Thermally and Chemically Stable Candle Soot Superhydrophobic-Surface with Excellent Self-Cleaning Properties in Air and Oil

In this report, a people-considered waste-candle soot generated from incomplete combustion of the middle zone of candle was used to coat the glass slide for fabricating the superhydrophobic surface. The candle soot coating surface followed by deposition of methyltrichlorosilane (MTCS) was characterized through field emission scanning electron microscope, contact angle measurement in air and oil, self-cleaning test, high temperature, and corrosive liquid resistance test and water drop impact experiment, respectively. Interestingly, the candle soot layer after deposition of MTCS presented a coral-like structure and exhibited high water contact angle of 161 and a low sliding angle of 3 in air, which demonstrated that it had excellent superhydrophobicity in air. Of course, the coating also exhibited high water contact angle and low sliding angle in oil. Apart from that, results of high temperature and corrosive liquid resistance tests implied that the superhydrophobic coating can keep stability after treatment by high temperature between 100 and 300 degrees C and can retain high contact angle when encountering the strongly acidic and basic water, which indicated that it exhibited excellent thermal and chemical stabilities. Moreover, the prepared thermally and chemically stable superhydrophobic coating not only displayed wonderful self-cleaning properties in air and oil but also resisted to water drop impaction after deposition of MTCS, which interconnected the carbon particles via the hydrolysis of MTCS in air. In summary, we provided a fast and cost-efficient method to prepare the superhydrophobic coating with excellent thermal and chemical stabilities, which showed great potential in application of antifouling materials under the high temperature and corrosive condition.