Preparation Of Polyurethane Based Modified Porous Film And Its Adsorption And Photocatalytic Properties

In recent years,with the rapid development of nanotechnology,more and more nanomaterials with efficient adsorption or catalytic properties have been developed.However,in the actual application and promotion of nanomaterials,there are mainly problems such as easy agglomeration and reduced activity,difficulty in separating from the reaction system,and cumbersome and inefficient recycling processes.At present,polymer-based porous modified materials are a popular carrier-type reactor,and their related research potentials are great,and the preparation of materials is relatively simple.The related research on polyurethane porous modified materials with adsorption properties and photocatalysis can be further expanded.Therefore,in this study,polyurethane as the research object,combines wet phase inversion technology and filling modification technology to prepare polyurethane-based porous modified films with adsorption and catalytic functions.The adsorption performance and photocatalytic properties of modified films were further studies.The main research work of this paper is the following parts:The iron salt/polyurethane(Fe/PU,Fe₂O₃/PU,Fe₃O₄/PU and C₁₀H₁₀Fe/PU)modified films were prepared by non-solvent induced phase separation(NIPS)and filling modification technology,and the effects of different iron salts on the performance of modified films were explored.The composition and structure of the modified films were analyzed by X-ray diffractometer(XRD),scanning electron microscopy(SEM),Fourier infrared spectroscopy(FTIR)and ultraviolet-visible spectrophotometer(UV-vis).And use contact angle measuring instrument to analyze the stability of the modified film.The results show that the modified films had a porous structure on the outside and inside,and the modified films had a large amount of iron salt powder distributed respectively,and its surface morphology varies with the type of iron salt,and the stability of the films surface also changed.When the filling powder was ferrocene,the surface roughness of the modified films appears;the adsorption performance of the modified films was enhanced after Fe was added,and the films surface had a microporous enrichment phenomenon that was superior to other modified films structures.Using congo red(CR)and methyl orange(MO)as model pollutants,the adsorption performance and stability of the modified films were explored.The results showed that the adsorption performance of the Fe/PU modified films was the best.After 24 hours of adsorption,they were 59.4%and 43.4%of CR and MO were adsorbed;in the cyclic adsorption experiments of CR and MO,the adsorption performance of the modified membrane decreased,but the overall adsorption performance was still maintained.A new type of negative oxygen ion powder modified titanium dioxide/polyurethane(NI-Ti O₂/PU)modified photocatalyst was prepared by NIPS and filling modification technology.The crystal structure,morphology,functional groups and optical characteristics of the modified film were analyzed.The composition and structure of the modified films were analyzed by XRD,FESEM,EDX,FTIR and UV-vis.The results show that the modified film was porous structures in the outside and the inside,and the modified film was distributed with titanium dioxide(Ti O₂)powder,and the distribution morphology increases with the content ratio of titanium dioxide and negative oxygen ion(NI)powder.The phenomenon of particle enrichment to layer upon layer accumulation,indicating NI powder had a certain effect on the dispersibility of Ti O₂;the modified film had a small response increase in the ultraviolet and visible light regions,and the band gap energy was increased from 3.00 e V to 3.06 e V;After adding the NI powder,the specific surface area of the modified membrane increases.At the same time,the NI powder reduces the recombination of electrons and holes,which improves the catalytic degradation efficiency.Used a model pollutant,Rhodamine B(Rh B),to evaluate the photocatalytic activity and stability of the modified film,under visible light irradiation.The results showed that when the mass ratio of NI/Ti O₂ was 0.6,the degradation efficiency of modified porous film increased from 26%to 36%after 120 minutes,under visible light irradiation.After five cycles of degradation experiments,the photocatalytic activity of the modified film decreased slightly.A new type of iron modified titanium dioxide/polyurethane-negative oxygen ion powder(Fe/Ti O₂-PU/NI)modified photocatalyst was prepared by non-solvent induced phase separation(NIPS)and filling modification technology.The crystal structure,morphology,functional group and optical characteristics of the modified film are analyzed by XRD,FESEM,EDX,FTIR and UV-vis.The results show that the modified film was in the outside and the inside are porous structures,and there are titania distributed on the modified films,and the morphology of the distribution appears as the content ratio of titania and iron powder increases with the phenomenon of rich pores or accumulation,indicating that the content of iron powder affects the pores of the films structure.The structure had a certain effect;the modified film had a small response improvement in the visible light region;after adding Fe,the surface pore structure of the modified film increases,and the efficiency of the recombination of electrons and holes decreases,and the catalytic degradation efficiency first increases and then decreases.The photocatalytic degradation of methyl orange(MO)and rhodamine B(Rh B)under UV light irradiation were chosen as model pollutants to explore the photocatalytic activity and stability of modified films.The results show that the mass ratio of 0.2 has the best catalytic performance,after 120 minutes of ultraviolet light irradiation,the degradation efficiency of MO and Rh B were 42.1%and 37.9%,respectively;and after three cycles of degradation experiments,the photocatalytic activity of the modified film decreased slightly.In short,this paper had successfully prepared a series of polyurethane porous modified materials with low cost,good stability,high efficiency,and easy separation and recovery.It provides a new idea for the design of a series of porous polyurethane-based reactors of new and efficient modified materials.The field of adsorption and degradation of pollutants has potential application value.