Using molecular dynamics to unravel the phase composition behavior of nano-size pores in frozen soils-Does Young-Laplace equation apply in the low temperature range?

• Main Authors: Zhang, Chao, Liu, Zhen, Deng, Peng
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2017
• Subjects: Laplace; permafrost
• Online Access: http://hdl.handle.net/1807/89144; http://www.nrcresearchpress.com/doi/abs/10.1139/cgj-2016-0150

The phase composition curve of frozen soils is a fundamental relationship in understanding permafrost and seasonally frozen soils. However, due to the complex interplay between adsorption and capillarity, a clear physically-based understanding of the phase composition curve in the low temperature range, i.e., less than 265 K, is still absent. Especially, it is unclear whether the Young-Laplace equation corresponding to capillarity still holds in nano-size pores where adsorption could dominate. In this paper, a framework based on molecular dynamics simulations was developed to investigate the phase transition behavior of water confined in nano-size pores. A series of simulations was conducted to unravel the effects of the pore size and wettability on the freezing and melting of pore water. It is the first time that the phase composition behavior of frozen soils is analyzed using molecular dynamics. It is found that the Young-Laplace equation may not apply in the low temperature range. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.