Preparation Of Titanium Dioxide Composite Nano-electrospun Fiber Membrane And Its Photocatalytic Degradation Of Toluene

Volatile organic compounds?VOCs?are prevalent components of indoor air pollutants and include benzene,toluene,styrene,formaldehyde and etc.Long-term exposure to VOCs will result in acute or chronic disease.Indoor air pollution has caused widespread concern.Photocatalytic oxidation?PCO?has been proved to be a convenient and innovative technology to degrade organic pollutants to CO₂ and H2 O completely in environmental-friendly reaction condition and has been applied in purify air universally.Nanotitanium dioxide?TiO₂?is the most frequently employed as a photocatalyst,however,it is always in the form of particles,which are easily aggregated and largely reduce their photocatalytic activities,besides,it is difficult to separate and recycle nano-TiO₂ power after its application.All of above limit their practical utilization.It can offer an attractive solution to this problem when the TiO₂ in the form of membranes or prepared one composite fiber that composed of TiO₂.Among the numerous thin-film fabrication techniques,electrospinning has attracted extensive attention to produce nanosized continuous fibers on account of simple equipment,convenient operation,low cost and wide range of application.Up to now,a lot of efforts have been devoted to fabricating TiO₂ nanofibrous membranes by electrospinning.The main content of this thesis as follows:?1?The fabrication of the TiO₂ via electrospinning or eletrospray?The exploration of the electrospinning experiment?The concentration of the polymer is the key to electrospinning.We fabricated different spinning solution through controlling the concentration of PVP?Mw=58000?.It will be eletrospray when the concentration of PVP is low and the production is the particle.We compared the morphology,phase structure and the performance of photocatalytic degradation toluene of the TiO₂ fabricated by the electrospinning and electrospray.?2?The fabric ation and performance of the TiO₂/PI composite membraneIn this work,a composite TiO₂/PI composite membrane constructed with TiO₂ and PI nanofibers in an interwoven structure was successfully fabricated by simultaneous electrospinning with a post-annealing process.The results showed that the TiO₂ nanofibers endowed the composite membranes with photocatalytic activity,while the PI nanofibers as the structural reinforcements in the composite membranecould remarkably improve the mechanical property of membrane.Finally,the morphologies,structures,mechanical properties and photocatalytic properties of composite membranes with different TiO₂/PI mass ratios were systematically studied.?3?The fabrication and performance of the TiO₂/PAN composite membraneThe TiO₂/PAN composite membranes were prepared by electrospraying of TiO₂ and electrospinning of PAN simultaneously.By this method,the TiO₂ nanoparticles are easily attached on the surfaces of nanofibers.Finally,the morphologies,structures,filtration efficiency and photocatalytic properties of composite membranes systematically studied.The results showed that the composite membranes that contained TiO₂ fabricated in this thesis exhibited excellent property in purification air and can be recycled after its application,which could provid possible solutions to improve the potential of TiO₂ in the application of photocatalytic.