Ion transport regulation through triblock copolymer/PET asymmetric nanochannel membrane: model system establishment and rectification mapping

Controlling ions transport across the membrane at different pH environments is essential for the physiological process and artificial systems. Many efforts have been devoted to pH-responsive ion gating, while rarely systems can maintain the rectification in pH-changing environments. Here, a composite nanochannel system is fabricated, which shows unidirectional rectification with high performance in a wide pH range. In the system, block copolymer (BCP) and polyethylene terephthalate (PET) are employed for the amphoteric nanochannels fabrication. Based on the composite system, a model is built for the theoretical simulation. Thereafter, rectification mapping is conducted on the system, which can provide abundant information about the relations between charge distribution and ions transport properties. The proposed rectification mapping can definitely help to design new materials with special ion transport properties, such as high-performance membranes used in the salinity gradient power generation field.