Synthesis Of Hybrid Mesoporous PVDF/TiO₂ Membrane And Its Application In The Photocatalytic Degradation Of Organic Pollutants

Porous titanium dioxide films have interconnected pores helpful to transport substances; activity centers can effectively improve the photocatalytic properties and photoelectric conversion efficiency. Therefore, the synthesis, characterization and application are one of the hotspots in the field of porous membrane material. This article briefly describes the main preparative methods and its applications of porous titania film. Consider that traditional inorganic film composite membranes are fragile, not resistant to acid, base and organic solvents as well as highly hydrophobic problem of polyvinylidene fluoride film, poly PVDF/ titanium composite mesoporous films were prepared and its applications in organic pollutants treatment via photocatalytic membrane reactor are studied. The main results are as follows:1、Sol-gel double template synthesis combined solvent extraction method was used to synthesize three-dimensional pore mesoporous titania material inside organic porous polyvinylidene fluoride (PVDF) membranes to form a PVDF/TiO2 hybid mesoporous membrane. PVDF/TiO2 hybid mesoporous membranes were characterized by SEM, EDS, TEM, XRD and N2 adsorption-desorption. The results indicated that TiO2 materials grew in the confined spaces of PVDF membrane. The average diameter of mesopores with partially ordered mesostructure is evaluated about 3.5 nm. In addition, compared with the polyvinylidene fluoride film, poly(vinylidene fluoride)/mesoporous titania composite membrane was found to have excellent hydrophilic property. This property facilitated its applications in the organic pollutants degradation using PVDF/TiO2 hybid mesoporous membrane. Assembling mesoporous materials makes this strong hydrophobic polyvinylidene fluoride film widely applicable to water treatment field.2、PVDF/TiCO2 hybid mesoporous membranes prepared by sol-gel double template method, not only have excellent hydrophilic properties, but also exhibit good adsorption and photocatalytic properties towards organic dyes. For this reason, we have studied the static adsorption and photocatalytic properties towards methyl orange using PVDF/TiO2 hybid mesoporous membrane, as well as the adsorption of Rhodamine B and photocatalytic ability of the composite film under dynamic condition. The influence of P123 surfactant on adsorption and photocatalytic properties of the PVDF/TiO2 hybid mesoporous membrane was investigated. The results showed that this PVDF/TiO2 hybid mesoporous membrane under both static and dynamic conditions have shown good adsorption and photocatalytic properties towards the dye molecules. Moreover, the surfactant P123 have a great impact on the properties of the film, for example, composite membrane after removing the surfactant has better adsorption and photocatalytic properties than that of composite membrane before removing the surfactant. Hence, the surfactant-free PVDF/TiO2 hybid mesoporous membrane has a better prospect in its practical applications.