The effect of three types of cross-linked hydrogels and volume fraction of polyacrylamide on the swelling and thermal behavior using molecular dynamics simulation

Abstract

The technology of hydrogels is three-dimensional polymer networks with transverse connections that can adsorb water or biofluids. These compounds can adsorb water without dissolving. Natural hydrogels are considered due to their variety, abundance, cheapness, non-toxicity, and biocompatibility with synthetic hydrogels. In this research, the effect of three types of cross-linked hydrogels polyacrylamide (PAM), polyvinyl alcohol (PVA), and polyethylene glycol (PEG) hydrogels), and volume fraction (5–15%) of PAM on the swelling, and thermal behavior (TB) of simulated samples were studied using molecular dynamics (MD) simulations. The results show that among the simulated hydrogels, the structure of PAM had better atomic behavior and TB. PAM hydrogel had the highest swelling, heat flux (HF), and thermal conductivity (TC), with a numerical value of 342,722 Å3, 1583 W/m2, and 0.57 W/m.K after 10 ns. In the following, by increasing the volume fraction of PAM hydrogel from 5% to 15%, swelling increased to 377,986 Å3, and the TC with 10% of PAM increased from 0.53 (W/m.K) to 0.66 (W/m.K). Furthermore, HF of the sample with 15% of PAM was increased from 1423 (W/m2) to 1761 (W/m2) after 10 (ns). Consequently, by increasing the volume fraction of PAM hydrogel, TB of simulated structure was improved.