Center for Advanced Materials , Qatar University , P.O. Box 2713, Doha , Qatar.
Department of Computer Science and Engineering, College of Engineering , Qatar University , P.O. Box 2713, Doha , Qatar.
Environ Sci Technol. 2019 Aug 6;53(15):9260-9268. doi: 10.1021/acs.est.8b06377. Epub 2019 Jul 11.
In this paper, we propose and investigate an original approach to energy conversion based on polyzwitterionic hydrogels, which exhibit an antipolyelectrolyte effect that enables them to swell in salt water and shrink in water of a different (i.e., desalinated water) salinity. The swelling and shrinking processes run cyclically and can move a piston up or down reversibly, thus transforming the antipolyelectrolyte effect into a mechanical force based on the salinity gradient. This phenomenon makes polyzwitterionic hydrogels suitable for use in a smart, polymeric engine. We apply this approach to investigate energy recovery from a polysulfobetaine-based hydrogel. The cross-linking density, external load, particle size, and repeatability of energy recoverability of hydrogels are examined. The maximum energy recovery from 0.4 g of hydrogel in feed (calculated based on dry form) of 102 mJ/kg was obtained by a hydrogel with a 3% cross-linking density, a 200-300 μm particle size, and 100 g external load. Excellent reproducibility of engine cycles was achieved over 10 cycles. This concept is complementary to the osmotic engine concept based on a polyelectrolyte hydrogel. In addition, polyzwitterionic materials have become a benchmark material for preventing biofouling, and the swelling properties of such materials can be further modulated and tuned.
本文提出并研究了一种基于聚两性离子水凝胶的能量转换的原始方法，该水凝胶具有反聚电解质效应，使其能够在盐水中膨胀并在不同盐度（即淡化水）的水中收缩。膨胀和收缩过程循环运行，可以可逆地上下移动活塞，从而将反聚电解质效应转化为基于盐度梯度的机械力。这种现象使聚两性离子水凝胶适用于智能聚合物发动机。我们应用这种方法来研究基于聚磺酸甜水凝胶的能量回收。研究了水凝胶的交联密度、外部负载、粒径和能量可回收性的重复性。通过交联密度为 3%、粒径为 200-300μm、外部负载为 100g 的水凝胶，从进料（基于干重计算）中 0.4g 的水凝胶中获得了 102mJ/kg 的最大能量回收。在 10 个循环内实现了发动机循环的出色可重复性。该概念与基于聚电解质水凝胶的渗透能发动机概念互补。此外，聚两性离子材料已成为防止生物污垢的基准材料，并且可以进一步调节和调整这些材料的溶胀性能。
