Fluorinated Water-Swollen Hydrogels with Molecular and Supramolecular Organization

Moderately water-swollen hydrogels were prepared by copolymerizing n-stearyl acrylate (SA), 2,2,2-trifluoroethyl acrylate (TFEA), and acrylic acid (AA), and the effects of water and TFEA on the molecular and supramolecular structure were investigated. An incorporation of TFEA brought about a decreased d2 spacing (long-range ordering) presumably due to a local render amorphous while d1 (short-range ordering) was kept constant. Enhanced effects of water and stretching on the supramolecular organization were demonstrated. The transition temperature at which Young's modulus abruptly changes could be controlled by changing the TFEA content of the gel.