Iranian scientists produce filters with an active carbon and silver nanoparticles coating
Iranian textile engineers from Islamic Azad University, Science and Research Branch in Tehran have produced filters with an active carbon and silver nanoparticles coating, which are capable of adsorbing chemical pollutants and microbes that carry contagious diseases.
Results of the research could help in the design of masks used in various medical or industrial sectors, and in high-performance filters used in various industries, including automobile manufacturing, steel, cement, petroleum, gas, and petrochemistry.
In this research, the filter was first produced by using polypropylene fibres and a 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 oven-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 effect on chemical and microbial pollutants.
The research results showed that a polypropylene layer coated with silver nanoparticles could deactivate micro-organisms such as Staphylococcus aureus and Escherichia coli. On the other hand, coating a layer with active carbon results in the adsorption of pollutants and 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 the adsorption ability of active carbon. The researchers concluded that to obtain the two desired characteristics – 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.