Superhydrophobic magnesium oxychloride cement based composites with integral stability and recyclability

Abstract Magnesium oxychloride (MOC) cement has attracted much interest due to the superior mechanical properties, however enhancing the poor water-resistance is facing challenges and it is worthwhile devoting much effort to it. Here, a simple method to produce MOC based composites (MOCBCs) with superhydrophobicity is proposed. The samples could maintain superhydrophobic (SHP) after bearing mechanical and chemical damages, and the SHP MOCBCs are also capable of anti-icing. Meanwhile, the modified MOCBCs overcomes the poor water-resistance, the fatal defect of MOC based materials, because the main phases are protected by hydrophobic silicone rubber. SHP ability of MOCBCs can attribute to the combination of dual-level fractal structure and addition of hydroxyl-terminated polydimethylsiloxane (HPDMS), and this characteristic helps to achieve the function of self-cleaning. Besides, the powders ground from wasted MOCBCs exhibit superhydrophobicity, suggesting the potential recyclability of this material, which can be applied to SHP coating and oil/water separation.