TY  - JOUR
AU  - Liu, Yun-Lin
AU  - Ren, Si-Yu
AU  - Wang, Dong-Hua
AU  - Yang, Ding-Wei
AU  - Kai, Ming-Feng
AU  - Guo, Dong
PY  - 2025
TI  - 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
JO  - AIMS Materials Science
SN  - 2372-0484
SP  - 258
EP  - 277
VL  - 12
IS  - 2
AB  - 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.
UR  - https://doi.org/10.3934/matersci.2025014
DO  - 10.3934/matersci.2025014