Synthesis of blood compatible PDMS-based organic-inorganic hybrid coatings

PDMS-TiO₂ hybrid coating sols were prepared from silanol-terminated polydimethylsiloxane and titanium tetraisopropoxide through sol-gel process. The coating sols were developed on stainless steel substrate with dip-coating technique. The surface structure of the hybrid coating was characterized by Fourier transform infrared (FT-IR) analysis, contact angle, and surface free energy on the hybrid coating. Blood compatibility was also evaluated in terms of blood clotting time and platelet adhesion. The hybrid coatings have high contact angles and low surface free energies compared to coating-free metal surface. The blood clotting properties were not affected by the hybrid coatings but the platelet adhesion was depressed to less than 1/20 as much as that for the coating-free substrate.