Authors Wieringa, R.H. ; Siesling, E.A. ; Geurts, P.F.M. ; Werkman, P.J. ; Vorenkamp, E.J. ; Erb, V. ; Stamm, M. ; Schouten, A.J.
Title Surface Grafting of Poly(L-glutamates). 1. Synthesis and Characterization
Date 27.11.2001
Number 10240
Abstract he ring-opening polymerization of N-carboxyanhydrides (NCA) of gamma -benzyl L-glutamate andy-methyl L-glutamate from (gamma -aminopropyl)triethoxysilane (APS) pretreated substrates such as silicon wafers and quartz slides was investigated. FT-IR transmission spectroscopy, circular dichroism measurements, and UV/vis spectroscopy confirmed the pure a-helix conformation of the grafted polypeptide layers. FT-IR spectroscopy also showed that the most important part of the polymer growth took place in the first 5 h of tl e polymerization. The average orientation of the rather rigid a-helical polypeptides, grown during a short period of time, was more perpendicular with respect to the substrate than the orientation of the polymers grown over a longer reaction time. For concentrations up to 2.0 M, the polymer growth from both NCA monomers showed a pronounced dependence on the monomer concentration. Moreover, it appeared that the higher the monomer concentration, the,more perpendicular the average orientation of the helices with respect to the substrate. The thickness of the grafted polypeptide layers up to 400 Angstrom was determined with ellipsometry and small-angle X-ray reflection measurements. The absence of chemical chain termination was demonstrated by additional polymer growth in a renewed polymerization.
Publisher Langmuir
Citation Langmuir 17 (2001) 6477-6484
Tags self-assembled monolayers poly(gamma-benzyl glutamate) helical polypeptides n-carboxyanhydride polymerization oxide (3-aminopropyl)triethoxysilane (co)polyglutamates (co)polyaspartates multilayers

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