Single-step synthesis and comprehensive characterization of hydroxyethyl cellulose grafted with (3-aminopropyl)triethoxysilane: mechanistic insights and evaluation of antimicrobial properties

This study focuses on the synthesis of new materials based on hydroxyethyl cellulose (HEC) and (3-aminopropyl)triethoxysilane (APTES) in a single-step process, adopting an efficient and innovative approach. The structural and physical properties of the synthesized polymers were meticulously characterized using analytical techniques, including FTIR/ATR, ¹H, ¹³C, 135-DEPT, ²⁹Si NMR, elemental analysis, and TGA/DTA. The morphology and amorphous profile of HEC-APTES were examined through SEM-EDX and XRD, respectively. In this study, a comprehensive analysis was conducted to gain a deeper understanding of the underlying mechanism and critical reaction conditions governing the interaction between HEC and the organosilane reagent. Various reaction parameters, such as reaction time, silane molar ratio (0.5:1, 1:1, 2:1, and 3:1 relative to HEC), and the autocatalysis of HEC alkoxides, were systematically investigated. Particularly, the combined influence of the reaction medium and the amount of added APTES on the grafting mechanism and mode was carefully examined. Lastly, an assessment of the solubility, dispersion, contact angle and bioactivity against various types of bacteria and fungi in the HEC-APTES samples was conducted to conclude this study. HEC-APTES demonstrates notable antifungal activity against Rhodotorula glutinis, Geotrichum candidum, and Aspergillus niger, with minimum fungicidal concentrations (MFC) of >20 mg/L, 2.5 mg/L, and 2.5 mg/L, respectively.