@article{Liu2025, 
author = {Yun-Lin Liu and Si-Yu Ren and Dong-Hua Wang and Ding-Wei Yang and Ming-Feng Kai and Dong Guo},
title = {Molecular structure and thermal conductivity of hydrated sodium aluminosilicate (N-A-S-H) gel under different Si/Al ratios and temperatures: A molecular dynamics analysis},
year = {2025},
journal = {AIMS Materials Science},
volume = {12},
number = {2},
pages = {258-277},
keywords = {thermal conductivity, thermal properties, Si/Al ratio, molecular dynamics (MD) modeling, N-A-S-H},
url = {https://www.sciopen.com/article/10.3934/matersci.2025014},
doi = {10.3934/matersci.2025014},
abstract = {Geopolymer materials have emerged as promising alternatives to ordinary Portland cementitious materials, offering more sustainable solutions for concrete production. Sodium aluminosilicate hydrate (N-A-S-H) serves as a crucial component in geopolymer concrete, while its thermomechanical properties at elevated temperatures remain relatively underexplored. This study examined the molecular structural variations of N-A-S-H within a temperature range of 300–900 K. The influence of different Si/Al ratios and temperature levels on molecular characteristics and atomic mobility was analyzed using the radial distribution function (RDF) and mean square displacement (MSD). The thermal conductivity of the N-A-S-H gel was determined using the Müller-Plathe reverse nonequilibrium molecular dynamics (RNEMD) method. Results show that as temperature increases, the mobility of Si and Al atoms is enhanced, and the thermal conductivity of N-A-S-H gel ranges from 1.431 to 1.857 W/m/K. The thermal conductivity increases with higher Si/Al ratios and elevated temperatures, suggesting decreased thermal insulation performance at higher Si/Al ratios and temperatures.}
}