Abstract

Polydimethylsiloxane (PDMS) materials’ surface is naturally hydrophobic due to their hydrophobic siloxane structure. Modifying the hydrophobic surface of PDMS materials to hydrophilic is a key step for its application in biomaterial and biomedical applications. In this work, a novel, simple, environment friendly and cost effective method for hydrophilic surface modification via one-step hydrolysis of hydrophobic Si-O bond to generate hydrophilic hydroxyl group was proposed. PDMS-PU films was prepared by ultraviolet copolymerization of PDMS-HEMA macromere and the hydrophilizing reagent 2‐(trimethylsiloxy) ethyl methacrylate (TMSEMA). The as-prepared PDMS-PU film surface was subjected to reversal treatment using potassium hydroxide (KOH) solution to generate hydroxyl groups on the surface. The water contact angle (WCA), ATR-FTIR, equilibrium water content (EWC), SEM, mechanical properties and protein adsorption (PA) analysis were conducted on PDMS-PU films. The TMSEMA content had no obvious effect on the WCA, EWC, surface morphology and PA value of the pristine PDMS-PU film, but increased the mechanical strength and elongation at break. After subjection to the reversal treatment, the WCA deceased from 108° to 16° while the EWC value increased to 13% when the content of TMSEMA was 16%. The IR spectrum proved reverse reaction generated the carboxylate and hydroxyl groups on the surface. The hydrophilicity was stable over a period of study (days) while the defects on the surface of the film were observed after treatment. The protein adsorption, tensile strength and elongation at break were also investigated.

Keywords: Polydimethylsiloxane, 2‐(trimethylsiloxy) ethyl methacrylate; Reversal technique; Hydrophilic; Protein adsorption