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1.
Employment of ultrasonic waves for the preparation of PVA/TiO2‐BSA nanocomposites: Mechanical,thermal, and optical properties
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The goal of this project is to obtain poly(vinyl alcohol) (PVA)/TiO2‐bovine serum albumin (BSA) nanocomposite (NC) films in different weight percentages of modified TiO2. For this purpose, to prevent the accumulation of nanoparticles (NPs) in the PVA matrix, the surface of the TiO2 NPs was treated with the BSA molecules. To achieve this aim, ultrasonic waves were used as an environmentally friendly and green process that decrease the time of reactions, help better spreading of TiO2 NPs and maintain dimensions of TiO2 NPs in the nanoscale range. In the end, the features of the PVA/TiO2‐BSA NC films were considered with a variety of techniques. The Fourier transform infrared spectroscopy, energy dispersive X‐ray, and X‐ray diffraction showed that the BSA was well placed on the surface of TiO2 NPs. The thermal gravimetric analysis and UV‐visible results demonstrated that all the PVA/TiO2‐BSA NC films have better thermal and optical properties than the pure PVA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46558. 相似文献
2.
Sarah Pourjafar Ahmad Rahimpour Mohsen Jahanshahi 《Journal of Industrial and Engineering Chemistry》2012,18(4):1398-1405
Novel polyethersulfone (PES)/poly (vinyl alcohol) (PVA)/titanium dioxide (TiO2) composite nanofiltration membranes were prepared by dip-coating of PES membrane in PVA and TiO2 nanoparticles aqueous solution. Glutaraldehyde (GA) was used as a cross-linker for the composite polymer membrane in order to enhance the chemical, thermal as well as mechanical stabilities. TiO2 nanoparticles with different concentrations (0, 0.05, 0.1, 0.5 wt.%) were coated on the surface of PVA/PES composite membrane. The morphological study was investigated by atomic force microscopy (AFM), scanning surface microscopy (SEM) and along with X-ray diffraction (XRD). In addition, the membranes performances, in terms of permeate flux, ion rejection and swelling factor were also investigated. It was found that the increase in TiO2 solution concentration can highly affect the surface morphology and filtration performance of coated membranes. The contact angle measurement and XRD studies indicated that the TiO2 nanoparticles successfully were coated on the surface of PVA/PES composite membranes. However, rougher surface was obtained for membranes by TiO2 coating. The filtration performance data showed that the 0.1 wt.% TiO2-modified membrane presents higher performance in terms of flux and NaCl salt rejection. Finally, TiO2 modified membranes demonstrated the lower degree of swelling. 相似文献
3.
Alireza Bahramian 《应用聚合物科学杂志》2021,138(10):49991
The environmental sustainability, mechanical durability, and thermal stability of the poly(ethylene terephthalate) (PET)-based nanocomposite films compared with pure PET were evaluated. The samples were obtained by incorporating 2 wt% of TiO2, SiO2, ZnO nanoparticles (NPs), and an equal mixture of NPs in polymer by melt-mixing in a twin-screw extruder. The mechanical properties and hardness of samples were determined by the tensile and the atomic force microscopy-based nanoindentation tests. The melting, crystallization, and glass transition temperatures of samples were studied by dynamic mechanical thermal analysis and differential scanning calorimetry. The effects of compatibility, dispersity, and hydrophobicity of NPs on the surface morphology, crystallinity, and thermomechanical properties of nanocomposites were studied. The interaction of SiO2 NPs with PET chains had a promising effect on the surface morphology, high elastic modulus, dispersibility, crystallinity, and thermostability of the sample. The mixing of ZnO and TiO2 NPs improved the UV-blocking effects, and photostability, while the SiO2 and TiO2 NPs maintained the thermal properties of the film against UV radiation. The resulting film could be a good candidate as a greenhouse covering material due to its suitable photosynthetically active radiation transmittance. 相似文献
4.
Organic–inorganic polyvinylidene fluoride (PVDF)–titanium dioxide (TiO2) composite hollow fiber ultrafiltration (UF) membranes were prepared by TiO2 sol–gel method and blending method, respectively. The membranes were characterized in terms of microstructure, hydrophilicity, permeation performance, thermal stability, and mechanical strength. The experimental results indicated that PVDF–TiO2 composite UF membranes exhibited significant differences in surface properties and intrinsic properties because of the addition of inorganic particles. The TiO2 particles improved the membrane strength and thermal stability of PVDF–TiO2 composite UF membranes. In particular, hydrophilicity and permeability increased dramatically with the increase of TiO2, whereas the retention property of UF membranes was nearly unchanged. However, high TiO2 concentration induced the aggregation of particles, resulting in the decline of hydrophilicity and permeability. Compared with PVDF–TiO2 composite hollow fiber UF membranes prepared by TiO2 blending method, PVDF–TiO2 composite hollow fiber UF membranes prepared by TiO2 sol–gel method formed a dispersed inorganic network, and the stronger interaction between inorganic network and polymeric chains led to TiO2 particles being uniformly dispersed in UF membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
5.
Mixed rutile–anatase TiO2 nanoparticles were synthesized by hydrothermal treatment under acidic conditions and incorporated into poly(vinyl alcohol) (PVA). These nanocomposites were electrospun to produce nanofibers of PVA/TiO2, which were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The photocatalytic degradation of Rhodamine B and degradation of the polymer by UV‐C lamps were also investigated. The results showed that TiO2 nanoparticles did not change the morphology and thermal behavior of the nanofiber polymer, but were effective in modifying the UV absorption of PVA without reducing its stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
6.
We prepared titanium dioxide/PVA nanocomposite fiber webs for application in multifunctional textiles by electrospinning. The morphological properties of the TiO2/PVA nanocomposite fibers were characterized using scanning electron microscopy and transmission electron microscopy. Layered fabric systems with electrospun TiO2 nanocomposite fiber webs were developed using various concentrations of TiO2 and a range of web area densities, and then the UV‐protective properties, antibacterial functions, formaldehyde decomposition ability, and ammonia deodorization efficiency of the fabric systems were assessed. Layered fabric systems with TiO2 nanocomposite fiber webs containing 2 wt% TiO2 nanoparticles at 3.0 g m?2 web area density exhibited an ultraviolet protection factor of greater than 50, indicating excellent UV protection. The same system showed a 99.3% reduction in Staphylococcus aureus. Layered fabric systems with TiO2 nanocomposite fiber webs containing 3 wt % TiO2 nanoparticles at 3.0 g m?2 web area density exhibited a 85.3% reduction in Klebsiella pneumoniae. Titanium dioxide nanocomposite fiber webs containing 3 wt % TiO2 nanoparticles at 3.0 g m?2 web area density exhibited a formaldehyde decomposition efficiency of 40% after 2 h, 60% after 4 h, and 80% after 15 h under UV irradiation. The same system showed an ammonia deodorization efficiency of 32.2% under UV irradiation for 2 h. These results demonstrate that TiO2 nanocomposite fibers can be used to produce advanced textile materials with multifunctional properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
7.
《Ceramics International》2023,49(12):20174-20184
In this work, silver nanoparticles (Ag NPs) were prepared using a plant extract which is a cost-effective and environmentally friendly method. The sol-gel method was used to synthesize titanium dioxide nanoparticles (TiO2 NPs). A solid polymer nanocomposite samples have been prepared via the well-known solution cast way. The present samples were examined using various analytical measurements. The XRD patterns showed a decrease in the degree of crystallinity of the PVA/SA blend due to the addition of the hybrid nanoparticles (Ag and TiO2 NPs). It was evident by the ATR-FTIR measurement that there is an interaction between the functional groups of the polymeric matrix and the hybrid nanoparticles. XPS confirmed that Ag NPs were loaded onto the surfaces of the PVA/SA/TiO2 organic-inorganic nanocomposite samples. The TGA curves of the doped samples showed an improvement in their thermal stability compared to the pure sample. From the AC conductivity and electrical modulus, the dynamic ions activity and the kind of relaxation process of the nanocomposites samples were examined. The highest conductivity was log −6.066 S/cm for the polymeric sample doped with 1.60% Ag@TiO2 NPs, as showed by the AC conductivity measurement. A wide dispersion is observed in the dielectric constant spectra at low frequency. It was also evident from the data that the antibacterial activity of the pristine PVA/SA matrix was growing due to the inclusion of the hybrid nanoparticles to the polymeric matrix. Therefore, the obtained results indicate the applicability of these samples and their potential for use in the semiconductor industry, portable electrochemical batteries and energy storage industry, due to the remarkable improvement in the structural, thermal and electrical properties. Also, the good antibacterial activity of these films provides new samples as effective biomaterials and has the potential to be used in the food packaging industry. 相似文献
8.
Leire Goi-Ciaurriz Marta Senosiain-Nicolay Itziar Vlaz 《International journal of molecular sciences》2021,22(5)
Polymeric materials, such as polyvinyl alcohol (PVA) and ethylene–PVA copolymers (EVOH) are widely used in the food sector as packaging materials because of their excellent properties. TiO2 nanoparticles (NPs) show photocatalytic activity; when added to the aforementioned polymers, on the one hand, they are expected to provide bactericidal capacity, whereas on the other hand, they could favor nanocomposite degradation. These types of nanoparticles can be derivatized with cyclodextrin macromolecules (CDs), which can act as food preservative carriers, increasing the packaging food protective properties. In this work, films containing β-Cyclodextrin (βCD)-grafted TiO2 nanoparticles and PVA or EVOH were prepared. Regarding the photocatalytic activity of the nanoparticles and the possible environmental protection, accelerated aging tests for PVA, EVOH, and their composites with cyclodextrin-grafted TiO2 nanoparticle (NP) films were performed by two methods, namely, stability chamber experiments at different conditions of temperature and relative humidity and UV light irradiation at different intensities. After analyzing the systems color changes (CIELAB) and Fourier transform infrared spectroscopy (FTIR) spectra, it was observed that the film degradation became more evident when increasing the temperature (25–80 °C) and relative humidity percentage (28–80%). There was no significant influence of the presence of CDs during the degradation process. When irradiating the films with UV light, the largest color variation was observed in the nanocomposite films, as expected. Moreover, the color change was more relevant with increasing NP percentages (1–5%) due to the high photocatalytic activity of TiO2. In addition, films were characterized by FTIR spectroscopy and variation in the signal intensities was observed, suggesting the increase of the material degradation in the presence of TiO2 NPs. 相似文献
9.
Hem Raj Pant Bishweshwar Pant Ram Kumar Sharma Altangerel Amarjargal Han Joo Kim Chan Hee Park Leonard D. Tijing Cheol Sang Kim 《Ceramics International》2013,39(2):1503-1510
In this paper, a simple and efficient strategy of one-pot synthesis of Ag doped TiO2/ZnO photocatalyst was developed using hydrothermal process. Simultaneous crystallization of Ag and ZnO crystals from their precursor solution containing P25 (TiO2) NPs could form effectively bonded Ag/TiO2/ZnO composite photocatalyst during hydrothermal treatment. Several analytical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR spectroscopy, and photoluminescence spectroscopy have been used to characterize the resulting Ag/TiO2/ZnO photocatalyst. Results showed that ZnO nano-flowers doped with TiO2 and Ag NPs were formed by this simple facile one-step process. The unique properties of Ag NPs on binary semiconductor composite not only provide the decreased rate of electron–hole separation but also prevent from the loss of photocatalyst during recovery due to the fixed attachment of Ag and TiO2 NPs on the surface of flower shaped large ZnO particles. Therefore, as-synthesized composite is an economically and environmentally friendly photocatalyst. 相似文献
10.
Firstly, preparation of porous polyvinyl alcohol (PVA) spheres were investigated in detail by phase inversion method using N,N-dimethylacetamide (DMAc) and polyvinylpyrrolidone (PVP) as pore-forming additives. The morphology and pore structure of PVA spheres were characterized by SEM and BET measurements. It was found that the addition of DMAc and PVP increased the pore volume and the surface pore size of PVA sphere respectively. The maximum surface area of the porous PVA sphere reached 220 m2/g. Secondly; the synthesis of photoactive TiO2 NPs (anatase type) at the low temperature was developed by controlling the aging process of the TiO2 precursors. The crystallinity and photoactivity of TiO2 NPs increased with the aging time. Finally, TiO2 NPs/PVA composite spheres were prepared by immersing PVA sphere into TiO2 precursor solution. Their structures were characterized by XRD pattern, TEM and TGA measurement. It was found that TiO2 NPs were successfully immobilized into PVA spheres. The photodegradation of methyl orange (MO) under UV light by TiO2/PVA spheres showed a good photocatalytic efficiency. Moreover, TiO2/PVA spheres can be easily regenerated by the repeated immersion process. Overall, the porous TiO2/PVA sphere displays a good photoactive property and an advantage of easier recovery, which facilitates its application in large-scale wastewater treatment. 相似文献
11.
《Ceramics International》2022,48(7):9434-9441
In this study, we investigated the effect of Ag addition on the photocatalytic reactivity of TiO2 nanoparticles (NPs). Controlled amounts of Ag were incorporated in TiO2 NPs using aerosol spray pyrolysis and subsequent calcination. Ag/TiO2 composite NPs containing different amounts of Ag (e.g., 0, 0.5, 1, 2, and 5 wt%) were successfully fabricated. The photodegradation performances of the as-prepared Ag/TiO2 composite NPs were tested using methylene blue (MB) solution under UV and visible light irradiation. Upon increasing the Ag content to 1 wt%, the resulting Ag/TiO2 composite NPs exhibited increased photocatalytic reactivity due to lowered bandgap energy, which promoted both charge generation and separation. However, when the Ag content exceeded 1 wt%, the photocatalytic reactivity of the resulting Ag/TiO2 composite NPs was considerably deteriorated due to the masking effect of the excess Ag on the reactive sites of TiO2. Hence, the incorporation of an optimized amount of Ag in the TiO2 matrix promotes the photocatalytic reactivity of Ag/TiO2 composite NPs by controlling their bandgap energy and charge generation and separation processes. These results could lead to the development of photodegradation active substances for water treatment in organic solutions. 相似文献
12.
For an efficient energy storage system, effective material is to be used. In the present work, novel poly(vinylidene fluoride)/titanium oxide (PVdF/TiO2) composite membranes were developed using electrospinning technique, as separator for supercapacitors. Different weight percentages of TiO2 nanoparticle (0, 5, 10, 15, and 20 wt%) were mixed with 20 wt% of PVdF in a 50:50 wt% of tetrahydrofuran and dimethylacetamide solvent. Various physical and electrochemical properties including fiber diameter, thermal stability, crystallinity, porosity, and electrolytic uptake were studied to identify the best membrane with optimum TiO2 wt% exhibiting superior characteristics. SEM and TGA studies revealed that the developed PVdF/TiO2 composite membrane with 10 wt% showed improved properties with a lower average diameter of about 66 ± 8 nm, enhanced thermal stability up to 513.15°C and higher porosity of 89%, respectively compared to other membranes. The crystallinity, ionic conductivity, and specific capacitance of the nonwoven separator membranes were determined using X-ray diffraction technique, electrolytic uptake, and charge–discharge studies, respectively. The present study revealed that the addition of TiO2 nanoparticles improved the physical and thermochemical properties of the separator membrane substantially and PVdF/TiO2 composite membrane with 10 wt% displayed superior performance compared to other membranes. 相似文献
13.
Sreejarani Kesavan Pillai Suprakas Sinha Ray Manfred Scriba Vincent Ojijo Mpitloane Joseph Hato 《应用聚合物科学杂志》2013,129(1):362-370
Biocomposites containing ultraviolet (UV) radiation absorbing inorganic nanofillers are of great interest in food packaging applications. The biodegradable polylactide (PLA) composite films were prepared by solvent casting method by incorporating 1 wt % of titanium dioxide (TiO2) and Ag‐TiO2 (silver nanoparticles decorated TiO2) nanoparticles to impart the photodegradable properties. The films were exposed to UV radiation for different time periods and morphology of the composite films before and after UV exposure were investigated. The results showed that homogenous filler distribution was achieved in the case of Ag‐TiO2 nanoparticles. The thermal properties and thermomechanical stability of the composite film containing Ag‐TiO2 nanoparticles were found to be much higher than those of neat PLA and PLA/TiO2 composite films. The scanning electron microscopy and X‐ray diffraction studies revealed that the photodegradability of PLA matrix was significantly improved in the presence of Ag‐TiO2 nanoparticles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
14.
Julián Jiménez Reinosa Carmen María Álvarez Docio Víctor Zapata Ramírez José Francisco Fernández Lozano 《Ceramics International》2018,44(3):2827-2834
TiO2 is a commonly used semiconductor photocatalyst but, as a paradox, it is also widely used as UV filter in sunscreens. Moreover, its capacity to form free radicals under UV irradiation generates reactive free radicals that provoke sunscreens degradation. In this work a hierarchical composite made of ZnO nanoparticles anchored onto TiO2 microparticles is developed in a safe-by-design way by using the sol-gel method. The aim of this composite is to gain the advantages of inorganic nanoparticles avoiding their potential drawbacks. The hierarchical composite presents higher UV absorption than the pure TiO2 or ZnO counterparts. The functional stability study on standard sunscreen reveals a 50% high Solar Protection Factor (SPF) values over time for the hierarchical composite lowering the photodegradation of the formulation. Under authors' knowledge, it is the first time that the combination of these oxides increases the UV attenuation as inhibits the negative effects of free radicals. The high UV absorption without degradation opens a new orientation for the effective use of UV-absorbers without the photocatalyst adverse effects. The results in sunscreens generate a proposed mechanism of functionality that explains the observed differences on the efficiency of photocatalytic activity of these materials for other application fields. 相似文献
15.
In the present investigation, at first, the surface of titanium dioxide (TiO2) nanoparticles was modified with γ-aminopropyltriethoxy silane as a coupling agent. Then a new kind of poly(vinyl alcohol)/titanium dioxide (PVA/TiO2) nanocomposites coating with different modified TiO2 loading were prepared under ultrasonic irradiation process. Finally, these nanocomposites coating were used for fabrication of PVA/TiO2 films via solution casting method. The resulting nanocomposites were fully characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), thermogravimetric analysis/derivative thermal gravimetric (TGA/DTG), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The TEM and SEM results indicated that the surface modified nanoparticles were dispersed homogeneously in PVA matrix on nanoscale and based on obtained results a possible mechanism was proposed for ultrasonic induced nanocomposite fabrication. TGA confirmed that the heat stability of the nanocomposite was improved. UV–vis spectroscopy was employed to evaluate the absorbance and transmittance behavior of the PVA/TiO2 nanocomposite films in the wavelength range of 200–800 nm. The results showed that this type of films could be used as a coating to shield against UV light. 相似文献
16.
M. K. Mohanapriya Kalim Deshmukh Jaroslav Kadlec Kishor Kumar Sadasivuni Muhammad Faisal N. A. Nambi Raj 《Polymer-Plastics Technology and Engineering》2020,59(8):847-863
ABSTRACTNovel tertiary nanocomposite films comprising of poly (vinyl alcohol) (PVA), poly (4-styrenesulfonic acid) (PSSA) and titanium dioxide (TiO2) nanoparticles (NPS) were prepared using simple solvent casting method. The structural, thermal, morphological, thermo-mechanical and electromagnetic interference (EMI) shielding properties of PVA/PSSA/TiO2 nanocomposite films were investigated. The EMI shielding effectiveness (SE) of PVA/PSSA/TiO2 nanocomposite films in the X and Ku band was found to be 12 dB and 13 dB respectively at 25 wt% TiO2 NPs loading. These results demonstrate the possible applications of PVA/PSSA/TiO2 nanocomposite films as low cost, lightweight and flexible material for EMI shielding. 相似文献
17.
Susan Azizi Mansor B. Ahmad Nor Azowa Ibrahim Mohd Zobir Hussein Farideh Namvar 《International journal of molecular sciences》2014,15(6):11040-11053
In this study, cellulose nanocrystals/zinc oxide (CNCs/ZnO) nanocomposites were dispersed as bifunctional nano-sized fillers into poly(vinyl alcohol) (PVA) and chitosan (Cs) blend by a solvent casting method to prepare PVA/Cs/CNCs/ZnO bio-nanocomposites films. The morphology, thermal, mechanical and UV-vis absorption properties, as well antimicrobial effects of the bio-nanocomposite films were investigated. It demonstrated that CNCs/ZnO were compatible with PVA/Cs and dispersed homogeneously in the polymer blend matrix. CNCs/ZnO improved tensile strength and modulus of PVA/Cs significantly. Tensile strength and modulus of bio-nanocomposite films increased from 55.0 to 153.2 MPa and from 395 to 932 MPa, respectively with increasing nano-sized filler amount from 0 to 5.0 wt %. The thermal stability of PVA/Cs was also enhanced at 1.0 wt % CNCs/ZnO loading. UV light can be efficiently absorbed by incorporating ZnO nanoparticles into a PVA/Cs matrix, signifying that these bio-nanocomposite films show good UV-shielding effects. Moreover, the biocomposites films showed antibacterial activity toward the bacterial species Salmonella choleraesuis and Staphylococcus aureus. The improved physical properties obtained by incorporating CNCs/ZnO can be useful in variety uses. 相似文献
18.
《Ceramics International》2023,49(8):12563-12569
The optical, thermal, and electrical properties of a blend of polyethylene oxide (PEO) and carboxymethyl cellulose (CMC) are examined in the current work in relation to the effects of zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles. To create hybrid ZnO/TiO2 NPs nanocomposites with a PEO/CMC matrix, the solution casting method was utilized. The XRD study results demonstrate that the nanocomposite films' crystallinity decreases with increasing ZnO/TiO2 NP concentrations. FT-IR spectra reveal the interaction between metal oxide NPs and the PEO/CMC composite. UV/Vis analytical spectroscopy was used to calculate the optical properties, such as the energy gap (Eg), refractive index (n), and the number of carbon atoms (M). The inclusion of 7 wt%ZnO/TiO2 NPs decreased the polymer matrix's allowed direct energy gap from 3.68 to 2.81 eV. The AC conductivity results show that the of the nanocomposite samples decreases with increasing ZnO/TiO2 NPs concentrations. The of the final sample (PEO/CMC@7 wt% ZnO/TiO2) was 5.18 × 10−7Scm−1. According to exponential factor (S) results, the dominates conduction mechanism is correlated barrier hopping (CBH) with non-Debye relaxation processes. Space charge polarization was demonstrated by large ε′ values in the low-frequency dielectric properties, whereas an increase in energy loss may be related with a larger εʹ' value in the composite samples. These results prove that these nanocomposites can be used in a variety of energy-related devices, such as flexible capacitors, and energy storage systems. 相似文献
19.
The nano‐ZnO and nano‐TiO2 were added into chitosan (CS) anion layer to prepare polyvinyl alcohol (PVA) ‐ sodium alginate (SA)/ TiO2‐ZnO‐CS (here, PVA:polyvinyl alcohol; SA:sodium alginate) bipolar membrane (BPM), which was characterized using scanning electron microscopy, atomic force microscopy (AFM), thermogravimetric analysis (TG), electric universal testing machine, contact angle measurer, and so on. Experimental results showed that nano‐TiO2‐ZnO exhibited better photocatalytic property for water splitting at the interlayer of BPM than nano‐TiO2 or nano‐ZnO. The membrane impedance and voltage drop (IR drop) of the BPM were obviously decreased under the irradiation of high‐pressure mercury lamps. At a current density of 60 mA/cm2, the cell voltage of PVA‐SA/TiO2‐ZnO‐CS BPM‐equipped cell decreased by 1.0 V. And the cell voltages of PVA‐SA/TiO2‐CS BPM‐equipped cell and PVA‐SA/ZnO‐CS BPM‐equipped cell were only reduced by 0.7 and 0.6 V, respectively. Furthermore, the hydrophilicity, thermal stability, and mechanical properties of the modified BPM were increased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
20.
PFSA-TiO2(or Al2O3)-PVA/PVA/PAN difunctional hollow fiber composite membranes with separation performance and catalytic activity have been prepared by dip-coating method. The good separation performance was brought about by the glutaraldehyde (GA) surface cross-linked PVA/PAN composite membrane, and the good catalytic activity of the membrane was achieved by the perfluorosulphonic acid (PFSA) used. The difunctional hollow fiber membranes were characterized by XRD, TGA, EDX, SEM, and FTIR. The separation performance was measured by dehydration of azeotropic top product of ethanol-acetic acid esterification, and the catalytic activity was obtained by investigating the esterification of ethanol and acetic acid. The FTIR spectra and the morphologies of difunctional hollow fiber composite membranes were similar for samples prior to esterification and post-esterification with ethanol and acetic acid for 24?h. Difunctional hollow fiber composite membranes with 2% PFSA, 8% TiO2 (named as DM-T1), and 2% PFSA, 8% Al2O3 (named as DM-A1) (all by weights) showed the best catalytic activity. They displayed fluxes of 165 and 173?g/m2?h, separation factors of water to ethanol of 279 and 161, PFSA contents in difunctional hollow fiber composite membrane of 3.2 and 2.4%, the ratios of PFSA to feed solution (acetic acid?Cethanol) of 0.031 and 0.023%, and the equilibrium conversion of ethanol at 53.5 and 57.6%, in the given order for TiO2 and Al2O3 containing samples. 相似文献