Preparation and assembly of nanosized polymer latex

Abstract

Monodispersed copolymer latexes of (styrene/butyl acrylate/acrylic acid) with diameter of less than 100 nm were prepared by semi-continuous emulsion polymerization using KPS (potassium persulphate) as initiator and SDS and OP (sodium dodecylsulfate and P-octyl-polyethylene glycol phenylether) as cosurfactant. It was found that the particle size and size distribution were affected by the total emulsifier amount, the pre-added emulsifier concentration, the agitation speed and so on. The latex particles were assembled into two-dimensional arrays on substrates. Owing to the surface groups such as -COOH and -SO 4 − derived from the comonomers and emulsifiers, the film formation to some degree, was affected by the electrostatic interaction between two particles as well as by capillary force. Different electrolytes were added into the colloid to adjust the particle interaction so that the attractive and repulsive forces were properly balanced and the ordered arrays were obtained.