Novel Fluorescent Nanocellulose Hydrogel Based on Nanocellulose and Carbon Dots for Detection and Removal of Heavy Metal Ions in Water

Abstract

Water is an important raw material in the food production process. Maintaining the quality and safety of water is very important in the food field. In this study, a simple novel fluorescent nanocellulose hydrogel (FNH) was prepared for the detection and removal of heavy metals (Fe3+ and Pb2+) in aqueous solutions based on carbon dots (CDs). The CDs were grafted onto the carboxylated nanocellulose (CNC) by the EDC/NHS coupling method, and then the nanocellulose (NC), CNC, and FNH were characterized by FTIR analysis. The effect of adsorption environment on FNH adsorption capacity was also investigated. After carboxylation and grafting of CDs, the adsorption capacity of nanocellulose to Fe3+ and Pb2+ was greatly improved, and it was also allowed to make fast visual responses to Fe3+ as an optical sensor to determine the concentration of Fe3+ through the visual signal. Static adsorption experiment demonstrated that the removal rate of Fe3+ and Pb2+ by FNH exceeded 69.4% and 98.2%, and the adsorption capacity amount reached 98.3 mg/g and 442.0 mg/g. At the same time, due to the fluorescence quenching effect of Fe3+, FNH could also be used for the detection of Fe3+ concentration in aqueous solution, and the limit of detection (LOD) could reach 62.5 mg/L.

Polymeric Materials Obtained by Extrusion and Injection Molding from Lignocellulosic Agroindustrial Biomass

“…Chemical reactions involving oxidation and acetylation processes or the addition of functional materials, polymers, and functional groups on the surface of the nanogranules allow the surface properties of the nanocellulose to be improved and associate with different non-polar matrices or change its affinity with certain polar and non-polar molecules [56]. The use of nanocellulose has aroused extensive industrial interest and has shed light on a variety of operations, such as the paper industry [57], packaging [58], cosmetics [59], the pharmaceuticals industry [60], medicine [61], biomedicine [62], paints and coating [63], hydrogel synthesis [64], and filtrations [65]. Nanocellulose has two basic disadvantages, namely a high number of hydroxyl compounds, which causes strong and resistant interactions by hydrogen molecules between two bundles of nanofibrils, and high hydrophilicity, which does not allow its application for a variety of industrial purposes, such as coating paper or composites, for example, without inducing a prominent surface modification to degrade the number of hydroxyl interactions and to stimulate compatibility with several other matrices [66].…”

Fluorescent cellulose nanocrystals/waterborne polyurethane nanocomposites for anti-counterfeiting applications

“…17,18 Recently, fluorescent nanocellulose has attracted increasing attention for bioimaging, sensing, and drug delivery. [19][20][21] Thus far, the use of fluorescent nanocellulose for anti-counterfeiting is rarely reported. Here, we synthesized and utilized AIE-labeled fluorescent nanocellulose (TPE-CNCs) as fluorescent materials for anti-counterfeiting applications.…”

Nanocellulose Prepared from Buckwheat Bran: Physicochemical Characterization, Cytotoxicity Evaluation, and Inhibition Effect on Fat Digestion and Absorption

“…The hydrolyzed FFAs will be absorbed by the intestine and resynthesized to TG after passing through the intestine. Nanocellulose, as a good renewable bioadsorption material, is widely used in the absorption of heavy metals, toxic and harmful substances, oil spills, and so forth. In the field of edible food, there are few studies on the use of nanocellulose.…”