New fluorinated hybrid organic/inorganic water soluble polymeric network

This work presents the elaboration of nanoparticle networks from HASE (hydrophobically alkali-soluble emulsion) thickeners grafted with silica nanoparticles. Three HASE were realized by copolymerization in emulsion of methacrylic acid and ethyl acrylate or trifluoroethyl methacrylate and a hydrocarbon or fluorocarbon macromonomer. The macromonomer contains a hydrophobic pendant group separated from the backbone by a polyethylene glycol spacer chain. The free acid functions of the copolymer were coupled with amine functionalized silica nanoparticles. In basic aqueous solutions, the suspensions containing 1 wt.% of this polymer/SiO2 nanocomposite characterized by DLS (size analysis) and Cryo-SEM are stable, translucent, and gel-like at pH = 7.5. Rheological measurements demonstrated that the grafting of silica nanoparticles did not affect the thickening effect of precursor co-polymers. Coating of glass plates was realized with these hybrid networks and characterized by AFM, indicating that the silica nanoparticles were more homogeneously dispersed when a fluorocarbon co-polymer was used.