Facile fabrication of poly(methyl methacrylate) monolith via thermally induced phase separation by utilizing unique cosolvency

Poly(methyl methacrylate) (PMMA) monoliths with a three-dimensional continuous interconnected porous structure in a single piece were fabricated via thermally induced phase separation (TIPS) by utilizing unique cosolvency toward PMMA. We found that PMMA was soluble in a mixture of non-solvents (ethanol and water) at 60 °C. Cooling the solution resulted in formation of a monolith having interconnected pores. Cross-sectional analysis using scanning electron microscopy (SEM) showed a continuous porous network with submicron-sized skeleton. The pore size of the monolith was readily controlled by varying the fabrication parameters such as the polymer concentration and molecular weight, the cooling temperature and the solvent composition. The cross-section of the monolith showed high water repellency. The PMMA monolith was also obtained in a mixture of isopropanol and water with an appropriate solvent ratio.