Huai-yin Ren, Mei-fang Zhu, Kazutoshi Haraguchi. MODIFICATION AND CHARACTERIZATION OF POLYMER/CLAY NANOCOMPOSITE HYDROGELS BY EXCHANGING WATER WITH ALCOHOLIC SOLVENTS[J]. Acta Polymerica Sinica, 2012,(7):689-693.
Huai-yin Ren, Mei-fang Zhu, Kazutoshi Haraguchi. MODIFICATION AND CHARACTERIZATION OF POLYMER/CLAY NANOCOMPOSITE HYDROGELS BY EXCHANGING WATER WITH ALCOHOLIC SOLVENTS[J]. Acta Polymerica Sinica, 2012,(7):689-693. DOI: 10.3724/SP.J.1105.2012.12035.
The effects of replacing water solvent of nanocomposite gels with alcoholic solvents are investigated on structure stability
swelling and mechanical properties of nanocomposite hydrogels (D-NC hydrogel).D-NC gels was prepared by in situ free radical polymerization of monomer (N
N-dimethylacrylamide) in the presence of exfoliated clay.Clay acts as the multifunctional plane crosslinking agent.NC hydrogels maintained the three-dimensional structure without collapsing after exchanging solvents with alcoholic solvents.It was found that NC gels that originally containing water exhibit different exchange and swelling behaviors depending on the type of alcohol in which the gels are immersed.In methanol
the swelling ratio of a D-NC gel increases monotonously as in the case of water.However
D-NC gels first shrink and then swell during immersing in other alcohols such as ethanol
propanol and butanol.Furthermore
D-NC alcoholic solvent gels with ultrahigh mechanical properties are obtained by solvent exchanging process of first swelling in a target solvent and then drying.For example
compared to those of D-NC5 hydrogels
the tensile strength of D-NC5 methanol gel increases by 67% (from 155 kPa to 259 kPa) and modulus increases by 49% (from 7.5 kPa to 11.2 kPa).Based on the reversibility of the structure during the solvent water/methanol alternative exchanging
the modification mechanism was discussed primarily.