Factors affecting stability and antibacterial properties of quaternary ammonium sol

The cotton fabric was treated with quaternary ammonium salt by sol-gel method in order to improve its antibacterial property.Cationic quaternized sol was synthesized from tetraethoxysilane(TEOS),ethanol with hydrochloric acid as catalyst and quaternary ammonium salt as additive.The effects of the ratio of acid,water,solvent ethanol and TEOS,and reaction temperature on the stability of cationic sol were studied.The results showed that the increase of the acid concentration and temperature increased the viscosity of the sol and decreased its centrifugal stability.With the increase of water in the system,the viscosity of the sol firstly increased and then decreased,while the centrifugal stability firstly droped and then rose.The viscosity of the sol decreased and the centrifugal stability increased considerably with increasing of the amount of ethanol.The fabric treated with the sol showed good antibacterial activity against Escherichia coli and also remained good antibacterial effect after many washing cycles.