Thermal dependence of nanofluidic energy conversion by reverse electrodialysis
Thermal dependence of nanofluidic energy conversion by reverse electrodialysis
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DOI：
10.1039/c7nr04387b
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发表时间：
2017-09-07
期刊：
影响因子：
6.7
通讯作者：
Daiguji, Hirofumi
中科院分区：
文献类型：
--
作者：
Hwang, Junho;Sekimoto, Tatsuki;Daiguji, Hirofumi
研究了含孔介孔二氧化硅薄膜在盐度梯度驱动下的反向电渗析能量转换的热依赖性。2-3在293-333 K温度范围内研究了直径为1.5nm的纳米晶。随着温度的升高，中孔的表面电荷密度由于孔壁的ζ电位的增加而增加，这又增加了双电层中的抗衡离子的浓度。由于液体粘度的降低，离子迁移率也随着温度的升高而增加。因此，温度的升高提高了中孔的离子电导率，无论是在表面电荷支配的制度在低离子浓度和在本体制度在高离子浓度。然而，温度的进一步增加诱导气泡成核。特别是在高浓度的盐溶液中，由于盐析效应，疏水斑块出现在孔表面上并掩盖表面电荷。介孔中的弱极性允许更多的共离子进入其中，降低了跨膜的电势差，导致能量转换效率的严重恶化。还评估了基于介孔二氧化硅的纳米流体装置的性能特性的热依赖性。
The thermal dependence of salinity-gradient-driven energy conversion by reverse electrodialysis using a mesoporous silica thin film with pores ca. 2-3 nm in diameter was studied in a temperature range of 293-333 K. As the temperature increases, the surface charge density of mesopores increases owing to an increase in the zeta potential of the pore walls, which in turn increases the concentration of counter-ions in the electrical double layer. The ion mobility also increases with increasing temperature owing to a decrease in the liquid viscosity. As a result, the temperature increase improves the ion conductance of mesopores both in the surface-charge-governed regime at low ion concentrations and in the bulk regime at high ion concentrations. However, further increases in temperature induce bubble nucleation. In particular, in highly concentrated salt solutions, hydrophobic patches appear on the pore surfaces because of the salting-out effect and mask the surface charge. The weakened polarity in mesopores allows more co-ions to enter them, decreasing the potential difference across the film, resulting in a serious deterioration of the energy conversion efficiency. The thermal dependence of the performance characteristics of mesoporous-silica-based nanofluidic devices was also evaluated.