脲、硫脲固体电解质导电机理分析

高分子固体电解质（ＳＰＥ）是一类很有发展前途的功能高分子材料．在高比能电池、二次电池、光电池、传感器、电显色器、电容器等方面具有广泛的应用前景,受到国内外高分子科学界和电化学界的普遍关注［１］．目前的研究方向仍是寻找室温下高电导率的固体电解质材料［２,３］．我们［４－６］以脲和硫脲为主体,添加聚乙烯醇等高分子材料制成的ＳＰＥ,室温电导率可达６．８４ × １０-３ Ｓ·ｃｍ－１,但其导电机理尚不清楚．搞清其导电机理对于认识和改进此类电解质非常有益．１实验部分１．１ＳＰＥ的制备电解质由质量分数为５１％脲…     

羧基负离子型聚电解质与重氮树脂的自组装及自组装膜的光和热反应

带相反电荷的聚电解质的自组装,由于方法简单,对环境无污染,近年来备受重视［１～８］。以重氮树脂为聚正离子的聚电解质复合物,由于光照时重氮基分解,致使复合物的离子键转为共价键,溶解性发生重大改变,从而以重氮树脂为聚正离子的聚电解质复合物是一种新的光成像体系［９,１０］。张希等用重氮树脂与聚苯乙烯磺酸钠成功地制备了对极性溶剂稳定的自组装超薄膜［１１］。本文用羧基负离子聚电解质与重氮树脂进行自组装,并研究该自组装膜的光,热反应。羧基负离子聚电解质与重氮树脂的自组装超薄膜,文献上报道较少。１　聚丙烯酸钠…     

用自组装法制备聚合物纳米复合膜

文章比较了自组装法（ｓｅｌｆ－ａｓｓｅｍｂｌｙ,ＳＡ）与Ｌａｎｇｍｕｉｒ－Ｂｌｏｄｇｅｔｔ技术（ＬＢ）及其它方法在制备聚合物纳米复合膜时的优劣。ＳＡ法由于操作简单、膜的结构稳定性较高,因此较ＬＢ技术等具有更大的实用价值。利用ＳＡ法,可以制备各种有机聚电解质与其带相反电荷的有机聚电解质、粘土化合物及无机纳米颗粒等组成的聚合纳米复合膜。     

全氟庚烷端基聚丙烯酸的制备及其水溶液的表面张力

高分子聚电解质既不同于简单的电解质,也不同于无离解基团的高聚物,表现出特殊的物理化学性能,其研究在理论上有重大的意义．同时,聚电解质具有重要的实用价值,如在污水处理、土壤改良、三次采油、钻井液添加剂、制药等领域有广泛的应用．在生命科学中,高分子聚电解质的研究对于正确理解生物大分子的作用（如蛋白质和脂类在生命体中的作用）是十分重要的［１］．聚丙烯酸（ＰＡＡ）是研究较多的合成聚电解质,其分子链在水溶液中离解而带有大量羧酸阴离子［２］,Ｉｓｈｉｍｕｒｏ等［３,４］较详细研究了ＰＡＡ水溶液的表面张力随其…     

聚(L-γ-氯乙基谷氨酸酯)的合成与构象

聚（Ｌ－γ－谷氨酸酯）类化合物是近年来被广泛用于蛋白质模拟及构象［１］、药物载体［２］和液晶大分子研究［３］,并可能是具有特殊场效应［４］的一类合成多肽．特别是在光电材料领域,人们发现将光致变色基团接入聚Ｌ－谷氨酸酯肽链的侧基是得到此类新型光电材料的最有效方法之一［５］．由于聚Ｌ－γ－谷氨酸酯是一类具有强旋光性的蛋白质,对其进行适当的改性后将对特定的小分子对映体有识别作用［６］,如将氨基糖接入聚Ｌ－谷氨酸酯的侧链就可制得能分离糖对映体的分离膜［７］．因此,将聚Ｌ－谷氨酸酯的侧链功能化,从而进一步…     

γ-射线辐照法制备纳米Cu-Pd合金粉末的影响因素

纳米Ｃｕ－Ｐｄ合金粉末在催化［１－４］、电导体［１,５,６］、导电胶［１,６］、传感器［７］、气体吸附与分离［８,９］等许多方面有着重要用途。其制备方法虽较多［１－４,１１－１７］,但多数方法制备温度较高,难以制得纳米Ｃｕ－Ｐｄ合金。γ－射线辐照还原...     

表面活性剂阴离子双水相新体系及其对卟啉、染料的萃取

由阴阳离子型表面活性剂水溶液混合形成的双水相［１,２］是水相分离技术中的一个新分支．ＺＨＡＯ等［２］将阴阳离子表面活性剂过量的体系分别称为阴阳离子双水相．由溴化十二烷基三乙铵（Ｃ１２ＮＥ）和十二烷基硫酸钠（ＳＤＳ）组成的阳离子双水相对蛋白质［１］、酶［３］、氨基酸［４］和卟啉［５,６］等的萃取分离已有报道．与阳离子双水相比较,阴离子双水相分相时间慢,其萃取应用研究尚未见报道．本文在详细研究了ＳＤＳ－Ｃ１２ＮＥ阴离子双水相的基础上,将全氟型阴离子表面活性剂全氟辛酸钠（ＳＰＦＯ）引入这类水相分离体系…     

重氮树脂型聚电解质复合物与SDS相互作用研究

由于聚电解质与表面活性剂的相互作用具有很多特别的性质而倍受关注［１～１０］,但具有感光性的重氮树脂作为正离子聚电解质与表面活性剂相互作用尚未见报道．本文研究了重氮树脂（ＤＲ）与聚苯乙烯磺酸钠（ＰＳＳ）形成的聚电解复合物（ＤＲ－ＰＳＳ）与十二烷基硫酸钠...     

纳米SnO2的制备

ＳｎＯ２在陶瓷、气敏半导体材料及催化剂等方面被广泛应用［１］．纳米级的ＳｎＯ２因具有明显的表面效应而受到关注，其制备方法也受到重视［２］．纳米ＳｎＯ２的制备方法较多，有沉淀法［２］、水热法［３，４］、溶胶－凝胶法［５］、火焰合成法［６］等．然而要制备...     

离子交换法提纯钯的优化工艺条件

钯由于其独特的物理和化学性能,目前广泛地用于航空、航天、微电子技术、石油化工、废气净化及冶金工业等领域．但它在自然界中含量少,二次资源中钯的含量反而大大高于原矿中的含量．钯的提纯方法有沉淀法、溶剂萃取法和色谱分离法［１,２］等．其中以氯钯酸铵沉淀法［３］和二氯二氨络亚钯法最为常用．但其工艺复杂,过程损失大．本文研究了离子交换法分离提纯钯,并用二次通用旋转组合设计法［４］对分离提纯的条件进行了优化．结果表明,该法工艺简单,分离提纯效果好,成本低．取７３２型阳离子交换树脂（粒度为０－６～１－２５ｍｍ…     

Peculiarities of the formation of polyacrylamide compound-based polyelectrolyte complexes in the course of the flocculation of clay-salt dispersions

Peculiarities of the formation of polyelectrolyte complexes based on cationic and anionic copolymers of acrylamide having different macromolecule charge densities on the surfaces of kaolin particles in highly concentrated salt solution are investigated. The interactions of the copolymers with the clay particle surface and with each other are studied by electrokinetic and IR spectroscopy methods. The rheological properties of kaolin suspensions are investigated in a salt solution in the presence of the polyelectrolytes. The flocculation ability of the polyelectrolytes and their binary mixtures with respect to clay-salt dispersion is estimated. The mechanism for the formation of polyelectrolyte complexes on the surface of clay particles is discussed. It is shown that the complexation of oppositely charged polyelectrolytes on the surfaces of clay particles intensifies the flocculation of clay-salt dispersions.     

Salt effect on surface modification of silica by interpolyelectrolyte complexes

The effect of a low-molecular-mass salt on the properties of interpolyelectrolyte complexes formed as a result of interactions between poly(diallyldimethylammonium chloride) and copolymers of maleic acid with propylene or α-methylstyrene in their salt containing non-stoichiometric mixtures has been studied. Properties of such interpolyelectrolyte complexes were found to be determined by the chemical nature of the polyelectrolytes and by the salt concentration. The effect of salt on the surface modification of silica particles via their interactions with interpolyelectrolyte complexes has been examined. Two different ways of the surface modification of silica particles were used: (i) silica particles were contacted with previously prepared interpolyelectrolyte complexes and (ii) silica particles were contacted with cationic polyelectrolyte at first and then anionic polyelectrolyte was added. The efficiency of the surface modification was shown to be also dependent on the salt concentration and the chemical nature of polyelectrolytes. Turbidimetry, quasi-elastic light scattering, laser microelectrophoresis, and polyelectrolyte titration were used to characterize studied systems.     

Successive adsorption of polyacrylamide compounds from electrolyte solutions on the surface of kaolinitic clay particles

Successive adsorption of oppositely charged polyelectrolytes, namely, cationic and anionic acrylamide copolymers, on a solid phase surface from solutions with high ionic strength is investigated. The constants of the Freundlich equation are calculated for the adsorption of different polymers. The interrelation between the adsorption values of polymers and their flocculation activity with respect to clay-salt suspensions is determined. The successive adsorption of oppositely charged polyelectrolytes strongly affects the flocculation due to the formation of polyelectrolyte complexes on the surface of clay particles. The mechanism for complexation is proposed.     

Colloid stability of lipid/polyelectrolyte decorated latex

The colloid stability of supramolecular assemblies composed of the synthetic cationic lipid dioctadecyldimethylammonium bromide (DODAB) on carboxymethyl cellulose (CMC) supported on polystyrene amidine (PSA) microspheres was evaluated via turbidimetry kinetics, dynamic light scattering for particle sizing, zeta-potential analysis, and determination of DODAB adsorption on CMC-covered particles. At 0.1 g L(-1) CMC and 2 x 10(11) PSA particles/mL, CMC did not induce significant particle flocculation, and a vast majority of CMC-covered single particles were present in the dispersion so that this was the condition chosen for determining DODAB concentration (C) effects on particle size and zeta potentials. At 0.35 mM DODAB, charge neutralization, maximal size, and visible precipitation indicated extensive flocculation and minimal colloid stability for the DODAB/CMC/PSA assembly. At 0.1 g L(-1) CMC, isotherms of high affinity for DODAB adsorption on CMC-covered particles presented a plateau at a limiting adsorption of 700 x 10(17) DODAB molecules adsorbed per square meter PSA which was well above bilayer deposition on a smooth particle surface. The polyelectrolyte layer on hydrophobic particles was swelled and fluffy (ca. 11-nm hydrodynamic thickness), and maximal adsorption of DODAB lipid onto this layer produced a compressed composite cationic film with 20 mV of zeta potential and about 10-nm mean thickness. The assembly of cationic lipid/CMC layer/polymeric particle was stable only well above charge neutralization of the polyelectrolyte by the cationic lipid, at relatively large lipid concentrations (at and above 1 mM DODAB) with charge neutralization leading to extensive particle aggregation.     

Adsorption of polyelectrolyte-nanoparticle systems on silica: influence of ionic strength

In this work the effect of ionic strength on the adsorption behavior of cationic polyelectrolyte (acrylamide-acrylamidopropyltrimethylammonium chloride) and negatively charged silica particles has been studied by means of ellipsometry. The adsorption of the polyelectrolyte was observed to increase with increasing salt concentration, a behavior typical for polyelectrolytes with a screening-reduced solvency and a nonelectrostatic affinity for the surface. A similar dependence on the ionic strength was observed when studying the electrolyte effect on the nanoparticle adsorption to the preadsorbed polyelectrolyte film, suggesting that the polyelectrolyte surface conformations largely govern the binding capacity of the particles to the surface.     

Hydrogel composites of neutral and slightly charged poly (acrylamide) gels with incorporated bentonite. Interaction with salt,linear polyelectrolytes and ionic surfactants

The swelling behavior in the solutions of sodium chloride, linear polyelectrolytes and ionic surfactants of the composites based on clay mineral bentonite (BENT) embedded in neutral and slightly charged poly(acrylamide) (PAAm) gels is studied. Negatively charged flat clay particles incorporated into polymer gel adsorb oppositely charged surfactant and linear polyelectrolyte and attract the charged chains of cationic polymer matrix. The results of SAXS study manifest the formation of lamella structure of the cationic surfactant adsorbed by the clay plates. The gels loaded with the clay show a strong response to changes in the nature and the composition of the ionic environment.     

Synthesis of cationic core-shell latex particles

Surfactant-free seeded (core-shell) polymerization of cationic polymer colloids is presented. Polystyrene core particles with sizes between 200 nm and 500 nm were synthesized. The number average diameter of the colloidal core particles increased with increasing monomer concentration. Cationic shells were introduced by co-polymerizing styrene with the cationic monomers (vinylbenzyl)trimethylammonium chloride (VBTMAC), [(2-methacryloyloxy)ethyl] trimethylammonium chloride (METMAC) and [(2-(acryloyloxy)ethyl] trimethylammonium chloride (AETMAC) onto the polystyrene cores. The cationic monomer AETMAC, undocumented to our knowledge in colloid synthesis, produced the best cationic shells and could be incorporated at much higher concentrations in the shell compared to the commonly used VBTMAC and METMAC, which yielded undesired polyelectrolyte side products already at relatively low cationic monomer concentrations. In shell formation, feed concentrations of AETMAC between 1.3 mol% (2.4 wt%) and 10.7 mol% (20 wt%) in styrene could be employed, allowing us to control colloid surface charge density over a wide range. The influence of various polymerization parameters (initiator concentration, cross-linking agent, and ionic strength) on the co-polymerization process with AETMAC is discussed. Core-shell particles were characterized using HR-SEM, potentiometric titration and zeta potential measurements.     

Substantivity and After‐Rinsing Hair Growth Promotion of Cationic Microparticles of Minoxidil

Cationic minoxidil (MXD) particles were prepared by passing a suspension containing MXD and distearyldimethylammonium chloride (DSDMAC) through a high pressure microfluidizer, operating at 500 bar to 1000 bar. The size of the particles is a few micrometers and the surface charge was+42 mV to+44 mV. The cationic MXD particles were included in a hair cleansing shampoo, of which a major detergent is sodium lauryl ether sulfate (SLES). On an UV spectrophotometer, the turbidity of the cationic MXD particles suspension increased with increasing amount of the anionic surfactant. At the same time, the surface charge of the cationic MXD particles was neutralized around equi‐molar ratio of SLES/DSDMAC, and the value became negative in the excess amount of SLES. These mean that DSDMAC adsorbed on MXD particles is complexed with SLES in the hair shampoo by an ionic interaction. Interestingly, even though the MXD particles contained in a shampoo exhibited negative surface charge, the skin‐retentive amount of MXD was appreciable and the after‐rinsing hair growth promotion effect was remarkable. One of possible mechanisms is that SLES would be desorbed from the complexed MXD particles during the rinsing step, and the charge of the particles might change from a positive value to a negative one, leading to an ionic interaction between the cationic particles and negatively charged skin.     

Colloidal Properties of Polychlorotrifluoroethylene-Based Multicomponent Dispersions

A polychlorotrifluoroethylene-based multicomponent dispersion in dimethylformamide (DMF) was used to prepare protective polymer coatings by the electrodeposition method. The properties of the fluoroplastic coatings were modified by the addition of a cationic polyelectrolyte and pigments of different natures to the dispersion, the pigments being codeposited on a cathode together with the fluoroplastic particles. The optimal composition of the dispersion was determined. It was found that all dispersion components were wetted by DMF; the surface properties of the coatings depended on the concentration of the polyelectrolyte added to the dispersion. The polyelectrolyte adsorption on F-3 and pigment particles was estimated by the UV spectroscopy; the electrokinetic potential of the particles was measured. The charge on a particle surface increased the dispersion stability, thus facilitating the formation of a more uniform electrodeposited layer, i.e., the coating.     

Adsorption of polyelectrolyte modified graphene to silica surfaces: monolayers and multilayers

Exfoliated graphene particles stabilised by the cationic polyelectrolyte polyethyleneimine (PEI) were used in conjunction with an anionic polyelectrolyte, poly(acrylic acid), to construct multilayers using the layer-by-layer technique on a silica substrate. In the first adsorption step, the surface excess of the cationic graphene was dependent on the overall charge on the nanoparticle which in turn can be tuned through modifying solution pH as PEI has weakly ionisable charged amine groups. The adsorbed amount onto the silica surface increased as the solution pH increased. Subsequently, a layer of PAA was adsorbed on top of the cationic graphene through electrostatic interaction. The multilayer could be assembled through this alternate deposition, with the influence of solution conditions investigated. The pH of the adsorbing solutions was the chief determinant of the overall adsorbed amounts, with more mass added at the elevated pH of 9 in comparison with pH 4. Atomic force microscopy confirmed that the graphene particles were adsorbed to the silica interface and that the surface coverage of the disc-like nanoparticles was complete after the deposition of five graphene-polyelectrolyte bi-layers. Furthermore, the graphene nanoparticles themselves could be modified through the consecutive addition of the oppositely charged polymers. A multilayered assembly of negatively charged graphene sheets modified with a bi-layer of PEI and PAA was also deposited on a silica surface with adsorbed PEI.