Study On Purifing Indoor Air With Wool Fiber Modified By Nano-TiO₂

In this theis, wool fiber is chosen as substrate material of functionality filter material, which would be combined with photochemical catalysis technology. The purification effect of indoor air by nano-TiO₂/ wool functionality filter material was studied.The correlative theory on adsorption and photochemical catalysis was studied. The internal and overseas study evolve of wool fiber on purification air was reviewed. The fiber structure of wool correlated to the adsorption was analyzed, and the industrial property of wool fiber was summarized. From the point of interface chemistry, the adsorption theory of physisorption and chemisorption and the influencing factor of adsorbing formaldehyde were analyzed. Meanwhile, the multiple adsorption and photochemical catalysis mechanism combined wool fiber and nano-pholocatalyst was systemically explained. The deactivation condition of pholocatalyst and the cooperation effect of wool fiber and pholocatalyst were discussed. The process of adsorption and photochemical catalysis was affected by pholocatalyst nano-TiO₂, the adsorption property of wool fiber and environment.Besides, the mechanism of anion produced from wool and the influence on producing anion by rubbing were theoretically analyzed.On the basis of summarizing the modification method of functionality filter material, three wool filter materials with different organization structure were modified by the way of padding. The resistance of wool filter material original sample and modified sample were tested. The results indicated that the modified sample of wool filter material relative to the original sample increased by 10%, and the resistance increase varied inversely with the surface density of wool filter material original sample. The relationship between the resistance change of three wool filter material and filter velocity was in the form of parabola.The influence of photochemistry reaction on the formaldehyde concentration in obturation chamber was tested on the static state experiment table, some conclusions were drawn as followings:(1) Photochemical reaction made formaldehyde concentration in chamber decreased by 12%;(2) The purification ratios of wool filter material original sample and modified sample were 39.22% and 67.6% respectively. On dynamic experiment table, the adsorption effect to formaldehyde by different wool filter original sample, the ratios of adsorption and photochemical catalysis of different wool filter modified sample to formaldehyde and the influence of the initial formaldehyde concentration on adsorption and photochemical catalysis were tested. Some results were drawn as followings:(1) The adsorption property of formaldehyde by wool filter material 3 original sample (wool felt) were better than wool filter material 1 original sample (wool woven fabric), and the purification ratio increased by 12.28%;(2) The purification ratios of adsorption and photochemical catalysis to formaldehyde by wool filter material 1 modified sample (wool woven fabric 1 modified sample), wool filter material 2 modified sample (wool woven fabric 2 modified sample) and wool filter material 3 modified sample(wool felt modified sample) were 68.74%, 66.61% and 57.71% respectively.(3) The purification efficiency to formaldehyde by wool filter material modified sample decrease with the increase of temperature, and the thicker initial formaldehyde concentration, the better purification efficiency of adsorption and photochemical catalysis.The anion emission measure of wool fabric of Brighton weave, twill weave and plain weave and the influence of photochemical catalysis modification on anion emission measure of wool fabric were measured. The results indicated that the anion emission measure of three wool fabrics with different fabric texture were above 3000·cm-3, after photochemical catalysis modification, the anion emission measure of wool fabric were remarkable increased, and the ultraviolet play an auto-action on the Anion emission measure.