Clean
water resources are essential to our human society. Oil leakage
has caused water contamination, which leads to serious shortage of
clean water, environmental deterioration, and even increasing number
of deaths. It is of great urgency to solve the oil-polluted water
problems worldwide. Efficient oil/water separation, especially emulsified
oil/water mixture separation, is widely used to mitigate water pollution
issues. Recently, advanced materials with special wettability have
been employed for oily wastewater remediation. Moreover, by endowing
them with various intelligent functions, smart materials can effectively
separate complex oil/water mixtures including extremely stable emulsions.
In this review, oil/water separation mechanisms and various fabrication
methods of special wettability separation materials are summarized.
We highlight the special wettable materials with intelligent functions,
including photocatalytic, self-healing, and switchable oil/water separation
materials, which can achieve self-cleaning, self-healing, and efficient
oily wastewater treatment. In each section, the acting mechanisms,
fabricating technologies, representative studies, and separation efficiency
are briefly introduced. Lastly, the challenges and outlook for oil/water
separation based on the special wettability materials are discussed.