Preparation of a heterogeneous hollow‐fiber affinity membrane modified with a mercapto chelating resin

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     

Polyamide/Polystyrene Blend Compatibilisation by Montmorillonite Nanoclay and its Effect on Macroporosity of Gas Diffusion Layers for Proton Exchange Membrane Fuel Cells

This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer‐based blends were carefully formulated using a twin‐screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.‐% of clay. It was observed that both macroporosity and pore size distribution were beneficially modified after blend compatibilisation. Final GDL conductivity of about 1.25 S cm^–1, a porosity of 53% and a specific pore surface area of 75 m² g^–1 were achieved.     

Porous biodegradable polyesters. I. Preparation of porous poly(L‐lactide) films by extraction of poly(ethylene oxide) from their blends

Porous poly(L ‐lactide) (PLLA) films were prepared by water extraction of poly(ethylene oxide) (PEO) from solution‐cast PLLA and PEO blend films. The dependence of blend ratio and molecular weight of PEO on the porosity and pore size of films was investigated by gravimetry and scanning electron microscopy. The film porosity and extracted weight ratio were in good agreement with the expected for porous films prepared using PEO of low molecular weight (M_w = 1 × 10³), but shifted to lower values than expected when high molecular weight PEO (M_w = 1 × 10⁵) was utilized. The maximum pore size was larger for porous films prepared from PEO having higher molecular weight, when compared at the same blending ratio of PLLA and PEO before water extraction. Differential scanning calorimetry of as‐cast PLLA and PEO blend films revealed that PLLA and PEO were phase‐separated at least after solvent evaporation. On the other hand, comparison of blend films before and after extraction suggested that a small amount of PEO was trapped in the amorphous region between PLLA crystallites even after water extraction and hindered PLLA crystallization during solvent evaporation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 629–637, 2000     

Thin-film membranes derived from co-continuous polymer blends: preparation and performance

Two approaches for preparing thin-film membranes from immiscible co-continuous polymer blends are presented. Approach 1 involves the melt blending of co-continuous polymer blends followed by the selective extraction of one of the phases and results in a microporous membrane material of high void volume. In that case, the pore size is defined by the phase size of one of the phases in the blend and hence composition, interfacial tension, viscosity ratio and other parameters influencing phase morphology can be used to control porosity. For that first approach, the blend system studied is high density polyethylene/polystyrene, compatibilized with SEBS (styrene-ethylene-buthylene-styrene) triblock copolymer. Both symmetric and asymmetric type membranes can be obtained. The symmetric membrane demonstrates porosity ranging from 80 to 230 nm. It is shown that extraction time can be used to develop asymmetry in the membrane and the effects of extraction time on the morphology, pore size distribution and performance are presented. High flux values and high apparent rejection factors estimated from permeability testing indicate that these materials could have potential in a variety of membrane applications.Approach 2 is a solventless approach that results in a membrane of very low void volume. A high interfacial tension immiscible co-continuous blend compatibilized at different levels by a weak interfacial modifier is prepared by melt mixing and extrusion through a sheet die. Microporosity in the bulk of the material is generated in situ during cooling by this approach. The thin sheet is then subjected to uniaxial or biaxial cold stretching to develop surface porosity. This technique exploits interfacial debonding and the weak interface of the co-continuous morphology acts as a template to guide the direction of porosity development. Highly percolated membranes of polycarbonate and high-density polyethylene with SEBS were prepared. These membranes possess pore sizes in the range of 100 nm and are of very low void volume. Oxygen permeation tests, carried out under atmospheric pressure, demonstrate a dramatic increase in oxygen flux from 1378 cm³/m²/day (non-stretched 50PE/50PC/15SEBS sample) to 106,270 cm³/m²/day (biaxially stretched sample). The results indicate that they could have potential as breathable barrier type materials. The effects of draw ratio on the permeation values are presented.     

Influence of additives on the morphology of PVDF membranes based on phase diagram: Thermodynamic and experimental study

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.     

Production of polymeric membranes made of polypropylene,poly(ethylene‐co‐vinyl acetate), and poly(vinyl alcohol)

In this study, we prepared and characterized membranes containing polypropylene, poly(ethylene‐co‐vinyl acetate) (EVA), and poly(vinyl alcohol) (PVA). The production process involved blend extrusion and calendering followed by solvent extraction by toluene and water of the EVA and PVA phases. Morphology studies involving scanning electron microscopy determined the pore size distribution at the surface and in the internal regions of the membrane. The resulting membrane properties were related to the processing variables (extension rate, process temperature, and solvent extraction methods) and blend composition. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3275–3286, 2004     

Density‐based phase‐separation asymmetric polyethylene–poly(dimethyl siloxane) blend membranes: Preparation and properties

A new concept of density‐based phase separation for the preparation of asymmetric membranes from polyethylene (PE) blended with liquid poly(dimethyl siloxane) (PDMS) has been tried. The PE/PDMS membranes were prepared via high‐temperature solution casting. The purpose of incorporating PDMS was to utilize its flexibility, relatively high density in comparison with PE, and dissolution in common solvent for the formation of asymmetric PE/PDMS membranes. The study has been carried out with 1.25, 2.5, 5, and 10% (v/w) loading of PDMS. A host of techniques were used to study morphology of PE/PDMS blend membranes. The membranes show nodular structure on surfaces in contact with solvent vapor environment, whereas the opposite surfaces have smoother texture devoid of nodules. Although differential scanning calorimetric (DSC) melting endotherms indicate enhancement of crystallinity with PDMS addition, chemical etching and subsequent scanning electron microscopic (SEM) observations show increasingly ordered spherulitic pattern on individual nodules with the incorporation of PDMS up to 2.5%. The density of the films also increases with the addition of PDMS as compared to the control. ATR‐FTIR data revealed asymmetric distribution of PDMS in membranes with more PDMS retention toward lower surface of membranes. Membrane cross sections were indicative of graded porosity with increasing pore size toward the bottom surface of membranes. The results were explained in terms of density‐based phase separation.© 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91:2278–2287, 2004     

Fabrication and characterization of chlorinated polyvinyl chloride microporous membranes via thermally induced phase separation process

Microporous chlorinated polyvinyl chloride (CPVC) membranes were prepared via thermally induced phase separation process for the first time using diphenyl ether (DPE) as diluent. The CPVC/DPE blends exhibit upper critical solution temperature (UCST)‐type phase behavior, which undergoes liquid‐liquid phase separation followed by sol‐gel transition during cooling process. Therefore, the resulting CPVC membranes presented symmetric morphology with uniformly distributed cellular pores. The cloud point (liquid‐liquid phase separation temperature) decreased with increasing CPVC content, while the sol‐gel transition temperature showed an opposite trend. Both the growth rate of diluent‐rich phase droplets and the gelation rate of the CPVC/DPE blends increased by decreasing CPVC concentration or cooling rate, leading to an increase of the pore size in the final membranes. Results of water permeation tests confirmed that the water flux of the membranes have a significant dependence on their porosity and pore size, that is the water flux increased with the increase of porosity and pore size. Moreover, the CPVC microporous membranes prepared by the TIPS process showed a high mechanical strength and excellent acid/alkali resistance, which has presented a great potential for application in the fields of water and wastewater treatment. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44346.     

Effect of the exposure time on the structure and performance of hydrophobic polydimethylsiloxane–poly(vinylidene fluoride) membranes via a non‐solvent‐induced phase separation process in a clean room

The objective of this study was to investigate the effects of the exposure time on the properties and permeability of polydimethylsiloxane (PDMS)–poly(vinylidene fluoride) (PVDF) blend hydrophobic microporous membranes, which were fabricated via a non‐solvent‐induced phase separation process at 25 °C and 60% relative humidity in a clean‐room circumstance. For the prepared PDMS–PVDF membranes, the membrane morphologies were observed by scanning electron microscopy. Crystalline structures were observed by X‐ray diffraction. Pore structures were analyzed by membrane porosity and mean pore size. Hydrophobicity was measured by contact angle measurement, and the mechanical properties were characterized by tensile strength testing. Our study results show that with increasing exposure time from 10 to 110 s, all of the membranes showed a similar pore structure: a spongelike substrate layer with a thin realm of fingerlike structures under the top surface. Phase separation between PDMS and PVDF occurred. The membrane porosity and mean pore radius decreased, and the membrane thickness increased. The membrane hydrophobicity decreased, and the mechanical properties first increased and then decreased. In addition, vacuum membrane distillation experiments were conducted. With the increase in the exposure time from 10 to 110 s, the membrane permeate flux decreased from 16.54 to 6.65 kg m⁻²·h⁻¹, and the salt rejection was higher than 99.9%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43842.     

Influence of the extrusion process on the morphology and micromechanical behavior of polystyrene‐block‐(polystyrene‐co‐butadiene)‐block‐polystyrene star block copolymer/homopolystyrene blends

The influence of the extrusion process on the morphology and micromechanical behavior of an asymmetric polystyrene‐block‐(polystyrene‐co‐butadiene)‐block‐polystyrene (SBS) star block copolymer and its blends with general‐purpose homopolystyrene (hPS) was studied with films prepared with a single‐screw extruder. The techniques used were transmission electron microscopy and uniaxial tensile testing. Unlike the pure SBS block copolymer possessing a gyroid‐like morphology, whose deformation was found to be insensitive to the processing conditions, the mechanical properties of the blends strongly depended on the extrusion temperature as well as the apparent shear rate. The deformation micromechanism was primarily dictated by the blend morphology. The yielding and cavitation of the nanostructures were the principal deformation mechanism for the blends having a droplet‐like microphase‐separated morphology, whereas cavitation dominated for the blends containing macrophase‐separated layers of polystyrene. The mechanical properties of the blends were further examined with respect to the influence of the temperature and shear rate on the phase behavior of the blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation and characterization of dense cellulose film for membrane application

Regenerated cellulose films were prepared with environmentally friendly process by utilized N‐methylmorpholine‐N‐oxide (NMMO)‐Cellulose system. To prepare a dense cellulose film for membrane application, some parameter process which influence porous forming such as cellulose DP, cellulose concentration, addition NMMO in coagulation bath, coagulation bath temperature, and drying condition were investigated. We resumed that the porosity and pore size of cellulose membrane decrease with lower cellulose DP, higher cellulose concentration, addition of NMMO in coagulation bath, applying room temperature in coagulation bath and drying, and applying vacuum on drying process resulted in membranes with porosity in range of 24–41% and pore size 13.4–20.2 nm. The main factor for controlling porosity and pore size of dense cellulose membrane was coagulation process condition especially addition of NMMO into coagulation bath. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Characteristics of poly(ether ether ketone) microporous membranes prepared via thermally induced phase separation (TIPS)

The morphology and bulk properties of microporous membranes based on poly (ether ether ketone) (PEEK) have been investigated as a function of initial casting composition and thermal and mechanical processing history. Membranes were prepared via solid—liquid phase separation of miscible blends of PEEK and polyetherimide (PEI), with subsequent extraction of the PEI diluent. Scanning electron microscopy studies revealed a microporous morphology with two distinct pore size scales corresponding to diluent extraction from interfibrillar and interspherulitic regions, respectively. The membrane structure was sensitive to both initial blend composition and crystallization temperature, with the resulting pore size distribution reflecting the kinetics of phase separation. For membranes prepared with lower initial diluent content or at lower crystallization temperatures, mercury intrusion porosimetry indicated a relatively narrow distribution of fine interfibrillar pores, with an average pore size of approximately 0.04 microns. Membranes prepared at higher diluent content or at higher crystallization temperatures displayed a broad pore distribution, with a sizeable population of coarse, interspherulitic pores (0.1 to 1 μm in size). Uniaxial drawing led to a fibrillated network structure with markedly higher water flux characteristics compared to the as-cast membranes. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2347–2355, 1997     

Effect of casting solvent on characteristics of hexanoyl chitosan/polylactide blend films

Blend films of hexanoyl chitosan (H‐chitosan) and polylactide (PLA) were cast from corresponding blend solutions in chloroform, dichloromethane, or tetrahydrofuran. Thermal degradation behavior of the as‐prepared blend films was intermediate to those of the pure components and no significant effect from the type of the casting solvent was observed. All of the blend films exhibited one composition‐dependent glass transition temperature, but the results only suggested partial miscibility of the components in the amorphous phase at “low” contents of H‐chitosan. As revealed by solvent etching technique, the as‐prepared blend films prepared from the blend solutions in chloroform and dichloromethane showed extensive phase separation of the two components, with the minor phase forming into discrete domains throughout the matrix. Both thermal and X‐ray analyses showed that the apparent degree of crystallinity of the PLA component in the blends decreased monotonically with increasing H‐chitosan content and the choice of the casting solvent did not have an effect on the structure of PLA crystals. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

A simple method for creating nanoporous block-copolymer thin films

We introduce a simple method to create block copolymer films with controlled porosity. We show that the pore structure can be varied over a broad range of length scales not obtainable in homopolymer blend films. The morphology is a random two phase kinetically trapped structure that is not limited by the equilibrium block copolymer structure. The morphology is obtained through blending homopolymer poly(4-vinylpyridine) (P4VP) with block copolymer polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) and then removing the homopolymer P4VP by washing with ethanol. The structure obtained prior to washing (which templates the nanoporous structure) is stabilized in the kinetically trapped morphology during spincoating and is not obtainable from either homopolymer blends or the pure block copolymer. When PS/P4VP blend solutions in tetrahydrofuran were spincoated at 25% relative humidity, continuous films with raised P4VP nanodomains were formed due to a preferential affinity of the spinning solvent for polystyrene. In a similar manner, when PS-b-P4VP/P4VP block copolymer/homopolymer solutions were spincoated, the P4VP homopolymer was solubilized in the P4VP block domains during spincoating, suppressing macro-phase separation. The film morphology is generated at the air surface and then propagates through the film, resulting in P4VP nanodomains oriented vertically to the substrate. In the resulting films, the size of P4VP nanodomains were varied by increasing the amount of P4VP homopolymer. The subsequent extraction of P4VP homopolymer from the PS-b-P4VP/P4VP blend films in ethanol resulted in nanopores with a distribution of length scales. The morphology of these materials makes the films potentially suitable for a range of applications such as anti-reflective coatings, nanoporous membranes and low-k materials. An illustrative example of an anti-reflective coating will be presented.     

Influences of the chain structure of PE‐b‐PEG on the properties of PE/PE‐b‐PEG blend membranes prepared by TIPS

In this article, a series of diblock copolymer polyethylene‐b‐ poly(ethylene glycol)s (PE‐b‐PEGs) with various molecular weight of polyethylene segment was blended with linear low‐density PE. The PE/PE‐b‐PEG blend porous membranes with high porosity were obtained by thermally induced phase separation (TIPS) process. The isothermal crystallization kinetics of PE/LP/PE‐b‐PEG blends indicated that the introduction of PE‐b‐PEG could inhibit the growth rate of polyethylene crystals which could increase the pore size and porosity of the membranes. The PE/PE‐b‐PEG blend membranes with PE₁₃₀₀‐b‐PEG₂₂₀₀ showed the largest pore size and porosity due to its crystallization behavior during TIPS. The surface of the membranes became smoother and the morphology of the membranes could be effectively tuned by introducing PE‐b‐PEG. Compared with the PE membrane, the PE/PE‐b‐PEG blend membranes exhibited higher hydrophilicity (the water contact angle decreased from 112° to 84°), water permeability (the permeation flux increased from 80 to 440 L/m² h under 0.1 MPa), rejection performance (completely reject carbon particles in the filtration of carbon ink solution), and fouling resistance (the value of protein adsorption dropped from 0.25 to 0.05 mg/cm²). The hydrophilicity and fouling resistance of PE/PE‐b‐PEG blend membranes increased as the length of PE segment in PE‐b‐PEGs decreased. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46499.     

Porous biodegradable polyester blends of poly(L‐lactic acid) and poly(ε‐caprolactone): physical properties,morphology, and biodegradation

Poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water‐extraction of PEG from solution‐cast phase‐separated PLLA‐blend‐PCL‐blend‐PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA‐blend‐PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07–1.4 GPa and elongation at break in the range 3–380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. Copyright © 2006 Society of Chemical Industry     

Effect of Casting Solution on Morphology and Performance of PVDF Microfiltration Membranes

The effects of preparation‐influencing parameters such as polymer concentration, thickness of casting solution, and type of solvent on morphology and performance of poly(vinylidene difluoride) (PVDF) microfiltration membranes for the treatment of emulsified oily wastewater were investigated. Flat‐sheet membranes were prepared from a casting solution of polymer and additive in various solvents by immersing the prepared films in nonsolvent‐containing mixtures of water and 2‐propanol. The membranes were characterized using scanning electron microscopy. Increasing the polymer concentration and membrane thickness significantly affected the pore size, leading to permeate flux decrease. An attempt was made to correlate the effect of the solvent on membrane morphology and performance employing solubility parameters between solvent and nonsolvent).     

Preparation of well‐controlled porous carbon nanofiber materials by varying the compatibility of polymer blends

The relationships between the compatibility in binary polymer blends and the pore sizes of carbon nanofibers (CNFs) prepared from the blends were investigated. Compatibility was determined by the difference between the solubility parameters of each polymer in the polymer blends. Porous CNFs were prepared by an electrospinning and carbonization process using binary polymer blends, consisting of polyacrylonitrile (PAN) as the carbonizing polymer and poly(acrylic acid) (PAA), poly(ethylene glycol), poly(methyl methacrylate) or polystyrene (PS) as the pyrolyzing polymer. The pore size of the CNFs increased with increasing difference in solubility parameter. The CNFs prepared using the PAN/PAA blend, which had the smallest solubility parameter difference, exhibited a pore size of 1.66 nm compared to 18.24 nm for the CNFs prepared using the PAN/PS blend. The prepared CNF webs with controlled meso‐sized pores showed a stable cycle performance in cyclic voltammetry measurements and improved impedance characteristics. This method focusing on the compatibility in polymer blends was simple to apply and effective for controlling the pore sizes and surface area of CNFs for application as electrode materials in energy storage systems. © 2013 Society of Chemical Industry     

Diffusional properties of chitosan hydrogel membranes

Chitosan membranes were prepared by a solvent evaporation technique, followed by crosslinking with glutaraldehyde and coating with BSA. The effects of crosslinking and BSA coating on the pore structure of such prepared hydrogel chitosan membranes were determined. The diffusion rates of 12 non‐electrolytes ranging in molecular radius between 2.5 and 14 Å through the membranes were measured, and the results were interpreted in terms of the capillary pore model and free volume model of solute diffusional transport through hydrogel membranes. Glutaraldehyde crosslinking was found to reduce the membrane water content and consequently the membrane pore size and surface porosity, whereas further BSA coating brought about the opposite effect. The latter effect lessened with an increase in glutaraldehyde pretreatment of the membranes. The optimal chitosan membrane preparation, compromising between the solute flux and membrane stability and durability was obtained when the membranes were crosslinked with glutaraldehyde at concentrations between 0.01 and 0.1% (w/w). The knowledge of transport properties and of physical strength of the membranes is of importance for the development of chitosan‐based controlled release systems. © 2001 Society of Chemical Industry     

Polyvinyl alcohol‐polyethylene oxide‐carboxymethyl cellulose membranes for drug delivery

The purpose of this research was to develop blends of poly(vinyl alcohol) (PVA)‐poly(ethylene oxide) (PEO) and carboxymethyl cellulose (CMC) by two approaches: solvent casting and freeze‐drying to develop membranes for various biomedical applications. The PVA/PEO/CMC blends in different compositions of 90/10/20, 80/20/20, 70/30/20, 60/40/20, and 50/50/20 were prepared and were coated on polyester (PET) nonwoven fabric and were subsequently freeze‐dried (FD). The influence of PEO concentration on the blend membranes was investigated and characterized by X‐ray diffraction (XRD), differential scanning calorimetry, and attenuated total reflectance‐fourier transform infra‐red (ATR–FTIR) techniques. The water vapor transmission rate (WVTR), swelling behavior, and surface morphology of the FD membranes was also investigated. It was observed that an increase of PEO concentration in blends makes the membranes more fragile. However, the coating of this blend on PET fabric helps in developing the stable membrane. Swelling of the membranes decreased with the increase in the PEO concentration. XRD showed decrease in crystallinity with increase in concentration of PEO. Morphological studies showed a highly porous structure with interconnected pores. The total porosity of the membranes was found to be in the range 89–92%. The FD membranes were found to have WVTR in the range 2000–3000 g/m²/day. A model drug, ciprofloxacin hydrochloride was also incorporated in the matrix and drug release was studied. The antimicrobial nature of the membranes was monitored against E. coli by zone of inhibition method. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013