in the region cm 1. For unmodified chitosan, iron oxide addition resulted in a sharpening of the amine band with a shift of the CO alcohol band, suggesting close proximity of the iron oxide to these motifs. 23 Solubility tests (see Table S2 of the SI) revealed that these observations are most likely a result of physical entrapment and not coordination for unmodified chiton-based composites. The FTIR spectral changes observed for mnp-cat CS composites were more pronounced, confirming the formation of the γ-fe 2 O 3 -catechol coordination bond through loss of the phenolic band at 1260 cm 1. Further indicative of the new coordination bonds, the aryl vibrational bands broadened and split into two distinct signals, which, commonly occurs when aryl groups are in close proximity to metals. 4,24 The amide I/II bands associated with the amide bond grew in intensity, which is also attributed to the close proximity of these motifs to iron oxide. 23 These changes in FTIR spectra signal highlighted the successful coordination of iron oxide with our catechol-chitosan composites

4 Langmuir Figure 2. Physical properties of CATCS and mnp-catcs composites. (A) Polymers hydrated in 5% acetic acid ph 3. (B) Magnetization curves for mnp-catcs films. Control measurements (inset) show an anhysteric loop typical of superparamagnetic nanoparticles, with saturation magnetization of 66.1 emu g 1. (C) Representative cat-mnpcs film magnetized with neodymium magnet. amide bond decreases the charged state of chitosan at low ph, thus improving the stability of the CATCS composites at ph 3. Addition of iron oxide into neat chitosan composites gave materials that were still susceptible to mild acidic environments, with the composites completely degrading within 24hrs. This was not seen for the mnp-catcs composites, highlighting the importance of γ-fe2o3-catechol coordination in maintaining physical integrity and opening the pathway for use under physiological conditions, which is a key feature for biomedical applications. In summary, the vibrational spectroscopy data indicate that our composites successfully mimic key interfacial chemistry features from both squid beaks and mussel thread cuticles. First they mimic through catechol-assisted dehydration the controlled dehydration of chitin as in the squid beak; and second the functionalized chitin/inorganic interfaces are stabilized through the formation of γ-fe2o3-catechol coordination bonds that mimic DOPA-Fe3+ bonds detected in cuticle mussel threads.6 The magnetic property measurements (Figure 2b; see Table S4 of the SI) showed the expected magnetization properties for 1:1 and 0.1:1 mnp-catcs composites, with a 10- and 100-fold decrease in magnetization compared to bare γ-fe2o3 (66.1 emu g 1). This demonstrates the first addition of superparamagnetic iron chitosan-based scaffolds. The appropriate decrease in magnetic saturation with mass fractions (CATCS:MNP; 10:1 and 100:1) indicates that: (i) iron oxide nanoparticles retain their magnetic properties once coordinatebonded, and (ii) no unbound iron oxide is present within the composite. Raman spectroscopy of mnp-catcs (Figure 1b) showed the presence of key [M O] vibrational frequencies in the range 500 to 700 cm 1, which also supports the presence of γ-fe2o3catechol coordination bonds. These vibrational frequencies have been previously outlined as key features for oxygen metal chelation, with the 591 and 635 cm 1 indicative of coordination of the metal center by the oxygens on C3 and C4 of the catechol ring, respectively.6,25,26 The 540 cm 1 band arises upon charge transfer that proceeds only when both phenolic motifs are chelated to a transitional metal as is the case with γfe2o3-catechol chelation.26 Upon wetting the samples, the signals associated with chelation remained unchanged even with applied strains 50% that of the strain to failure. These results suggest that the γ-fe2o3-catechol coordinated network is stabilized by a relatively strong binding energy and that the coordinated bonds do not undergo reversible binding interactions, as has been documented for Fe3+-DOPA rich mfp-1 protein27,28 but in contrast to functionalized PEG singlemolecules.29 Further to this TGA measurement indicated that these prevailing coordination bonds are thermally stable up to 276 C (see Figure S6 and Table S3 of the SI). With higher catecholic (DOPA/DHA) content in the composites, water uptake decreased leading to a dehydration effect due to the increasing hydrophobic motifs expelling water. In tandem, this modification led to improved stability (Figure 2a), with all of the modified films shown to be resistant to a wider ph range from basic ( 10) to acidic ( 3) conditions. It has been well-documented30 33 that chitosan is soluble in mild acidic conditions with its exposed hydrophilic amine groups protonated at low ph. With our process, the newly formed 10902

5 Figure 3. Nanoindentation analysis of composites. (A) Young s modulus (E) of dehydrated and hydrated composites. (B) Relative change in Young s modulus (E) expressed in terms of the ratio E wet /E dry. (C) Representative load displacement curves for each state, left-dehydrated; righthydrated. The mechanical properties of the composites were probed by nanoindentation in both dry and hydrated states, using a sphero-conical tip (20 μm nominal radius) and Hertzian contact mechanics. Data summary (see Table S5 of the SI) and representative curves are presented in Figure 3. Nanomechanical values of the elastic modulus of chitosan and other polysaccharides are usually obtained using the classical Oliver-Pharr analysis. 34 However, we found that chitosan-based materials in this work systematically exhibited moduli approximately 3-fold higher when using the Oliver-Pharr method instead of the loading Hertzian portion of an indentation cycle, and attribute this phenomenon to poroelastic behavior. 35 Chitosan film contain a certain degree of porosity, hence it is likely that the network is axially packed during indentation, leading to higher modulus values at the peak load. The Hertzian contact solution is thus deemed more accurate in order to obtain elastic moduli of our materials. The indentation response of functionalized chitosan in the dry state highlighted a 25% stiffer network with addition of the catechol motif. Along with the hydrogen bonding of chitosan, addition of the phenolic motif can induce additional aryl interactions, as well as increase dehydration and π π organized packing. With MNP addition, the elastic modulus of mnp-dopa CS increased, going from 1.45 GPa (±0.06) for unreinforced DOPA CS, to 1.65 GPa (±0.17) with 0.1 M iron oxide, up to 1.88 GPa (±0.19) with 1 M iron oxide. The increase in modulus was more pronounced for mnp-dha CS composites, with elastic modulus values of 1.84 GPa (±0.21) and 2.37 GPa (±0.29) for 0.1 and 1 M iron oxide, respectively. We speculate that with 0.1 molar iron oxide, the moderate increase in elastic modulus is a result perhaps due to γ-fe 2 O 3 -DOPA coordination bonds being masked by the inherently high stiffness of dry chitosan fibers. Increasing iron oxide content to 1 molar led to high increases in elastic modulus, with mnp-dha CS demonstrating nearly a 2-fold increase while in the case of mnp-dopa CS, the elastic modulus only increased slightly. We speculate that this observation is a function of the amine side arm of DOPA imparting sites of irregular organizational packing in the composites, which decreases H-bonding and aryl π π interactions. In the hydrated state, differences between unmodified chitosan and the hybrid composites become more obvious, with the addition of MNPs mitigating the loss in stiffness upon hydration. Expressed in terms of the ratio E wet /E dry (Figure 3b) the relative decrease was lower for functionalized chitosan, and even less pronounced for iron oxide reinforced composites. The E wet /E dry ratio was 0.24 for raw chitosan, increasing to for functionalized chitosan, and maximal values in the range for MNPs-reinforced composites. Representative nanoindentation curves obtained under hydrated conditions (Figure 3c) demonstrate the clear effect of adding MNPs on the indentation response of mnp-cat CS composites. It should also be mentioned that in the wet state, no significant 10903

6 Figure 4. Hardness (left) and Young s Modulus E (right) of composites DOPA CS, DHA CS and native materials (hydrated conditions); muscle thread cuticle (M. galloprovincialis) 37 and Humboldt squid beak (tip). 2. differences were noticed for the two types of composites (mnp- DOPA CS versus mnp-dha CS ), with similar elastic moduli values obtained in both cases. Overall, the best-performing composite (mnp-dha CS 1:1 molar ratio) displayed a more than 3-fold increase in elastic modulus in comparison to raw chitosan in hydrated conditions with a value of 1.3 GPa, which is higher than currently available chitosan-based materials. 36 In the hydrated state, our composites exhibit higher modulus ( 50%) and hardness (2-fold) compared to the native muscle thread cuticle (M. galloprovincialis), 37 while significantly less than the squid beak. 2 γ-fe 2 O 3 coordination improves the mechanical properties of the functionalized chitosan, though we anticipate that further covalent cross-linking of the catechol motif would yield further improvements in modulus and hardness as observed in the squid beak. 2 Hybrid composites exhibit slight increases in mechanical properties in the dry state. Differences in mechanical response are much more dramatic in the hydrated state, where the elastic modulus of the hybrid composites is as much as 10-fold higher than the unmodified chitosan. Previous studies have underlined the key role of controlled water desolvation and cross-linking in increasing the strength and stiffness of sclerotized/chitosan composites, including squid beaks. 3 The present data can be explained on the basis of equivalent physicochemical mechanisms resulting from the chemical design inspired by our model systems. First, by mimicking the squid beak model (chitinuous network dehydration), controlled functionalization of DOPA/DHA moieties imparts the chitosan network with hydrophobic aryl motifs, thereby preventing excessive water uptake, which has a direct role in plasticizing the chitosan network. Second, the γ-fe 2 O 3 catechol coordinated network acts as a mimic of the mussel thread coating chemistry (DOPA- Fe 3+ coordination), providing sites on the surface of the polysaccharide fibrils for efficient load transfer to the iron oxide particles. Finally, a dual role of these two mechanisms is also plausible. It is reasonable to assume that the dense network of γ-fe 2 O 3 -catechol coordination bonds further prevents adsorption of water molecules on the surface of the chitosan chains, thereby mitigating the plasticization effect of water associated with interchain shearing during deformation. Overall, the combined mechanical and chemical degradation results highlight that the γ-fe 2 O 3 catechol coordination bond is an efficient means to prevent extreme losses in structural integrity (elastic modulus/hardness). CONCLUSIONS One major challenge in bioinspired materials synthesis and processing resides in preparing materials that mimic multiple length scales of the biological system. Here we have established a route toward γ-fe 2 O 3 -catechol clad composites that fulfills this goal, whereby chitosan was functionalized with catecholic motifs up to 82% and coordinated bonded with γ-fe 2 O 3 nanoparticles. Raman spectroscopy confirmed bidentate γ- Fe 2 O 3 -catechol chelation, while nanoindentation measurements demonstrated that this form of cross-linking is an efficient means to prevent loss in structural integrity in the hydrated condition. This bioinspired strategy also allows us to overcome two key drawbacks of chitosan, namely its poor load-bearing capability in hydrated conditions and its solubility in mild acidic microenvironments, which chitosan or iron oxide doped chitosan cannot achieve. The composites exhibit multifunctional properties after coordination bonding, displaying superparamagnetic behavior provided by the iron oxide nanoparticles. Biocompatible and magnetically responsive polymermagnetic nanoparticle composites 38,39 have been typically limited by their low stiffness in the physiological milieu, thus limiting the actuation forces that can be generated. The present coordinated-bonded hybrid composites, with an elastic modulus exceeding 1 GPa in hydrated conditions, overcomes this key limitation, opening the pathway for their use as stimuli- materials in various regenerative applications. responsive ASSOCIATED CONTENT *S Supporting Information Experimental details; 1 H NMR, TGA, TEM, XRD; nanoindentation and magnetization data for chitosan, catecholchitosan and mnp-cat CS. This material is available free of charge via the Internet at AUTHOR INFORMATION Corresponding Author * Notes The authors declare no competing financial interest. ACKNOWLEDGMENTS A.Mi. acknowledges the support of the Singapore National Research Foundation (NRF) through a NRF Fellowship. A.Ma

7 is grateful for support by the Alexander von Humboldt Foundation and the Max Planck Society in the framework of the Max Planck Research Award funded by the Federal Ministry of Education and Research. R.V.R. acknowledges the support of the U.S. AOARD, Tokyo. REFERENCES (1) Studart, A. Towards High-Performance Bioinspired Composites. Adv. Mat. 2012, 24 (37), (2) Miserez, A.; Li, Y.; Waite, J. H.; Zok, F. Jumbo Squid beaks: Inspiration for design of robust organic composites. Acta Biomater. 2007, 3 (1), (3) Miserez, A.; Schneberk, T.; Sun, C.; Zok, F. W.; Waite, J. H. The transition from stiff to compliant materials in squid beaks. Science 2008, 319 (5871), (4) Sever, M. J.; Weisser, J. T.; Monahan, J.; Srinivasan, S.; Wilker, J. J. Metal-mediated cross-linking in the generation of a marine-mussel adhesive. Angew. Chem., Int. Ed. 2004, 43 (4), (5) Holten-Andersen, N.; Mates, T. E.; Toprak, M. S.; Stucky, G. D.; Zok, F. W.; Waite, J. H. Metals and the integrity of a biological coating: The cuticle of Mussel Byssus. Langmuir 2008, 25 (6), (6) Harrington, M. J.; Masic, A.; Holten-Andersen, N.; Waite, J. H.; Fratzl, P. Iron-clad fibers: A metal-based biological strategy for hard flexible coatings. Science 2010, 328 (5975), (7) Sedo, J.; Saiz-Poseu, J.; Busque, F.; Ruiz-Molina, D. Catecholbased biomimetic functional materials. Adv. Mater. 2013, 25 (5), (8) Miserez, A.; Rubin, D.; Waite, J. H. Cross-linking chemistry of squid beak. J. Biol. Chem. 2010, 285 (49), (9) Taylor, S. W.; Luther, G. W.; Waite, J. H. Polarographic and spectrophotometric investigation of iron(iii) complexation to 3,4- dihydroxyphenylalanine-containing peptides and proteins from Mytilus edulis. Inorg. Chem. 1994, 33 (25), (10) Amstad, E.; Gillich, T.; Bilecka, I.; Textor, M.; Reimhult, E. Ultrastable iron oxide nanoparticle colloidal suspensions using dispersants with catechol-derived anchor groups. Nano Lett. 2009, 9 (12), (11) Sever, M. J.; Wilker, J. J. Synthesis of peptides containing DOPA (3,4-dihydroxyphenylalanine). Tetrahedron 2001, 57 (29), (12) Lai, W.-F.; Lin, M. C.-M. Nucleic acid delivery with chitosan and its derivatives. J. Controlled Release 2009, 134 (3), (13) Arnow, L. E. Colorimetric determination of the components of 3,4-dihydroxyphenylalaninetyrosine mixtures. J. Biol. Chem. 1937, 118 (2), (14) Barnum, D. W. Spectrophotometric determination of catechol, epinephrine, dopa, dopamine and other aromatic vic-diols. Anal. Chim. Acta 1977, 89 (1), (15) Kim, K.; Ryu, J. H.; Lee, D. Y.; Lee, H. Bio-inspired catechol conjugation converts water-insoluble chitosan into a highly watersoluble, adhesive chitosan derivative for hydrogels and LbL assembly. Biomater. Sci. 2013, 1 (7), (16) Heo, J.; Kang, T.; Jang, S. G.; Hwang, D. S.; Spruell, J. M.; Killops, K. L.; Waite, J. H.; Hawker, C. J. Improved performance of protected catecholic polysiloxanes for bioinspired wet adhesion to surface oxides. J. Am. Chem. Soc. 2012, 134 (49), (17) Waite, J. H.; Tanzer, M. L. Specific colorimetric detection of o- diphenols and 3,4-dihydroxyphenylalanine-containing peptides. Anal. Biochem. 1981, 111 (1), (18) Chen, F.; Wang, Z. C.; Lin, C. J. Preparation and characterization of nano-sized hydroxyapatite particles and hydroxyapatite/chitosan nano-composite for use in biomedical materials. Mater. Lett. 2002, 57 (4), (19) Jenjob, S.; Sunintaboon, P.; Inprakhon, P.; Anantachoke, N.; Reutrakul, V. Chitosan-functionalized poly(methyl methacrylate) particles by spinning disk processing for lipase immobilization. Carbohydr. Polym. 2012, 89 (3), (20) Zhao, D.-L.; Wang, X.-X.; Zeng, X.-W.; Xia, Q.-S.; Tang, J.-T. Preparation and inductive heating property of Fe 3 O 4 chitosan composite nanoparticles in an AC magnetic field for localized hyperthermia. J. Alloys Compd. 2009, 477 (1 2), (21) Zhu, H. Y.; Jiang, R.; Xiao, L.; Li, W. A novel magnetically separable gamma-fe 2 O 3 /crosslinked chitosan adsorbent: Preparation, characterization and adsorption application for removal of hazardous azo dye. J. Hazard. Mater. 2010, 179 (1 3), (22) Bilinska, B. On the structure of human hair melanins from an infrared spectroscopy analysis of their interactions with Cu 2+ ions. Spectrochim. Acta A-Mol. Biomol. Spectrosc. 2001, 57 (12), (23) Hernandez, R.; Zamora-Mora, V.; Sibaja-Ballestero, M.; Vega- Baudrit, J.; Lopez, D.; Mijangos, C. Influence of iron oxide nanoparticles on the rheological properties of hybrid chitosan ferrogels. J. Colloid Interface Sci. 2009, 339 (1), (24) Gulley-Stahl, H.; Hogan, P. A.; Schmidt, W. L.; Wall, S. J.; Buhrlage, A.; Bullen, H. A. Surface Complexation of catechol to metal oxides: An ATR-FTIR, adsorption, and dissolution study. Environ. Sci. Technol. 2010, 44 (11), (25) Farquhar, E.; Emerson, J.; Koehntop, K.; Reynolds, M.; Trmcǐc, M.; Que, L., Jr. In vivo self-hydroxylation of an iron-substituted manganese-dependent extradiol cleaving catechol dioxygenase. JBIC J. Biol. Inorg. Chem. 2011, 16 (4), (26) Hwang, D. S.; Harrington, M. J.; Lu, Q.; Masic, A.; Zeng, H.; Waite, J. H. Mussel foot protein-1 (mcfp-1) interaction with titania surfaces. J. Mater. Chem. 2012, 22 (31), (27) Holten-Andersen, N.; Fantner, G. E.; Hohlbauch, S.; Waite, J. H.; Zok, F. W. Protective coatings on extensible biofibres. Nat. Mater. 2007, 6 (9), (28) Zeng, H.; Hwang, D. S.; Israelachvili, J. N.; Waite, J. H. Strong reversible Fe 3+ -mediated bridging between dopa-containing protein films in water. Proc. Natl. Acad. Sci. U.S.A. 2010, 107 (29), (29) Lee, H.; Scherer, N. F.; Messersmith, P. B. Single-molecule mechanics of mussel adhesion. Proc. Natl. Acad. Sci. 2006, 103 (35), (30) Cho, Y.-W.; Jang, J.; Park, C. R.; Ko, S.-W. Preparation and solubility in acid and water of partially deacetylated chitins. Biomacromolecules 2000, 1 (4), (31) Pillai, C. K. S.; Paul, W.; Sharma, C. P. Chitin and chitosan polymers: Chemistry, solubility and fiber formation. Prog. Polym. Sci. 2009, 34 (7), (32) Rinaudo, M.; Pavlov, G.; Desbrie res, J. Influence of acetic acid concentration on the solubilization of chitosan. Polymer 1999, 40 (25), (33) Sogias, I. A.; Khutoryanskiy, V. V.; Williams, A. C. Exploring the factors affecting the solubility of chitosan in water. Macromol. Chem. Phys. 2010, 211 (4), (34) Aryaei, A.; Jayatissa, A. H.; Jayasuriya, A. C. Nano and micro mechanical properties of uncross-linked and cross-linked chitosan films. J. Mech. Behavior Biomed. Mater. 2012, 5 (1), (35) Hu, Y.; Chan, E. P.; Vlassak, J. J.; Suo, Z. Poroelastic relaxation indentation of thin layers of gels. J. Appl. Phys. 2011, 110 (8), (36) Gray, K. M.; Kim, E.; Wu, L.-Q.; Liu, Y.; Bentley, W. E.; Payne, G. F. Biomimetic fabrication of information-rich phenolic-chitosan films. Soft Matter 2011, 7 (20), (37) Holten-Andersen, N.; Zhao, H.; Waite, J. H. Stiff coatings on compliant biofibers: The cuticle of Mytilus californianus Byssal Threads. Biochemistry 2009, 48 (12), (38) Nguyen, V. Q.; Ahmed, A. S.; Ramanujan, R. V. Morphing soft magnetic composites. Adv. Mater. 2012, 24 (30), (39) Purushotham, S.; Ramanujan, R. V. Thermoresponsive magnetic composite nanomaterials for multimodal cancer therapy. Acta Biomater. 2010, 6 (2),

8 Langmuir NOTE ADDED AFTER ASAP PUBLICATION This paper was published on the Web on August 7, 2013, with an error in Figure 4. The corrected version was reposted on August 8,

Supporting Information

Supporting Information Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry 2014 Supporting Information Au nanoparticles supported on magnetically separable Fe 2 O 3 - graphene

More information

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, , Singapore. b

School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, , Singapore. b Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2014 Dopamine-Mo VI complexation-assisted large-scale aqueous synthesis of single-layer MoS 2 /carbon

More information

MAGNETIC NANOPARTICLES FOR HYPERTHERMIA APPLICATIONS. Mohamed DARWISH and Ivan STIBOR

MAGNETIC NANOPARTICLES FOR HYPERTHERMIA APPLICATIONS. Mohamed DARWISH and Ivan STIBOR MAGNETIC NANOPARTICLES FOR HYPERTHERMIA APPLICATIONS Mohamed DARWISH and Ivan STIBOR Institute for Nanomaterials, Advanced Technology and Innovation, Technical University of Liberec, 461 17Liberec, Czech

More information

Supporting Information

Supporting Information Electronic Supplementary Material (ESI) for CrystEngComm. This journal is The Royal Society of Chemistry 2015 A rare case of a dye co-crystal showing better dyeing performance Hui-Fen Qian, Yin-Ge Wang,

More information

Electronic Supplementary Information

Electronic Supplementary Information Electronic Supplementary Material (ESI) for Polymer Chemistry. This journal is The Royal Society of Chemistry 2015 Electronic Supplementary Information Tetraphenylethene-containing supramolecular hyperbranched

More information

Multi-Layer Coating of Ultrathin Polymer Films on Nanoparticles of Alumina by a Plasma Treatment

Multi-Layer Coating of Ultrathin Polymer Films on Nanoparticles of Alumina by a Plasma Treatment Mat. Res. Soc. Symp. Vol. 635 2001 Materials Research Society Multi-Layer Coating of Ultrathin Polymer Films on Nanoparticles of Alumina by a Plasma Treatment Donglu Shi, Zhou Yu, S. X. Wang 1, Wim J.

More information

Supporting Information:

Supporting Information: Supporting Information: In Situ Synthesis of Magnetically Recyclable Graphene Supported Pd@Co Core-Shell Nanoparticles as Efficient Catalysts for Hydrolytic Dehydrogenation of Ammonia Borane Jun Wang,

More information

Sub-10-nm Au-Pt-Pd Alloy Trimetallic Nanoparticles with. High Oxidation-Resistant Property as Efficient and Durable

Sub-10-nm Au-Pt-Pd Alloy Trimetallic Nanoparticles with. High Oxidation-Resistant Property as Efficient and Durable Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2014 Electronic Supplementary Information Sub-10-nm Au-Pt-Pd Alloy Trimetallic Nanoparticles with High

More information

enzymatic cascade system

enzymatic cascade system Electronic Supplementary Information Fe 3 O 4 -Au@mesoporous SiO 2 microsphere: an ideal artificial enzymatic cascade system Xiaolong He, a,c Longfei Tan, a Dong Chen,* b Xiaoli Wu, a,c Xiangling Ren,

More information

Synthesis of 12 nm iron oxide nanoparticles

Synthesis of 12 nm iron oxide nanoparticles Electronic Supporting Information for Dendronized iron oxide nanoparticles as contrast agent for MRI Brice Basly, a Delphine Felder-Flesch,* a Pascal Perriat, b Claire Billotey, c Jacqueline Taleb, c Geneviève

More information

Urchin-like Ni-P microstructures: A facile synthesis, properties. and application in the fast removal of heavy-metal ions

Urchin-like Ni-P microstructures: A facile synthesis, properties. and application in the fast removal of heavy-metal ions SUPPORTING INFORMATION Urchin-like Ni-P microstructures: A facile synthesis, properties and application in the fast removal of heavy-metal ions Yonghong Ni *a, Kai Mi a, Chao Cheng a, Jun Xia a, Xiang

More information

Supplementary Information. Formation of porous SnS nanoplate networks from solution and their application in hybrid solar cells

Supplementary Information. Formation of porous SnS nanoplate networks from solution and their application in hybrid solar cells Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2015 Supplementary Information to Formation of porous SnS nanoplate networks from solution and their

More information

Top down and bottom up fabrication

Top down and bottom up fabrication Lecture 24 Top down and bottom up fabrication Lithography ( lithos stone / graphein to write) City of words lithograph h (Vito Acconci, 1999) 1930 s lithography press Photolithography d 2( NA) NA=numerical

More information

Polymer Science, Series A, 2017, Vol. 59, No. 3 SUPPORTING INFORMATION. The Screening and Evaluating of Chitosan/β-cyclodextrin

Polymer Science, Series A, 2017, Vol. 59, No. 3 SUPPORTING INFORMATION. The Screening and Evaluating of Chitosan/β-cyclodextrin Polymer Science, Series A, 2017, Vol. 59, No. 3 SUPPORTING INFORMATION The Screening and Evaluating of Chitosan/β-cyclodextrin Nanoparticles for Effective Delivery Mitoxantrone Hydrochloride Yiwen Wang,

More information

Achiral CdSe quantum dots exhibit optical activity in the visible region upon post-synthetic ligand exchange with D- or L-cysteine

Achiral CdSe quantum dots exhibit optical activity in the visible region upon post-synthetic ligand exchange with D- or L-cysteine This journal is The Royal Society of Chemistry Supporting Information for the manuscript entitled Achiral CdSe quantum dots exhibit optical activity in the visible region upon post-synthetic ligand exchange

More information

Supplementary Information

Supplementary Information Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry 2016 Supplementary Information Multifunctional Fe 2 O 3 /CeO 2 Nanocomposites for Free Radical Scavenging

More information

Electronic Supplementary Information

Electronic Supplementary Information Electronic Supplementary Information Selective Diels-Alder cycloaddition on semiconducting single-walled carbon nanotubes for potential separation application Jiao-Tong Sun, Lu-Yang Zhao, Chun-Yan Hong,

More information

Supporting Information. for. Advanced Materials, adma Wiley-VCH 2008

Supporting Information. for. Advanced Materials, adma Wiley-VCH 2008 Supporting Information for Advanced Materials, adma.200701537 Wiley-VCH 2008 69451 Weinheim, Germany Supporting Information (adma.200701537) Nano-Carbon Superhydrophobic Surface Created from Fullerene

More information

dissolved into methanol (20 ml) to form a solution. 2-methylimidazole (263 mg) was dissolved in

dissolved into methanol (20 ml) to form a solution. 2-methylimidazole (263 mg) was dissolved in Experimental section Synthesis of small-sized ZIF-8 particles (with average diameter of 50 nm): Zn(NO 3 ) 2 (258 mg) was dissolved into methanol (20 ml) to form a solution. 2-methylimidazole (263 mg) was

More information

One-pot Solvent-free Synthesis of Sodium Benzoate from the Oxidation of Benzyl Alcohol over Novel Efficient AuAg/TiO 2 Catalysts

One-pot Solvent-free Synthesis of Sodium Benzoate from the Oxidation of Benzyl Alcohol over Novel Efficient AuAg/TiO 2 Catalysts Electronic Supplementary Information One-pot Solvent-free Synthesis of Sodium Benzoate from the Oxidation of Benzyl Alcohol over Novel Efficient AuAg/TiO 2 Catalysts Ying Wang, Jia-Min Zheng, Kangnian

More information

LAYER BY LAYER (LbL) SELF-ASSEMBLY STRATEGY AND ITS APPLICATIONS

LAYER BY LAYER (LbL) SELF-ASSEMBLY STRATEGY AND ITS APPLICATIONS LAYER BY LAYER (LbL) SELF-ASSEMBLY STRATEGY AND ITS APPLICATIONS A. Z. Cheng 1, R. Swaminathan 2 1 Nanotechnology Engineering, University of Waterloo, azcheng@uwaterloo.ca; 2 Nanotechnology Engineering,

More information

The Chinese University of Hong Kong Department of Chemistry

The Chinese University of Hong Kong Department of Chemistry Prof. Yue Zhao University of Sherbrooke Canada Control of Stimult-Responsive Polymers by New Methods December 1, 2014 (Monday) 2:30 p.m. Room G35 Lady Shaw Building Prof. Chi Wu Prof. Petr Štěpánek Institute

More information

Supporting Information

Supporting Information Electronic Supplementary Material (ESI) for Biomaterials Science. This journal is The Royal Society of Chemistry 2016 Supporting Information Preserving the Adhesion of Catechol Conjugated Hydrogels by

More information

Efficient Co-Fe layered double hydroxide photocatalysts for water oxidation under visible light

Efficient Co-Fe layered double hydroxide photocatalysts for water oxidation under visible light Supplementary Information Efficient Co-Fe layered double hydroxide photocatalysts for water oxidation under visible light Sang Jun Kim, a Yeob Lee, a Dong Ki Lee, a Jung Woo Lee a and Jeung Ku Kang* a,b

More information

Supporting Information

Supporting Information Supporting Information Phenyl-Modified Carbon Nitride Quantum Dots with Distinct Photoluminescence Behavior Qianling Cui, Jingsan Xu,* Xiaoyu Wang, Lidong Li,* Markus Antonietti, and Menny Shalom anie_201511217_sm_miscellaneous_information.pdf

More information

Three Dimensional Nano-assemblies of Noble Metal. Nanoparticles-Infinite Coordination Polymers as a Specific

Three Dimensional Nano-assemblies of Noble Metal. Nanoparticles-Infinite Coordination Polymers as a Specific Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2014 Electronic Supplementary Information Three Dimensional Nano-assemblies of Noble Metal Nanoparticles-Infinite

More information

Magnetic cellulose-chitosan hydrogels prepared from ionic liquids as reusable adsorbent for removal of heavy metal ions

Magnetic cellulose-chitosan hydrogels prepared from ionic liquids as reusable adsorbent for removal of heavy metal ions Magnetic cellulose-chitosan hydrogels prepared from ionic liquids as reusable adsorbent for removal of heavy metal ions Zhen Liu, Haisong Wang*, Chao Liu, Yijun Jiang, Guang Yu, Xindong Mu* and Xiaoyan

More information

Supporting Information

Supporting Information Supporting Information Polyoxometalate-based crystalline tubular microreactor: redox-active inorganic-organic hybrid materials producing gold nanoparticles and catalytic properties Dong-Ying Du, Jun-Sheng

More information

Supporting Information

Supporting Information Supporting Information Eco-friendly Composite of Fe 3 O 4 -Reduced Grapene Oxide Particles for Efficient Enzyme Immobilization Sanjay K. S. Patel a,, Seung Ho Choi b,, Yun Chan Kang b,*, Jung-Kul Lee a,*

More information

RESULTS AND DISCUSSION Characterization of pure CaO and Zr-TiO 2 /CaO nanocomposite

RESULTS AND DISCUSSION Characterization of pure CaO and Zr-TiO 2 /CaO nanocomposite RESULTS AND DISCUSSION 4.1. Characterization of pure CaO and Zr-TiO 2 /CaO nanocomposite 4.1.1. Scanning electron microscopy analysis (SEM) SEM images of prepared CaO are shown in Fig. 4.1 (a and b). CaO

More information

International Journal of Pure and Applied Sciences and Technology

International Journal of Pure and Applied Sciences and Technology Int. J. Pure Appl. Sci. Technol., 9(1) (2012), pp. 1-8 International Journal of Pure and Applied Sciences and Technology ISSN 2229-6107 Available online at www.ijopaasat.in Research Paper Preparation,

More information

A soft-templated method to synthesize sintering-resistant Au/mesoporous-silica core-shell nanocatalysts with sub-5 nm single-core

A soft-templated method to synthesize sintering-resistant Au/mesoporous-silica core-shell nanocatalysts with sub-5 nm single-core A soft-templated method to synthesize sintering-resistant Au/mesoporous-silica core-shell nanocatalysts with sub-5 nm single-core Chunzheng Wu, ab Zi-Yian Lim, a Chen Zhou, a Wei Guo Wang, a Shenghu Zhou,

More information

Supporting Information

Supporting Information Supporting Information Bamboo-Like Carbon Nanotube/Fe 3 C Nanoparticle Hybrids and Their Highly Efficient Catalysis for Oxygen Reduction Wenxiu Yang a,b, Xiangjian Liu a,b, Xiaoyu Yue a,b, Jianbo Jia,

More information

Electrically pulsatile responsive drug delivery platform for treatment of Alzheimer s disease

Electrically pulsatile responsive drug delivery platform for treatment of Alzheimer s disease Electronic Supplementary Material Electrically pulsatile responsive drug delivery platform for treatment of Alzheimer s disease Li Wu 1,2, Jiasi Wang 1,2, Nan Gao 1, Jinsong Ren 1, Andong Zhao 1,2, and

More information

Hybrid Gold Superstructures: Synthesis and. Specific Cell Surface Protein Imaging Applications

Hybrid Gold Superstructures: Synthesis and. Specific Cell Surface Protein Imaging Applications Supporting Information Hybrid Gold Nanocube@Silica@Graphene-Quantum-Dot Superstructures: Synthesis and Specific Cell Surface Protein Imaging Applications Liu Deng, Ling Liu, Chengzhou Zhu, Dan Li and Shaojun

More information

Jordan M. Rhodes, Caleb A. Jones, Lucas B. Thal, Janet E. Macdonald*

Jordan M. Rhodes, Caleb A. Jones, Lucas B. Thal, Janet E. Macdonald* Supporting Information for: Jordan M. Rhodes, Caleb A. Jones, Lucas B. Thal, Janet E. Macdonald* Department of Chemistry and Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University,

More information

Intensity (a.u.) Intensity (a.u.) Raman Shift (cm -1 ) Oxygen plasma. 6 cm. 9 cm. 1mm. Single-layer graphene sheet. 10mm. 14 cm

Intensity (a.u.) Intensity (a.u.) Raman Shift (cm -1 ) Oxygen plasma. 6 cm. 9 cm. 1mm. Single-layer graphene sheet. 10mm. 14 cm Intensity (a.u.) Intensity (a.u.) a Oxygen plasma b 6 cm 1mm 10mm Single-layer graphene sheet 14 cm 9 cm Flipped Si/SiO 2 Patterned chip Plasma-cleaned glass slides c d After 1 sec normal Oxygen plasma

More information

The characterization of MnO nanostructures synthesized using the chemical bath deposition method

The characterization of MnO nanostructures synthesized using the chemical bath deposition method The characterization of MnO nanostructures synthesized using the chemical bath deposition method LF Koao 1, F B Dejene 1* and HC Swart 2 1 Department of Physics, University of the Free State (Qwaqwa Campus),

More information

Development of NIR Bioimaging Systems

Development of NIR Bioimaging Systems Journal of Physics: Conference Series 16 (28) 1223 doi:1.188/1742-6596/16/1/1223 Development of NIR Bioimaging Systems Kohei SOGA 1, Takashi TSUJI 1, Fumio TASHIRO 1, Joe CHIBA 1 Motoi OISHI 2, Keitaro

More information

Sensing: a unified perspective for integrated photonics

Sensing: a unified perspective for integrated photonics Sensing: a unified perspective for integrated photonics Chemical detection Environmental monitoring Process control Warfighter protection Biological sensing Drug discovery Food safety Medical diagnosis

More information

SUPPLEMENTARY INFORMATION

SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION Covalent Bulk Functionalization of Graphene Jan M. Englert a, Christoph Dotzer a, Guang Yang b, Martin Schmid c, Christian Papp c, J. Michael Gottfried c, Hans-Peter Steinrück

More information

Electronic Supplementary Information

Electronic Supplementary Information Electronic Supplementary Information Facile synthesis of halogenated carbon quantum dots as an important intermediate for surface modification Jin Zhou, Pei Lin, Juanjuan Ma, Xiaoyue Shan, Hui Feng, Congcong

More information

Supporting Information

Supporting Information Supporting Information Wiley-VCH 2008 69451 Weinheim, Germany Supporting information: Iron Nanoparticle Catalyzed Hydrolytic Dehydrogenation of Ammonia Borane for Chemical Hydrogen Storage Jun-Min Yan,

More information

Electronic Supplementary Material. Methods. Synthesis of reference samples in Figure 1(b) Nano Res.

Electronic Supplementary Material. Methods. Synthesis of reference samples in Figure 1(b) Nano Res. Electronic Supplementary Material Shaped Pt Ni nanocrystals with an ultrathin Pt-enriched shell derived from one-pot hydrothermal synthesis as active electrocatalysts for oxygen reduction Jun Gu 1,, Guangxu

More information

NANOMEDICINE. WILEY A John Wiley and Sons, Ltd., Publication DESIGN AND APPLICATIONS OF MAGNETIC NANOMATERIALS, NANOSENSORS AND NANOSYSTEMS

NANOMEDICINE. WILEY A John Wiley and Sons, Ltd., Publication DESIGN AND APPLICATIONS OF MAGNETIC NANOMATERIALS, NANOSENSORS AND NANOSYSTEMS NANOMEDICINE DESIGN AND APPLICATIONS OF MAGNETIC NANOMATERIALS, NANOSENSORS AND NANOSYSTEMS Vijay K. Varadan Linfeng Chen Jining Xie WILEY A John Wiley and Sons, Ltd., Publication Preface About the Authors

More information

Influence of temperature and voltage on electrochemical reduction of graphene oxide

Influence of temperature and voltage on electrochemical reduction of graphene oxide Bull. Mater. Sci., Vol. 37, No. 3, May 2014, pp. 629 634. Indian Academy of Sciences. Influence of temperature and voltage on electrochemical reduction of graphene oxide XIUQIANG LI, DONG ZHANG*, PEIYING

More information

Supporting information

Supporting information Electronic Supplementary Material (ESI) for Journal of Materials Chemistry C. This journal is The Royal Society of Chemistry 2015 Supporting information Porosity induced emission: exploring color-controllable

More information

Relaxivity of Hydrogen Protons of Water Molecules in the Aqueous Solutions of Dextran - and Chitosan - Coated Ferrite Nanoparticles

Relaxivity of Hydrogen Protons of Water Molecules in the Aqueous Solutions of Dextran - and Chitosan - Coated Ferrite Nanoparticles ISSN 1749-8023 (print), 1749-8031 (online) International Journal of Magnetic Resonance Imaging Vol. 01, No. 01, 2007, pp. 015-020 Relaxivity of Hydrogen Protons of Water Molecules in the Aqueous Solutions

More information

Polydopamine as a promoter layer of MOF deposition on inert polymer surfaces to fabricate hierarchically structured porous films

Polydopamine as a promoter layer of MOF deposition on inert polymer surfaces to fabricate hierarchically structured porous films Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2015 Polydopamine as a promoter layer of MOF deposition on inert polymer surfaces to fabricate hierarchically

More information

CHAPTER 10. Characteristics of the Surfaces of Biomaterials

CHAPTER 10. Characteristics of the Surfaces of Biomaterials CHAPTER 10 Characteristics of the Surfaces of Biomaterials 10.1 Surface Characteristics Related to Chemical Bonding 10.2 Surface Chemistry Related to Bonding of Biological Molecules 10.3 Porosity 10.4

More information

A Novel Polytriazole-based Organogel Formed by the Effects. of Copper Ions

A Novel Polytriazole-based Organogel Formed by the Effects. of Copper Ions Supporting Information for A Novel Polytriazole-based Organogel Formed by the Effects of Copper Ions Key Laboratory for Specially Functional Polymeric Materials and Related Technology of the Ministry of

More information

Improving the accuracy of Atomic Force Microscope based nanomechanical measurements. Bede Pittenger Bruker Nano Surfaces, Santa Barbara, CA, USA

Improving the accuracy of Atomic Force Microscope based nanomechanical measurements. Bede Pittenger Bruker Nano Surfaces, Santa Barbara, CA, USA Improving the accuracy of Atomic Force Microscope based nanomechanical measurements Bede Pittenger Bruker Nano Surfaces, Santa Barbara, CA, USA How can we improve accuracy in our nanomechanical measurements?

More information

Yin and yang in chemistry education: the complementary nature of FTIR and NMR spectroscopies

Yin and yang in chemistry education: the complementary nature of FTIR and NMR spectroscopies APPLICATION NOTE Yin and yang in chemistry education: the complementary nature of FTIR and NMR spectroscopies No. 52742 Authors: Matthew Gundlach, Katherine Paulsen, Michael Garry, Steve Lowry, Thermo

More information

Study on the Selective Hydrogenation of Nitroaromatics to N-aryl hydroxylamines using a Supported Pt nanoparticle Catalyst

Study on the Selective Hydrogenation of Nitroaromatics to N-aryl hydroxylamines using a Supported Pt nanoparticle Catalyst Electronic Supplementary Material (ESI) for Catalysis Science & Technology. This journal is The Royal Society of Chemistry 204 Supporting Information Study on the Selective Hydrogenation of Nitroaromatics

More information

INFLUENCE OF CLAY ON MECHANICAL PROPERTIES OF POLYVINYL(ALCOHOL)/ MONTMORILLONITE MEMBRANES

INFLUENCE OF CLAY ON MECHANICAL PROPERTIES OF POLYVINYL(ALCOHOL)/ MONTMORILLONITE MEMBRANES INFLUENCE OF CLAY ON MECHANICAL PROPERTIES OF POLYVINYL(ALCOHOL)/ MONTMORILLONITE MEMBRANES Maria C. Carrera 1*, Eleonora Erdmann 1, Hugo A. Destéfanis 1 Marcos L. Dias 2, Victor J. R. R. Pita 2 1 Instituto

More information

A label-free DNA reduced graphene oxide-based fluorescent. sensor for highly sensitive and selective detection of hemin

A label-free DNA reduced graphene oxide-based fluorescent. sensor for highly sensitive and selective detection of hemin A label-free DNA reduced graphene oxide-based fluorescent sensor for highly sensitive and selective detection of hemin Yan Shi, Wei Tao Huang, Hong Qun Luo and Nian Bing Li* Key Laboratory on Luminescence

More information

Adsorption of Cd(II) ions by synthesize chitosan from fish shells

Adsorption of Cd(II) ions by synthesize chitosan from fish shells British Journal of Science 33 Adsorption of Cd(II) ions by synthesize chitosan from fish shells Angham G. Hadi Babylon University, College of Science, Chemistry Department. Abstract One of the major applications

More information

Pt-Ni alloyed nanocrystals with controlled archtectures for enhanced. methanol oxidation

Pt-Ni alloyed nanocrystals with controlled archtectures for enhanced. methanol oxidation Supplementary Information Pt-Ni alloyed nanocrystals with controlled archtectures for enhanced methanol oxidation Xiao-Jing Liu, Chun-Hua Cui, Ming Gong, Hui-Hui Li, Yun Xue, Feng-Jia Fan and Shu-Hong

More information

PHYSICAL AND CHEMICAL PROPERTIES OF ATMOSPHERIC PRESSURE PLASMA POLYMER FILMS

PHYSICAL AND CHEMICAL PROPERTIES OF ATMOSPHERIC PRESSURE PLASMA POLYMER FILMS PHYSICAL AND CHEMICAL PROPERTIES OF ATMOSPHERIC PRESSURE PLASMA POLYMER FILMS O. Goossens, D. Vangeneugden, S. Paulussen and E. Dekempeneer VITO Flemish Institute for Technological Research, Boeretang

More information

Ultrasensitive Immunoassay Based on Pseudobienzyme. Amplifying System of Choline Oxidase and Luminol-Reduced

Ultrasensitive Immunoassay Based on Pseudobienzyme. Amplifying System of Choline Oxidase and Luminol-Reduced Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2014 Supporting Information Ultrasensitive Immunoassay Based on Pseudobienzyme Amplifying System of

More information

CONFOCHECK. Innovation with Integrity. Infrared Protein Analysis FT-IR

CONFOCHECK. Innovation with Integrity. Infrared Protein Analysis FT-IR CONFOCHECK Infrared Protein Analysis Innovation with Integrity FT-IR CONFOCHECK: FT-IR System for Protein Analytics FT-IR Protein Analysis Infrared spectroscopy measures molecular vibrations due to the

More information

Supplementary Information

Supplementary Information Supplementary Information Time-dependent growth of zinc hydroxide nanostrands and their crystal structure Xinsheng Peng, ab Jian Jin, a Noriko Kobayashi, a Wolfgang Schmitt, c and Izumi Ichinose* a a Organic

More information

Linear Dependence of Water Proton Transverse Relaxation Rate on Shear Modulus in Hydrogels

Linear Dependence of Water Proton Transverse Relaxation Rate on Shear Modulus in Hydrogels Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 214 ESI (Electronic Support Information) Linear Dependence of Water Proton Transverse Relaxation Rate

More information

Facile Synthesis and Catalytic Properties of CeO 2 with Tunable Morphologies from Thermal Transformation of Cerium Benzendicarboxylate Complexes

Facile Synthesis and Catalytic Properties of CeO 2 with Tunable Morphologies from Thermal Transformation of Cerium Benzendicarboxylate Complexes Electronic Supplementary Information Facile Synthesis and Catalytic Properties of CeO 2 with Tunable Morphologies from Thermal Transformation of Cerium Benzendicarboxylate Complexes Yuhua Zheng, Kai Liu,

More information

Electrospun UV-responsive Supramolecular Nanofibers from Cyclodextrin-Azobenzene Inclusion Complex

Electrospun UV-responsive Supramolecular Nanofibers from Cyclodextrin-Azobenzene Inclusion Complex Electrospun UV-responsive Supramolecular Nanofibers from Cyclodextrin-Azobenzene Inclusion Complex Menglin Chen,* a Søren Rosegaard Nielsen, a Tamer Uyar, b Shuai Zhang, a Ashar Zafar, c Mingdong Dong

More information

Electronic Supplementary Information

Electronic Supplementary Information Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2014 Electronic Supplementary Information MoS 2 nanosheet/mo 2 C-embedded N-doped

More information

Clean synthesis of propylene carbonate from urea and 1,2-propylene glycol over zinc iron double oxide catalyst

Clean synthesis of propylene carbonate from urea and 1,2-propylene glycol over zinc iron double oxide catalyst Journal of Chemical Technology and Biotechnology J Chem Technol Biotechnol 81:794 798 (2006) DOI: 10.1002/jctb.1412 Clean synthesis of propylene carbonate from urea and 1,2-propylene glycol over zinc iron

More information

Surface modification of Microfibrillated Cellulose films by Gas-Phase Esterification: Improvement of Barrier Properties.

Surface modification of Microfibrillated Cellulose films by Gas-Phase Esterification: Improvement of Barrier Properties. Surface modification of Microfibrillated Cellulose films by Gas-Phase Esterification: Improvement of Barrier Properties. G. Rodionova*, M. Lenes**, Ø. Eriksen**, B. H. Hoff*, Ø. W. Gregersen* * Norwegian

More information

Supplementary Information

Supplementary Information Supplementary Information (1) Synthesis and Characterization Figure S1. 1 H-NMR of 3 (400 MHz; CDCl3; rt). Figure S2. 13 C-NMR of 3 (100 MHz; CDCl3; rt). S2 8000 7500 7000 6500 6000 5500 5000 4500 4000

More information

Chapter 6 Magnetic nanoparticles

Chapter 6 Magnetic nanoparticles Chapter 6 Magnetic nanoparticles Magnetic nanoparticles (MNPs) are a class of nanoparticle which can be manipulated using magnetic field gradients. Such particles commonly consist of magnetic elements

More information

Structure and Properties of Chitosan/Chitin-Nanofibrils Based Materials

Structure and Properties of Chitosan/Chitin-Nanofibrils Based Materials Structure and Properties of Chitosan/Chitin-Nanofibrils Based Materials Jindřich Hašek, IBT AV ČR Praha Chitosan random co-polymer GlcN/GlcNac with content of GlcNac (i.e. DA - Degree of Acetylation) lower

More information

Impact of multivalent charge presentation on peptide

Impact of multivalent charge presentation on peptide Supporting Information File 1 for Impact of multivalent charge presentation on peptide nanoparticle aggregation Daniel Schöne 1, Boris Schade 2, Christoph Böttcher 2 and Beate Koksch* 1 Address: 1 Institute

More information

Rapid Preparation of Polymersomes by a Water Addition/Solvent Evaporation Method. Supporting Information

Rapid Preparation of Polymersomes by a Water Addition/Solvent Evaporation Method. Supporting Information Rapid Preparation of Polymersomes by a Water Addition/Solvent Evaporation Method Supporting Information Hana Robson Marsden, Luca Gabrielli, Alexander Kros* Department of Soft Matter Chemistry, Leiden

More information

Surface Modification of Biomaterials

Surface Modification of Biomaterials Lecture 9: Surface Modification of Biomaterials Supporting notes 3.051J/20.340J Materials for Biomedical Applications, Spring 2006 1 Purpose: Alter surface properties to enhance performance in biological

More information

An Optimal Substrate Design for SERS: Dual-Scale Diamond-Shaped Gold Nano-Structures Fabricated via Interference Lithography

An Optimal Substrate Design for SERS: Dual-Scale Diamond-Shaped Gold Nano-Structures Fabricated via Interference Lithography Supporting Information An Optimal Substrate Design for SERS: Dual-Scale Diamond-Shaped Gold Nano-Structures Fabricated via Interference Lithography Hyo-Jin Ahn a, Pradheep Thiyagarajan a, Lin Jia b, Sun-I

More information

Constructing covalent organic frameworks in water via dynamic covalent bonding

Constructing covalent organic frameworks in water via dynamic covalent bonding Supporting information IUCrJ Volume 3 (2016) Supporting information for article: Constructing covalent organic frameworks in water via dynamic covalent bonding Jayshri Thote, Harshitha Barike Aiyappa,

More information

Preparation of Aminated Mesoporous Silica Nanoparticles (MSNs) by Delayed Co-condensation Technique

Preparation of Aminated Mesoporous Silica Nanoparticles (MSNs) by Delayed Co-condensation Technique Extra Supporting Information (ESI) Experimental Procedures General All chemicals were purchased from Sigma-Aldrich and used as received, unless otherwise specified. 2,2',2''-(10-(2-((2,5-dioxopyrrolidin-1-yl)oxy)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-

More information

Application of nanoindentation technique to extract properties of thin films through experimental and numerical analysis

Application of nanoindentation technique to extract properties of thin films through experimental and numerical analysis Materials Science-Poland, Vol. 28, No. 3, 2010 Application of nanoindentation technique to extract properties of thin films through experimental and numerical analysis A. WYMYSŁOWSKI 1*, Ł. DOWHAŃ 1, O.

More information

Mussel-inspired polydopamine coating as a versatile platform for in situ synthesis of graphene-based nanocomposites. Supporting information

Mussel-inspired polydopamine coating as a versatile platform for in situ synthesis of graphene-based nanocomposites. Supporting information Mussel-inspired polydopamine coating as a versatile platform for in situ synthesis of graphene-based nanocomposites Liangqia Guo, a,b Qian Liu, a Guoliang Li, a Jianbo Shi, a Jiyan Liu, a Thanh Wang, a

More information

Supporting Information

Supporting Information Supporting Information For the manuscript Catalyst-free Preparation of Melamine-based Microporous Polymer Networks through Schiff Base Chemistry by Matthias Georg Schwab, + Birgit Faßbender, + Hans Wolfgang

More information

Improving Adhesion: Examining the Electrochemistry of Organic Inhibitors

Improving Adhesion: Examining the Electrochemistry of Organic Inhibitors Improving Adhesion: Examining the Electrochemistry of rganic Inhibitors Benefits of rganics Chemisorb onto metallic substrates Complex with metal ions at substrate Neutralize & absorb the corrodents Decrease

More information

hs( T T ) Q I max surr 0 A808

hs( T T ) Q I max surr 0 A808 Electronic Supplementary Material One-pot synthesis of MoSe 2 hetero-dimensional hybrid self-assembled by nanodots and nanosheets for electrocatalytic hydrogen evolution and photothermal therapy Baoguang

More information

Supporting Information. Robust Bioinspired Graphene Film via π-π Cross-linking

Supporting Information. Robust Bioinspired Graphene Film via π-π Cross-linking Supporting Information Robust Bioinspired Graphene Film via π-π Cross-linking Hong Ni, a Feiyu Xu, a Antoni P. Tomsia, a,b Eduardo Saiz, c Lei Jiang, a and Qunfeng Cheng* a a Key Laboratory of Bio-inspired

More information

MATERIALS SCIENCE POLYMERS

MATERIALS SCIENCE POLYMERS POLYMERS 1) Types of Polymer (a) Plastic Possibly the largest number of different polymeric materials come under the plastic classification. Polyethylene, polypropylene, polyvinyl chloride, polystyrene,

More information

The design and construction of 3D rose petal-shape MoS 2. hierarchical nanostructures with structure-sensitive. properties

The design and construction of 3D rose petal-shape MoS 2. hierarchical nanostructures with structure-sensitive. properties Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A. This journal is The Royal Society of Chemistry 2014 The design and construction of 3D rose petal-shape MoS 2 hierarchical nanostructures

More information

MATERIALS AND METHODS

MATERIALS AND METHODS THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 285, NO. 33, pp. 25850 25858, August 13, 2010 2010 by The American Society for Biochemistry and Molecular Biology, Inc. Printed in the U.S.A. Protein- and Metal-dependent

More information

Supporting Information. Synthesis of Metallic Magnesium Nanoparticles by Sonoelectrochemistry. Iris Haas and Aharon Gedanken*

Supporting Information. Synthesis of Metallic Magnesium Nanoparticles by Sonoelectrochemistry. Iris Haas and Aharon Gedanken* Supporting Information Synthesis of Metallic Magnesium Nanoparticles by Sonoelectrochemistry Iris Haas and Aharon Gedanken* Experimental Materials and chemical preparation The Gringard reagents, ethyl-mgcl

More information

Low Molecular Weight Gelator Dextran Composites

Low Molecular Weight Gelator Dextran Composites Low Molecular Weight Gelator Dextran Composites Lin Chen, a Steven Revel, a Kyle Morris, b David G. Spiller, c Louise Serpell, b and Dave J. Adams*,a a Department of Chemistry, University of Liverpool,

More information

Structural effects on catalytic activity of carbon-supported magnetite. nanocomposites in heterogeneous Fenton-like reactions

Structural effects on catalytic activity of carbon-supported magnetite. nanocomposites in heterogeneous Fenton-like reactions Electronic Supplementary Material (ESI) for RSC Advances. This journal is The Royal Society of Chemistry 2018 Supplementary Information Structural effects on catalytic activity of carbon-supported magnetite

More information

EE C247B / ME C218 INTRODUCTION TO MEMS DESIGN SPRING 2014 C. Nguyen PROBLEM SET #4

EE C247B / ME C218 INTRODUCTION TO MEMS DESIGN SPRING 2014 C. Nguyen PROBLEM SET #4 Issued: Wednesday, Mar. 5, 2014 PROBLEM SET #4 Due (at 9 a.m.): Tuesday Mar. 18, 2014, in the EE C247B HW box near 125 Cory. 1. Suppose you would like to fabricate the suspended cross beam structure below

More information

CHEM-C2410: Materials Science from Microstructures to Properties Composites: basic principles

CHEM-C2410: Materials Science from Microstructures to Properties Composites: basic principles CHEM-C2410: Materials Science from Microstructures to Properties Composites: basic principles Mark Hughes 14 th March 2017 Today s learning outcomes To understand the role of reinforcement, matrix and

More information

Karine Chesnel BYU. Idaho State University, Physics department 22 September 2014

Karine Chesnel BYU. Idaho State University, Physics department 22 September 2014 Karine Chesnel BYU Idaho State University, Physics department 22 September 2014 Potential applications of magnetic nanoparticles Magnetic recording Biomedical applications J. Mater. Chem., 19, 6258 6266

More information

X-ray excitable luminescent polymer dots doped with iridium(iii)

X-ray excitable luminescent polymer dots doped with iridium(iii) Electronic Supporting Information for X-ray excitable luminescent polymer dots doped with iridium(iii) complex Yasuko Osakada,* a,b Guillem Pratx, c Lindsey Hanson, a Paige Elana Solomon, a Lei Xing* c

More information

Application of Nano-ZnO on Antistatic Finishing to the Polyester Fabric

Application of Nano-ZnO on Antistatic Finishing to the Polyester Fabric Modern Applied Science January, 2009 Application of Nano-ZnO on Antistatic Finishing to the Polyester Fabric Fan Zhang & Junling Yang School of Material Science and Chemical Engineer Tianjin Polytechnic

More information

One-pot synthesis of micron partly hollow anisotropic dumbbell shaped silica core-shell particles

One-pot synthesis of micron partly hollow anisotropic dumbbell shaped silica core-shell particles Electronic Supplementary Material (ESI) for ChemComm. This journal is The Royal Society of Chemistry 2016 Supporting Information One-pot synthesis of micron partly hollow anisotropic dumbbell shaped silica

More information

Supporting Information Detailed Experiments Materials: All the reagents were analytical grate and used without further purification.

Supporting Information Detailed Experiments Materials: All the reagents were analytical grate and used without further purification. Supporting Information Detailed Experiments Materials: All the reagents were analytical grate and used without further purification. Synthesis of the Steep Rhombohedra MnCO 3 : In a typical synthesis,

More information

Title of file for HTML: Supplementary Information Description: Supplementary Figures and Supplementary References

Title of file for HTML: Supplementary Information Description: Supplementary Figures and Supplementary References Title of file for HTML: Supplementary Information Description: Supplementary Figures and Supplementary References Supplementary Figure 1. SEM images of perovskite single-crystal patterned thin film with

More information

Chapter 10. Nanometrology. Oxford University Press All rights reserved.

Chapter 10. Nanometrology. Oxford University Press All rights reserved. Chapter 10 Nanometrology Oxford University Press 2013. All rights reserved. 1 Introduction Nanometrology is the science of measurement at the nanoscale level. Figure illustrates where nanoscale stands

More information

A novel Ag 3 AsO 4 visible-light-responsive photocatalyst: facile synthesis and exceptional photocatalytic performance

A novel Ag 3 AsO 4 visible-light-responsive photocatalyst: facile synthesis and exceptional photocatalytic performance Electronic Supplementary Material (ESI) for Chemical Communications Supporting Information A novel Ag 3 AsO 4 visible-light-responsive photocatalyst: facile synthesis and exceptional photocatalytic performance

More information

Graphene is a single, two-dimensional nanosheet of aromatic sp 2 hybridized carbons that

Graphene is a single, two-dimensional nanosheet of aromatic sp 2 hybridized carbons that Chemical Identity and Applications of Graphene-Titanium Dioxide Graphene is a single, two-dimensional nanosheet of aromatic sp 2 hybridized carbons that enhances the performance of photocatalysts. 1 The

More information