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1.
    
This work explores the possibilities to blend block copolymers, i.e., Pebax MH 1657, with a variety of cheap poly(propylene oxide)‐rich molecules which could potentially play a double role in the resulting membranes as dispersing/stabilizing agents in multi‐component casting solutions and as a gas transport medium in the final membrane. These membranes were prepared by solution casting and were characterized by differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, X‐ray diffraction, density measurements, and Fourier transform infrared‐attenuated total reflection, while additive incorporation was also studied with theoretical calculations. Gas permeation measurements showed that this approach resulted in increased permeabilities at the expense of mixed‐gas selectivity. An interpretation of the blend structure was finally made using gas transport models. The compatibility of these additives with the synthesis of selective gas separation membranes may enable a potential double role in membrane synthesis, i.e., as stabilizing agents in membrane synthesis and as a gas transport medium in the final membrane. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46433.  相似文献   

2.
    
The TiO2 nanoparticles were incorporated into an ethyl cellulose (EC) matrix to improve the pervaporation (PV) performance of the membrane for gasoline desulfurization. The microstructures of different EC membranes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and X‐ray and transmission electron microscopy. The PV experiments showed that the hybrid membrane of EC/TiO2 demonstrated an improved permeation flux (J ) of 7.58 kg m?2 h?1 and a sulfur enrichment factor (α) of 3.13 in comparison with the pure EC membrane, with a J of 3.73 kg m?2 h?1 and an α of 3.69. In addition, the effects of the operating conditions, including the operating temperature, layer thickness, crosslinking time, feed flow rate, and feed sulfur content level, on the PV performance of the EC/TiO2 membrane were investigated. Under a 100 mL/min feed flow rate and a 85 μg/g sulfur content, J of the 10 μm thick membrane increased to 7.58 kg m?2 h?1 with α of 3.13 compared to the pure EC membrane (3.73 kg m?2 h?1, 3.69) at 80 °C with 30 min of crosslinking time. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 : 134 , 43409.  相似文献   

3.
    
In the present study, the morphology of asymmetric poly(vinylidene fluoride) blend membranes which were prepared by the phase inversion method is rationalized by comparing two non‐dimensional number represent thermodynamic and kinetic properties of the prepared membrane. These two parameters change phase diagram and demixing rate between solvent and nonsolvent. TiO2 nanoparticles and polyvinylpyrrolidone were used as additives. Hansen solubility parameters of the components are calculated by Van Krevelen method. Furthermore, kinetic and thermodynamic properties of the prepared solutions are determined by drawing phase diagrams and controlling mass transfer rate during precipitation of casting solution. Besides, to further analyze different tests encompass; permeability, rejection, porosity, pore size determination, contact angle, and field emission scanning electron microscopy images were carried out. It is shown, additives as pore former induced higher permeability and porosity, however, at higher concentration of additives high viscosity obstacle mass transfer and sponge‐like morphology is obtained. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46225.  相似文献   

4.
    
In this study, we endowed a poly(vinylidene fluoride) (PVDF) membrane with outstanding antifouling ability by blending the hierarchical amphiphilic brushlike copolymer [poly(hydroxyethyl methacrylate)-b-polydimethylsiloxane-b-poly(hydroxyethyl methacrylate)]-g-poly(N,N-dimethylamino-2-ethyl methacrylate) with different initial monomer/initiator feed ratios and performing a one-step surface zwitterionization of spontaneously segregated poly(N,N-dimethyl aminoethyl methacrylate) segments. Interestingly, nanoscale granular micelles were formed on the surface during zwitterionization because of the migration and self-assembly of the amphiphilic copolymer; this contributed to the membrane hydrophilicity and antifouling ability. During the filtration of the model foulant bovine serum albumin (BSA) aqueous solution, the BSA rejection ratio and flux recovery ratio increased remarkably to 94.8 and 100.0%, respectively. Moreover, the modified membranes also possessed stable and durable antifouling properties after three cycles of BSA filtration. Thus, this study provided a versatile method for constructing a PVDF ultrafiltration membrane that could achieve high permeability and good antifouling properties in efficient wastewater treatment. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47637.  相似文献   

5.
    
Biodegradable membranes with different compositions of polycaprolactone (PCL) and polybutylene succinate (PBS) are prepared via immersion precipitation. The morphology, hydrophilicity, chemical structure, crystalline structure, mechanical properties, and biodegradability of the membranes are studied to assess the effect of PBS concentration in the polymer blend on membrane properties. Furthermore, the performance of the obtained membranes is assessed through the treatment of wastewater sampled from the chips and snacks factory. Also, membranes' antifouling properties are assessed by filtration of a model foulant. The investigations revealed that the addition of PBS to PCL increases the membrane hydrophilicity and biodegradability. Regarding the results, the PCL membrane blended with 30 wt% PBS has 106%, 26%, and 37% higher pure water flux, flux recovery ratio, and permeate flux, in addition to the higher rejection of pollution indices, in comparison with the PCL membrane.  相似文献   

6.
    
Polymer blending as a modification technique is a useful approach for augmenting the gas‐separation and permeation properties of polymeric membranes. Polysulfone (PSF)/poly(ether sulfone) (PES) blend membranes with different blend ratios were synthesized by conventional solution casting and solvent evaporation technique. The synthesized membranes were characterized for miscibility, morphology, thermal stability, and spectral properties by differential scanning calorimetry (DSC), field emission scanning electron microscopy, thermogravimetric analysis, and Fourier transform infrared (FTIR) spectroscopy, respectively. The permeation of pure CO2 and CH4 gases was recorded at a feed pressure of 2–10 bar. The polymer blends were miscible in all of the compositions, as shown by DSC analysis, and molecular interaction between the two polymers was observed by FTIR analysis. The thermal stability of the blend membranes was found to be an additive property and a function of the blend composition. The morphology of the blend membranes was dense and homogeneous with no phase separation. Gas‐permeability studies revealed that the ideal selectivity was improved by 65% with the addition of the PES polymer in the PSF matrix. The synthesized PSF/PES blend membranes provided an optimized performance with a good combination of permeability, selectivity and thermal stability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42946.  相似文献   

7.
    
Immiscible blends of polymers were cast from solution, and the rate of evaporation was controlled relative to the rate of phase separation to produce different morphologies; upon crosslinking, stable nonequilibrium nanoblends were realized. This process of forced assembly produced useful membrane materials that could be designed for solubility selectivity with the group contribution methodology. Crosslinked ternary blends of nitrile butadiene rubber (NBR), poly(methyl methacrylate) (PMMA), and a tercopolymer of ethylene oxide/epichlorohydrin/allyl glycidyl ether (Hydrin) were examined for use in the separation of benzene from cyclohexane by pervaporation. For a 50 : 50 wt % benzene/cyclohexane feed, blend 811 (containing 80 wt % NBR, 10 wt % Hydrin, and 10 wt % PMMA) gave a separation factor of 7.3 and a normalized flux of 28 kg μm/m2 h; such a performance is unmatched in the literature, with the flux being very high for the reported separation factor. Among the samples tested, the flux of the membrane increased as the amount of NBR in the ternary blend decreased; however, the separation factor was not largely affected. Blended samples showed no sign of deformation after 48 h at the operating temperature as compared to pure NBR, which did show evidence of creep. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

8.
    
The present work concerns a development of new membranes for performing ions separation. These membranes were prepared by solution casting followed by solvent evaporation, using a commercial cellulose triacetate (CTA), synthesized poly (N,N‐dimethylaminoethyl methacrylate), macrocylic polyethers (15‐crown‐5 and Dibenzo‐24‐crown‐8) as carrier and dioctylphtalate as plasticizer. Different Polymer Inclusion Membranes were characterized using physical and chemical techniques as well as Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy. Transport of lead and cadmium in aqueous solution has been studied using these systems. The selective separation of these membranes is accomplished by the presence of specific compounds, called carriers, in the membrane phase. The carriers are responsible to facilitate the transport of the target component across selective membranes. The influence of the membrane nature has been studied using some supports of different physical characteristics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46592.  相似文献   

9.
    
This study describes the production of a membrane by blending polyvinyl alcohol (PVA) and water-absorbing agents for the selective permeation of CO2 by optimizing the type of water-absorbing agent and its ratio to PVA. A CO2-facilitated transport membrane is prepared by adding an aqueous cesium carbonate solution to a coated polymer blend matrix. When sodium polyacrylate (PAANa) is blended with PVA as a water-absorbing agent, the resulting membrane shows promising heat and pressure resistances and a relatively high CO2/He separation performance. Particularly, the CO2/He selectivity of the membrane composed of PVA, PAANa, and another water-absorbing agent exceeds 400 under a total pressure of 0.1 MPa and a CO2 partial pressure of 0.08 MPa at 85°C. Moreover, the CO2/He selectivity is approximately 100 even under a total pressure of 0.7 MPa and a CO2 partial pressure of 0.56 MPa. Thus, a high-performance CO2 separation membrane at 85°C is produced.  相似文献   

10.
    
The separation of ethanol/ethyl‐tertiobutylether mixtures by pervaporation was studied with new membranes prepared from N‐vinyl‐pyrrolidinone (NVP) and N‐[3‐(trimethylamoniopropyl)]methacrylamidemethylsulfate) (TMA). The pervaporation results showed that highly EtOH selective membranes could be obtained from PVP blends and from pyrrolidinone‐based crosslinked copolymers. The influences of the polymer blend composition and the role of the polymer microstructures on the membrane properties were investigated. Whatever the exact NVP/TMA composition used, the membranes strongly favored the pervaporation of ethanol. The ethanol selectivity was higher for the lower PVP/TMA ratio. On the one hand, these results were ascribed to the high pyrrolidinone residues content, which is responsible of the enhanced EtOH sorption affinity. The observed permeation selectivity was in agreement with the swelling data also recorded with the different polymers, showing higher affinity for ethanol with PVP‐enriched materials compared with TMA ones. This is a direct consequence of the Lewis base feature of pyrrolidinone sites towards EtOH molecules. On the other hand, the TMA residues improved the overall stability and selectivity of the membranes thanks to crosslinking reactions, which were induced by thermal treatment. A close comparison made between polymer blend and copolymer pervaporation results helped to clarify the TMA role of the membrane transport properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99:3622–3630, 2006  相似文献   

11.
    
A high‐quality, heterogeneous hollow‐fiber affinity membranes modified with mercapto was prepared through phase separation with blends of a chelating resin and polysulfone as membrane materials, poly(ethylene glycol) as an additive, N,N‐dimethylacetamide as a solvent, and water as an extraction solvent. The effects of the blending ratio and chelating resin grain size on the structure of the hollow‐fiber affinity membrane were studied. The effects of the composition of the spin‐cast solution and process parameters of dry–wet spinning on the structure of the heterogeneous hollow‐fiber affinity membrane were investigated. The pore size, porosity, and water flux of the hollow‐fiber affinity membrane all decreased with an increase in the additive content, bore liquid, and dry‐spinning distance. With an increase in the extrusion volume outflow, the external diameter, wall thickness, and porosity of the hollow‐fiber affinity membrane all increased, but the pore size and water flux of the hollow‐fiber affinity membrane decreased. It was also found that the effects of the internal coagulant composition and external coagulant composition on the structure of the heterogeneous hollow‐fiber affinity membrane were different. The experimental results showed that thermal drawing could increase the mechanical properties of the heterogeneous hollow‐fiber affinity membrane and decrease the pore size, porosity, and water flux of the heterogeneous hollow‐fiber affinity membrane, and the thermal treatment could increase the homogeneity and stability of the structure of the heterogeneous hollow‐fiber affinity membrane. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007  相似文献   

12.
    
Development in the area of glycosylated membranes has been actively pursued in the past few years. This kind of promising biomimetic material is inspired by cell membranes. The recent surge of interest in these glycosylated membranes stems from their widespread number of applications to many areas in science and technology. With the glycosylation strategy, membrane separation properties, such as flux and antifouling, are greatly improved. Moreover, the ability to modulate biocompatibility, protein recognition, separation of biomolecules, enzyme immobilization, cell culture, and microorganisms capture are important in a variety of biological and medical applications. This review focuses on the recent progress in the preparation of these glycosylated membranes and highlights their applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39658.  相似文献   

13.
    
To investigate the influence of magnetic materials combined with carbon nanotubes (CNTs) as fillers on the membrane properties, multi‐walled carbon nanotubes (MWCNTs) functionalized by mixed acids (VH2SO4:VHNO3=3:1) were loaded by Fe3O4 through a hydrothermal method. The obtained MWCNTs/Fe3O4 hybrids were characterized by X‐ray diffraction (XRD), Infrared spectroscopy (IR) spectrum, and scanning electron microscope (SEM) and then blended with polyvinyl chloride (PVC) to prepare ultrafiltration (UF) membranes through a phase inversion process. Simultaneously, two other UF membranes, PVC blended with acid‐treated MWCNTs and PVC blended with nothing, were also prepared. The results showed that the membrane porosity and mean pore size increased slightly with the addition of fillers. Static contact angle showed that MWCNTs/Fe3O4 hybrids improved the hydrophilicity of membrane surface better than the acid‐treated MWCNTs. Pure water flux increased consistently with the hydrophilicity of the membrane surface. SEM and atomic force microscope (AFM) images showed that the MWCNTs/Fe3O4 blended membrane formed a relatively complete pore structure throughout the cross‐section and had a rougher top surface. However, the mechanical properties of membranes with fillers were reduced compared with the pristine PVC membrane. The rejections of membranes for Bovine serum albumin (BSA), Bisphenol A (BPA), and Norfloxacin (NOR) showed that MWCNTs/Fe3O4 played an important role in trapping pollutants in membrane filtration. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43417.  相似文献   

14.
    
Oily wastewater, especially the emulsified one, causes serious environment pollution and poses threats to the ecosystem and resource recycling. Among various filtration media, porous polymeric membranes have gained tremendous attention in dealing with oily emulsions due to their energy-saving, cost-effective, and highly efficient features. However, to alleviate membrane fouling by oil droplets and ensure high separation efficiency, endowing membrane with superhydrophilicity and underwater superoleophobicity via facile strategy is highly desired. Taking advantages of the mild forming conditions, universality and cost-efficiency, more and more efforts have been devoted to membrane hydrophilic modification by plant polyphenol-inspired coatings in recent years. In this review, we focus on recent advances in constructing plant polyphenol-involved coatings on membrane surface for oil-in-water emulsion separation. The interactions between plant polyphenol and functional materials including amino-functionalized materials, transition metal ions and oxidants via covalent chemistry, coordination chemistry, and rapid oxidation are highlighted. In addition, the impacts of the resultant coating on the wettability, oily emulsion separation performance, and anti-oil fouling performance of the modified membrane are systematically summarized. Finally, future outlooks in membrane surface engineering with plant polyphenol-involved coatings are discussed to further broaden the research related to high-efficiency oil/water separation based on membrane technology.  相似文献   

15.
    
In this work, ether oxide (EO)-based multilayer composite membranes were prepared via interfacial polymerization (IP) of trimesoyl chloride (TMC) and polyetheramine (PEA) on polydimethylsiloxane precoated polysulfone support membrane. The effects of preparation parameters, such as monomer concentrations, reaction time, and heat-treatment temperature on the membrane performance were investigated. The optimal preparation parameters have been concluded. The results showed the increasing monomers concentration of both PEA and TMC can lead to the decrease of CO2 permeance and increase of CO2/N2 selectivity. The optimal monomers concentration was found. When monomer concentrations are higher than the optimal values, the CO2 permeance decreases continually while CO2/N2 selectivity only shows a very limited improvement with the further increase of monomers concentration. The reaction time has similar effects on membrane performance as the monomers concentration. The effect of heat-treatment temperature was also studied. With the increasing heat-treatment temperature, the CO2 permeance shows a decrease tendency, while the CO2/N2 selectivity shows a maximum at 80 °C. When PEA is 0.013 mol L−1, TMC is 0.020 mol L−1, reaction time is 3 min, and heat-treatment temperature is 80 °C, the optimum preparation conditions are achieved with CO2 permeance of 378.3 gas permeation unit (GPU) and CO2/N2 selectivity of 51.7 at 0.03 MPa. This work may help to design and fabricate gas separation membranes with desired performance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47755.  相似文献   

16.
    
Prussian blue (PB), as a kind of regulator of charge-loading capacity, was first used to modify polyethersulfone (PES) membrane, and a novel PB/PES ultrafiltration membrane was prepared by non-solvent induced phase separation method. The physicochemical properties of PB-NPs and PB/PES membranes were analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, atomic force microscope, and zeta potential analysis. It was observed that PB-NPs were uniformly distributed in the PES matrix and a lotus-seedpod structure was formed inside the membrane. The addition of PB-NPs improved the charge-loading capacity of the PES membrane. The permeation and antifouling performance were investigated by filtering bovine serum albumin aqueous solution with different pH values. The results showed that the PB/PES membrane with 0.2-wt% PB-NPs content had the excellent antifouling performance and the flux recovery ratio value reached 90.73%. Moreover, the long-term stability test showed that PB-NPs did not fall off after continuous pure water filtration, indicating that PB/PES membrane had a good stability.  相似文献   

17.
    
Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) as a novel membrane material was successfully prepared from poly(phthalazinone ether sulfone ketone), with concentrated sulfuric acid as the solvent and catalyst, and chloromethyl octyl ether with lower toxicity as the chloromethylated regent. The effects of the reaction conditions on the preparation of CMPPESKs with different degrees of chloromethylation were examined. The quantity of chloromethyl groups per repeated unit (DCM) of CMPPESK was determined by the method of analysis of the chlorine element, and structures were characterized by 1H‐NMR spectroscopy. The introduction of chloromethyl groups into the polymer chains led to a decrease in the decomposition temperature. With increasing DCM, the initial degradation temperature declined. CMPPESK had good solubility and was soluble in N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylacetamide (DMAc), and chloroform. However, quaternized poly(phthalazinone ether sulfone ketone) (QAPPESK) had excellent solvent resistance, was only partly soluble in sulfuric acid (98%), and was swollen in N,N‐dimethylformamide. QAPPESK nanofiltration (NF) membranes had about 90% rejection for MgCl2, and the performance of the NF membrane prepared with DMAc as the solvent was superior to that of the NF membrane prepared with NMP as the solvent. In addition, the rejection to the different salt solutions followed the following sequence: MgCl2 > MgSO4 > NaCl > Na2SO4. Furthermore, the thermotolerance of the QAPPESK NF membrane was examined, and the results show that when the solution temperature rose from 11 to 90°C, the water flux increased more than threefold with stable salt rejection. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

18.
    
Synthesized by the reaction between α-cellulose and m-tolyl isocyanate (MTI), cellulose carbamate (CC) was blended with polyvinyl chloride (PVC) to fabricate substrates for thin-film composite (TFC) forward osmosis (FO) membranes. The introduction of CC into substrates improved both membrane structure and performance. The substrates exhibited higher porosity and hydrophilicity, and better connective pore structure; while rejection layer exhibited better morphology but limited cross-linked degree decrease after the introduction of CC. According to the results, the CC blend ratio of 10% was the optimal ratio. With this blend ratio, the TFC-10 membrane presented favorable water permeability (1.86 LMH/bar) and structure parameter (337 μm), which resulted in excellent FO performance (water flux with a value of 40.40 LMH and specific salt flux with a value of 0.099 g/L under rejection layer faces draw solution [DS] mode when 1 M NaCl and deionized water were utilized as DS and feed solution). In addition, the TFC-10 membrane showed good water flux and low-sulfate ion leakage in the potential application of brackish water desalination.  相似文献   

19.
    
In an effort to develop a membrane system with low cost and easy fabrication process for oil/water separation, cellulose nanocrystals (CNC), chitin nanocrystals (ChiNC), and cationic guar gum (CGG) are used to prepare a complex membrane on top of a poly(ethylene terephthalate) (PET) nonwoven fabric via a vacuum filtration method. The interactions among CNC, ChiNC, and CGG complexation are discussed, and the functionalization of the PET nonwoven fabric with these polysaccharide derivatives provides a high rate of water absorption and permeability on applying pressure. The morphology and wettability studies demonstrate that the as-prepared membrane has a porous structure and exhibits hydrophilic and underwater superoleophobic properties. The results of separation experiments show that the membrane can effectively separate oil/water emulsions with a relatively high flux and rejection ratio. This low-cost process can easily be scaled up to fabricate complex membranes for oil/water separation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47947.  相似文献   

20.
    
Microbial polysaccharides are characterized by high molecular structure variability which translates into a wide range of different properties offering interesting opportunities for application in many different areas, including membrane‐based products and processes. Due to their new or improved properties, microbial polysaccharides can replace plant, algae, and animal products, either in their traditional or in new applications. The main constraint to their wider use is the production costs that are still higher than that of other natural and synthetic polymers. The current applications of microbial polysaccharide membranes in medical, food, and industrial processes are outlined. The limitations still faced by these membranes and the requirements for obtaining innovative products and processes are also addressed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40047.  相似文献   

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