Hybrid microgels with ZnS inclusions

We report on a preparation of hybrid microgels filled with ZnS inclusions. Temperature-sensitive poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate) (VCL/AAEM) microgels have been used as containers for deposition of ZnS by reaction of zinc acetate and thioacetamide under ultrasonic agitation. ZnS was deposited directly into microgels, leading to formation of composite particles which exhibit temperature-sensitive properties, high ZnS contents, and excellent colloidal stability. The influence of ZnS load on microgel size, morphology, swelling-deswelling behavior, and stability is discussed. Hybrid particles contain up to 20 wt % of ZnS, and particle stability decreases with increase of inorganic filler content. Detailed microscopy investigations confirm incorporation of ZnS nanoparticles into microgel network. The possibility of self-assembly of hybrid particles on different surfaces was studied. It has been found that microgels filled with ZnS can form organized particle arrays after water evaporation.