Iranian textile engineers from Islamic Azad University, Science and Research Branch, in Tehran succeeded in the production of filters with active carbon and silver nanoparticles coating, which are highly capable of adsorbing chemical pollutants and microbes that carry contagious diseases.
Results of the research can help the designing of masks used in various medical or industrial sections, and high-performance filters in various industries, including automobile manufacturing, steel, cement, petroleum, gas, and petrochemistry.
In this research, the filter was produced firstly by using polypropylene fibers through layer needle-punch method. In the next stage, a solution of active carbon was made by using distilled water and the material was coated on the texture-free layer by using foulard. Layers were put in the oven to be dried after being treated. The obtained layer was sprayed in the next stage by using various concentrations of nanosilver solutions. The final filter obtained from the experiment was subjected to various tests to measure its affection on chemical and microbial pollutants.
Results of the research showed that polypropylene layer coated with silver nanoparticles could deactivate microorganisms such as Staphylococcus aureus and Escherichia coli. On the other hand, the coating of layer with active carbon results in the adsorption of pollutants gases, including NO, CO and NO2. The simultaneous presence of active carbon particles and silver nanoparticles in the surface of polypropylene film decreases the antimicrobial activity of silver particles.
Nevertheless, no significant reduction was observed in adsorption ability of active carbon. It can be concluded that to obtain the two desired characteristics, that are antimicrobial properties and adsorption of pollutants, active carbon particles and silver nanoparticles should be placed on two different sides of the filter layer.
Results of the research have been published in details in Journal of Industrial Textiles, vol. 42, issue 3, January 2013, pp. 219-230.