Thermo and pH Dual-Responsive\nMaterials for Controllable\nOil/Water Separation

Abstract

Thermo and pH dual-controllable oil/water\nseparation materials\nare successfully fabricated by photo initiated free radical polymerization\nof dimethylamino ethyl methacrylate (DMAEMA). The PDMAEMA hydrogel\ncoated mesh shows superhydrophilicity and underwater superoleophobicity\nat certain temperature and pH. Due to the double responsiveness of\nPDMAEMA hydrogel, the as-prepared mesh can selectively separate water\nfrom oil/water mixtures and make water and oil permeate through the\nmesh orderly and be collected separately by adjusting the temperature\nor pH. Water can pass through the as-prepared mesh under 55 °C\n(pH 7) and pH less than 13 (<i>T</i> = 25 °C) while\noil is kept on the mesh. When the temperature is above 55 °C\nor pH is larger than 13, the water retention capacity of PDMAEMA hydrogel\nis significantly reduced and the swelling volume is decreased. Therefore,\noil can permeate through the mesh and be collected in situ. Additionally,\nthis material has excellent potential to be used in practical applications\nand has created a new field for water/oil separation in which the\nprocess can be diversified and more intelligent.