StudStudy On Hydrophilic Silane Self-assembly And Its Resistance To Protein Adsorption

The polyethylene oxide was widely used in biocompatibility materials, due to the fexiblechains,hydrated and biologically inert. The organic silane with reactive group such aschlorine atoms,methoxy group,ethoxy group and acetoxyl group were incorporatedcovalently on the self-assembled substrate surface , increasing of the stability of selfassembledmonolayers, So the organic silane and the polyethylene oxide reacted to form anovel self-assembled material. A novel hydrophilic and reactive methoxy polyethylene oxidepropyl trimethoxysilane were synthesized by hydrosilylation reaction using trimethoxysilaneand methoxy polyethylene oxide monoallyl ether.The effect of reaction time,reaction temperature,mass f raction of catalyst,molar ratioof reagents and molecular weight on hydrosilylation were investigated . The structure ofreaction products were charactered by Fourier Transform Infrared Spectroscopy (FTIR) andHydrogen-Nuclear Magnetic Resonance (1H-NMR). The results indicated that the monomersconversion had good conversion yield, when temperature was 85℃, the reaction time was 8hours, the catalyst concent was 35ppm and the molar ratio of reagents wasn(trimethoxysilane):n(methoxy polyethylene oxide monoallyl ether)=1.2:1.The self-assembled monolayers of hydrophilic silane on silicon substrate was preparedby liquid-phase process. We had explored the effects of time, the mass fraction and differentmolecular weight on the formation of self-assembled monolayers of the hydrophilic silane.The elements, topography and hydrophilicity of self-assembled monolayers werecharacterized with X-ray Photoelectron Sectroscopy(XPS),Atomi Force Microscopy(AFM),Contact Angle wettability(CA) and Scanning Electron Microscope(SEM). When theenviroment temperature was 26±3℃, the self-assembly time was 60 minutes and the massfraction of hydrophilic silane in solution was 0.5wt%, The contact angle wettability of theself-assembled monolayers of hydrophilic silane was 8.78o.The self-assembled monolayers of the hydrophilic silane was tested to resistence toprotein adsorption. The protein adsorption of self-assembled monolayers of differentmolecular weight hydrophilic methoxy polyethylene oxide propyltrimethoxy silane was adynamic behavior. The bovine serum albumin(BSA) of isotherm was obtained according tothe langmiur formula. When the concentration of bovine serum albumin(BSA) was0.04mg/mL, the pH value was 4.7 of the bovine serum albumin(BSA) isoelectric point(PI) , the temperature of enviroment was 28±3℃and the adsorption of protein was 120 minutes,the maximum protein adsorption quantity of self-assembled monolayers surface were only80.30μg/cm2 and 82.89μg/cm2. When the self-assembled monolayers of molecular weightof the methoxy polyethylene oxide propyl trimethoxysilane were increased, the bovine serumalbumin(BSA) adsorption quantity of self-assembled monolayers surface were decreased. Theself-assembled monolayers surface displayed highly resistant to protein adsorptionperformance.