| 초록 |
Poly(N-isopropylacrylamide) (PNIPAM) hydrogels and polydimethylsiloxane (PDMS) have completely different wetting properties against water. Whereas PDMS is extremely hydrophobic, PNIPAM is relatively hydrophilic. And the hydrophilicity of PNIPAM depends on temperature, i.e., more hydrophobic above and more hydrophilic below their low critical solution temperature (LCST). Due to quite different surface energies, the preparation of composites based on the two extreme polymers, hydrophilic and hydrophobic polymers, has been difficult. In this study, composites of the two polymers were developed as stimuli-responsive materials from PNIPAM hydrogels of through-thickness pores prepared by directional melt crystallization of solvent. The structures of the two polymers in composites were identified by a scanning electron microscope (SEM). After swelling, the PNIPAM phase becomes distinctly swollen, which was obvious under SEM. The contact angle of water droplet depends on the surface compositions of the two polymers. With swelling in water, significant bending moment of composite films developed, which in turn depends on temperature. |
