No abstract

A multi-block compositing graft concept is investigated to fabricate proton exchange membranes. The prepared membranes demonstrate excellent ion conductive capacity and better fuel cell performance over the entire relative humidity conditions, compared to Nafion.

conductivity, which requires high ion permeability and low resistance. [5] Increasing the charge density in the membrane and constructing relatively big channel are the important methods to promote ion transmembrane transport. [6] However, the stability and mechanical strength of the membrane will be affected by an excessive increase in charged groups, limiting the applications. [7] Therefore, it is essential to effectively tune the distribution of the charges in the membrane.In nature, the cell membrane of the electric eel is an effective model for realizing efficient and continuous ion transmembrane transport regulation, which could maintain the various physiological functions in life processes. [1a] The architecture of the cell membrane is not homogenous. The phospholipid bilayer is the basic scaffold of the cell membrane, and efficient ion transport depends on the ion channel proteins. [8] This simple and delicate architecture inspires us to design a membrane with excellent selectivity and high stability.In this study, the bioinspired architecture is constructed utilizing the nanophase separation induced by ionic crosslinking. Sulfonated poly(arylene ether ketone) copolymer (SPAEK) and imidazolium-functionalized poly(arylene ether sulfone) (IPAES) copolymers are selected for their chemical resistance, high toughness, [9] and proton conductivity. [10] Further, the two designed polymers, which have similar number-average molecular weights but opposite charges, are mixed to prepare an ionic crosslinking membrane (ICM). The ICM exhibits a nanophase-separated structure with clearly distributed ion channels, showing functional differentiation. Owing to the aggregation of functional groups, the size of the channel increases accordingly. Therefore, the resistance is reduced, as well as the adverse effect of charge polarization. [6b] Also, the ICM exhibits better cation selectivity compared to the membrane without ionic crosslinking, indicating the full utilization of charges. With this convenient process, both ion permeability and permselectivity of ICM are enhanced, and it is noteworthy that the stability and mechanical strength of the ICM are superior. To further confirm the superiority of ionic crosslinking, the osmotic energy conversion of ICM was performed. As a result, the ICM-based osmotic energy generator can efficiently convert the Gibbs free energy between water with a salinity gradient and electric power. The maximum output power is up to 16.72 W m −2 under Charge-governed ion transport is crucial to numerous industries, and the advanced membrane is the essential component. In nature, the efficient and selective ion transport is mainly governed by the charged ion channels located in cell membrane, indicating the architecture with functional differentiation. Inspired by this architecture, a membrane by ionic crosslinking sulfonated poly(arylene ether ketone) and imidazolium-functionalized poly(arylene ether sulfone) is designed and fabricated to make full use of the charges. This ionic crosslinking i...