Heidelberg, 20. Nov. 2014

Transcription

1 AG Zharnikov Surface Science & Analytics Angewandte Physikalische Chemie Heidelberg, 20. Nov. 2014

2 Research areas of the group Focal objects are thin organic films, self-assembled monolayers (SAMs), nanotechnology, and bio-relevant molecular systems SAM design & properties lithography & nanofabrication molecular electronics CT dynamics ultrathin membranes SAM hybrid systems s s ssdna films s biology & liquids standard surface science industrial projects Synchrotron-based research (BESSY, Max-lab, ALS, etc.) and a broad, world-wide collaboration with many partner groups

3 Nanofabrication on the SAM basis several examples Electrochemical synthesis of metal nanoparticles on molecular-engineered template Chemical Lithography: gradient patterns Adv. Mat. 19, 998 (2007) cm Control over surface topography I II III 5 m m 5µm Ang. Chem. Int. Ed. 48, 5833 (2009) Nature 460, 308 (2009) - Res. High. nm B artificial dolphin skin 1 µm Ang. Chem. Int. Ed. 44, 2 (2005) Ang. Chem. Int. Ed. 47, 1421 (2008) Ang. Chem. Int. Ed. 47, 6786 (2008)

4 Fabrication of metal films & NP assemblies on SAM surface Used an advanced SAM design and combining functionalization of the SAM by the thiol group with its cross linking by e beam, we were able to prepare well defined metal film at the SAM ambient interface 48% ISS inte ensity (a arb. units s) Ni CL-TPDMT/Au 45mC/cm 2 in 5 min in 24 h Au ISS erosion time (min) also nanoparticles (Co, 10 nm) can be assembled on SAM surface Y. Tai, MZ, et al., Adv. Mater. 17, 1745 (2005) J. Zhao, MZ, et al., Adv. Func. Mater. 21, 4724 (2011)

5 Femtosecond charge transfer dynamics through the molecular framework core hole clock approach device coupling to the substrate resonant X ray photon molecular wire resonantly excitable e group resonant spectrum non resonant spectrum Different decay scenarios result in different decay spectra P CB CT CB UV OV IS UV OV IS + = SP CB A CB UV OV IS UV OV IS well defined CT path 9 fs 31.5 fs S. Neppl, MZ et al., Chem. Phys. Lett. 447, 227 (2007) H. Hamoudi, MZ et al., Phys. Rev. Lett. 107, (2011)

6 Prototypes of molecular switches: light driven trans cis isomerisation in molecular junction V. Ferri, MZ, et al., Ang. Chem. Int. Ed. 47, 3407 (2008)

7 A schematic model of the photo induced, cooperative isomerization: molecular domino trans cis The arrows indicate the direction of the bending. G. Pace, MZ et al., PNAS 104, 9937 (2007)

8 Surface bound ssdna: properties, hybridization ability, and patterning orientation of the individual segments could be monitored hybridization ability could be monitored C. Howell, MZ, et al., Chem. Phys. Lett. 513, 267 (2011) A25 SH imbedded intoa protein repelling repelling matrix by IPER EBL S. M. Schreiner, MZ, et al., Anal. Chem. 83, 4288 (2011) M. Khan, MZ, et al., Ang. Chem. Int. Ed. 51, (2012)

9 Studies of liquid and biologically-relevant objects in native (aqueous) environment flow-through liquid cell 100 nm SiN membrane X-rays fluorescence NEXAFS, XES, RIXS Normalized in ntensity (a. u. XES )EXAFS, H2O non res. D 2 O non res. 22 D 2 O-H 2 O H 2 O-D 2 O NaOH res. biointerfaces proteins cells Emission energy (ev) The experiments rely on precise knowledge of the XAS spectra of the basic building blocks of biological macromolecules O. Fuchs, MZ et al., Phys. Rev. Lett. 100, (2008)

10 Design of non disruptive, free standing monomolecular membranes for biological applications ferritin core lattice N. Meyerbröker, MZ, et al., Chem. Mater. 24, 2965 (2012)

11 Hydrogel films & nanomembranes for sensor applications PEG + Cross-Linking = STAR-branched PEGs Hymidity/temperature sensor Sensing element in MEMS applications 22 C 65 nm hybrid hydrogel/aunp film 2 C 100 nm membrane free-standing over 1 mm opening N. Meyerbröker, MZ, et al. ACS Appl. Mater. Interfaces 5, 2641 (2013) N. Meyerbröker & MZ, Adv. Mater. 26, 3328 (2014)

12 Hydrogel membranes as transient templates for nanopatterning a) b) c) d) e) PHF patterning Structured PHF transferring PHM template NP seeding NP / PHM composite hydrogen plasma Patterned NP array N. Meyerbröker & MZ, ACS Appl. Mat. Interfaces 6, (2014)

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14 Gruppezusammensetzung und Leistung Momentan: 4D Doktoranden und d2p Postdocs Jeder Doktorand/Postdoc hat sein eigenes Projekt bzw. Projekte und mitarbeitet, unter Umständen, auch an anderen Projekten. nur Drittmittel-Finanzierung : 72 Publikationen in referierten Zeitschriften 87 Tagungsbeiträge, davon 24 eingeladen