Dolores Melgar, Qianjie Zhou, Sourav Chakraborty, Lionel Porcar, Ira A. Weinstock, Josep Bonet A?valos, Bin Wu,* Carles Bo,* and Panchao Yin*
Water in different physical states has been attracting great interest for decades for its strong association with the origin of life, the biophysical behaviors of biomacromolecules, and the transportation of matter and energy. Structurally well-defined, monodispersed nanocapsules provide excellent opportunities to understand water under confinement. Herein a group of porous and hollow polyoxometalates with varied inner ligands have been studied to investigate the distributions of water inside them in solution states via contrast variation small angle neutron scattering (CV-SANS) techniques. Meanwhile, molecular dynamics simulations have been conducted to cross-examine fitting results of SANS daprovide structural details of the formation of such water distribution patterns. Our work suggests that the densities of water in the core of nanocapsules rely highly on the dimensions of hydrophobic confinement space (cores inside nanocapsules) and can approach the dewetting state at the critical dimension, ca. 1.1 nm.
数十年来，处于不同物理状态的水与生命的起源、生物大分子的生物物理行为以及物质和能量的运输密切相关，因此引起了人们极大的研究兴趣。结构明确的单分散纳米胶囊为了解受限条件下的水提供了极好的机会。本文中研究了一组具有不同内部配体的多孔和中空多金属氧酸盐，以通过对比变化小角度中子散射（CV-SANS）技术研究其内部水在溶液状态下的分布。同时，对其进行了分子动力学模拟来交叉检查SANS数据的拟合结果，并提供形成这种水分布格局形成的结构细节。我们的工作表明，纳米胶囊核心中水的密度高度依赖于疏水约束空间的尺寸（纳米胶囊内部的核心）的尺寸，并且可以在临界尺寸接近脱水状态，约为1.1 nm。
文章链接：https://dx.doi.org/10.1021/acs.jpcc.0c01019