Cellulose-based materials for air purification: A review

Air-purification utilizing an air filtration system is vital in maintaining optimum interior air quality, despite the highly polluted air that anthropogenic activities have exacerbated. Since the constituents of air pollutants are so unstable and diverse, conventional air-filtering materials made of glass fibres or non-biodegradable polymers are facing a considerable dilemma in completely removing particulate pollutants of finer size like PM2.5 and gaseous pollutants like harmful chemicals, CO2, and other contaminants. These synthetic polymers are likewise non-biodegradable, resulting in their disposal in landfills. Therefore, developing a fully biodegradable filtering system for air purification is undeniably urgent. Cellulose is a widely dispersed natural biopolymer and due to its porous, sustainable and surface-modifiable nature, it has demonstrated extraordinary relevance in numerous fields, including as high-performance air filtration system. In the present review, we discussed the significance, characteristics, functioning and ability of pure and surface functionalized cellulose and its derivatives-based filter system to remove particulate matter, volatile organic compounds and CO2. In addition, different composite filters/membranes made using cellulose and its derivatives have also been discussed. Furthermore, we have also tried to investigate the mechanism for the absorption or removal of different pollutants utilising cellulose-based air filters. A comparative view of the properties of different cellulosic forms is also given here. Cellulose is one of the essential polymeric materials in the air purifying industries. This study analyses the impact of various surface functionalisation techniques and blending materials such as carbon nanotubes, a natural biopolymer, polymer matrix, etc. on the performance of resulted filtering system. This review provides data pertinent to the use of cellulose in air purification based on an exhaustive analysis of the available literature. In addition, several future considerations are also discussed.