Fabrication of a Flexible Si-cotton Filter Membrane for Efficient Hot Oil/Hot Water Separation

Increasing oily industrial waste water at room and high temperatures has become one of the most significant threats to the global ecosystem. Finding a suitable method for separating hot-oil/water pollution with an appropriate filter is highly necessary to effectively solve this problem. In this study, high-temperature oil/water separation was achieved using a silicon-modified textile (Si-cotton) as a filter, which was fabricated using polydimethylsiloxane (PDMS) solution as the precursor and through plasma polymerization. The plasma polymerization generated a uniform micro and nanoscale hierarchical structure on the Si-cotton surface. Furthermore, XPS and FT-IR analysis showed the lowering of the O/C ratio on the Si-cotton surface with respect to the pristine textile, and the presence of silicon on the Si-cotton surface after the plasma process. The results of these factors can be critical in making the final hydrophobic/oleophilic behaviour of the textile. More importantly, the Si-cotton membrane was tested for the separation process of hot oil/hot water mixture, which showed an acceptable efficiency even after fifteen separation cycles. The findings offered a two-step method, efficient and green, which was capable of working well even at a high temperature, to fabricate a flexible and scalable Si-cotton textile filter for reducing the necessity of additional and complicated cooling processes in the presence of high-temperature oil/water mixture.