Atomistic modelling and experimental study of tensile strength of nanocomposite hydrogel

Hydrogels are emerging as a potential material for tissue engineering. However, weak mechanical strength is limiting its application in many diversified fields that includes tissue engineering. In this article, experimental and atomistic simulations were performed to study the effect of water content and h-BN (hexagonal boron nitride) reinforcement on the tensile behaviour of poly ethylene glycol diacrylate (PEGDA) hydrogels. The PEGDA was reinforced with different weight percentages of h-BN in conjunction with varying water content for enhancing the tensile strength. It was revealed from the experimental analysis that h-BN acts as a superior reinforcement at lower water content in PEGDA hydrogels. In contrast, the effect of reinforcement gets mitigated by increasing the water content above a certain limit. Incorporating the h-BN nanofillers in PEGDA hydrogel helps in enhancing their mechanical tensile strength that mimics the strength of human articular cartilage. The experimental analysis provides insight into the micro-and macro-level understanding of the mechanical behaviour of h-BN reinforced PEGDA hydrogel; however, the interfacial properties elucidate the strength of these hydrogels. The MD-based simulations were performed to capture and investigate the effect of h-BN nanosheet orientation and distribution (stack and dispersed) on the mechanical properties of the hydrogel. It was revealed from the simulations that the mechanical property of h-BN-reinforced PEGDA hydrogel decreases with an increase in water content due to decrement in mechanical entanglement between polymer chains. The experimental trend of tensile behaviour concerning water content and h-BN reinforcement agreed with the MD-based results.