Cellulose-based Antimicrobial Composites and Applications: A Brief Review

Cellulose-based antimicrobial composites,typically in the form of functional films and cloth,have received much attention in various applications,such as food,medical and textile industries.Cellulose is a natural polymer,and is highly biodegradable,green,and sustainable.Imparting antimicrobial properties to cellulose,will significantly enhance its applications so that its commercial value can be boosted.In this review paper,the use of cellulose for antimicrobial composites’preparation was discussed.Two different approaches:surface loading/coating and interior embedding,were focused.Three most widely-applied sectors:food,medical and textile industries,were highlighted.Nanocellulose,as a leading-edge cellulose material,its unique application on the antimicrobial composites,was particularly discussed.

Nano-copper ions assembled cellulose-based composite with antibacterial activity for biodegradable personal protective mask

The current SARS-CoV-2 pandemic has resulted in the widespread use of personal protective equipment,particularly face masks.However,the use of commercial disposable face masks puts great pressure on the environment.In this study,nano-copper ions assembled cotton fabric used in face masks to impart antibacterial activity has been discussed.To produce the nanocomposite,the cotton fabric was modified by sodium chloroacetate after its mercerization,and assembled with bactericidal nano-copper ions(about 10.61 mg·g^(–1))through electrostatic adsorption.It demonstrated excellent antibacterial activity against Staphylococcus aureus and Escherichia coli because the gaps between fibers in the cotton fabric allow the nano-copper ions to be fully released.Moreover,the antibacterial efficiency was maintained even after 50 washing cycles.Furthermore,the face mask constructed with this novel nanocomposite upper layer exhibited a high particle filtration efficiency(96.08%±0.91%)without compromising the air permeability(28.9 min·L^(–1)).This green,economical,facile,and scalable process of depositing nano-copper ions onto modified cotton fibric has great potential to reduce disease transmission,resource consumption,and environmental impact of waste,while also expanding the range of protective fabrics.

Novel robust cellulose-based foam with pH and light dual-response for oil recovery

We fabricated pH and light dual-responsive adsorption materials which could induce the transition of surface wettability between hydrophobicity and hydrophilicity by using ATRPo The structure and morphology of adsorption materials were confirmed by ATR-FTIR, XPS, TGA and SEM. It showed that the modified cellulose （CE）- based foam was hydrophobic, which can adsorb a range of oils and organic solvents in water under pH = 7.0 or visible light irradiation （λ〉500 nm）. Meanwhile, the wettability of robust CE-based foam can convert hydrophobicity into hydrophilicity and underwater oleophobicity under pH = 3.0 or UV irradiation （λ = 365 nm）, giving rise to release oils and organic solvents. Most important of all, the adsorption and desorption processes of the modified CE-based foam could be switched by external stimuli. Furthermore, the modified CE-based foam was not damaged and still retained original performance after reversible cycle repeated for many times with variation of surface wettability. In short, it indicates that CE-based foam materials with switchable surface wettability are new responsive absorbent materials and have owned potential application in the treatment of oil recovery.

Naked Eye and Selective Detection of Copper(II) in Mixed Aqueous Media Using a Cellulose-based Support

A new colorimetric sensor based-azo dye for Cu^2+ detection was synthesized and characterized by FTIR and NMR spectroscopies. The results showed that the azo dye had a high selective and sensitive recognition toward Cu^2+. The solution containing the sensor changed color from pink to pale yellow with a hypsochromic shift in the presence of Cu^2+. The sensor selectivity and sensitivity toward Cu^2+ ions were investigated by colorimetry and UV-Vis spectroscopy. For practical applications, a cellulosic textile test strip for high-selectivity detection of Cu^2+ ions in aqueous solution was developed using the synthesized azo dye as chromogenic chemosensor molecule, while using a solid cellulose textile as a substrate. As a result, a spectacular color change of the test strip was observed do pending on the amount of copper ions in contact with the strip, which allows an estimation of Cu^2+ concentration by naked eye.