Van 't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
FOM Institute for Atomic and Molecular Physics, Science Park 104, 1098 XG Amsterdam, The Netherlands.
J Chem Phys. 2017 Apr 7;146(13):131101. doi: 10.1063/1.4979714.
We investigate proton-charge mobility in nanoscopic water droplets with tuneable size. We find that the diffusion of confined proton charges causes a dielectric relaxation process with a maximum-loss frequency determined by the diffusion constant. In volumes less than ∼5 nm in diameter, proton-charge diffusion slows down significantly with decreasing size: for diameters <1 nm, the diffusion constant is about 100 times smaller than in bulk water. The low mobility probably results from the more rigid hydrogen-bond network of nanoconfined water, since proton-charge mobility in water relies on collective hydrogen-bond rearrangements.
我们研究了具有可调尺寸的纳米尺度水滴中的质子电荷迁移率。我们发现，受限质子电荷的扩散导致介电弛豫过程，其最大损耗频率由扩散常数决定。在直径小于约 5nm 的体积中，质子电荷的扩散随着尺寸的减小而显著减慢：对于直径<1nm 的情况，扩散常数比在体相水中小约 100 倍。低迁移率可能是由于纳米受限水中的氢键网络更加刚性，因为质子电荷在水中的迁移率依赖于氢键的集体重排。
