Smart Sand by Surface Engineering: Toward Controllable Oil/Water Separation

Sand, an abundant resource from the nature, is a promising candidate for oil/water separation. Herein, raw sand was designed with switchable surface wettability to enable recyclability and versatility in practical oil/water separation. The smart sand was fabricated by grafting pH-responsive poly(4-vinylpyridine) (P4VP) and oleophilic/hydrophobic octadecyltrimethoxysilane (OTS) onto its surface. The decorated sand can be used as the oil sorbent for controllable oil sorption and desorption in response to different pHs, as well as a filter to selectively separate either oil or water on demand. This novel design offers an intelligent, low-cost, large-scale, and highly efficient route to potentially settle the issues of industrial oily wastewater and oil spill.

Automated summary

By grafting pH-responsive polymer and oleophilic/hydrophobic compound onto the surface of sand, a smart sand with recyclability and versatility was designed for controllable oil sorption and desorption, selective oil/water separation, offering an intelligent, low-cost, large-scale, and highly efficient solution to industrial oily wastewater and oil spill issues.