Optimization of hydrophobic nonresponsive sol-ketal acrylate gel film to hydrophilic thermo-responsive gel by graft-polymerization

Abstract

AbstractThis work has been done in three steps. First, the preparation of acrylate monomers; they are [dimethyl-1,3-dioxoylan-4-yl-methylacrylate (sol-ketal acrylate) (SKA)], [4-acetylphenyl acrylate (APHA)], and [4-formyl-2-methoxyphenylacrylate (VA)]. All monomers were evaluated using 1H, 13C-NMR, and FT-IR. In the next step, two kinds of polymers were prepared. Two series of copolymers and terpolymers were carried out via the free-radical polymerization; SKA with the photo-cross-linker for poly (SKA-co-DMIAm) photo-cross-linker polymer and VA and APHA with N-isopropylacrylamide for poly (NIPA-co-VA-co-APHA) functional-thermo-responsive terpolymer. All fabricated polymers were investigated by (1H-NMR, FT-IR, UV, GPC, and DSC). The phase separation temperature of polymer solutions has been measured through the turbidity and the change in transmittance to the temperatures using UV–Vis spectroscopy. Eventually, the UV was used to form the gel layer after the deposition of the gold layer. The nonresponsive gel layer was grafted with poly (NIPA-co-VA-co-APHA) to optimize the upper layer to the thermo-responsive functional layer. SPR/OW measured the swelling properties of the gel layers. The active layer will immobilize biological molecules with the primary amine group. Graphical abstract The schematic diagram shows the steps of gel formation: The cross-linking initiated by UV; SPR/OW for film thickness; grafting for gel optimization.