Synthesis and application of novel superhydrophilic nylon composites loaded with Zn, Mg, Al-layered double hydroxide and TiO2

Oily wastewater has become one of the great threats to the environment. Membrane separation technology has become a research focus in wastewater treatment due to its advantages in environment protection, low sedimentation cost, low energy consumption and reusability. NPA/ZnMgAl-LDHs (NPA, nylon film material loaded with nano-TiO 2 particles, LDHs , layered double hydroxides) material based on nylon film material (PA) was synthesized using a two-step method. Various characterization methods confirmed the successful introduction of TiO 2 and ZnMgAl-LDHs. The testing of water contact angle (WCA) and underwater oil contact angle (UOCA) confirmed that the original PA substrate possesses hydrophobicity and lipophilicity. The superhydrophilicity and superoleophobicity of NPA/ZnMgAl-LDHs material were brought by the introduction of TiO 2 and ZnMgAl-LDHs. NPA/ZnMgAl-LDHs material shows stable and efficient separation efficiency (> 99%), and exhibits high separation flux in simple oil-water separation and oil in water emulsion demulsification. In addition, its separation efficiency is almost unaffected under environments of different pH, and the separation flux remains at a high level. The photocatalytic activity is another satisfactory result of NPA/ZnMgAl-LDHs material. Methyl orange solution was effectively degraded by NPA/ZnMgAl-LDHs material within 120 min, and the efficiency is up to 99.09%.