Designable block copolymer (BCP) membranes are emerging for reverse electrodialysis to capture the salinity gradient energy between seawater and river water. However, present BCP based nanochannels are usually prepared from flexible blocks. Flexible blocks adopt random coil in phase-separated nanostructure that cage charge carriers, increasing the counterions transport resistance. To free the charge carriers, this work engineers a hierarchical ordered hybrid membrane composed of a rod-coil BCP containing positively charged ionic groups and a porous polymeric membrane with negatively charged groups. The rod-coil BCP can self-assembly into hierarchical ordered nanochannels. The rod block adopts rigid rod-like structure inside the channels which improves the orderliness of channels and effectively avoids embedding of ionic groups, dominating the ion transport. The porous polymeric membrane functioning as a supporting layer also participates in the ion transport. This hierarchical ordered device with asymmetric geometry and charge polarity achieves high performance in ion rectification and energy conversion. This strategy highlights the promise in BCP for salinity gradient energy conversion due to its designability and controllability.

可设计的嵌段共聚物（BCP）膜正在出现，用于反向电渗析，以捕获海水和河水之间的盐度梯度能量。但是，目前基于BCP的纳米通道通常由柔性嵌段制备。柔性块在相分离的纳米结构中采用无规线圈，该结构可笼罩电荷载流子，从而增加了抗衡离子的传输阻力。为了释放电荷载流子，这项工作设计了一种分层有序的混合膜，该膜由包含带正电的离子基团的棒状线圈BCP和带负电的基团的多孔聚合物膜组成。棒状线圈BCP可以自组装成有序的有序纳米通道。棒块在通道内部采用刚性杆状结构，提高了通道的有序性，有效避免了离子基团的嵌入，主导离子传输。用作支撑层的多孔聚合物膜也参与离子传输。这种具有不对称几何形状和电荷极性的分级有序器件在离子整流和能量转换方面实现了高性能。由于其可设计性和可控性，该策略凸显了BCP在盐度梯度能量转换方面的前景。