Preparation Of SEBS Films Functionalized By Sugar-based Gemini Surfactants And Research On Its Hemocompatibility

A series of sugar-based gemini surfactants with different chain lengths weresynthesized by using natural saccharide and long chain amines as raw materials. Thechemical structures of the sugar-based gemini surfactants were characterized by means ofFourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR). Thesurface properties of the products, such as surface tension, critical micelle concentrations(cmc) and foaming abilities, were respectively measured by pendant drop method (PDM)and enhanced Ross-Miles method. Sugar-based gemini surfactants could reduce thesurface tension down to33.0~38.6mN/m, and their critical micelle concentrations were inrange of2×10-4~5×10-4mol/L, which were one order of magnitude lower than those ofsingle head group surfactants. Meanwhile, N-octalkyl glucitol and N-dodecyl glucitolgemini surfactants exhibited favorable foaming property and foam stability. It meant thatsugar-based gemini surfactants with special dimeric structures possessed better capacityand efficiency of reducing surface tension than those of the conventional linearsurfactants.Poly (styrene-b-(ethylene-co-butylene)-b-styrene)(SEBS) functionalized by epoxygroups were prepared via a technique of UV-induced surface graft polymerization. Effectof grafting parameters including UV irradiation time, monomer concentration and initiatorconcentration had been adjusted to optimize the protocol for the surface modification ofSEBS substrate. Then the sugar-based gemini surfactants were chemically immobilizedonto the SEBS surfaces based on the ring-opening of the epoxy groups and the hydroxylgroups. The surface graft polymerization was verified by FTIR and XPS. The relationshipbetween chain length of the surfactants and the amphiphility and hemocompatibility of themodified surface were evaluated by means of static contact angle, protein adsorption andplatelet adhesion. It was found that the SEBS surfaces modified with surfactants of shorteralkyl chain length presented good hydrophilicity and amphiphility, thus possessed the positive anti-platelet adhesion and protein-resistant behavior. Increasing the alkyl chainlength of gemini surfactants, the hydrophobicity of the surface got stronger and thehydrophilicity got weaker. Therefore, surface of that kind could not inbibit the proteinadsorption and platelet adhesion effectively, thus exhibiting poor hemocompatibility.