Homoporous membranes

Homoporous membranes (HOMEs) are featured as ordered through pores with homogenous pore sizes and pore geometries. HOMEs are the key to improve the separation precision, and to simultaneously increase selectivity and permeability. The concept of HOMEs and their structural characteristics are discussed at first. HOMEs are not only just a type of membranes with new structures but also represent one important aspect in the development of membrane separation. Then, the diverse methods to prepare HOMEs are summarized, and their specific advantages and disadvantages are discussed. Homoporous structures with tunable pore sizes typically in the range of 10-50 nm can be achieved based on the microphase separation of block copolymers (BCPs). The BCPs-enabled methods are distinguished from others for their simple processing, low cost, no need of cumbersome devices, and upscalability. The mechanism of selective swelling-induced pore generation of amphiphilic BCPs, its uniqueness in the tuneability of pore sizes and the geometries (including cylindrical and slitted-shaped pores), and inherently permanent hydrophilicity are discussed in detail. The perspectives of HOMEs derived from BCPs are finally discussed and the bottleneck in the BCP raw materials is identified. Furthermore, focused studies on HOMEs with pore sizes < 10 nm, the design of new pore geometries with enhanced permselectivity and the expanded applications of HOMEs in diverse fields are suggested.