March 29, 2024

Wildly Counterintuitive: Dissolved Salt Can Reassemble at Nanoscale

Zeng and his associates just recently ran computer simulations to identify how salt chloride and its salty cousin, lithium chloride, may react when immersed in a nanoscopic stream of water bordered by 2 smooth, water-repellent walls.
An atomic-level rendering of sodium chloride (left), the main component in salt, and lithium chloride (right). New research from Nebraskas Xiao Cheng Zeng and others has actually suggested that, when confined to a nanoscopic space, salt (dark blue) and chlorine (light blue) atoms can reassemble after being liquified. Lithium (pink) and chlorine atoms can do the very same, according to the groups simulations. Credit: University of Nebraska– Lincoln.
After initially dissolving in the water, the charged, arbitrarily distributed atoms of both sodium and lithium chloride would spontaneously reassemble into 2D layers, according to the simulations. In the case of sodium chloride, that layer would be identical to its solid, pre-dissolved state: a crystalline pattern of squares, with each sodium atom surrounded by 4 chlorine atoms, or vice versa.
Based on the teams computations, the unforeseen habits emerges partly due to the fact that nanoscale confinement reduces the interaction strength in between a charged atom– salt, chlorine or lithium– and the water particles that generally form a shell around it. That hydration shell usually keeps oppositely charged particles, such as sodium and chlorine, from reassembling after dissolving– however not when restricted to a nanoscopic area, the scientists discovered.
Zeng and his fellow computational chemists hope their forecasts will motivate other scientists to carry out experiments that confirm or challenge their simulations.
Those forecasts may ultimately notify the design of nanofluidic gadgets that transport charged atoms to recreate neuronal activity, Zeng said.
Referral: “Two-dimensional monolayer salt nanostructures can spontaneously aggregate rather than dissolve in water down liquid solutions” by Wenhui Zhao, Yunxiang Sun, Weiduo Zhu, Jian Jiang, Xiaorong Zhao, Dongdong Lin, Wenwu Xu, Xiangmei Duan, Joseph S. Francisco and Xiao Cheng Zeng, 23 September 2021, Nature Communications.DOI: 10.1038/ s41467-021-25938-0.

Any cook worth their salt knows that a dash of the stuff– which consists mostly of the compound sodium chloride– will dissolve when dropped into a pot of even room-temperature water.
But as a chemist who has actually spent decades investigating how compounds act when restricted to infinitesimal areas, Nebraskas Xiao Cheng Zeng likewise knows that what takes place at the macroscale does not necessarily hold at the nanoscale.

An atomic-level rendering of sodium chloride (left), the primary active ingredient in table salt, and lithium chloride (right). After at first liquifying in the water, the charged, arbitrarily distributed atoms of both salt and lithium chloride would spontaneously reassemble into 2D layers, according to the simulations. In the case of salt chloride, that layer would be identical to its solid, pre-dissolved state: a crystalline pattern of squares, with each sodium atom surrounded by 4 chlorine atoms, or vice versa.