Simulation of the composition and proportions of anions in polymerized silicate melts

Abstract

A new statistical model is proposed for describing an equilibrium structure of polymer complexes in a silicate melt. The model makes it possible to calculate the molecular-mass distributions of polyanions of the general formula (Si i O 3 i + 1 - j ) 2( i + 1 - j )- , where i is the number of silicon atoms and j is the number of intramo- lecular closures of bridging bonds. The proposed model is implemented as the STRUCTON computer program (version 1.1, 2006) intended for calculating the composition and proportions of polyanions at different degrees of polymerization of the system. The executable code is implemented on personal computers. The distributions of Q n structons, which are obtained experimentally from Raman and NMR spectroscopic data or evaluated the- oretically, are used as input parameters for the computer program. The testing calculations are performed with the STRUCTON program for three arbitrary distributions of Q n particles corresponding to different degrees of polymerization 0.25 ≤ α ≤ 0.49 for the model system containing 10 4 initial structons. The results of the statis- tical simulation have demonstrated that a limited ensemble of polymer complexes is formed in the system, so that the mean number of different types of complexes varies from 46 to 141. This result correlates with an increase in the mean size of anions from 1.87 to 8.60 and with a decrease in the total number of polymer particles from 5320 to 1166 in the aforementioned range of degrees of polymerization α .