Experimental and first-principle computational exploration on biomass cellulose/magnesium hydroxide composite: Local structure, interfacial interaction and antibacterial property

The specification of the local structure and clarification of interfacial interactions of biomass composites is of tremendous significance in synthesizing novel materials and advancing their performance in various demanding applications. However, it remains challenging due to the limitations of experimental techniques, particularly for the manner that biomass composites commonly have hydrogen bonds involved in the vicinity of active sites and interfaces. Herein, the cellulose/Mg(OH)2 nanocomposite has been synthesized via a simple hydrothermal approach and examined by density functional theory (DFT) calculations. The composite exhibits a layered morphology; Mg(OH)2 flakes are around 50 nm in size and well-dispersed. They either anchor onto the cellulose surface or intercalate between layers. The specific composite structure was confirmed theoretically, in line with XRD, SEM and TEM observations. The interfacial interactions were found to be hydrogen bonding. The average adsorption energy per hydroxyl group was computed to be within −0.47 and −0.26 eV for a composite model comprising three cellulose chains and a two-layered Mg(OH)2 cluster. The combined computational/experimental results allow to postulate the antibacterial mechanism of the nanocomposite. The synergy of experiment and first-principle computation recognized local structure of biomass cellulose/Mg(OH)2 nanocomposite, unraveled interfacial nature/strength, and rationalized antibacterial mechanism. [Display omitted] •Biomass cellulose/Mg(OH)2 composite was synthesized by a facile method.•The cooperation of experiment and DFT computation recognizes interfacial structure.•Cellulose is found to render Mg(OH)2 particle with two kinds of adsorption sites.•The interfacial interaction is of hydrogen-bond nature.•Proposed antibacterial mechanism involves both physical and chemical processes.