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Zinc oxide (ZnO) nanostructures have received widespread attention due to their unique structure and broad application possibilities, but high preparation costs and agglomeration limit their usage. In this article, low-cost and environmentally friendly cellulose and ZnCl2 are used to synthesize ZnO nanoparticles (ZnO NPs). Subsequently, multifunctional ZnO/polyacrylonitrile hybrid nanofiber mats (ZnO/PAN@NFMs) with mechanical stability suitable for large-scale application are prepared via solution blow-spinning. The synthesized ZnO/PAN@NFMs exhibit higher photodegradation of organic dyes than earlier reported semiconductors and good recycling performance with an organic dye degradation above 94%–98% after five cycles, which is ascribed to fixation of the ZnO NPs in the nanofibers. In addition, the inhibition rate for Escherichia coli and Staphylococcus aureus is above 99.9% and the bacteriostatic rate against E. coli remains as high as 99% after 10 cycles. From these properties, the synthesized composite ZnO/PAN@NFMs are promising for wastewater cleaning and antibacterial fabrics.

The porous polyvinylidene fluoride hollow fiber membranes were prepared via the thermally induced phase separation process using mixed diluent. The effects of take-up speed on the structure of membranes were investigated by scanning electron microscopy, differential scanning calorimetry, and wide-angle X-ray diffraction. The membrane properties were measured in terms of the pure water flux, porosity, and mechanical properties. The results showed that the cross-sectional structure of membrane had an obvious change and presented a uniform structure when TS increased to 72 m min−1, whereas the membrane made from TS

Mixed matrix membranes (MMMs) containing fluorinated-sulfonated poly(ether ether ketone) (F-SPEEK) and zeolite 4A filler, were prepared by solution casting. F-SPEEK with a fixed degree of sulfonation (40%) was used for membrane synthesis. The SEM pictures showed good interfacial adhesion between filler particles and polymer, which was also confirmed by the increase in glass transition temperature of MMMs with increase in filler particles. Pure and mixed gas permeation experiments were carried out to investigate the potential of this membrane material. The results revealed that addition of zeolite 4A fillers enhanced both permeability and selectivity owing to the intrinsic nature of polymer and modified membrane morphology due to filler. The highest permeability obtained for CO2 at 30% filler loading was 49.2 Barrer, while highest selectivities obtained for CO2/CH4 and CO2/N2 were 55 and 58 compared to 47 and 51 for the unfilled polymer, respectively. Intrinsic CO2 solubility of F-SPEEK was observed to be decreased from 10.7 to 1.9 (10−2) cm3 (STP)/cm3 cmHg with the addition of Zeolite 4A. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 135, 45952.

Polyvinylidene fluoride (PVDF) membranes were prepared via a thermally induced phase separation method with a mixed diluent (dibutylphthalate/dioctyl phthalate). The effects of PVDF concentration and cooling bath temperature (CBT) on the structure and properties of the membranes were investigated. Scanning electron microscopy photos showed that the cross-section of all the membranes, regardless of PVDF concentration and CBT, presented a bi-continuous structure with the spherulitic pattern; moreover, the spherulitic patterns became clear gradually from the top surface to the bottom surface, and the top surface was denser than the bottom surface. As a result, all the membranes exhibited an asymmetric structure. The membrane property measurement indicated that, as PVDF concentration increased from 25 to 35 wt %, the pure water flux (PWF) decreased from 342 to 80 L m−2 h−1, and the porosity decreased slightly, whereas the minimum bubble point pressure (BPP) increased, which indicates maximum pore size decreased. In addition, with the increase in CBT, the PWF increased, but, the minimum BPP and porosity decreased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Through sol-gel reactions, a series of sulfonated poly(ether ether ketone) (SPEEK)/TiO2 hybrid membranes with various contents of nano-sized TiO2 particles were prepared and characterized. It was found that with the increasing of the TiO2 contents in the hybrid membranes, the water uptake and water retention increased. Meanwhile, the introduction of inorganic particles reduced the methanol permeability. The proton conductivity was enhanced by introduction of hydrophilic inorganic particles into the SPEEK membranes, which might be an effective approach to increase the working temperature of PEM. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Sulfonated poly(aryl ether ketone)s (SPAEK) copolymers were synthesized by aromatic nucleophilic polycondensation from 3,3′, 5,5′-tetramethyl-4, 4′–biphenol, 1,4-bis(4-fluorobenzoyl) benzene, and disulfonated difluorobenzophenone. The SPAEK membranes did not exhibit excessive swelling in hot water and at the same time show the proton conductivities in the range of 0.030 S/cm to 0.099 S/cm at 80°C. The methanol diffusion coefficients of the SPAEK membranes were in the range of 4.7 × 10−7 to 8.1 × 10−7cm2/s measured at 25°C. The transport properties of this series of SPAEK copolymers were compared to poly(aryl ether ether ketone)s (SPEEK), poly(aryl ether ether ketone ketone)s (SPEEKK), and Nafion® membranes. It was found that the transport properties (including proton conductivity and methanol permeability) follows the trend of SPEEKK-60 < SPAEK-60 < SPEEK-60 < Nafion® 117, the order of which is also attributed to the differences in the chemical structure of the polymers and the membrane morphology. In general, this novel series of SPAEK membranes possess various advantages, such as low cost of the initial monomers, high thermal and mechanical stability, and low methanol permeability while simultaneously possessing sufficient proton conductivity, which makes them notably promising as proton exchange membrane (PEM) materials in direct methanol fuel cell (DMFC) applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The effects of a mixed diluent (MD) composition [dibutyl phthalate/dioctyl phthalate (DOP)] on poly (vinylidene fluoride) (PVDF) membrane morphology were investigated with scanning electron microscopy, and a bicontinuous morphology could be obtained with MD in a thermally induced phase-separation process. The reasons for the morphology formation were explained according to the effect of MD on the phase diagrams. In addition, the effects of the PVDF concentration on the membrane morphology were examined. For the system with less DOP, the large spherulite morphology was obvious under all investigated concentrations, whereas no large spherulite structure existed in the membrane as the DOP content increased to concentrations other than 20%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Novel aromatic sulfonated poly(ether ether sulfone)s (SPEESs) with tert-butyl groups were synthesized by aromatic nucleophilic polycondensation of disodium 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (SDCDPS), 4,4′-dichlorodiphenylsulfone (DCDPS), and tert-butylhydroquinone (TBHQ). The resulting copolymers showed very good thermal stability and could be cast into tough membranes. The morphology of the membranes was investigated with atomic force microscopy. The proton conductivity of SPEES-40 membranes increased from 0.062 S/cm at 25°C to 0.083 S/cm at 80°C, which was higher than the 0.077 S/cm of Nafion 117 under the same testing conditions. These copolymers are good candidates to be new polymeric electrolyte materials for proton exchange membrane fuel cells. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1443–1450, 2007

The sulfonated poly(ether ether ketone ketone)/phosphotungstic acid (SPEEKK/PWA) composite membranes were researched for proton exchange membranes. The effect of casting condition on the properties of membranes was studied in detail. The study showed that the casting condition has great influence on the membrane properties because of the hydrogen bond between the SPEEK and PWA and the interaction between the SPEEKK and dimethylformamide (DMF). The PWA particles are well crystallized on the surface when the velocity of the solvent volatilization is very slow under the SEM. The study will favor further research on excellent composite membranes for proton exchange membrane fuel cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4020–4026, 2007

Polyvinylidene fluoride hollow fibers were prepared by melt-spinning technique under three spinning temperatures. The effects of annealing treatment on the structure and properties of hollow fiber were studied by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), tensile test, and scanning electron microscopy (SEM) measurements. DSC and WAXD results indicated that the annealing not only produced secondary crystallization but also perfected primary crystallization, and spinning and annealing temperature influenced the crystallinity of hollow fiber: the crystallinity decreased with the increase of spinning temperature; 140°C annealing increased the crystallinity, and hardly influenced the orientation of hollow fiber; above 150°C annealing increased the crystallinity as well, and furthermore had a comparative effect on the orientation. The tensile tests showed that the annealed samples, which did not present the obvious yield point, exhibited characteristics of hard elasticity, and all the hollow fiber had no neck phenomenon. Compared with the annealed sample, the precursor presented a clear yield point. In addition, the annealed samples had a higher break strength and initial modulus by contrast with the precursor, and the 140°C annealed sample showed the smallest break elongation. SEM demonstrated the micro-fiber structure appeared in surface of drawn sample. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 935–941, 2007

Polyvinylidene fluoride (PVDF) and its blend films were prepared by melt-blending the binary mixture of PVDF/dibutyl phthalate (DBP) and the ternary mixture of PVDF/CaCO3/DBP in combination of TIPS. Their morphologies were characterized by scanning electron microscope depended on preparation condition, such as the diluent and CaCO3 weight fraction, and the cooling rate, and the crystallization information was also investigated by DSC. The results showed that CaCO3 influenced the morphology of PVDF in the TIPS process regardless of the cooling conditions, and the formation of the spherulitic morphology can be disturbed by CaCO3 at the quenching condition. The effect of CaCO3 weight fraction on the tensile strength of PVDF was measured, which indicated CaCO3 had a negative effect on PVDF tensile strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2944–2952, 2006

Novel sulfonated poly(ether ether ketone ketone)s were prepared directly by nucleophilic polycondensation. They showed excellent thermal stability and good solubility and could be easily cast into tough membranes. The sulfonated membranes showed swelling of 16.08–26.71% and an ion-exchange capacity of 1.01–1.57. The transport properties of different cations (H+, Na+, and K+) of membranes based on these polymers were evaluated. The potential for ion-exchange membranes looks good. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2481–2486, 2005

A series of sulfonated poly(ether ether ketone ketone)s derived from bisphenol S were prepared by nucleophilic polycondensation. They showed high thermal resistance and good solubility. Most of the polymers were easily cast into tough membranes. The swelling of the membranes (6.02–16.02%) was lower than that of Nafion membranes, and the ion-exchange capacity of the membranes (0.67–1.44) was higher than that of Nafion membranes. The proton conductivity of the membranes was 0.022–0.125 s/cm. They could be used as proton-exchange membranes in fuel cells. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1569–1574, 2004

A novel series of sulfonated poly(ether ether ketone ketone)s (SPEEKKs) were prepared by aromatic nucleophilic polycondensation with different ratios of 1,3-bis(3-sodium sulfonate-4-fluorobenzoyl)benzene to 1,3-bis(4-fluorobenzoyl)benzene. 1H-NMR spectroscopy was used to confirm the degrees of sulfonation (DS) of the polymers. Thermal stabilities of the SPEEKKs in acid form were characterized by thermogravimetric analysis (TGA), which showed that SPEEKKs were excellently thermally stable at high temperatures. SPEEKK polymers can be easily cast into tough membranes. Both of proton conductivity and methanol diffusion coefficient have been tested in this article. Other properties of the SPEEKK membranes were investigated in detail. The results show that the SPEEKK membranes are promising in proton exchange membrane fuel cells (PEMFCs) application. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010