(403b) A New Approach to Prepare Polystyrene(Pst)/CaCO3 Core-Shell Composite Nanoparticles

Yang Hu, Guanzhi Cheng, WenJiao Ji, Yiming Jiang, Chengyou Kan, Key Laboratory of Advanced Materials, Department of Chemical Engineering, Tsinghua University, Beijing, China

Polystyrene (Pst)/CaCO₃ core-shell composite nanoparticles have been attracted great attentions of many researchers. Such core/shell structure composite particles are utilized in broad areas for its improved compression strength and anti-scratch resistant. Here a new approach was developed to prepare polystyrene(Pst)/CaCO₃ core-shell composite nanoparticles. Sodium poly(4-styrenesulfonate) was utilized as a stabilizing agent, which was grafted on the Pst particles to form the hair structure as the core particles. The Pst core particles with hairy structure was prepared by modifying the particle surface with sodium poly(4-styrenesulfonate). A certain amount of Ca(OH)₂ was added into the core latex, followed by feeding CO₂, and the CaCO₃ was synthesized through the reaction of Ca(OH)₂ and CO₂, and the CaCO₃ amorphous primary particles deposited on Pst core particles with hairy structure. The thickness of hair structure of core particles was 10 nm, which was determined by D_P^DLS 350 nm and D_P^TEM 330 nm. The influences of key parameters including particle size, shell thickness, the amount of initiator, the density of sulfonic acid groups, temperature and pH on deposition process was investigated, and the optimized condition was obtained.