The study on preparing anti-radiation material by reverse microemulsion method

A new way to prepare PMMA contain lead salt was presented. This work firstly prepares the material by microemulsion polymerization. The ability of anti-radiation, transmittance ratio and glass transition temperature （Tg） of the material was characterized. The anti-radiation ability is enhanced with the increasing of lead salt content and the thickness of the material. The transmittance ratio decreased with the content of the lead salt. The glass transition temperature of the material is increased with the lead salt content of the organic glass.     

聚合物固体电解质中的离子状态与导电机理的研究

制备得到了一种新颖的聚氨酯和丙烯酸酯复合梳形交联聚合物 (Combcross linkedpolymer) ,并以此聚合物为基体加入不同含量的高氯酸锂盐制得一系列聚合物固体电解质 ,其室温电导率可以达到 3 4× 10 - 5S·cm- 1 .通过Raman、DSC、SEM及电性能等研究了电解质中的盐浓度与离子存在状态及离子电导率之间的关系 .结果显示随着盐浓度的增加 ,聚合物固体电解质中离子对的比例和电导率都迅速增加 ,说明离子对 (由多个醚氧原子、阴离子和阳离子组成 )对体系导电起着积极的作用 .     

Ion distribution around electrostatically stabilized polystyrene latex particles studied by ellipsometric light scattering

The ion distribution around electrostatically stabilized polystyrene latex spheres for different ionic strengths is investigated by ellipsometric light scattering. This method is sensitive to the refractive index profile around colloidal particles, which is affected by the local salt content. At an average salt concentration of c* = 10(-4) mol L(-1), the ion concentration at the particle interface increases discontinuously, and a layer of high salt content with 20-30 nm thickness is built up. The observation cannot be explained within the framework of the Poisson-Boltzmann equation; it rather resembles a prewetting transition. Interactions that could possibly lead to a stabilization of the observed layer of high salt content are discussed.     

Empirical correlations between Krafft temperature and tail length for amidosulfobetaine surfactants in the presence of inorganic salt

Long-chain amidosulfobetaine surfactants, 3-(N-fattyamidopropyl-N,N-dimethyl ammonium) propanesulfonates (n-DAS, n > 18), are insoluble in pure water due to their high Krafft temperature (T(K)), while they are soluble when inorganic salt is added to the surfactant solution as the T(K) of these zwitterionic surfactants is decreased. The influence of the salt content and ionic species of the added electrolytes on the T(K) of the series of amidosulfobetaine surfactants was examined by means of UV-vis spectrophometry and visual inspection. It was found that the T(K) of these surfactants depends strongly on not only the hydrophobic alkyl length (n), but also the salinity of the aqueous environment. When the salt concentration is increased from 0 to 100 mM, the T(K) shows a sharp decrease; when the salinity is fixed between 100 and 2000 mM, the T(K) varies linearly with n with a slope of ~7.7 irrespective of the salt species and the salt content. When the salt concentration is further increased above 2000 mM, a linear function is still observed, but the slope increases slightly.     

Growth rate and some physiological features of Deleya halophila CCM 3662 at different salt concentrations

The growth rate of the type strain of the new, moderately halophilic species Deleya halophila (Deleya halophila CCM 3662) at different salt concentrations was determined and its optimal marine salt concentration for growth was established. Oxygen uptake and some cellular chemical composition characteristics of cells grown at their optimal salt concentration (7.5 % w/v) and at a higher concentration (15 % w/v) were compared, showing that both protein and carbohydrate intracellular contents decreased when the external medium salt concentration was increased, with the carbohydrate content reaching 50 % of the value presented by cells cultured at optimal salinity conditions. Oxygen uptake and poly-β-hydroxybutyric acid content were not significantly affected by changes in external salinity.     

Effect of lithium iodide addition on poly(ethylene oxide)-poly(vinylidene fluoride) polymer-blend electrolyte for dye-sensitized nanocrystalline solar cell

The effect of lithium iodide concentration on the conduction behavior of poly(ethylene oxide)-poly(vinylidene fluoride) (PEO-PVDF) polymer-blend electrolyte and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. The conduction behavior of these electrolytes was investigated with varying LiI concentration (10-60 wt % in polymer blend) by impedance spectroscopy. A "polymer-in-salt" like conduction behavior has been observed in the high salt concentration region. The transition from "salt-in-polymer" to "polymer-in-salt" conduction behavior happened at the salt content of 23.4 wt %, which is much lower than 50 wt % as generally reported. The electrolyte shows the highest ionic conductivity (approximately 10(-3) S cm(-1)) at the salt concentration above 23.4 wt %. From the evaluation of salt effect on the performances of corresponding DSSC, we find that increasing LiI concentration leads to increased short-circuit photocurrent density (Jsc) caused by enhanced I3(-) diffusion up to an LiI content of 28.9 wt %. Above this limitation, the Jsc decreases as a result of increased charge recombination caused by the further increased I3(-) concentration. The open-circuit voltage (Voc) increases gradually with LiI concentration owing to the enhanced I(-) content in DSSC. The optimized conversion efficiency is obtained at a salt content of 28.9 wt % in the "polymer-in-salt" region, with high ionic conductivity (1.06 x 10(-3) S cm(-1)). Based on these facts, we suggest that the changes of conduction behavior and the changes of I3(-) and I(-) concentrations in the electrolytes contribute to the final performance variation of the corresponding DSSC with varying LiI concentration.     

主链玻璃化转变区在室温附近的梳形聚合物电解质

主链玻璃化转变区在室温附近的梳形聚合物电解质＊齐力林云青夏永姚王佛松（中国科学院长春应用化学研究所长春１３００２２）关键词梳状高分子，固体电解质，离子导电性，玻璃化转变，分子运动＊１９９４－１０－３０收稿；１９９５－１２－１０修稿７３２高分子固体电解...     

Investigating the Effect of Chromatographic Conditions on Retention of Organic Acids in Hydrophilic Interaction Chromatography Using a Design of Experiment

Small organic acids have shown significant retention on various stationary phases, such as amide, amino, aspartamide, silica and sulfobetaine phase commonly used in hydrophilic interaction chromatography (HILIC). This study investigated the effect of chromatographic conditions on the retention behavior of organic acids in HILIC using the tool of design of experiment (DOE). The results of the DOE study indicated that both the content of organic solvent (i.e., acetonitrile) and salt concentration in the mobile phase had significant effects on the retention of organic acids. Higher content of organic solvent in the mobile phase led to a significant increase in retention on all types of stationary phases. Increasing salt concentration also resulted in a moderate increase in retention; however, the effect of salt concentration varied with the type of stationary phase. The study also revealed that column temperature had less impact on retention than organic solvent content and salt concentration in HILIC.     

Visualization of different pathways of DNA release from interpolyelectrolyte complex

The release of double-stranded DNA from its interpolyelectrolyte complex with positively charged poly(allylamine hydrochloride) via exchange reaction with added polyanion, poly(sodium styrenesulfonate), is directly observed by fluorescence microscopy. It is shown that the pathways of DNA release depend essentially on the amount of added low-molecular-weight salt. At low salt content, the DNA release proceeds via the formation of an intermediate "beads-on-string" structure, whereas at high salt content the release goes directly from globule to coil states without any intermediate structures. The reasons for different character of DNA release are discussed.     

Synthesis of γ-Aminobutyric Acid-Modified Chitooligosaccharide Derivative and Enhancing Salt Resistance of Wheat Seedlings

Salinity is one of the major abiotic stresses limiting crop growth and productivity worldwide. Salt stress during germination degenerates crop establishment and declines yield in wheat, therefore alleviating the damage of salt stress to wheat seedlings is crucial. Chitooligosaccharide (COS) was grafted with γ-aminobutyric acid based on the idea of bioactive molecular splicing, and the differences in salt resistance before and after grafting were compared. The expected derivative was successfully synthesized and exhibited better salt resistance-inducing activity than the raw materials. By activating antioxidant enzymes such as superoxide dismutases (SOD), catalase (CAT) and phenylalanine ammonia-lyase (PAL) and subsequently eliminating reactive oxygen species (ROS) in a timely manner, the rate of O⁻₂ production and H₂O₂ content of wheat seedlings were reduced, and the dynamic balance of free radical metabolism in the plant body was maintained. A significantly reduced MDA content, reduced relative permeability of the cell membrane, and decreased degree of damage to the cell membrane were observed. A significant increase in the content of soluble sugar, maintenance of osmotic regulation and the stability of the cell membrane structure, effective reduction in the salt stress-induced damage to wheat, and the induction of wheat seedling growth were also observed, thereby improving the salt tolerance of wheat seedlings.     

Synthesis of Polymers by Using Divalent Metal Salts of Mono(hydroxyethyl) Phthalate: Metal-Containing Three-Dimensional Polyesters from Metal Salts,Pyromellitic Dianhydride,and Epoxides

Syntheses of metal-containing three-dimensional polyesters were investigated by the reactions of divalent metal salts of mono(hydroxyethyl) phthalate-pyromellitic dianhydride-epoxide in DMF at 90° C. The metal carboxylate groups of these metal salts catalyzed the reactions. Systems with low metal salt content gelled during reaction. The yield of the products obtained by precipitating or washing with water increased with decreasing metal salt content in the feed. The products were metal-containing, three-dimensional polyesters containing ionic links; they were slightly yellow powdery materials. Hydroxyl values of the products were much higher than the values of acidity. Inherent viscosities (in DMF at 30° C) of the products obtained from the systems which did not gel were low, ranging from 0.031 to 0.083. The thermal stability of the products showed a tendency to increase with decreasing metal salt content in the feed.     

Acid recovery using diffusion dialysis with poly(4-vinylpyridine)-filled microporous membranes

Two series of membranes have been produced by photoinitiated polymerization of 4-vinylpyridine (4VP) and divinylbenzene (DVB) within the pores of polypropylene microfiltration membranes. The first series was comprised of membranes with varying mass gain and constant DVB content. The second series of membranes had similar mass gains but varying DVB content. The membranes were tested by diffusion dialysis of acid/salt solutions (HCl/NaCl/MgCl₂) in order to determine the effects of both mass gain and degree of crosslinking on dialysis coefficients and acid/salt separation. It was found for the first series of membranes that the dialysis coefficients of the acid and salts decreased and then leveled off with increasing mass gain while separation increased and then also leveled off. The second series of membranes showed a decrease in acid and salt dialysis coefficients but a dramatic increase in separation as the DVB content was increased. These results are interpreted in terms of the fixed charge concentration and the water content of the membranes. A comparison is made with a commercial diffusion dialysis membrane.     

A general gel layer model for the transport of colloids and macroions in dilute solution

A general boundary element methodology for studying the dilute solution transport of rigid macroions that contain gel layers on their outer surfaces is developed and applied to several model systems. The methodology can be applied to particles of arbitrary size, shape, charge distribution, and gel layer geometry. Account is also taken of the steady state distortion of the ion atmosphere from equilibrium, which makes it applicable to the transport of highly charged structures. The coupled field equations (Poisson, ion-transport, low-Reynolds-number Navier-Stokes, and Brinkman) are solved numerically and from this, transport properties (diffusion constants, electrophoretic mobilities, excess viscosities) can be computed. In the present work, the methodology is first applied to a gel sphere model over a wide range of particle charge and the resulting transport properties are found to be in excellent agreement with independent theory under those conditions where independent theory is available. It is then applied to several prolate spheroidal models of a particular silica sol sample in an attempt to identify possible solution structures. A single model, that is able to account simultaneously for all of the transport behavior, which does not undergo significant conformational change with salt concentration, could not be found. A model with a thin (相似文献   

Highly hydrophobic microporous low‐density polyethylene hollow fiber membranes by melt‐extrusion coupled with salt‐leaching technique

Microporous and highly hydrophobic low‐density polyethylene (LDPE) hollow fiber membranes were successfully prepared via a solvent‐free method, combining melt‐extrusion, and salt‐leaching techniques. NaCl particles with particle size of 5–10 µm were mixed with LDPE pellets to produce a blend of 35, 40, 50, 60, 65 and 68 wt% of salt. A microporous structure was produced by leaching the salt particles from the hollow fiber matrix via immersion in water at 60°C. The fabricated membranes were then characterized in terms of morphology, porosity and pore size distribution, surface roughness, and hydrophobicity, as well as mechanical properties. The remarkable increase in the water contact angles from 98° for LDPE hollow fibers fabricated without the addition of salt (blank sample) to 130° for membranes fabricated with initial salt content of 68 wt% is mainly attributed to the rough surface structure, comprising a large number of micropapillas produced by removing the imbedded salt crystals. The increase in surface roughness and porosity of hollow fiber membranes with increasing initial salt content was confirmed by scanning electron microscope and atomic force microscopy. Copyright © 2013 John Wiley & Sons, Ltd.     

新型聚醚聚氨酯/硬段模型化合物/高氯酸钠复合物的制备和表征

以聚醚聚氨酯和硬段模型化合物为聚合物基体,高氯酸钠为掺杂盐,合成了一系列新型的聚氨酯／硬段模型化合物／高氯酸钠复合物,利用FR－IR,DSC,AFM和复阻抗谱等表征手段对其形态和性能进行了基团和羰基都可与钠离子进行络合,温度变化可以导致不同程度的络合,在低盐浓度下,复合物的Tk随盐浓度的增加逐渐上升,而在一定的浓度之上,玻璃化转变温度又明显下降;通过调整盐的含量可以得到不同的表面形态。随着温度的升高,该体系的离子电导率显著增加。     

Dielectric investigations on how Mg salt is dispersed in and released from polylactic acid

Composite biomaterials made of biodegradable polylactic acid （PLA） and bioactive magnesium （Mg） salt are developed for orthopaedic implants or metal implant coatings. The releasing of Mg salt into the biological environment benefits the bone growth, while with the releasing of Mg salt and degradation of PLA there forms a porous scaffold for tissue engineering. The size and morphology of the salt and voids are adjustable with such preparation conditions as salt content, pH of casting solution, and the solidification rate, so that we can control the salt releasing and degradation rate of PLA. Dielectric spectroscopy is used to investigate the dispersive structures of Mg salt and voids in the polymer matrix and to monitor the in situ releasing of Mg salts in the simulated body fluid （SBF）. The current study provides us with an orthopedic biomaterial with controllable multi-phase structures, and a tool to investigate the in vivo behaviors of biomaterials.     

Poly(ethylene oxide)/poly(2vinylpyridne)/lithium perchlorate blends as solid polymer electrolytes: Composition/property/structure interrelationship

Poly(ethylene oxide) (MW 600,000)/poly(2vinylpyridine) (MW 200,000)/LiClO₄ blends have been prepared by the solution blending process. The ionic conductivities of the blends containing lower weight fractions (15, 17.5, 20 and 22.5%) of poly (2vinylpyridine) initially increases as the salt content is increased, reaches a maximum at an ethylene oxide/Li⁺ mole ratio of 10 and decreases as the salt content is further increased. Blends, which have higher weight fractions of poly(2vinylpyridine) (25 and 35%) display different electric behavior, i.e., the ionic conductivity continously increased as the salt content is increased to an ethylene oxide/Li⁺ mole ratio of 2. Thermal, ⁷Li solidstate NMR and semiempirical MNDO molecular orbital studies indicate that this contrasting behavior may be explained by the structure and ratios of the solvates (mixed solvate or homosolvate) of LiClO₄ present in the blends. © 1995 John Wiley & Sons, Inc.     

Single-Li~+ conductivity in ionomeric network

Ionomeric networks(IN)with lithium sulfate and sait-solvating oligo(oxyethylene)chainwere synthesized on the purpose of improving the conductivity of single-Li~+-ionic conductors.Li~+-ionicconductivity depends considerably on the salt content of the INs although the apparent degree of cross-linking is fixed in a constant of 10 mol%.As salt content(Li/O value)equals 0.0467,conductivity ofthe IN containing neither small-molecular salt nor low molecular weight plasticizer reaches a maximumof 7×10~(-6) S/cm at 25℃.Temperature-conductivity relationship of the INs shows curved Arrheninsplots,suggesting that the ionic conduction is primarily influenced by segmental motion of the polymerhost.In addition,WLF(Williams-Landel-Ferry)equation is used to analyze the conductivity data,from which the related WLF parameters are determined.     

Synthesis of silver/poly(2-hydroxyethyl methacrylate) particles via a combination of inverse miniemulsion and silver ion reduction in a "nanoreactor"

Silver salt/poly(2-hydroxyethyl methacrylate) (poly(HEMA)) hybrid particles were first prepared by inverse miniemulsion polymerization of 2-hydroxyethyl methacrylate (HEMA) with silver tetrafluoroborate (AgBF(4)) as a lipophobe. High silver salt loads of up to 13% with respect to the disperse phase were achieved. The silver/poly(HEMA) hybrid particles were subsequently formed via a gas-phase in situ reduction of AgBF(4) by hydrazine on the surfaces of silver salt/poly(HEMA) particles. The formation of silver nanoparticles was confirmed by UV-vis spectroscopy and X-ray diffraction. The morphology of the hybrid particles of silver salt/poly(HEMA) and silver/poly(HEMA) was fully characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), and dynamic light scattering (DLS). The influence of the reaction parameters including the type and amount of cosolvent, salt content, and type of surfactant on the particle properties and colloidal stability during the reduction process was thoroughly investigated.     

凝胶型聚合物电解质的电导率与温度的关系

凝胶型聚合物电解质的电导率与温度的关系孙晓光，林云青，齐力，景遐斌，王佛松（中国科学院长春应用化学研究所长春１３００２２）关键词凝胶电解质，离子电导率，活化能无定形聚合物电解质电导与温度的依赖关系一般可用Ｖｏｇｅｌ－Ｔａｍｍａｎ－Ｆｕｌｃｈｅｒｃ（Ｖ...