Guanidylated poly(2,6-dimethyl-1,4-phenylene oxide) (GPPO) hollow fiber membrane (HFM) supported Au nanoparticles are prepared by a simple adsorption-reduction of Au³⁺ with sodium borohydride as a reducing agent and polyvinyl pyrrolidone as a dispersant. The novel heterogeneous catalyst shows high catalytic activity for the reduction of various aromatic nitro compounds in an aqueous medium at room temperature and can be easily reused for several runs, for example, for the reduction of nitrobenzene, the yield reaches up to 92% even after 10 cycles, indicating the potential application of GPPO HFM as a catalysts support material for sustainable chemistry. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41268

Bioproducts have been used as bulk chemicals for processing and producing materials, chemicals and energy. The growing environmental concerns and shrinking reserves of fossil fuel have directed the attention to the production of bioproducts from renewable resources. Integrating sustainability considerations into bioproducts development make biotechnology a dominating technology platform. As bioproducts transformation and purification often contribute most to the final cost, improvements in separation techniques are essential to achieve competitive and efficient bioprocesses. One major breakthrough in transforming bioproducts is thus expected to come from novel separation techniques. Among them, electrodialysis (ED) with ion exchange membranes (IEM) has deserved special attention due to its diversity, sophisticated functions and technological compatibility. It is considered a very competitive technology when it comes to the transformation and separation of bioproducts. This review will focus on some noteworthy issues about ED technologies in producing and transforming bioproducts. © 2014 Society of Chemical Industry

Poly(ether ketone)s bearing pendent sulfonate groups (SPEK-x/y/z) have been successfully synthesized via copolyacylation of a presulfonated monomer SBP and two isomeric AB-type self-condensable comonomers, that is, 4-phenoxybenzoic acid (p-POBA) and 3-phenoxybenzoic acid (m-POBA). Proton-exchange membranes (PEMs) with precisely controlled ion-exchange capacity (IEC) and high strength can be readily prepared from these ionomers. PEMs prepared from p-POBA other than m-POBA exhibit much higher dimensional stability and proton conductivity at elevated temperature above 60 °C, showing prominent isomeric (para vs. meta) effects of polymer structural units. Furthermore, properties of PEMs prepared from p-POBA are optimized by tuning IEC. SPEK-1.0/2.2/0 with an IEC of 1.84 mmol g⁻¹ exhibits acceptable swelling, much higher proton conductivity, and lower methanol permeability than commercial Nafion 115, implying potential application in direct methanol fuel cells. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 200–207

Quaternary phosphonium-based polyelectrolyte was synthesized from bromomethylated poly(2,6-dimethyl-1,4- phenylene oxide) (BPPO) by functionalization with tris(2,4,6-trimethoxyphenyl) phosphine (TTMPP). Typically, excellent solubility of the polyelectrolyte in polar solvents, such as NMP and DMSO, allowed a solution-casting strategy for preparation of anion exchange membrane (AEM) with properly ordered hydrophilic/hydrophobic nano-scale phase separation morphology, which was visible in atomic force microscopic phase images. Accordingly, the optimized ionmeric AEM exhibited excellent hydroxide conductivity of 110 mS/cm at 70°C, but extremely restricted linear expansion ratio of below 7% at the same temperature. Additionally, such membrane could maintain flexibility and conductivity after an immersion treatment in 1 mol/L NaOH solution at 60°C for about 100 h, implying its potential in alkaline fuel cells.

A series of free-standing hybrid anion-exchange membranes were prepared by blending brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) with poly(vinylbenzyl chloride-co-γ-methacryloxypropyl trimethoxy silane) (poly(VBC-co-γ-MPS)). Apart from a good compatibility between organic and inorganic phases, the hybrid membranes had a water uptake of 32.4–51.8%, tensile strength around 30 MPa, and T_d temperature at 5% weight loss around 243–261°C. As compared with the membrane prepared from poly (VBC-co-γ-MPS), the hybrid membranes exhibited much better flexibility, and larger ion-exchange capacity (2.19–2.27 mmol g⁻¹) and hydroxyl (OH⁻) conductivity (0.0067–0.012 S cm⁻¹). In particular, the hybrid membranes with 60–75 wt % BPPO had the optimum water uptake, miscibility between components, and OH⁻ conductivity, and were promising for application in fuel cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

One type of negatively charged alkoxysilane, that is, sulfonated 3-(mercaptopropyl)trimethoxysilane (SMPTS), has been developed from 3-(mercaptopropyl)trimethoxysilane (MPTS) and hydrogen peroxide. SMPTS is used to modify sulfonated poly(ether sulfone) (SPES) through in situ sol–gel process. The membranes with proper SMPTS dosage show enhanced ion exchange capacity (IEC), hydrophilicity, mechanical strength, chemical stability, and proton conductivity, which prove that SMPTS is an effective modifier for preparing proton-exchange hybrid membranes. With MPTS of 5–20%, the hybrid membranes exhibit IEC 1.34–1.50 mmol g⁻¹, thermal stability 264–316°C, and proton conductivity 0.0015–0.0102 S cm⁻¹ and thus recommended for potential application in fuel cells. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The conjugation of PAMAM dendrimer and folic acid is a well-studied multivalent targeted drug delivery system, but it is expensive and difficult to be synthesized. To construct an inexpensive and well-defined multivalent targeted drug delivery system, a cheap carrier — Boltorn® series hyperbranched aliphatic polyester — was proposed as the nanodevice to carry fluorescein, folic acid, and methotrexate. The construction follows a facile route: (1) synthesizing the carrier — a hybrid hyperbranched polymer with acyclic hydroxyls and cyclic carbonate, (2) linking fluorescein to the hyperbranched polymer via the acyclic hydroxyls, (3) opening the ring of the cyclic carbonate with the amino group of folic acid, and (4) attaching the drug methotrexate to the resulting hydroxyls by ring-opening reaction. In this route, the peripheral hydroxyls of the hyperbranched polymer are divided into two groups and reacted with three reagents in sequence to form the desired multivalent targeted drug delivery system. Copyright © 2009 John Wiley & Sons, Ltd.

A series of anion exchange membranes with pyridinium groups were prepared by aminating 100% bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) with 4-vinylpyridine. These membranes exhibited higher ion exchange capacity, lower water uptake, lower area resistance, and better thermal stabilities than the membranes prepared from pyridine. Trimethylamine was used for further amination, but it did not enhance the membrane's permselectivity for fluoride, chloride, bromide, iodide, hydroxyl, nitrate, nitrite, or thiocyanate anions. Accordingly, 4-vinylpyridine was the better aminating agent to enhance the permselectivity of membranes for some monovalent anions. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

To develop ion-exchange membranes for application in severe conditions, such as those with high temperatures, strongly oxidizing environments, or organic solvents, new hollow-fiber anion-exchange hybrid membranes were prepared by the immersion of brominated poly(2,6-dimethyl-1,4-phenylene oxide) base hollow fibers in a tetraethoxysilane–ethanol solution followed by sol–gel and quaternary amination. Compared to conventional polymeric charged membranes, the prepared hybrid membranes were higher in both thermal and dimensional stabilities. The results suggest that tetraethoxysilane concentration was an important factor affecting the membrane's intrinsic properties. When the tetraethoxysilane concentration was in the range 15–45%, the final hollow-fiber anion-exchange hybrid membranes had an ion-exchange capacity of 1.9–2.0 mmol/g, a water uptake of.83–1.23 g of water/g of dry weight, and a dimensional change ratio of 13–18%. An evaluation on the membranes' separation performances is underway. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) was modified by γ-ray irradiation-reduced grafting of polyacrylamide. The grafting reaction was proved by the elemental composition of grafted SPPO, which was determined by XPS data. The influences of both the irradiation dose and the concentration of polymerization inhibitor on grafting copolymerization rate were investigated and the effect of graft rate on water content of SPPO film was fully discussed. Bipolar membranes were prepared by using these grafted SPPO as the cation exchange layers (and thus the grafted polyacrylamide is used as interfacial layer) and their I–V curves were studied. The results showed that γ-ray irradiation-reduced grafting copolymerization of acrylamide was one of the most efficient methods to improve the properties of a bipolar membrane. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

A novel route for the preparation of hybrid zwitterionic membranes containing both sulfonic and carboxylic acid groups is reported. Based on this synthetic methodology, a series of membranes were synthesized via sol–gel reaction, zwitterionization process, and the oxidization of the SH group. FTIR spectra confirmed the corresponding reactions. The properties of these prepared membranes were characterized by ion-exchange capacity (IEC), water content, and pure water flux, etc. The anion-exchange capacity (AIEC), total cation-exchange capacity (CIEC_total), and the CIEC of the sulfonic groups (CIEC_sulf) of the membranes coated for 1–3 times were in the range of 0.017–0.12, 0.1–0.53, and 0.029–0.14 mmol g⁻¹, respectively. The measurement of water content showed that it was independent of pH values whether for the membranes coated once or twice. Pure water flux revealed a downward trend with the increased coating times. The surface SEM images of the produced membranes exhibited that these membranes' textures could be affected highly by the curing temperature, and excessively higher curing temperature would lead the membranes to brittle and chasm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Anion-exchange organic-inorganic hybrid membranes were prepared through sol-gel reaction and UV/thermal curing of positively charged alkoxysilane and the alkoxysilane containing acrylate or epoxy groups. Properties of prepared hybrid membranes were varied by control of the molar ratio of the precursors. It was shown that the thermal degradation temperatures (T_d) of the membranes were in the range of 212–226°C, water uptakes in the range of 9.6–14.6% and IEC values in the range of 0.9–1.6 mmol g⁻¹. The hybrid membranes show high permeability to anions, as reflected by the high static transport number (t₋) of the anion (Cl⁻). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008