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

This 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 H-1, C-13-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.