Poly(N,N-dimethylacrylamide)s with perfluorocarbon pendent groups connected through poly(ethylene glycol) tethers give physical gels in organic solvents

The synthesis is reported of copolymers of N,N-dimethylacrylamide (DMA) and methacrylates containing 1,1-dihydroperfluorononyl groups separated from the methacrylate by long PEG tethers (between 1000 and 14 000 Da). The copolymers with macromonomer contents of 1 mol % or less give gels in organic solvents such as dioxane, THF, or methanol, as well as in water, at copolymer concentrations between 1 and 8 mol %. Copolymer gel formation is enhanced in the presence of longer PEG tethers and higher comonomer contents and copolymer concentrations. These factors also increase polymer association, as indicated by steady shear viscosities. This is consistent with fluorophilic association mediated by liquid crystalline domains involving very small numbers of perfluorocarbon groups.