Active transport membrane for chlorine ion

A specific functional group that could interact with ions was introduced in a synthetic membrane to achieve an active transport of ions. One way to synthesize the active transport membrane was to introduce a functional group which has a tautomerism upon pH changes in an aqueous solution. A polymer having pendent N-hydroxyethyl amide groups was synthesized to form a membrane, and the membrane was fixed in a cell as a partition film, in which one side of the solution was adjusted to be acidic and the other side basic. It was then possible to transport chlorine ion through the membrane owing to the carrier functions caused by tautomerism of the N-hydroxyethyl amide group from the acidic to the basic sides. The transport of the chlorine ion was not dependent on diffusion control.     

Copolymeric network crown ether resins with pendent functional group: Synthesis and adsorption for metal ions

Three network crown ether resins with a high content of pendent functional groups were prepared and characterized by IR, elemental analysis, and thermal analysis. The slight variance of the thermal stability of the resins was related to the kind and content of the pendent functional group. The adsorption capacity of the resins for Mg(II), Cu(II), Co(II), Pb(II), and Hg(II) was determined. Toward Hg(II), the adsorption capacity of the resins was high and the adsorption process was easy and spontaneously performed. The XPS study showed that the adsorption of the NCR–SN resin toward Cu(II), Pb(II), and Hg(II) was mainly the coordinate interactions between the ligand atom (S, N) of the pendent functional groups and the metal ions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1457–1465, 2000     

Biocidal polystyrene beads. III. Comparison of N‐halamine and quat functional groups

A comparison has been made between the biocidal efficacies of N‐chlorinated polymeric beads and two derivatives of polyquat beads. Biocidal effects were measured after brief contact exposures of aqueous suspensions of either Staphylococcus aureus or Escherichia coli to the water‐insoluble beads. The polymeric backbone was held the same in all three types of beads, so they differed only in their biocidal derivative moieties. In all cases, functionalization of crosslinked chloromethylated polystyrene beads was performed to introduce the biocidal properties. Synthetic methods and test data will be presented. The most effective biocide, as measured by degree of inactivation in the shortest contact time of the two species of bacteria, was the N‐chlorinated hydantoinyl derivative of methylated polystyrene. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 363–367, 2004     

Preparation of macroporous silica-based crown ether materials for strontium separation

To develop a separation process of Sr(II), a macroporous silica-based 4,4′,(5′)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) polymeric material, (DtBuCH18C6+Oct)/SiO₂-P, was synthesized by impregnating and immobilizing DtBuCH18C6 and 1-octanol into the pores of the macroporous SiO₂-P particles support. DtBuCH18C6 was modified with 1-octanol through hydrogen bonding. The adsorption of simulant elements of some typical fission products Ru(III), Pd(II), Ba(II), Mo(VI), La(III), Y(III), Sr(II), Cs(I) and those of non-fission products Na(I) and K(I) onto (DtBuCH18C6+Oct)/SiO₂-P were studied at 298 K. The effects of the HNO₃ concentration in a range of 0.1–5.0 M and contact time on the adsorption were investigated. (DtBuCH18C6+Oct)/SiO₂-P showed excellent adsorption ability and high selectivity for Sr(II) over all of the tested metals except Ba(II). Partitioning of Sr(II) from a 2.0 M HNO₃ solution containing ~5.0 × 10^?3 M of the tested metals was conducted utilizing (DtBuCH18C6+Oct)/SiO₂-P packed column. Pd(II), Mo(VI), Y(III), La(III), Ru(III), K(I), Cs(I), and Na(I) showed no adsorption and flowed into effluent along with 2.0 M HNO₃. Sr(II) was retained on (DtBuCH18C6+Oct)/SiO₂-P and was eluted effectively by H₂O, while Ba(II) showed similar elution behavior. The bleeding of total organic carbon leaked from (DtBuCH18C6+Oct)/SiO₂-P was evaluated. It was demonstrated that the macroporous silica-based (DtBuCH18C6+Oct)/SiO₂-P materials are promising in separation of Sr(II) from high level radioactive waste.     

Chemical transformations of poly(arylene ether ketones) containing side functional groups

Conditions for chemical transformations of poly(arylene ether ketones) containing side carboxyl and phthalimidine functional groups have been investigated. The reason why the chemical modification of poly(arylene ether ketones) with side acid chloride groups leads in some cases to the formation of insoluble products is established. Ionogenic and comb-shaped poly(arylene ether ketones) with hydrophobic fragments in side branches are obtained through chemical transformations of previously synthesized polymers containing side carboxyl, hydroxyl (alcohol), and phthalimidine groups. The properties of poly(arylene ether ketones) can be varied in a wide range via chemical reactions of side reactive groups.     

Membrane transport of organics. III. Permeation of some carboxylic acids through bipolar polymer membrane

The permeation of acetic (AA), propionic (PA), lactic (LA), oxalic (OA), citric (CA), and tartaric (TA) acids through the bipolar ion‐exchange membrane Neosepta BP‐1 (Tokuyama Corp.) was studied. It was found that the fluxes (J, mol cm^?2 s^?1) and mass‐transfer coefficients (k, cm s^?1) increase in the following order: CA < OA < LA < TA < PA ≤ AA. The transport processes in the Neosepta BP‐1 membrane are concentration‐dependent and can be described phenomenologically using I‐Fick's law for diffusion. The permeation phenomena correspond to the solution–diffusion model similarly as to the permeation of carboxylic acids through strongly acidic cation‐exchange membranes. However, in competitive AA–PA transport experiments, typically for strongly basic membranes, the separation ability of the BP‐1 membrane with a preference toward AA was observed. The selectivity coefficients α calculated as the ratio of the respective mass‐transfer coefficients vary in the range from 1.31 ± 0.2 to 2.1 ± 0.6. These values depend on the feed composition and the system arrangement, which means that α is always higher for the system with the anion‐exchange layer is in contact with a feed solution. Rather low fluxes of PA, AA, and other acids, as compared to some monopolar membranes (Neosepta AFN‐7, Nafion‐120, Flemion), are promising for the application of the bipolar membrane in an electrodialytic separation of carboxylic acids from their aqueous solutions or mixtures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2705–2717, 2001     

Solubility and esterification kinetics of terephthalic acid in ethylene glycol III. The effects of functional groups

Clear time (t_cl), the time required for the turbid mixture of terephthalic acid (TPA) and ethylene glycol (EG) to be clear, was measured to examine the effect of poly(ethylene terephthalate) (PET) prepolymer (DP of 1–5) on the kinetics of dissolution and/or ester-ification of TPA with EG. The t_cl of the mixture of TPA/EG (1 : 1.5 in molar ratio) was reduced to 1 : 2.2 or 1 : 3.5 by addition of 30 wt % of PET prepolymer or bis-(2-hydroxyl ethyl) terephthalate (BHET), respectively. Diethyl terephthalate (DET) as an addititive was used as a model compound to examine the effects of the —OH group on the esterification reaction of TPA/EG. The t_cl value increased with addition of DET. The effect of the carbonyl group was also examined by determining esterification rates of benzoic acid (BA) with either ethylene glycol monobezoate (EGMB) as a compound with carbonyl group, or 2-penoxyethanol (2-PhE) as a compound without the carbonyl group. The reaction rate of BA with EGMB was much higher than that of BA with 2-PhE, which indicates that the carbonyl group gave an increasing effect of the esterification rate. Fourier transform infrared spectra showed that the —OH group in both BHET and EGMB formed intramolecular hydrogen bonding with the ester carbonyl group. On the basis of these observations, we concluded that the electron density of oxygen in the hydroxyl group increased through the formation of the intramolecular hydrogen bond. The increased electron density gave the —OH group easier access to the carbonyl carbon in BA, leading to an increase in the esterification rate. © 1996 John Wiley & Sons, Inc.     

Radiation-induced graft polymerization of functional monomer into poly(ether ether ketone) film and structure-property analysis of the grafted membrane

Radiation-induced graft polymerization of sulfo-containing styrene derivatives into crystalline poly(ether ether ketone) (PEEK) substrates was carried out to prepare thermally and mechanically stable polymer electrolyte membranes based on an aromatic hydrocarbon polymer, so-called “super-engineering plastics”. Graft polymerization of the sulfo-containing styrene, ethyl 4-styrenesulfonate (E4S) into a high crystalline PEEK substrate (degree of crystallinity: 32%) hardly progressed, whereas graft polymerization into a low crystalline PEEK substrate (degree of crystallinity: 11%) gradually progressed, achieving a grafting degree of more than 50% after 72 h. Oxygen radicals appeared in the ESR spectra of irradiated PEEK films, indicating that graft polymerization initiates from the phenoxy radicals generated by scission of PEEK main chains and proceeds so as to yield block type grafts. The PEEK-based polymer electrolyte membrane (PEM) converted by aqueous hydrolysis of grafted films exhibited mechanical strength (100 MPa), being 88% of the original PEEK substrates. These mechanical properties of PEEK-based PEM are much higher than those of graft-type fluorinated PEM reported previously and almost three times higher than that of Nafion (35 MPa). Wide- and small-angle X-ray scattering (WAXS and SAXS) indicated that the graft polymerization was accompanied with recrystallization of the amorphous phase of PEEK substrate, the well known solvent-induced recrystallization of amorphous PEEK solids, to form a weak lamellar structure with 8 nm spacing. Complementary SAXS and small-angle neutron scattering (SANS) observations clearly showed that the graft-type PEEK membranes possessed ion channel domains with the average distance of 13 nm, being larger than that of Nafion. Furthermore, there was a micro-structure in the ion channels with the average distance of 1.8 nm.     

Electrodialytic transport of inorganic and of organic anions

The electrodialysis of monocarboxylic acids and their potassium salts in the series formic acid to valeric acid has been investigated. A laboratory-scale continuous-flow unit was operated over the current density range 0·4 to 6·0 mA/cm² with total feed concentrations of 13·1 and 26·2 meq/1. Initial experiments were conducted with chloride and sulphate, for which the total transport and selectivities are established. At pH values set to assure 95% dissociation of the monocarboxylic acids, the transport (in the presence of chloride) of formate, acetate and propionate was about 20%, but that of butyrate and valerate was less. Acid salt selectivities (transport compared with chloride) ranged from 0·5 for formate through propionate to 0·3 for butyrate and valerate. For butyrate, the percentage transport increased approximately linearly with current density and was a random function of equivalent fraction of butyrate in the feed. Increases in total concentration produced no increases in transport. Butyrate selectivities were somewhat independent of current density and of equivalent fraction. Throughout the study, there was only limited evidence of fouling of the membrane by the organic acids and their salts, although valerate did produce temporary fouling.     

Coupling of living polystyryllithium anions and living polyethyl vinyl ether cations

Summary Living polystyryllithium anions and living polyethyl vinyl ether cations have been successfully coupled. Indeed, no residue of any of the two original homopolymers is observed in the final product, when they are used in a stoichiometric amount. This method has been exploited in order to synthesize AB and ABA polyethyl vinyl ether (PEVE) (A)/polystyrene (PSt) (B) block copolymers with a high efficiency.     

润湿性对纳米多孔陶瓷膜输运性能的影响

为了实现复杂环境中高效回收水资源,采用先进的膜技术,基于建立的半连续超临界相反应改性实验装置对纳米多孔陶瓷膜分别进行亲水和疏水表面改性,通过接触角测量、微观结构观测等方法对润湿改性前后的纳米多孔陶瓷膜进行表征。基于单管管外水蒸气冷凝传热实验系统,对润湿改性前后的纳米多孔陶瓷膜进行了冷凝液输运特性的实验研究,揭示了混合气体温度、冷却水流速、跨膜压差和水蒸气体积分数等典型运行参数对纳米多孔陶瓷膜的冷凝液输运通量的影响规律与机理。同时,采用分子动力学方法,构建了水在不同润湿性纳米孔内输运模拟体系,研究水分子在不同润湿性纳米孔内的输运规律。     

Synthesis and self-assembly study of two-armed polymers containing crown ether core

Two functional crown ether initiator, bis[4′-(2-bromobutyryl)]dibenzo-18-crown-6 (BBDC) was synthesized through the condensation of dibenzo-18-crown-6 with 2-bromobutyric acid in the presence of polyphosphoric acid. Atom transfer radical polymerizations of styrene (St), methyl acrylate, methyl methacrylate and butyl acrylate were carried out in bulk to produce the polymers with well-controlled molecular weights and narrow molecular weight distributions (1.12-1.32). Based on ¹H NMR results, both the two bromides of BBDC initiated the polymerizations. The well-defined two-armed polymers were self-assemblized in the presence of potassium cations. Their morphologies of the film obtained were studied by atomic force microscopy with tapping mode.     

液晶冠醚的合成及在分析化学中的应用

讨论了近年来液晶冠醚的合成方法及其性质,并总结了其离子传输,分子识别以及在色谱分析,LB膜等方面的应用。     

Active transport of alkali metal ion through a membrane composed of gluconolactone-containing polymer

Summary The membrane composed of gluconolactone-containing polymer was prepared by the following three steps, (1) the copolymerization between acrylonitrile and a styrene derivative carrying a protected glucose substituent, (2) casting a membrane from the DMF solution of the copolymer, and (3) a sequence of reactions for the membrane. It exhibited active transport of Na⁺ ion against the concentration gradient.     

Synthesis of crown ether modified cation exchange polymer particles for 90Sr urinalysis

Cation exchange polymer particles have been synthesized for urinalysis to monitor levels of strontium-90 (⁹⁰Sr) exposure in humans. Two techniques were utilized in the incorporation of a Sr²⁺ selective chelating agent, di-tert-butyl-cyclohexano-18-crown-6 (DtBuCH18C6). The ion imprinting technique involved entrapment of DtBuCH18C6 during the formation of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) polymer particles. In the surface immobilization technique, adsorption of DtBuCH18C6 onto the surface of AMPS polymer particles was assisted by a molecular modifier. Ethylene glycol dimethacrylate (EGDMA) and divinylbenzene (DVB) were evaluated as cross-linking agents to provide better support for DtBuCH18C6. These polymer particles were characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. Radiometric binding assays demonstrated that surface immobilization, in comparison to matrix imprinting, achieved greater Sr²⁺ uptake. Application of the surface immobilized particles in urinalysis was successful, attaining 86 ± 2% ⁹⁰Sr uptake at pH 9.     

冠醚化学交换分离锂同位素的影响因素分析及进展

锂同位素6 Li和7 Li是核聚变所需的重要原料,故锂同位素分离是核能开发必须解决的关键技术。本文系统综述了以冠醚类化合物为化学交换体系分离锂同位素的研究进展,详细讨论了冠醚分子的结构如冠醚环大小、给体原子种类、侧链种类,以及锂盐配位阴离子种类,溶剂种类,化学交换温度等因素对冠醚锂同位素分离效应的影响规律。结果表明,冠醚类化合物具有高的锂同位素分离因子,是非常有前途的锂同位素分离方法,但是以小分子冠醚为萃取剂的液-液萃取体系冠醚易于流失,无法重复利用,因此其未来发展方向是制备冠醚固载聚合物,采用固载冠醚的液-固体系分离锂同位素,提高分离效率,以实现其工业化应用。     

Preparation of a functional poly(ether imide) membrane for potential alkaline fuel cell applications: Chloromethylation

We have developed a novel poly(ether imide)‐based alkaline anion‐exchange membrane. The effects of several important parameters on the chloromethylation of the membrane have been investigated. These parameters include the reaction temperature, reaction time, concentration of the chloromethylation agent, concentration of the polymer, and amount of the catalyst. The results show that all the studied parameters have significant impacts on chloromethylation. Among them, the concentration of the chloromethylation agent plays a key role in increasing the attachment of chloromethyl functional groups onto the polymer. It ha been found that gelation can be avoided if these reaction parameters are controlled. This study also provides useful information for the successful chloromethylation of other membrane‐related polymers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

新型冠醚化合物的合成应用新进展

简要介绍了冠醚化学的产生、发展及应用;重点介绍了:(1)新型冠醚化合物的合成及应用;(2)新型冠醚超分子聚合物的合成及自组装;(3)新型金属冠醚的合成及应用,并对冠醚化学的发展进行了展望。     

新型冠醚化合物的合成性能及应用研究的新进展

介绍了冠醚化学的产生发展及应用,详细综述了:①新型冠醚的合成及其对阳离子的选择性识别作用;②新型双冠醚配体及其稀土过渡金属配合物的合成;③新型氮杂冠醚的合成及应用。并对冠醚化学的发展进行了展望。