CNT@LDH functionalized poly(lactic acid) membranes with super oil-water separation and real-time press sensing properties

Controlling wettability is crucial to designing separation membrane with high performance. In order to achieve the goal, chain modification method is frequently utilized to optimize surface nature of raw materials. However, the development of the method is of significance but challenging due to the high processing cost and complexity. Herein, we developed a rough surface induction strategy to prepare poly(lactic acid) (PLA) membrane. Layered double hydroxides (LDH) were loaded with carboxylation carbon nanotubes (CNT), and the prepared CNT@LDH was surface modified with aminopropyltriethoxysilane. Then the CNT@LDH was blended with PLA to prepare composites and PLA electrospinning membranes. The morphology of synthesized CNT@LDH mimics sea urchin liked structure, which prevented the aggregation of LDH cubes, and induced an efficient conductive network. The combination of CNT@LDH greatly changed the membranes' porous structure, thermal stability, and crystallization properties. The hydrophilicity of PLA membranes increased 112.74%, whereas the pore size and fiber diameter decreased 76.43% and 79.56%, respectively. The oil absorption capacity of the composite membrane was up to 35 g/g with a high absorption speed. Meanwhile, the prepared PLA membrane had a quick response of press-sensing. This research provides a method for designing separation membranes with high separation efficiency, great selectivity, environment friendliness, and real-time pressure monitor function, which is considered as a potential material in intelligent oil-water separation or wearable electronics fields.

Automated summary

In this study, a rough surface induction strategy was developed to prepare poly(lactic acid) (PLA) membranes with improved porous structure and properties. The use of CNT@LDH increased the hydrophilicity and oil absorption capacity of the membranes, while also providing a quick response to pressure. This research provides a potential method for designing high-performance separation membranes.