A bifunctional cation exchange fiber was prepared by an efficient and environmentally benign method. In this method, sodium p-styrene sulfonate (SSS) was cografted directly onto the polypropylene (PP) fiber along with acrylic acid (AA), which eliminated the sulfonation process of grafting fiber with concentrated sulfuric acid or chlorosulfonic acid in the conventional method. Effects of the grafting conditions such as reaction temperature, reaction time, pH value, and the influence of acrylic acid and metallic salt on the graft copolymer reaction were investigated. The physicochemical properties of the cation exchange fibers were characterized with diffuse reflectance infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometer (XRD), thermal gravimetric analysis (TGA), TG-IR analysis, and monofilament tensile properties test. The experimental results indicate that the optimal conditions of pre-irradiation grafting are 80 degrees C for 5 hr, and the mechanical properties and thermal stability of the product are better than those of commercial materials (Fiban.K-1). The total static ion exchange capacity (IEC) of the cationic exchange fiber is up to 5.33 mmol/g. The maximal IEC contribution from the strong acid part is 2.47 mmol/g. This synthetic method provides a clean industrial way for the preparation of bifunctional cation exchange fibers. Copyright (C) 2009 John Wiley & Sons, Ltd.

Viscose-based activated carbon fiber (VACF) was modified with acrylonitrile (AN) by gamma-irradiation-induced grafting polymerization. Effects of the grafting conditions, such as concentrations of AN and divinylbenzene (DVB), pH value, and solvent on the grafting process were studied. The physicochemical properties of the fibers were characterized. The results show that AN can be effectively grafted onto the surface of VACF with the addition of DVB. The grafting yield is higher than 12% according to thermogravimetric (TG) analysis. The study shows that DVB can improve the grafting degree of AN in the form of grafting chains or agglomerate materials. After grafting modification, VACF shows a small decrease in the specific surface area. Copyright (C) 2009 John Wiley & Sons, Ltd.

We successfully prepared a novel fibrous adsorbent for carbon dioxide (CO2) capture by coating polyethylenimine (PEI) on a glass fiber matrix, using epoxy resin (EP) as crosslinking agent. The physicochemical properties of the fibrous adsorbents were characterized in terms of Fourier transform infrared spectrometry and thermogravimetric analysis. Factors that affected the adsorption capacity of the fibrous adsorbent were studied, including the crosslinking agent dosage, coating weight, moisture, adsorption temperature, and CO2 concentration of the simulated flue gas. The experimental results indicate that the properly crosslinked fibrous adsorbent had a high thermal stability at about 280 degrees C. With a PEI/EP ratio of 10:1, a maximum adsorption capacity of 276.96 mg of CO2/g of PEI was obtained at 30 degrees C. Moisture had a promoting influence on the adsorption of CO2 from flue gas. The CO2 adsorption capacity of the fibrous adsorbent in the presence of moisture could be 19 times higher than that in dry conditions. The fibrous adsorbent could be completely regenerated at 120 degrees C. The CO2 adsorption capacity of the regenerated fibrous adsorbent was almost the same as that of the fresh adsorbent. (C) 2008 Wiley Periodicals, Inc.

A novel type of weakly acidic cation exchange fiber (SC-IEF) was prepared by oxidizing the semi-carbonized polyacrylonitrile fiber (SC-PAN) with nitric acid solution. The physicochemical properties and adsorption performance of SC-IEF were characterized. Effects of the temperature, reaction time, concentration and dosage of nitric acid on the oxidation process of SC-PAN were studied. The experimental results indicate that the SC-IEF prepared shows higher thermal stability than conventional ion exchange fiber based on the hydrolysis of polyacrylonitrile. The content of the surface oxygen-containing groups on SC-IEF is up to 3.78 mmol/g. The static adsorption capacities of SC-IEF for Pb2+, Cu2+ and Mg2+ ions are 25.4, 8.2 and 4.5 mg/g, respectively, which reveals an excellent adsorption property of this novel ion exchange fiber. SC-IEF also shows an excellent selectivity for the adsorption of Pb2+ ions with the coexistence of Cu2+ and Mg2+ ions in the solution.

This work focuses on developing a novel adsorbent for CO2 capture, by coating polyethylenimine (PEI) on glass fiber matrix and using epichlorohydrin (ECH) as cross-linking agent. The physicochemical properties of the fibrous adsorbent were characterized. The CO2 adsorption capacity was evaluated. Factors that affect the adsorption capacity of the fibrous adsorbent were studied. The experimental results show that this fibrous PEI adsorbent exhibits a much higher adsorption capacity for CO2 compared with another PEI fiber prepared in our previous work, which employed epoxy resin as the cross-linking agent. A CO2 adsorption capacity as high as 4.12 mmol CO2/g of adsorbent was obtained for this fibrous PEI adsorbent at 30 degrees C, equal to 13.56 mmol CO2/g of PEI, with a PEI/ECH ratio of 20:1. The adsorbent can be completely regenerated at 120 degrees C.

A novel anion-exchange fiber with strong basic groups has been prepared by grafting styrene onto poly(tetrafluoroethylene) fibers via irradiation. Experiments were carried out to analyze the effects of synthesis conditions on the grafting degree and to characterize the physicochemical properties of the anion-exchange fibers. The experimental results showed that preirradiation grafting styrene onto poly(tetrafluoroethylene) fiber could significantly reduce the waste of raw material and the formation of homopolymer, although the grafting degree was relatively low. The grafting reaction could be effectively enhanced through the addition of magnesium powder into the reaction system. The optimal temperature and time for preirradiation grafting were 80 degrees C and 6 h, respectively. The experimental results also showed that the anion-exchange fibers had excellent mechanical properties and thermal stability at a temperature up to 420 degrees C. The fibers were stable in acidic, alkali, and oxidative solutions. The static ion-exchange capacity of the fibers was as high as 6.08 mmol/g. The static adsorption capacities for Cr2O72- and MnO4- ions were 214.08 and 290.98 mg/g, respectively. (C) 2008 Elsevier Inc. All rights reserved.

We successfully prepared a novel fibrous adsorbent for carbon dioxide (CO2) capture by coating polyethylenimine (PEI) on a glass fiber matrix, using epoxy resin (EP) as crosslinking agent. The physicochemical properties of the fibrous adsorbents were characterized in terms of Fourier transform infrared spectrometry and thermogravimetric analysis. Factors that affected the adsorption capacity of the fibrous adsorbent were studied, including the crosslinking agent dosage, coating weight, moisture, adsorption temperature, and CO2 concentration of the simulated flue gas. The experimental results indicate that the properly crosslinked fibrous adsorbent had a high thermal stability at about 280°C. With a PEI/EP ratio of 10:1, a maximum adsorption capacity of 276.96 mg of CO2/g of PEI was obtained at 30°C. Moisture had a promoting influence on the adsorption of CO2 from flue gas. The CO2 adsorption capacity of the fibrous adsorbent in the presence of moisture could be 19 times higher than that in dry conditions. The fibrous adsorbent could be completely regenerated at 120°C. The CO2 adsorption capacity of the regenerated fibrous adsorbent was almost the same as that of the fresh adsorbent. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

A hydrogen peroxide biosensor has been presented in this paper. Gold nanoparticles (GNs) was self-assembled onto a platinum electrode to form a negatively charged surface, and cationic dye-thionine (Thio) was linked by Au-S and Au-N covalent bond and electrostatic adsorption as an electron transfer mediator. The mixture of GNs and horseradish peroxidase (HRP) was assembled on the electrode at the same procedure, and chitosan (Chit) was dropped onto the electrode surface to fabricate a novel hydrogen peroxide biosensor. The effects of applied potential, pH and temperature on the response currents have been investigated. The surface configuration, electrochemical impedance, reproducibility and stability have also been researched. Activation energy for enzymatic reaction of the biosensor was 12.4 kJ/mol, and the apparent Michaelis-Menten constant was 6.5 X 10(-4) mo/L. And the linear range of the biosensor was from 5.6 X 10(-5) to 2.6 X 10(-3) mol/L with a detection limit of 1.5 X 10(-5) mol/L. The method has been applied to construct a bienzyme-based biosensor of HRP and glucose oxidase (GOD) for the determination of glucose.

A new method is described for the determination of dopamine (DA) by cyclic voltammetry based on its catalytic oxidation currents on a L-cysteine self-assembled modified gold electrode (L-Cys/Au electrode) in 0.2 mol/L pH 7.6 PBS(contain 0.1 mol/L KCl) solution.The oxidation potential was shifted negatively 112 mV compared with a bare gold electrode,and the oxidation current increases evidently.In the optimal experimental conditions,the linear range of the method was from 6.7×10-5 mol/L to 4.6×10-3 mol/L,with a detection limit of 8.4×10-6 mol/L.The method has been applied to the determination of DA in injection samples,and satisfactory results have been obtained.

通过辐照接枝的方法，采用对苯乙烯磺酸钠（sodium p-styrene sulfonate，SSS）及丙烯酸（acrylic acid，AA）等单体对聚丙烯（polypropylene，PP）纤维的接枝，制备了高磺酸基含量的双官能离子交换纤维，此方法避免了传统工艺磺化过程中对高浓度混酸（浓硫酸、浓硝酸）或氯磺酸的使用，从而解决了环境污染及易于工业化等难题。考察了制备过程中影响接枝效率的关键因素，利用酸碱滴定、反射红外、热重分析等分析手段表征了纤维的表面基团的含量、化学结构、热稳定性。结果表明，在辐照接枝过程中，AA单体的存在能有效提高纤维表面亲水性能，是SSS接枝于PP上的必要条件。另外，在接枝SSS的过程中加入适量金属盐会由于离子对效应而显著提高反应接枝率。制得的离子交换材料静态交换容量大于5mmol/g，其中磺酸基交换容量大于2mmol/g,产品具有良好的热稳定性，可以在200℃左右的温度下长期使用, 是一种具有工业化应用价值的新型材料制备方法。