Porous Gels Made by Phase Separation: Recent Progress and Future Directions

Recent progress in the sol-gel science concerning the porous gels made by phase separation has been reviewed. Based on the principle and technique explored for monoliths, the material shape has been extended to a macroporous thick film and a macroporous gel in a confined space such as capillary, both of which are expected to find useful applications in the chromatography. The modifiable size range of the additional porosity within the micrometer-sized gel skeleton has been broadened from micropores by zeolite, mesopores by surfactant templates to macropores by intensive hydrothermal treatments. A detailed investigation of 3D interfacial structure in real space has been performed using the laser scanning confocal microscope, which enabled quantitative comparison of the structure with those of other phase-separating systems.