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Mol Cn,1. Lly C r y / , VOI. 35s. pp 401-41 I Kcprints avdilable directly fiom the puhlishrr Photocopying permitted by liceme only 0 2001 OPA (Oier\e.c\ I'uhliihcn Awiclanon) N.V. Published by licence under the Gordon and Breach Science Publishers imprint.The light induced switching of self-assembled monolayers containing azobenzenes is observed in situ by the Kelvin probe method. The switching process is optimized by preparing monolayers from mixed solutions of azobenzene thiols and n-alkylene thiols. In a film the efficiency of the E/Zisornerization depends on both the spacer length between azobenzene group and gold surface as well as the free volume in the film, tuned by the n-alkylene thiol fraction in the mixture. An optimum was found in a mixed self-assembling film conlaining 33% 4-fluoromethyl-4'-(lO-carboxy-decyloxy) azobenzene in a dodecane thiol matrix. The structure of the films were characterized by lTIR and AFM.

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Fluorinated poly(imide-amide)s containing pendant cyano groups have been synthesized by solution polycondensation of aromatic diamines which contain cyano groups with diacid chlorides which have both hexafluoroisopropylidene and imnide groups. Thermal crosslinking of these polymers has been attempted in NMP, or by heating the polymer films up to 370-400 'C. The solubility, thermal stability, glass transition temperature and dielectric constant of both linear and crosslinked polymers have been studied.