1.Chitosan-silane sol-gel hybrid thin films with controllable layer thickness and morphology.
Spirk S1, Findenig G, Doliska A, Reichel VE, Swanson NL, Kargl R, Ribitsch V, Stana-Kleinschek K. Carbohydr Polym. 2013 Mar 1;93(1):285-90. doi: 10.1016/j.carbpol.2012.04.030. Epub 2012 Apr 27.
The preparation of thin films of chitosan-silane hybrid materials by combining sol-gel processing and spin coating is reported. A variety of silanes can be used as starting materials for the preparation of such thin films, namely tetraethoxysilane, tri-tert-butoxysilanol, trimethylethoxysilane, p-trifluoromethyltetra-fluorophenyltriethoxysilane, trivinylmethoxysilane, (methoxymethyl)trimethyl-silane, and hexamethoxydisilane. These silanes are subjected to a sol-gel process before they are added to acidic chitosan solutions. The chitosan:silane ratio is kept constant at 6:1 (w/w) and dilutions with ethanol are prepared and spin coated. Depending on the degree of dilution, film thickness can be controlled in a range between 5 and 70 nm. For the determination of additional surface properties, static water contact angle measurements and atomic force microscopy have been employed.