Etching of Silicone Elastomers: Controlled Manipulation of Surface Roughness

摘要

The compatibility of biomaterials is related, among many other factors, to surface roughness. We describe a simple method using aqueous solutions of KOH in methanol (optionally with THF) to etch silicone elastomers to give materials ranging from about 20 nm to nearly 1 μ rms roughness. Surface depolymerization occurred linearly with time: roughness also increased with time, but not linearly. The degree of roughness was dependent on base concentration, reaction time and the presence of THF. Once the catalyst migrates into the silicone phase, base-catalyzed silicone degradation is more rapid than transfer back to the alcoholic solution, which leads to asymmetric surface pitting, the depth and frequency of which are controlled by solvency.