Preparation, characterization and dye adsorption potential of quaternized cellulose nanomaterials

<p>Cellulose nanomaterials are emerging as one of the main types of potential eco-friendly adsorbents. In this study, cellulose nanomaterials were synthesised and comprehensively characterised and were subsequently functionalised using ionic liquids. The main focus of the research was on optimising the process for producing materials with precisely defined morphological characteristics. This allows for deliberate structural engineering, which is essential for use in specifically tailored environmental applications. Acid hydrolysis with ultrasonication as a pretreatment of microcrystalline cellulose enabled the formation of nanocellulose, which was subsequently quaternised in a further stage of the research. The quaternisation process was further optimised to avoid the hydrolysis of epoxides. The more stages of functionalization, the greater the disruption to the porous structure. The physicochemical characterization carried out confirmed both the functionalisation process and the material’s adsorption capabilities. Preliminary adsorption studies on dyes demonstrated promising adsorption capabilities, resulting from a range of different interactions. The relationships between structure and properties indicate that further modification, i.e. adjusting porosity or using a crosslinker, could improve the strength, stability and adsorption efficiency of selected materials. Furthermore, this could potentially increase the adsorbent’s lifespan and resistance to fluctuating environmental conditions, which would be of crucial importance in water treatment technology. The results provide a basis for the future optimization and upscaling of production of these cellulose-based adsorbents. They suggest that the functionalisation developed could be adapted to other natural polymers, which would significantly improve the prospects for creating biodegradable adsorbents. </p>