盐差能因具有清洁无碳排放、储量丰富、可再生等特点受到广泛关注。目前盐差能收集主要通过反向电渗析，反向电渗析的核心组件离子交换膜因膜内阻大、选择性差、通量低导致盐差能能量转化效率低从而限制其应用。针对膜内阻与膜选择性之间的矛盾关系，本项目拟基于仿生原理，构建由大孔、高荷电、亲水的高通量离子传输层和超薄离子选择层构成的纳米纤维素复合膜以提高盐差能转化利用效率。先通过分子设计制备高荷电的纳米纤维素，自组装交联成大孔膜，然后通过在其表面进行界面聚合或原位生成有机框架聚合物膜（COF）的方式得到纳米纤维素复合膜并构建盐差能器件。测试纳米纤维素复合膜的膜内阻和膜离子选择性，探索离子传输性能与膜内阻及膜离子选择性之间关系。发现离子传输性能与盐差能转化效率之间的规律，阐明盐差能转化机理，为盐差能提取提供实验和理论依据。

Salinity gradient energy have attracted great attention due to its clean without carbon emission, abundant and renewable. Reverse electrodialysis (RED) have great potential in salinity energy conversion. However, the salinity energy conversion has relative low efficiency due to the high internal resistance, the low ion selectivity and the low ion flux of the membranes used in RED system. In this program, asymmetric cellulose nanofiber composite membranes consist of microporous, highly charged and hydrophilic ionic transport layer and ultrathin ion-selective layer were fabricated in order to overcome the trade-off between the intrinsic resistance and the selectivity. First, highly charged cellulose nanofibers will be designed and prepared to membranes, then cellulose nanofiber composite membranes would be obtained through interfacial polymerization or in situ form covalent organic framework membrane. The device based on cellulose composite membranes would be fabricated. The internal resistance and the ionic selectivity of the membranes should be evaluated. The effects of the internal resistance and ion selectivity of the membrane should be observed. The relationship between the proprieties of ion transport and the efficiency of salinity energy conversion should be figure out. The mechanism of the salinity gradient energy conversion would be revealed. This project will be helpful to develop theory of salinity gradient energy conversion.