双季铵盐改性纳米SiO_2的乳化性能研究

Studies on the emulsifying performance of nano-SiO_2 particles modified with bis-quaternary ammonium salts

用双季铵盐BQAS-16对纳米SiO_2进行表面改性,并以改性后的纳米SiO_2为乳化剂,制备了Pickering乳液。探究了改性比例、pH、盐的加入和油水体积比对Pickering乳液稳定性的影响。结果表明,与纳米SiO_2相比,BQAS-16改性后的纳米SiO_2具有更优异的乳化性能。随着BQAS-16用量的增加,乳液的稳定性增加。随着pH的增大,乳液的稳定性基本不变;但当pH增至13时,乳液的稳定性显著降低。随着NaCl浓度的增加,乳液的稳定性基本不变。当油水体积比为1∶1时,乳液的稳定性最好。

Bis-quaternary ammonium salts BQAS-16 were used for the surface modification of nano-SiO2 particles,and the modified SiO2 nanoparticles were used as emulsifying agent for preparation of Pickering emulsion. Effects of the ratio of modification,the pH value,the addition of salt and the volume ratio of oil to water on the stability of Pickering emulsion were examined. Results show that the nano-SiO2 particles modified by BQAS-16 display better emulsifying performance as comparing with the nano-SiO2 particles. The stability of emulsion increases with increasing of the dosage of BQAS-16. With increasing the pH value, the stability of emulsion is basically no change. However,at the pH = 13,the stability of emulsion decreases significantly. Moreover,as the NaCl dosage increases,the stability of emulsion is basically no change. When the volume ratio of oil to water is 1： 1,the emulsion is at the most stable state.