| 초록 |
Directional freezing is a simple and eco-friendly technique for producing aligned structures. Microfibrilated cellulose (MFC), an eco-friendly and reinforcing material was obtained from bacterial cellulose. Porous poly(N-isopropylacrylamide) (PNIPAm) and their composite hydrogels with MFC fibers in the gel phase, were successfully engineered by in-situ photopolymerization and unidirectional freezing. The surface and cross-sectional morphologies gives evidences of aligned micropores. The immobilized MFC reduced the swelling ratio whereas aligned micropores increased the swelling ratio and reduced the elastic modulus above the LCST, resulting in enhanced volume transition. Aligned micropores facilitated the fast water infiltration, confirmed by monitoring the water contact angles with time which is beneficial for superabsorbent applications. This combination of crystalline nanofibers and aligned microporeswithin PNIPAm could explore new route for the development of stimuli-responsive superporous hydrogels. |
