SiO_2空心纳米微球的合成

Synthesis and Investigation of Hollow SiO_2 Nanospheres

为了改善聚合物粒子与SiO2粒子之间的亲和力及SiO2粒子在聚合物粒子表面的吸附,首先使用共单体4-乙烯基吡啶(4VP)功能化苯乙烯(PS)粒子,合成了聚(苯乙烯-共-4-乙烯基吡啶)(P(St-4VP))粒子。然后在NH4OH/乙醇介质中,将溶胶-凝胶法生成的SiO2粒子包覆在P(St-4VP)粒子表面,聚合物核被溶解得到SiO2空心纳米微球。随着P(St-4VP)粒子中共单体4VP含量以及正硅酸乙酯(TEOS)用量增加,SiO2空心纳米微球的壳层厚度增加,且壳层表面变得粗糙。随着PVP用量增加,SiO2空心纳米微球的平均尺寸下降,其壳层从松散粗糙变得致密光滑。NH4OH用量增加对SiO2空心纳米微球尺寸和形态的影响不大。

The hollow SiO2 nanospheres form silica-coated P（styrene-co-4-vinylpyridine）（P（St-4VP））particles were synthesized.The SiO2 coating and the solution of P（St-4VP）cores were accomplished in one NH4OH/ethano medium,the synthetic method was thus a simple and low-cost.The P（St-4VP）particles were synthesized first by copolymerization of the styrene and 4-vinylpyridine（4VP）.The intention of introduction of the 4VP as comonomer was function of the polystyrene（PS）particles,which provide affinity between the polymer particles and SiO2 and accelerate adsorption of the SiO2 particles on the polymer particles surface.The thickness and roughness of the shell of the hollow SiO2 nanospheres increased with increasing content of 4VP and tetraethoxysilane（TEOS）.The size of the hollow SiO2 nanospheres decreased with increasing PVP content.The size and morphology of the hollow SiO2 nanospheres kept unchanged when NH4OH dosage is enhanced from 0.425 g to 1.700 g.