Macromolecules, Vol.36, No.10, 3689-3694, 2003
Hydrosilation-cured poly(dimethylsiloxane) networks: Intrinsic contact angles via dynamic contact angle analysis
A method for measuring intrinsic advancing (theta(adv)) and receding (theta(rec)) water contact angles is reported for hydrosilylation-cured poly(dimethylsiloxane) network coatings that are analogues of biomedical materials. Static and dynamic contact angle (DCA) methods were used to evaluate coatings prepared from commercial divinyl-terminated poly(dimethylsiloxane) (C-DVPDMS) and synthesized low polydispersity divinyl-terminated poly(dimethylsiloxane) (N-DVPDMS). DCA measurements showed that coatings prepared with both C-DVPDMS and N-DVPDMS contaminated the water surface during analysis. For ambient temperature cure, the rate of contamination was C-DVPDMS > N-DVPDMS. Methods for acquiring intrinsic contact angles on the PDMS coatings include using a large surface area reservoir or changing the water reservoir between DCA cycles. Intrinsic contact angles for hydrosilylation-cured PDMS coatings are as follows: theta(adv), 118degrees, theta(rec), 83degrees; after contamination of the water surface the contact angles change to theta(adv), 108degrees, theta(rec) 87degrees.