Removal of formaldehyde from liquid phase by polyacrylonitrile / TiO2 Nanofibers

Formaldehyde is carcinogenic so it is necessary to remove it from air and water. An efficient way to remove formaldehyde is to photodegrade it under UV source. In this paper removing of formaldehyde from liquid phase was done by PAN / TiO2 nanowebs. PAN / TiO2 nanowebs containing various amounts of TiO2 were prepared by electrospining method. First of all 10 wt% PAN / DMF solution was prepared by stirring the polymer in the solvent for 24hr. PAN / TiO2 solution was prepared by adding various amounts of TiO2 to PAN / DMF solution. The nano filler content varied from 10-20 wt%. This solution was injected into a syringe and electrospining was done with 15 kv voltage. In order to investigate the photocatalytic activity of the nanowebs, we put them in the formalin solution and irridated them under UV source for 20-30hr.For analyzing the remained solution after filtration, we used a new method based on spectrophotometry and Fehling solution. Because formalin solution is colorless we need to use a colored solution which can also react with formaldehyde to detect it. Fehling solution is the best choice for this purpose. The results of spectrophotometry showed that an increase in TiO2 loading , increased the efficiency of nanofilter. Also, by increasing of exposure time , the efficiency of nanofilter increased. Because of large specific area and small pore size of nanofibers , formaldehyde was absorbed easily on nanofiber surface. Under UV source , TiO2 acted as a photocatalyst and decomposed the absorbed formaldehyde into CO2 and H2O

کلیدواژه ها:

Electrospinning ، Formalin ، Photocatalytic degradation ، nanofilteration ، UV source