Chitosan-based membrane materials are promising biomaterials with excellent biodegradability, biocompatibility, high hydrophilicity, and cost efficiency. However, their low proton conductivity greatly limits their use as proton exchange membranes, and the previously reported methods to improve their proton conductivity generally introduced non-biodegradable groups and compounds, which caused this natural polymer to lose its basic advantage of biodegradability. In this work, a facile and efficient strategy has been developed for fabricating new chitosan-based whole-biopolymers to satisfy both sustainability and high-performance simultaneously. The modified chitosan with introduced purine groups has significantly improved proton conductivity up to 50 fold higher than that of chitosan itself, due to the unique structures of the grafted purine groups that produced a large number of proton-hopping sites, and the adenine monophosphate-grafted membrane materials exhibited higher proton conductivity (0.1867 S cm⁻¹) at 100 °C than Nafion, indicating their capability for use in high-temperature fuel cells. Meanwhile their methanol permeability was much lower than that of Nafion (7.888 × 10⁻⁷ cm² s⁻¹vs. 1.550 × 10⁻⁶ cm² s⁻¹). Blending of NCC with modified chitosan further improves its mechanical properties and dimensional stability. This study paves a new way to prepare environmentally friendly membrane materials in the place of commonly used non-degradable membranes, highlighting the prospects of natural polymer-based membrane materials in the sustainable fields of fuel cells, supercapacitors and solid-state batteries.

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腺嘌呤和单磷酸腺苷功能化的高质子传导性壳聚糖全生物膜材料的制备

基于壳聚糖的膜材料是具有良好的生物降解性，生物相容性，高亲水性和成本效率的有前途的生物材料。然而，它们低的质子传导性极大地限制了其用作质子交换膜的能力，并且先前报道的改善其质子传导性的方法通常引入了不可生物降解的基团和化合物，这导致该天然聚合物丧失了其生物降解性的基本优势。在这项工作中，开发了一种简便有效的策略来制造基于壳聚糖的新型全生物聚合物，以同时满足可持续性和高性能要求。带有嘌呤基团的改性壳聚糖具有显着改善的质子传导性，其性能比壳聚糖本身高50倍，^-1）在比Nafion高100°C的温度下，表明它们具有在高温燃料电池中使用的能力。同时，它们的甲醇渗透率远低于Nafion（7.888×10 ^-7 cm ² s ^-1对1.550×10 ^-6 cm ² s ^-1）。NCC与改性壳聚糖的共混进一步改善了其机械性能和尺寸稳定性。这项研究开辟了一种新的方法来制备环保膜材料，以代替常用的不可降解膜，从而突出了基于天然聚合物的膜材料在燃料电池，超级电容器和固态电池可持续领域中的前景。