新型拟双子表面活性剂构筑的蠕虫状胶束及其pH和温度响应行为（英文）

将短链二元酸(丁二酸(SA)、戊二酸(GA)、己二酸(AA))和长链N-(3-(二甲基氨基)丙基)硬脂酰胺(C18N3N)以1∶2的摩尔比混合,通过静电相互作用,构筑了三种新型的拟双子表面活性剂。该过程无需复杂的合成。通过表面张力仪和流变仪测试了该系列表面活性剂的表面活性和流变性能。结果发现,2C18N3N/GA拟双子表面活性剂的cmc为4.60×10^-5 mol/L,该值远低于传统双子表面活性剂,说明构筑的拟双子表面活性剂2C18N3N/GA具有很强的胶束聚集能力,2C18N3N/SA和2C18N3N/AA体系也具有类似的特征。在浓度超过50 mmol/L时,该系列表面活性剂可形成蠕虫状胶束,溶液表现出黏弹行为,且黏弹溶液具有较好的耐温耐剪切性能。还考查了上述黏弹溶液的pH和温度响应性,发现体系pH为6.1时,溶液黏度很高,pH为4.0或9.3时,黏度下降。随着温度的升高,体系的黏度也会迅速增加。在60℃时,该体系的零剪切黏度可高达11 967.73 Pa·s。该表面活性剂制备简单,性能优良,拓展了新型表面活性剂的制备方法和应用范围。     

简述离子表面活性剂构筑蠕虫状胶束的研究现状

粘弹性蠕虫状胶束具有特殊的微观结构,其流变性能在不同领域具有重要的应用。本文介绍了表面活性剂构筑的蠕虫状胶束的结构特点、应用及研究现状。传统离子表面活性剂构筑蠕虫状胶束通常需要一些外加作用,Gemini表面活性剂因其结构优势,可以自身形成蠕虫状胶束。     

表面活性剂蠕虫状胶束缔合体系研究进展

介绍了表面活性剂蠕虫状胶束体系的研究进展情况,包括蠕虫状胶束的生长,稀溶液向亚浓溶液的过渡、粘弹体系的动态特性和非线性粘弹性以及剪切诱导粘弹性。     

pH对油酸钠/盐酸三乙胺蠕虫状胶束流变性质的影响

用流变学方法研究了pH对油酸钠/盐酸三乙胺(NaOA/Et3NHCl)蠕虫状胶束溶液流变性质的影响。通过稳态剪切和动态流变实验发现,30℃时,NaOA(0.12 mol/L)/Et3NHCl(0.2 mol/L)溶液在pH=8.20~9.40循环变化时,pH对溶液黏度的改变具有"开关"效应,可实现黏度在3~27 649 mPa·s时反复变化3次以上。体系在pH=8.55~9.02时为蠕虫状胶束,其流变行为符合Maxwell模型。这种溶液流变性对pH的响应行为是由于pH对反离子Et3NH+与NaOA的相互作用影响而产生的。当pH降低时,反离子Et3NH+的离子势增大,导致胶束表面电荷密度降低,蠕虫状胶束进一步增长。当pH=8.64,胶束因相互吸引而析出。而在初始条件下,升高pH=9.40,反离子Et3NH+从胶束中解吸出来,蠕虫状胶束受到破坏。     

碳量子点掺杂的蠕虫状胶束

以富勒烯生产过程中的副产物炭灰为原料,利用酸回流法制备了表面含有羧基的碳量子点(CQDs)。将所制备的CQDs代替传统有机酸,发现其与十四烷基二甲基氧化胺(C_(14)DMAO)在水溶液中能形成蠕虫状胶束。考察了CQDs质量浓度、pH等对蠕虫状胶束流变性质的影响。结果表明,CQDs质量浓度的增加和溶液pH值的降低均有利于蠕虫状胶束的形成。利用低温透射电镜可以原位地观察到蠕虫状胶束和CQDs的存在。CQDs外围-COOH解离出的H~+可以使C_(14)DMAO质子化为C_(14)DMAOH~+,而C_(14)DMAOH~+与C_(14)DMAO之间形成的氢键是蠕虫状胶束形成的主要驱动力。以上结果表明,CQDs可以有效地诱导C_(14)DMAO形成蠕虫状胶束。     

表面活性剂的性能与应用(Ⅷ)——表面活性剂的蠕虫状胶束及其应用

首先简单介绍了表面活性剂蠕虫状胶束的结构和形成,列出了常见的表面活性剂蠕虫状胶束体系,重点阐述了蠕虫状胶束的基本性质和常用的研究手段,最后着重综述了表面活性剂蠕虫状胶束在采油领域的应用。     

NaSal/NaCl诱导阳离子蠕虫状胶束的形成及流变性研究

以阳离子三联表面活性剂双(2-羟基-二亚甲基醚)-α,ω,γ-三(十六烷基二甲基氯化铵)(TrimerC16)为主剂,水杨酸钠(Na Sal)为有机反离子,氯化钠(Na Cl)为无机反离子,制备了阳离子蠕虫状胶束体系。利用电导率-表观黏度法研究了TrimerC16的相行为,考察了不同有机反离子Na Sal、苯甲酸钠(Na BENZ)及甲酸钠(Na FM)对TrimerC16克拉夫特温度(Tk)的影响,通过动态流变手段研究了TrimerC16/Na Sal/Na Cl的流变行为,并采用表观黏度法考察了温度(T)及剪切时间(ts)对该体系表观黏度(ηa)的影响。结果表明:TrimerC16的临界囊泡浓度(CVC)为0.015 mmol?L?1,临界胶束浓度为0.042mmol?L?1;三种有机反离子对TrimerC16的Tk影响大小顺序为:Na SalNa BENZNa FM;剪切速率(r′)为100 s?1时,TrimerC16/Na Sal/Na Cl体系的黏度仍高达70 m Pa·s;T=100℃时,转速为50 r?min?1下,TrimerC16/Na Sal/Na Cl体系的ηa为61.8 m Pa?s,而同一测试条件下,相同摩尔浓度的单链表面活性剂胶束体系的ηa已接近水的黏度。TrimerC16/Na Sal/Na Cl蠕虫状胶束体系耐较高温、耐剪切且破胶彻底。     

一种胺基型阳离子表面活性剂的合成及其溶液性能

该文以2-氯乙胺盐酸盐和十八烷基叔胺为原料,合成了一种胺基型阳离子表面活性剂——N-十八烷基-N,N'-二甲基-乙基-1,2-胺。通过IR和1HNMR对其结构进行了确证;并得到优化的合成条件为:物料比nb/na为1.20,反应温度为70℃,反应时间为7 h,p H=7。采用电导法测定不同p H下该表面活性剂的临界胶束浓度(CMC),发现CMC随着p H的降低而减小。该表面活性剂在Na Sal溶液质量分数为1%时,能形成蠕虫状胶束。流变性能测试表明,体系具有蠕虫状胶束的剪切稀释性特征和凝胶特性,同时具有p H响应,能在酸性条件下增黏,是一种智能型蠕虫状胶束体系。     

一种胺基型阳离子表面活性剂的合成及其溶液性能研究

该文以2-氯乙胺盐酸盐和十八烷基叔胺为原料,合成了一种胺基型阳离子表面活性剂——N-十八烷基-N,N’-二甲基-乙基-1,2-胺,通过IR和1HNMR对其结构进行了确证,并得到了优化的合成条件：物料比nb/na 为1.20,反应温度为70 oC,反应时间为7 h,pH为7。此外,采用电导法测定了该种表面活性剂的临界胶束浓度(CMC)随着pH的降低而减小。该表面活性剂在NaSal质量百分浓度为1%条件下,能形成蠕虫状胶束。流变性能测试表明,体系具有蠕虫状胶束的剪切稀释性特征和凝胶特性,同时具有pH响应,能在酸性条件下增黏,是一种智能型蠕虫状胶束体系。     

添加盐对Gemini阳离子表面活性剂溶液的影响

通过流变学方法研究了水杨酸钠(NaSal)对Gemini阳离子表面活性剂2-羟亚丙基-1,3-双(二甲基十二烷基氯化铵)(以12-3(OH)-12(2Cl)表示)水溶液黏弹性能的影响。结果发现,无机盐诱导12-3(OH)-12(2Cl)产生盐析作用,而NaSal可促使胶束生长;在固定n(NaSal)/n(12-3(OH)-12(2Cl))=0.6,12-3(OH)-12(2Cl)质量摩尔浓度较低时,溶液的黏度很小;随12-3(OH)-12(2Cl)质量摩尔浓度增加,溶液黏度明显增大并显示Maxwell流体行为;溶液的零剪切黏度(η_0)随12-3(OH)-12(2Cl)质量摩尔浓度增加有一个最大值出现,是因为体系中12-3(OH)-12(2Cl)的阳离子和水杨酸根(Sal~-)反离子形成的氢键使棒状胶束之问相互连接,导致网络结构形成;测定的晶体结构验证了分子间氢键的形成。     

阳离子三联表面活性剂/NaSS/St蠕虫状胶束及性能

引言蠕虫状胶束是基于非共价键作用的表面活性剂分子的自组装结构[1-2],胶束处于断裂-重新生成的动态平衡中[3-4]。由于其具有独特的流变性质,被广泛应用于清洁压裂中,其中使用的主剂大多为普通单链的阳离子表面活性剂、阴离子表面活性剂及两性离子表面活性剂[5-6]。然而,蠕虫状胶束对温度、离子强度、应力等[7-9]因素的变化过于敏感,     

油酸钠蠕虫状胶束的性质及驱油效率研究

分别通过稳态、动态流变的方法和冷冻蚀刻透射电镜、室内模拟驱油实验和平板夹砂微观模型驱油实验,研究了由碳酸钠诱导形成的油酸钠蠕虫状胶束的流变学性质及形貌和蠕虫状胶束驱油配方的驱油效果及驱油微观机理。结果表明,在油酸钠(NaOA)溶液中,加入一定量的Na2CO3能够形成蠕虫状胶束;孤岛东区稠油注聚驱后,蠕虫状胶束驱油配方(w/%,1.83 NaOA 4.24 Na2CO3)的室内模拟驱油可提高采收率25%原始石油地质储量(OO IP);平板夹砂微观驱油模型显示蠕虫状胶束驱油体系进入模型中,能够使注聚后束缚残余油重新启动、变形,渐渐形成油墙向出口处运移,蠕虫状胶束驱油体系能够有效扩大波及体积,提高洗油效率,从而提高驱油效率。     

基于“lock-in”效应的阳离子三联表面活性剂蠕虫状胶束流变性能

以三联阳离子表面活性剂双(2-羟基-二亚甲基醚)-α,ω,γ-三(十六烷基二甲基氯化铵)(16-4(OH)-16-4(OH)-16)在水杨酸钠(NaSal)及氯化钠(NaCl)作用下形成的蠕虫状胶束为研究对象,向该体系中增溶苯乙烯(S_t)引发聚合,探讨了聚合前后胶束溶液的流变性能。通过表观黏度法研究了16-4(OH)-16-4(OH)-16/NaSal/NaCl及十六烷基三甲基溴化铵(CTAB)/NaSal两种体系聚合后溶液的耐温(T)及耐剪切性,并利用流变测试对16-4(OH)-16-4(OH)-16/NaSal/NaCl体系增溶S_t聚合前后溶液性能进行了表征。结果表明:CTAB/NaSal胶束体系中S_t最佳增溶量为0.05 g,T=100℃或剪切90 min,聚合后溶液表观黏度(η_a)分别为66.9、15.5 mPa·s;而16-4(OH)-16-4(OH)-16/NaSal/NaCl胶束中S_t 最佳增溶量为0.10 g,T=100℃且连续剪切90 min后,聚合后溶液的η_a 始终维持在99.1 mPa·s,该体系聚合后稳态模量(G₀)高于未增溶S_t体系,由此说明蠕虫状胶束内S_t聚合物链可以产生对其微结构的“lock-in”效应。     

烷基聚葡糖苷表面活性剂形成微乳液的研究

以烷基聚葡糖苷(APG或CiGi)为表面活性剂，C4～C6正构醇为助表面活性剂，采用肉豆蔻酸异丙酯为油相，与水一起得到微乳液体系。研究了在不同烷基链长度的醇作用下，不同烷基碳链长度的烷基聚葡糖苷形成微乳液体系的拟三元相图以及δ—γ相图，并用HLB方程计算了微乳液界面的一些重要参数。发现使用较长碳链的醇以及用较长碳链的APG均有利于单相及中相微乳液的形成，并对此进行了解释，同时确定了单相微乳液效率最高的体系。     

非离子表面活性剂形成微乳体系的规律性研究

研究了非离子型表面活性剂形成微乳液体系的相行为,同时采用单因素变量法考察了乳化温度、组分含量、多元醇链长、添加剂以及p H对微乳液液滴粒径及Zeta电位值的影响。结果表明:较优乳化温度为80℃,在此乳化温度下微乳液液滴粒径较小、体系各组分的较优质量分数为1%甜杏仁油、10%聚氧乙烯(21)硬脂醇醚、10%1,2-丙二醇、0.4%Na Cl以及78.6%去离子水。此外,添加1,2-丙二醇作助乳化剂,当p H相对较低时生成的微乳液液滴粒径较小,体系较稳定。     

Study on the rheological behaviors of UHMWPE/CA‐MMT nanocomposite

In our previous study, we have prepared a novel antibacterial ultra‐high molecular weight polyethylene/chlorhexidine acetate‐montmorillonoid (UHMWPE/CA‐MMT) composites and examined its crystallization process and kinetics [1]. In this work, the rheological behaviors of pure UHMWPE, UHMWPE/MMT, UHMWPE/CA, and UHMWPE/CA‐MMT were characterized. The results showed that MMT can increase the viscosity of the polymer composites and CA can act as a plasticizer in the composites. Compared with UHMWPE/CA, UHMWPE/CA‐MMT had lower η*, G′, and G″. The TGA result indicated that CA‐MMT has higher thermostability than CA. Hence, CA‐MMT has the lower thermal decomposition ratio at high temperature than CA when it is blended with polymer. The TGA result could be used to explain that UHMWPE/CA‐MMT composites had better plasticizer effect than UHMWPE/CA composites. POLYM. COMPOS., 36:47–50, 2015. © 2014 The Authors Polymer Composites published by Wiley Periodicals, Inc.     

多孔胺基化氧化石墨烯基材料对CO2的吸附性能研究

以乙二胺(EDA)、二乙烯三胺(DETA)、四乙烯五胺(TEPA)、聚乙烯亚胺(PEI)等多胺基化合物为表面改性剂,氧化石墨烯(GO)材料为载体,采用嫁接法辅以超声处理制备了表面胺基功能化多孔吸附材料,用于CO₂气体的吸附捕集。所制备的多孔吸附材料孔径约为1.35~4.34 nm,比表面积约为98.032~210.465 m²/g。制备的四种吸附材料中,以PEI功能化吸附材料对CO₂的吸附容量最大,70℃下达到了1.5 mmol/g,且经过20次循环吸附/脱附实验后,其CO₂吸附量基本不变。吸附过程的吸附等温线线型为Ⅰ型优惠型,另外吸附实验数据与Avrami模型模拟结果符合性较好。     

Study of mechanical and rheological behaviors of linear and branched polycarbonates blends

A study of the mechanical and rheological properties of linear and branched polycarbonates blends is presented. Phase separations of the blends were checked through DSC and SEM, and, subsequently, mechanical and rheological properties were investigated. Phase separations were not observed in the blends. The mechanical properties were examined through tensile, flexural, and impact tests. All the mechanical properties of the blends were relatively independent of the compositions. For study of the rheological properties, melt viscosity, storage and loss moduli, and melt tension of the blends with various compositions were examined at various temperatures. The dependence of the viscosity on the molecular weight was also studied. As the content of branched polycarbonate increases, the dependence of the viscosity on the molecular weight and the shear thinning behavior became more marked. Melt tensions were also increased as the branched polycarbonate content increased in the blends for all tested temperatures. In this study, the blend systems which have same mechanical properties but different rheological properties can be obtained through blending of linear and branched polycarbonates. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1814–1824, 2001     

Interaction of an anionic surfactant with hydrous ferric oxide sol

The effect of sodium dodecyl sulfate (SDS) on positively charged hydrous ferric oxide sols (FOS) was studied by following turbidity and electrophoretic mobility as a function of increasing concentration of added SDS and by determining the adsorption isotherm. Adsorption of SDS reduced the electric charge of FOS and caused flocculation. Complete precipitation occurred near zero charge. Further increase in SDS concentration resulted in smaller additional adsorption, charge reversal, and redispersion of FOS. The effect of increasing particle size, resulting from aging or dialysis, on SDS adsorption is discussed qualitatively. Presented at the Second Middle Atlantic Regional Meeting, American Chemical Society, New York, N.Y., February 1967.     

Enhancement of enzymatic catalysis of Bacillus amyloliquefaciens α-amylase by nonionic surfactant micelles

Some enzymes are considerably more stable when formulated with nonionic surfactants than when formulated with anionic surfactants. The effect of a nonionic surfatant, polyoxyethylene mono-N-dodecyl ether (Brij 35; number of units of ethylene oxide moieties, 23), on the kinetic behavior of hydrolysis of amylopectin with Bacillus amyloliquefaciens α-amylase (BAA) was studied at a temperature of 25°C and a pH of 7.0. The hydrolytic rate was accelerated by the addition of the nonionic surfactant above its critical micelle concentration. Lineweaver-Burk plots for the enzymatic hydrolysis in the absence and presence of the nonionic surfactant at 0.5 to 2.5% (wt/vol) had linear relationships, and the kinetic parameters, K _m and k _cat were obtained. The value of k _cat was increased with an increased concentration of Brij 35, whereas the K _m value was approximately constant. Therefore, the increase in k _cat contributed to the acceleration of the apparent hydrolytic rate. The interaction of amylopectin with the surfactant was examined by a surface tension measurement, and the result confirmed the corresponding binding between the substrate and the surfactant. A fluorescence analysis due to tryptophan in BAA suggested that BAA bound to the nonionic micelles. The increase in k _cat suggested that hydrolytic catalysis at the micellar pseudophase was more efficient than that at the aqueous pseudophase. The enhancement of the catalytic rate contributed to the effective removal of food stains containing starch when BAA was added with Brij 35 in a laundry detergent washing test.