| Cite this article as: Zhou Jun-Jie,Du Lei,Xu Yan-Yan. Microsimulation of sol-gel preparation by aerogel based on molecular dynamics [J]. J. At. Mol. Phys.(原子与分子物理学报), 2026, 43: 056001 (in Chinese) |
| Microsimulation of sol-gel preparation by aerogel based on molecular dynamics |
| Hits 213 Download times 2 Received:March 31, 2025 Revised:April 29, 2025 |
| View Full Text View/Add Comment Download reader |
| DOI
10.19855/j.1000-0364.2026.056001 |
| Key Words
Perl script Crosslinking degree Molecular dynamics Molecular weight distribution Bond length |
|
|
| Abstract
|
| The sol-gel stage in the preparation of aerogels significantly influences the formation of their final microstructure. In this study, molecular dynamics (MD) simulations combined with Perl scripting and the COMPASS II force field were used to investigate the crosslinking behavior of three precursors: tetraethoxysilane (TEOS), methyltrimethoxysilane (MTMS), and dimethyldimethoxysilane (DMDMS) during the sol-gel process. The Si-O-Si bond formation was determined using the cutoff radius method, and the evolution of crosslinking degree, molecular weight distribution, and microstructural development was analyzed.The results show that as the crosslinking degree increases, the systems evolve from loose short chains into three-dimensional crosslinked networks. At high crosslinking degrees, stable structures with cyclic formations appear. The TEOS system (T system) exhibited the highest crosslinking degree at 94.5%, with the most significant increase (29.4%) occurring in the 3–3.5 ? range. The maximum molecular weight of the generated polymer reached 931.5, forming a relatively dense crosslinked network. The crosslinking degrees of the MTMS (M system) and DMDMS (D system) systems were lower, at 85.8% and 72.7%, respectively. The most significant crosslinking increments for the M and D systems occurred in the 4.5–5 ? range, with increases of 16.3% and 18.0%, respectively. The maximum molecular weights of the polymers in the M and D systems were 1013.9 and 833.7, respectively. The D system exhibited the fewest high-molecular-weight polymers, resulting in a relatively loose crosslinked network. The essence of the crosslinking reaction lies in the reorganization of the network structure and changes in bond quantity rather than alterations in bond length. |
|
|
|
|
|
|
