两性聚电解质在黄河高浊度水中的应用

本文合成了一系列不同阴、阳离子度的强碱弱酸型的两性聚电解质[丙烯酰胺(AM)-二甲基二烯丙基氯化铵(DMDAAC)-丙烯酸(AA)共聚物]。研究了阴、阳离子单体的配比对两性聚电解质分子量的影响;以及两性聚电解质阴、阳离子度对絮凝效果的影响。并将所合成的两性聚电解质作为絮凝剂,首次应用到黄河高浊度水的处理中。填补了国内两性聚电解质高分子絮凝剂应用于上水的空白。研究结果表明:在等电点范围内的两性聚电解质对黄河高浊度水的絮凝效果明显优于传统的非离子型、阳离子型及阴离子型絮凝剂。     

胶体滴定法测定胺甲基化聚丙烯酰胺的阳离子度

本文以胶体滴定法测定了阳离子型聚电解质——胺甲基化聚丙烯酰胺的离子度,准确性可达1%左右;并就聚电解质稀溶液性质考察了共存无机盐(KCl)浓度对滴定的影响。     

AM/AMPS/DMC聚两性电解质的合成、表征与溶液性能

以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,在0.5 mol/L NaC l溶液中,以2,2-偶氮二[2-(2-咪唑啉-2-代)丙烷]二氢氯化物(VA-044)为引发剂,合成了AM/AMPS/DMC系列聚两性电解质。利用13C NMR对共聚产物结构进行表征,结果表明,在高转化率情况下,共聚物组分与投料比基本一致。考察外加小分子电解质和温度对聚两性电解质溶液性能的影响,结果显示,阴、阳离子数量相近的聚两性电解质溶液的粘度随外加盐浓度增大而增大,在温度升高时,其表观粘度保留率高于聚丙烯酰胺,说明AM/AMPS/DMC系列聚两性电解质具有一定的抗温、耐盐能力。     

聚丙烯酰胺/聚乙烯吡咯烷酮与表面活性剂十二烷基硫酸钠的相互作用

通过对聚合物聚丙烯酰胺/聚乙烯吡咯烷酮(PAM/PVP)与表面活性剂十二烷基硫酸钠(SDS)混合体系的相对黏度和表面张力研究,证明聚合物PAM/PVP与表面活性剂SDS之间存在着明显的相互作用,通过缔合,形成混合胶束状聚集体,导致溶液黏度剧增。随聚合物溶液中SDS的加入,溶液黏度发生起伏变化,出现最大值(最小值)。而2者的相互作用使体系溶液的表面张力在SDS的临界胶束浓度(CMC)前后呈现先减小后增大,最后趋于平衡的情况。且聚表相互作用使溶液界面的界面张力比纯表面活性剂溶液的界面张力有所升高。     

黏度法研究两性聚丙烯酰胺的水溶性

利用水溶液聚合合成了不同组成的两性聚丙烯酰胺(AM/MADQUAT/NaAMPS),对其溶液黏度受NaCl溶液浓度的影响进行了研究。结果表明,净电荷含量较大的两性聚丙烯酰胺溶液,在低NaCl浓度下特性黏度大、溶解性好;而净电荷含量较小的两性聚丙烯酰胺溶液(特别是带有高电荷密度时),在较高的NaCl浓度下,聚合物溶液特性黏度大、溶解性好,反聚电解质效应明显。     

阳离子聚丙烯酰胺的研制

阳离子聚丙烯酰胺是一种用途广泛的有机高分子聚合物,其分子量和阳离子度是决定其性能的重要指标。在氧化-还原引发体系中,以丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体共聚合成了阳离子型聚丙烯酰胺聚合物(CPAM),考察了反应温度、酸碱度、引发剂、单体及阳离子单体浓度等因素对CPAM分子量和阳离子度的影响。结果表明,较高分子量和阳离子度CPAM的最佳聚合条件为:聚合单体浓度为35%,阳离子单体的含量约15%,引发剂0.4%,反应体系温度35℃,pH值为6左右。     

槐糖脂与聚丙烯酰胺的相互作用

通过表面张力和表观黏度的测定,研究了槐糖脂与聚丙烯酰胺(PAM)的相互作用。结果表明,加入PAM,槐糖脂溶液的表面张力略有升高,临界胶束浓度(CMC)由约30 mg/L升高为约40 mg/L,但槐糖脂/PAM混合溶液的表面张力主要受槐糖脂浓度的影响。温度升高,混合溶液的表面张力略有降低,CMC保持不变;加入氯化钠,混合溶液的表面张力略有降低。由于槐糖脂与PAM的"疏水微区"相互作用形成混合胶束,加入槐糖脂,PAM溶液的表观黏度出现不同程度的升高,当槐糖脂浓度为30 mg/L时,PAM溶液的表观黏度最高。槐糖脂与聚丙烯酰胺复配在降低表面张力的同时能提高体系的表观黏度,适用于三次采油技术。     

槐糖脂与聚丙烯酰胺的相互作用

通过表面张力和表观黏度的测定,研究了槐糖脂与聚丙烯酰胺(PAM)的相互作用。结果表明,加入PAM,槐糖脂溶液的表面张力略有升高,临界胶束浓度(CMC)由约30 mg/L升高为约40 mg/L,但槐糖脂/PAM混合溶液的表面张力主要受槐糖脂浓度的影响。温度升高,混合溶液的表面张力略有降低,CMC保持不变;加入氯化钠,混合溶液的表面张力略有降低。由于槐糖脂与PAM的"疏水微区"相互作用形成混合胶束,加入槐糖脂,PAM溶液的表观黏度出现不同程度的升高,当槐糖脂浓度为30 mg/L时,PAM溶液的表观黏度最高。槐糖脂与聚丙烯酰胺复配在降低表面张力的同时能提高体系的表观黏度,适用于三次采油技术。     

阳离子聚丙烯酰胺溶液黏度降低的研究

降低聚丙烯酰胺的黏度对于研究聚合物驱采油及其采出水的处理、煤气化灰渣的循环利用等有重大意义。本文考察了pH值、氧化物及矿化度对阳离子聚丙烯酰胺溶液黏度的影响,实验结果表明当pH值达到8.5时,阳离子聚丙烯酰胺溶液黏度急剧下降;当NaClO加入浓度达到60 mg/L时就能有效的分解聚丙烯酰胺;当NaCl加入量在250 mg/L时就能使聚丙烯酰胺溶液的黏度降低一半。     

紫外光敏引发合成的P(AM-DAC)污泥脱水絮凝应用研究

采用紫外光敏引发聚合方式合成的较高相对分子质量和阳离子度的阳离子聚丙烯酰胺[P(AM-DAC)]产品作絮凝剂,进行污水处理实验。与紫外光敏引发合成的非离子型PAM和市售阳离子型聚丙烯酰胺对污泥水的絮凝效果进行了比较,探讨了絮凝剂相对分子质量、阳离子度、用量以及种类对污泥水絮凝效果的影响,最终确立了1.1×107相对分子质量、30%阳离子度、4 mg/L絮凝剂、搅拌次数15次为最佳实验条件。     

Thermodynamic Association Behaviors of Sodium Dodecyl Sulfate (SDS) with Poly(4-vinylpyridine <Emphasis Type="Italic">N</Emphasis>-oxide) (PVPNO) at Different pH Values and Ionic Strengths

The interaction of sodium dodecyl sulfate (SDS) with poly(4-vinylpyridine N-oxide) (PVPNO) at different pH values and ionic strengths has been studied by isothermal titration microcalorimetry, electrical conductivity and turbidity measurements. The solution pH significantly effects the formation of the PVPNO/SDS complex. At pH 1.5, the polymer PVPNO is a strong polycation, and the binding is dominated by electrostatic 1:1 charge neutralization with the anionic surfactant. At pH 6 and 8, the electrostatic attraction between SDS and PVPNO is weak, and the hydrophobic interaction becomes stronger. The effect of salt concentration on the interaction of SDS and PVPNO depends on the competition between the increase of interaction and the screening of interaction. This study based on the thermodynamic process gained deep insight into the effects of pH value and ionic strength on the interaction mechanism of surfactant with polyelectrolyte. We also constructed a simple model for the interaction of PVPNO and SDS system in different solution regions.     

The Effect of Ethanol on Nanostructures of Mixed Cationic and Anionic Surfactants

Micellization of tetradecyl trimethyl ammonium bromide (TTAB) and sodium dodecyl sulfate (SDS) in water–ethanol (ET) micellar solutions, with the weight percent of ET changing within the range 0–30, was studied by means of surface tension and conductivity measurements. Surface tension measurements also provided information about the dependence of the surface excess concentration, the minimum area per surfactant molecule, and the standard Gibbs energy of adsorption on the added weight percent of the organic solvent. Information about the degree of counterion dissociation and phase transition was obtained through conductivity measurements. Cyclic voltammetry (CV) and dynamic light scattering (DLS) was also employed to investigate the mixed micellar behavior of the binary mixtures. It was shown that an excess of cationic surfactant and ET resulted in a phase transition of vesicles and large micelles to mixed micelles. The regular solution theory approximation was used to determine various micellar parameters of ideal systems. The regular solution interaction parameter (β) suggests that the formation of mixed micelles is due to the synergistic interactions in the case of TTAB/SDS systems and becomes affected by the water/ET ratio.     

表面活性剂对气体水合物生成过程的定量影响

为确定HCFC?141b水合物生成条件下阴离子表面活性剂十二烷基硫酸钠(SDS)和十二烷基苯磺酸钠(SDBS)的临界胶束浓度(CMC),在0~20℃温度下,通过圆环法实验研究了不同浓度表面活性剂溶液体系的表面张力,考察了表面活性剂对溶液体系表面张力的影响机理并通过C3H8水合物的生成过程实验进行了验证,确定了SDS和SDBS的临界胶束浓度. 结果表明,当SDS和SDBS的质量浓度分别低于500?10?6和100?10?6时,表面活性剂降低水表面张力的效果最明显,二者的CMC分别为1950?10?6和400?10?6,表面活性剂能明显缩短水合反应的诱导时间,提高了其平均生成速率.     

The Adsorption Layer in the System: Carboxymethylcellulose/Surfactants/NaCl/MnO2

The influence of surfactants (anionic sodium dodecyl sulfate, and nonionic tert-octylphenol ethoxylate with 9.5EO) and their mixtures on the adsorption of carboxymethylcellulose (CMC) in the presence of 0.001?M NaCl on the manganese dioxide surface (MnO(2)) was studied. The increase in CMC adsorption was observed in all measured systems in the presence of surfactants. The reason for this is the formation of complexes between polymer macromolecules and surfactants. Moreover, the dependence between the amount of surfactants adsorption and the CMC initial concentration was also studied. It proves that surfactant adsorption does not depend on the initial concentration of CMC. Another observation is that the increase in pH caused the decrease in CMC adsorption. The explanation of this phenomenon is connected with the influence of pH on the dissociation degree of the polyelectrolyte, kind and concentration of?the surface active groups of the adsorbent. To characterize the compact and diffuse adsorption layer the surface charge density and the zeta potential of MnO(2) in the presence of CMC and surfactants were measured. The surface charge density of MnO(2) decreases in the presence of CMC or CMC/surfactant complexes. This is due to the presence of negatively charged groups in the compact part of the electric double layer. The zeta potential of MnO(2) is also lower in the presence of CMC and the CMC/surfactants complexes. The main reason for that is the shift of the slipping plane towards the bulk solution.     

A Study of the Buffer Capacity of Polyelectrolyte Microcapsules Depending on Their Concentration and the Number of Layers of the Polyelectrolyte Shell

Polyelectrolyte microcapsules are used in the development of new forms of targeted delivery systems, self-healing materials, sensors, and smart materials. Nevertheless, their buffer capacity has not been practically studied, although that characteristic makes it possible to estimate the change in the state of protonation of the entire polyelectrolyte system. This is necessary both for creating a buffer barrier system for pH-sensitive compounds (metals, enzymes, polyelectrolytes, drugs) and for the correct interpretation of the results of research and studying of the PMC structure. The buffer capacity of a PMC can be affected by the concentration of microcapsules in solution and the number of shell layers since the listed parameters affect other physicochemical properties of the PMC shell. This includes, for example, the electrical conductivity, permeability (of ions), osmotic pressure, charge density, etc. In this regard, we studied the change in the buffer capacity of polyelectrolyte microcapsules depending on their concentration and the number of shell layers. As a result, it was found that with an increasing concentration of microcapsules, the buffering capacity of the PMC increases, but at the same time, in the pH range from 4 to 5.5, the calculated buffering capacity of 1 billion capsules decreases with increasing their concentration. This effect may be associated with a decrease in the available -NH₂ groups of the PMC’s shell. In addition, it was found that the main contribution to the buffer capacity of a PMC is made by the entire shell of the microcapsule and not just its surface. At the same time, the buffer capacity of the capsules has non-linear growth with an increase in the number of PMC shell layers. It is presumably associated either with a decrease in the polyelectrolyte layer with an increase in their number or with a decrease in the permeability of hydrogen protons.     

X-ray evanescent wave-induced fluorescence study of adsorption of a sulfonated polystyrene ionomer from dimethyl sulfoxide to the solution / vapor interface

We have studied the adsorption of an ionomer, poly(styrene-ran-manganese styrene sulfonate), from dimethyl sulfoxide solution to the solution/vapor interface at 20°C. The polymer sulfonation level was 15 mol% and the solution concentration studied was 1.00% (wt/wt). The adsorption was followed over time (4 days) by X-ray evanescent wave-induced fluorescence (XEWIF), which is a non-destructive probe of the polymer adsorption profile. We found that a state of apparent equilibrium was reached after a 4-day period and that the amount of polymer adsorbed was rather larger than anticipated from surface tension measurements. This anomaly is explained by the influence of image charge forces, which increase the surface energy and must be balanced with the surface energy reduction of placing the non-polar repeat segments at the surface. We suggest that this effect may be generalized to aqueous polyelectrolytes.     

添加不同物质的聚乙烯醇/海藻酸钠静电纺丝研究

分别添加少量NaCl、乙酸、表面活性剂十二烷基硫酸钠(SDS),研究少量添加物对海藻酸钠/聚乙烯醇(PVA)溶液性质和静电纺纤维的影响,并初步探讨了溶液静电纺丝机制。结果表明:NaCl改变了溶液的电导率和黏度,乙酸降低了溶液的黏度、提高了溶剂挥发性,SDS降低了溶液的表面张力;适量的添加物可使纤维形貌得到改善;添加物对电纺纤维化学结构无本质影响;无机盐离子加剧了纤维拉伸作用,结晶性有所提高;处于泰勒锥处液滴表面受到静电排斥力、表面张力、同种聚合物分子间的氢键作用力、不同聚合物分子间的氢键作用力以及聚合物同水等溶剂形成的氢键作用力。     

Properties of polyelectrolyte‐modified clays: Influence of the particle concentration on the degree of modification

Adsorption of polycation as well as the modification with oppositely charged polyelectrolytes is a useful tool for surface modification. As shown previously, a strong enhancement of the attainable specific cationic surface charge was observed, e.g., with poly(diallyl‐dimethylammonium chloride) (PDADMAC) as the polycation and poly(maleic acid‐co‐α‐methylstyrene) (P(MS‐α‐MeSty) as the polyanion, at a ratio of anionic to cationic charges of n−/n+ = 0.6 … 0.7. However, because the surface charge seemed to be strongly affected by the conditions of modification, the influence of particle concentration was investigated in detail. One gram of clay was suspended in different volumes of water so that the particle concentration was varied from 1 to 100 g/L. These suspensions were treated under the same conditions. For characterizing the surface charge of clay polyelectrolyte titration, dye adsorption, or microelectrophoresis was used. The comparison between the results of polyelectrolyte titration and the carbon content in the residual solution allowed prediction of the existence of a polyelectrolyte complex and calculation of the stoichiometry. It was found for a constant concentration of PDADMAC per 1 g of clay that the surface charge of modified clays changed from negative (1 g/L) to strong positive, depending on the particle concentration. The cause was assumed to be the differences in the probability of interaction of particles, combined with the changes in the stoichiometry of the polyelectrolyte complex built in the solution, whereas the effect of other factors (conductivity, time of adsorption) was rather low. A strong cationic surface modification was obtained for medium and high particle concentrations only. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 16–25, 2000     

烷基三甲基溴化铵添加剂对十二烷基硫酸钠水溶液表面活性的影响

研究了烷基三甲基溴化铵（Ｃ１２ＴＡＢ或Ｃ１４ＴＡＢ）作为添加剂对十二烷基硫酸钠（ＳＤＳ）水溶液表面活性的影响。实验结果表明,复配体系胶束生成和表面张力降低效率的局部增效均发生在Ｃ１２ＴＡＢ或Ｃ１４ＴＡＢ加入量仅约为ＳＤＳ的１／１００（Ｘ１≈０．０１）时。对于以ＳＤＳ为主成分的二元复配应用体系,当要求具有较高胶束生成能力或较高表面张力降低能力时,以添加烷基链长对称匹配的Ｃ１２ＴＡＢ为好;若希望具有良好的表面张力降低效率,则应加入单组分表面活性较高的Ｃ１４ＴＡＢ。