Nanocomposites based on cellulose nanofibers: preparation methodologies and applications Carmen S. R. Freire
CICEC CENTRE FR RESEARCH IN CERAMICS AND CMPSITE MATERIALS CICEC main lines of expertise are: - Nano- and Micro-Structured Materials for Information and Communication Technology - Materials for Energy and Industrial Applications - Sustainability and Biomaterials Biorefineries, Biobased Materials and Recycling macromolecular lignocellulosic and materials CICEC-UAveiro
CICEC New (nano)omposite materials from biopolymers: - Polysacharides, proteins, etc. - ther polymers - Inorganic nanophases New polymeric materials from renewable resources : - 2,5-Difurancarboxylic acid - Vegetable oils derivatives High value extractives from biomass residues, fruits and algae: - Lipophilic extractives - Phenolics New materials from biomass residues (e.g bio-based PU foams from cork powder and other agro-forest residues, etc.)
utline Hybrids with metal/ metal oxide NPs Surface functionalization/ modification Nanostructured materials (in situ polymerization) Transparent (Nano) composites
utline Hybrids with metal/ metal oxide NPs Surface functionalization/ modification Nanostructured materials (in situ polymerization) Transparent (Nano) composites
Hybrid materials with metal /metal oxide nanoparticles NFC nanocomposites with Ag and Zn NPs for antibacterial paper products
Hybrid materials with metal /metal oxide nanoparticles NFC nanocomposites with Ag and Zn NPs for antibacterial paper products: LBL assembly Paper coating NFC 2.3 % solid content (1) Assembly of NFC and Zn or Ag NPs using polyelectrolytes (PDDA, PSS) as macrolinkers 2) Application of the obtained NFC/Zn or NFC/Ag nanofillers in paper coating starch based formulations (16 % solid content)
Hybrid materials with metal /metal oxide nanoparticles NFC nanocomposites with Ag and Zn NPs for antibacterial paper products: S. aureus Zn <0.03% (w/w) Ag 4.5x10-5 % (w/w) Applications: functional packaging, bioactive coatings, etc.
Hybrid materials with metal /metal oxide nanoparticles BC composites with Cu nanostructures (NPs and nanowires)
Hybrid materials with metal /metal oxide nanoparticles BC composites with Cu nanostructures (NPs and nanowires) (1) Cu NPs; in situ synthesis (2) Cu nanowires; ex situ synthesis + Dispersion
Hybrid materials with metal /metal oxide nanoparticles BC composites with Cu nanostructures (NPs and nanowires) 3 days - The use of Cu nanowires and BC has shown improved chemical stability against oxidation when exposed to normal ambient conditions - The nanocomposites were stable for periods of time (30 days) that makes the production of Cu-based products more attractive for emerging technologic applications as electronic nanopaper 5 months
Hybrid materials with metal /metal oxide nanoparticles BC composites with Cu nanostructures (NPs and nanowires) Cu nanocomposites showed antibacterial action against both bacteria, however with a more marked effect in respect to K. pneumoniae For both bacteria studied, BC/Cu nanowires nanocomposite present an antibacterial activity significantly lower (more than 2 log bacterial growth) in relation to the nanocomposite with copper NPs with similar copper amount (BC/Cu NPs2)
utline Hybrids with metal/ metal oxide NPs Surface functionalization/ modification Nanostructured materials (in situ polymerization) Transparent (Nano) composites
Transparent nanocomposite films Transparent nanocomposite films based on nanocellulose fibers and polysacharides starch chitosan pullulan
Transparent nanocomposite films Transparent nanocomposites based on NFC (or BC) and chitosan
Transparent nanocomposite films Transparent nanocomposites based on NFC (or BNC) and chitosan LCH - WSLCH HCH - WSHCH 1.5% (v/w) Dispersion Ultra-Turrax 20 500 rpm 30 min. Degassing NFC or BC (up to 40%) HCH HCHBC10 Casting 30ºC ventilated oven 16 h A fully green process
Transparent nanocomposite films Transparent nanocomposites based on NFC (or BNC) and chitosan CH 5% 40 % 10 % SEM images show the good dispersion of the NFC nanofibres at the surface of chitosan films The good dispersion together with the good interfacial adhesion of CH and cellulose gave rise to nanocomposites with improved mechanical properties
Transparent nanocomposite films Multipolysaccharide (starch, nanocellulose fibers, chitosan) based nanocomposite films Mechanical properties (NFC or BC) Tranparency and antimicrobial activity (chitosan) Thermal stability (starch)
Transparent nanocomposite films Transparent nanocomposites based on NFC (or BC) and pullulan
Transparent nanocomposite films Transparent nanocomposites based on NFC (or BC) and pullulan Improved thermal stability and mechanical properties
Transparent nanocomposite films Applications of transparent thin nanocomposite films: functional packaging, biomedical applications (bioactive films/coatings, wound healing films, drug delivery systems, etc.) organic electronics Work in progress: Self-standing chitosan based films as dielectrics in organic thin-film transistors (express Polymer letters 7, 2013, 960-965 Nanocellulose as substrates for inkjet printing of organic thin film transistors
Aqueous coating compositions for use in surface treatment of cellulosic substrates W 2011012934 A2 Transparent nanocomposite films Nanocellulose blends for paper coating Improved printability (gamut area, intercolour bleeding, etc.) and surface properties
utline utline Hybrids with metal/ metal oxide NPs Surface functionalization/ modification Nanostructured materials (in situ polymerization) Transparent (Nano) composites
Surface functionalization/modification Antimicrobial and biocompatible BC membranes obtained by surface functionalization with aminoalkyl groups
In addition, the bioactive nanostructured BC-NH 2 membranes also present improved mechanical and thermal properties. Applications wound healing membranes, bioactive scaffolds, etc. Surface functionalization/modification Antimicrobial and biocompatible BC membranes obtained by surface S. aureus functionalization with aminoalkyl groups BC H H log CFU T 24 10 9 8 7 6 5 4 3 2 1 0 Inoculated Broth + 5% NB BC E. coli BC-NH 2 H H H Immersion of BC membrane in the solution BC-NH 2 NH 2 log CFU T 24 9 8 7 6 5 4 3 2 1 0 Inoculated Broth + 5% NB BC BC-NH 2 Acetone H 3 C NH 2 Si CH 3 Thermal Treatment 2 h T=110 C Si Si NH 2 Si Si H CH 3 NH 2 rbital stirring 5h at 25 C (Si 7.3%, N 3.4 % (w/w))
Surface functionalization/modification Surface hydrophobization of nanocellulose fibers using ILs as solvent media and catalysts H R H +? R H R H H The use of cellulose fibers in the development of (nano)composites with thermoplastic matrices requires its preliminary surface chemical modification
Surface functionalization/modification Surface hydrophobization of nanocellulose fibers using ILs as solvent media and catalysts Modification Reaction time H H H + H H 80 ºC P F F N S S F solvent F F F Acetic Anhydride Butyric Anhydride Hexanoic Anhydride Alkenyl succinic anhydrides Hexanoyl chloride 6 hours 4 days 11 days 15 days 24 hours R H 2 S 4 as catalyst R or R Cl N N N S F F F catalyst F S F F H R H H H R
Surface functionalization/modification Surface hydrophobization of nanocellulose fibers using ILs as solvent media and catalysts The modification reactions involved essentially the H groups at the surface and the amorphous regions of the nanofibers (DS= 0.002-0.41)
Surface functionalization/modification Transparent nanocomposites based on bacterial nanocellulose and polylactic acid (PLA)
Applications: packaging, biomedical products and devices, electronic devices etc. Surface functionalization/modification Transparent nanocomposites based on bacterial nanocellulose and PLA Melting mixing PLA - Higher homogeneity Acetylated BC (DS = 0.02) (1, 3, 6 % (w/w)) - Thermal stability and - Mechanical performance - Low water up-take
Surface functionalization/modification Nanocellulose fibers/acrylic resins nanocomposites: comercial aqueous acrylic emulsions
Surface functionalization/modification Nanocellulose fibers/acrylic resins nanocomposites: comercial aqueous acrylic emulsions Dispersion of BC into the acrylic emulsions Solvent casting
Surface functionalization/modification Nanocellulose fibers/acrylic resins nanocomposites: comercial aqueous acrylic emulsions 1,0 0,8 TGA DTGA 1,0 380 o C 414 o C 0,8 0,6 m/m i 0,6 0,4 0,4 0,2 0,0 320 340 360 380 400 420 440 AC 0,2 AC-BC1 AC-BC2.5 AC-BC5 AC-BC10 0,0 0 100 200 300 400 500 600 700 800 Temp ( o C) Improved thermal and mechanical properties The good compatibility between unmodified fibers and the matrix is due in this case to the presence of surfactants used in the acrylic resin emulsion
utline Hybrids with metal/ metal oxide NPs Surface functionalization/ modification Nanostructured materials (in situ polymerization) Transparent (Nano) composites
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization techniques: ATRP
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization : ATRP Step 1- BC functionalization with the ATRP initiator Step 2- ATRP grafting from the BC macroinitiator
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization : ATRP The grafting of the polymers from BC macroinitiator was confirmed by FTIR and 13 C CP- MAS solid state
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization : ATRP The characteristic tridimensional network of nano and microfibrils of BC is clearly visible on the surface and cross-section of grafted BC-membranes. After grafting an increment of the diameter of the cellulose fibrils is observed which is obviously associated with the chemical sleeving by the PMMA or PBA polymeric chains.
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization : ATRP Grafting PMMA or PBA yielded highly hydrophobic membranes. The values of the elastic moduli across the whole temperature range are lower than that of the ungrafted BC membrane Because acrylate polymers are more flexible than the BC nanofibrillar network
Nanostructured materials Nanostructured cellulose composites prepared by in situ polymerization : Radical polymerization
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization The success of the polymerization reaction inside BC membranes was confirmed by FTIR and NMR analysis
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization BC/PHEMA/PEGDA (1:3:0) BC/PHEMA/PEGDA (1:3:0.5) BC/PHEMA/PEGDA (1:3:0) BC/PHEMA/PEGDA (1:3:0.5) The nanocomposites without crosslinker displayed a less homogenous morphology, with several unfilled parts, suggesting a considerable surface lixiviation of PHEMA during the washing step. The cross-section micrographs of the nanocomposite films displayed the typical lamellar morphology of BC completely impregnated with PHEMA
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization BC/PHEMA/PEGDA (1:3:0.5) The nanocomposites present distinct degradation profiles and the considerable increments on the Ti and Tdmax a when compared with BC and PHEMA
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization BC/PHEMA/PEGDA (1:3:0.5) BC/PHEMA nanocomposite films showed a considerably higher swelling ratio than BC membranes
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization BC/PHEMA/PEGDA (1:3:0.5) BC/PHEMA/PEGDA (1:3:0.05) are not cytotoxic for ADSCs and seem to be ideal for harboring cell growth Can be seen as a promising materials for several biomedical applications, including the design of 3D matrices to maintain a cellular niche for stem cell-mediated tissue regeneration
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization BC/PHEMA/PEGDA (1:3:0.5)
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization The homogeneous distribution of PSSA through the entire membrane thickness is supportive that electrical percolation can be attained
Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization The excellent mechanical behavior of pure BC is reflected on the composites both on magnitude of E (at least 20 times higher than that of Nafion) and on the thermomechanical stability
Drug delivery systems Nanocellulose as new biopolymer systems for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac)
Drug delivery systems Nanocellulose as a new biopolymer system for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac) Lidocaine Ibuprofen Wet BC membrane ven dried (30ºC) drug Glycerol Solution, 1h SEM No drug agglomerates Good dispersion
Drug delivery systems Nanocellulose as a new biopolymer system for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac) In vitro permeation tests 8h, 37ºC, PBS (phosphate buffer) drug determination: UV-Vis Human skin Franz cell Pharmaceutical Forms - BC membrane with drugs - Drugs solutions - Commercial gels or patches
Drug delivery systems - The permeation rate of drugs in nanocellulose membranes depends strongly on its nature. - This methodology can be successfully applied for the dermal administration of several drugs, regarding the release profile and ease of application.
Conlusions NanoCellulose fibers A unique biomacromolecular material Multiple opportunities Sustainable Development
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