Synergistically engineered surface nanostructure of cellulose nanocrystals through aminosilane and their...

Nanocellulose, extracted from the most abundant renewable resource in nature, features environmental friendliness, wide availability, high specific surface area and high mechanical strength. The modification aimed at expanding its applications often only alters the chemical structure of its surface, with less focus on simultaneously regulating its surface morphology. This work used cellulose nanocrystals (CNCs) as a template and employed 3-aminopropyltriethoxysilane (APTES) along with inorganic nanoparticle precursors (represented by tetraethoxysilane) for the synergistic modification of CNCs. A strategy was developed to achieve the simultaneous introduction of amino-silane groups and the deposition of SiO₂ nanoparticles on the CNC surface in a controllable manner. Moreover, the underlying mechanism of the synergistic modification was elucidated based on various characterization methods. The modified CNCs exhibited not only improved thermal stability but also an increase in specific surface area from 1.54 to 149.20 m²/g. Upon extending this modification approach to APTES in synergy with FeCl₃^.6H₂O, the modified CNCs exhibited the photocatalytic degradation capability towards methylene blue dye, achieving a degradation ratio of up to 86.76%. This work provides a mild strategy to regulate the surface structure and functionality of CNCs.