0000000000422014
AUTHOR
D. Beyer
Second harmonic generation in self-assembled alternating multilayers of hemicyanine containing polymers and polyvinylamine
Abstract Assembly of noncentrosymmetric multilayers is a facile technique for preparing noncentrosymmetric films avoiding electrical poling procedures and problems from subsequent relaxation of the induced orientational order. A maximum Xzzz of 13 × 10−9 esu was achieved for the assembly of up to six layers. Current problems are the long-term hydrolysation of the hemicyanine nonlinear optical chromophores and the reduction of polar orientation with increasing layer thickness.
Micropatterning of neurons using organic substrates in culture
Abstract In this study, we have used spatially defined surfaces of organic thin films to micropattern the outgrowth of central nervous system neurons in culture. Glass substrates were first chemically modified with synthetic peptides derived from an extra-cellular matrix protein laminin to couple a functionality that promotes a neuron-substrate interaction. The modification procedure was verified using X-ray photoelectron spectroscopy. The functionality of the modified glass surfaces was examined by growing neurons dissociated from mammalian central nervous tissues in culture. Spatially defined surfaces of the peptide were then fabricated by selectively attaching the peptide to coplanar sur…
Complex Ordering in Thin Films of Di- and Trifunctionalized Hexaalkoxytriphenylene Derivatives
We have used pressure−area isotherms, X-ray diffraction, atomic force microscopy, and infrared dichroism to study Langmuir and Langmuir−Blodgett films of 2,3,6,7,10,11-hexaalkoxytriphenylenes which...
Covalently attached polymer mono- and multilayers on silanized glass substrates
Abstract Applying grazing incidence FTIR and ellipsometry, the reaction of poly [(1-methyl-vinyl isocyanate)-alt-(maleic anhydride)](IAP) with amino-silanized glass and silicon oxide surfaces has been investigated. A reactive surface containing isocyanate and anhydride groups was formed after the adsorption of the polymer. The layer could be further functionalized using 2-aminoethanol. Multilayers could be built up by adsorbing a second layer of IAP onto an already reacted first layer of IAP.
Thiopeptide-Supported Lipid Layers on Solid Substrates
The sequential layer-by-layer formation of peptide-supported bimolecular lipid membranes at solid supports is described. In the first step, thiol-derivatized peptide sequences of 5 and 7 amino acids are assembled on a Au substrate. After activation of their COOH-terminus phospholipid molecules (DMPE) are covalently attached via an amid bond to form a tethered monolayer on the Au electrode. The different preparation steps are analyzed by Fourier transform IR, X-ray reflectometry, and surface plasmon spectroscopy. The latter technique is then also used to on-line monitor at the solid/solution interface the formation of a bilayer by fusion of vesicles prepared from a fluid lipid mixture with a…