酯基Gemini型季铵盐表面活性剂与AEO9的复配体系研究

通过考察酯基Gem in i型季铵盐表面活性剂Ⅱ-10-n(n=3,4,6)与十二烷基聚氧乙烯(9)醚(AEO9)的复配体系的表面活性发现,复配体系的临界胶团总浓度CMCT值介于二元复配体系中各组分的临界胶团浓度CMC01和CMC02之间。当溶液中含有少量AEO9时(在溶液体相中的摩尔分数α2=0.1),混合胶团中AEO9的摩尔分数均已超过0.35;随着溶液中AEO9含量的增大,混合胶团中逐渐以AEO9为主成分。复配体系的混合胶团聚集数介于二元复配体系中各组分的胶团聚集数之间,随着溶液中酯基Gem in i型季铵盐表面活性剂含量的增加,混合胶团聚集数逐渐减少。     

阴阳离子复配体系的表面活性及应用性能

研究了2种具有不同EO加合数的阴离子表面活性剂壬基酚聚氧乙烯醚丙基磺酸钠[NPSO-n(n=5,8)]与阳离子表面活性剂十二烷基二甲基苄基氯化铵(1227)复配体系的表面活性和应用性能、混合吸附层和混合胶束的组成及相互作用参数(βs和βm)。结果表明:复配体系的临界胶束浓度(cmc)较单一组分低得多,并随1227摩尔分数的增加而降低,当1227的摩尔分数达0.5时,cmc最低,比单一表面活性剂的cmc低2个数量级;并且混合胶束和混合吸附层中的分子相互作用较强,混合胶束和混合吸附层中阴阳离子表面活性剂的摩尔比接近1∶1;2种复配体系均具有比单一阴离子表面活性剂更好的泡沫、润湿和乳化性能。     

双子两性磷酸酯/十二烷基硫酸钠复配体系的表面活性

研究了阴离子表面活性剂十二烷基硫酸钠(SDS)和双子两性磷酸酯表面活性剂(C12GP)的形成胶束能力和降低表面张力能力的协同作用,发现C12GP与SDS摩尔比为4∶1时增效作用显著.考察了无机盐、醇对复配体系表面活性的影响.结果表明:加盐能够提高表面活性;短链脂肪醇作为添加剂应用于复配体系后,当混合表面活性剂的浓度较低时,其临界胶束浓度(ccm)比直接使用混合表面活性剂的ccm有所下降;同时长链脂肪醇作为添加剂应用于复配体系后,其ccm比直接使用混合表面活性剂的ccm下降显著.     

协同效应对复配体系表面化学性能及聚集体的影响

将N-月桂酰基谷氨酸钠(SLG)分别与十二烷基三甲基氯化铵(DTAC)和十二烷基甜菜碱(BS-12)以不同比例混合,研究不同类型表面活性剂之间的相互作用对表面化学性能和形成胶束的影响。通过规则溶液理论研究了不同摩尔比的复配体系的表面化学性质,使用激光光散射表征复配体系的胶束分布和平均流体力学半径,使用荧光探针法测量复配体系的微极性和胶束聚集数。结果表明,两个复配体系均表现出全面增效的协同作用,均在SLG摩尔分数x=50%时表现出最佳协同效应,并且阴离子表面活性剂与阳离子表面活性剂之间具有更强的作用力。SLG/DTAC复配体系在10倍cmc下趋向于产生单一稳定且小于单一组分的聚集体,SLG/BS-12复配体系在10倍cmc下形成棒状胶束,胶束大小分布较宽。     

α-烯基磺酸钠和十六烷基三甲基溴化铵复配体系的泡沫性能

利用Ross-Miles法、电导率法和光学法等研究了阴离子表面活性剂α-烯基磺酸钠(AOS)和阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)不同摩尔比复配溶液的泡沫性能。结果表明,在表面活性剂的总浓度为cT=7.8×10-3mol/L时,AOS/CTAB不同摩尔比复配溶液的发泡性能与AOS溶液基本相当,但AOS/CTAB复配能较明显地提高体系的泡沫稳定性;不同摩尔比复配溶液的泡沫稳定性顺序为:AOS/CTAB 5∶1>AOS/CTAB 10∶1>AOS/CTAB15∶1>AOS/CTAB 20∶1>AOS。     

环保型餐具洗涤剂用表面活性剂复配体系研究

表面活性剂的许多特性在单独使用时往往不能充分发挥。但当一种表面活性剂与其他表面活性剂复配时 ,溶液的物理化学性质会发生明显的变化 ,其表面活性优于各个组分的性能。从表面活性剂复配着手 ,选择阴离子型表面活性剂仲烷基磺酸钠 (SAS)、脂肪醇聚氧乙烯醚硫酸钠 (AES)和非离子型表面活性剂烷基多糖苷 (APG)进行复配实验。改变不同表面活性剂之间的配比 ,通过对临界胶团浓度 (CMC)的分析研究 ,解释了胶团的形成过程和胶团的具体组成。APG SAS、APG AES体系分子间相互作用系数 βm 为负值 ,表明它们在胶团中分子间的相互作用比同种分子间的相互作用要强 ;而且| βm|的值在 3附近 ,表明APG SAS、APG AES体系分子间存在中等强度的相互作用 ;同时在形成胶团能力方面符合增效作用判断准则 ,这些结论将有助于实际配方的确定     

四氟乙烯五聚体氧基苯磺酸钠与辛基三乙基溴化铵的相互作用

研究不同摩尔比的正负离子碳氢-碳氟表面活性剂——辛基三乙基溴化铵〔C8H17N(CH2CH3)3Br,C8NE〕与四氟乙烯五聚体氧基苯磺酸钠(C10F19OC6H4SO3Na,6201)混合溶液的表面张力,得到其临界胶束浓度(CMC)、最低表面张力(γCMC)、总饱和吸附量、不同表面张力时表面吸附层的组成;利用Gibbs-Duhem方程求得CMC处的胶团组成。采用规则溶液理论计算胶团中分子间相互作用参数(βm)以及CMC后的胶团组成。C8NE-6201复配体系的CMC明显小于单体系,这与βm负值很大相符(胶团内分子相互作用强)。但复配体系γCMC较6201单体系变化很小,这可能由于6201疏水链过长导致和C8NE复配后溶解性较差。6201自身的强疏水性使其成为表面吸附层和胶团在初始形成时的主导组分,而反电性C8NE参与提供协同作用。但是CMC后的胶团组成中6201的摩尔分数x6201m基本维持在0.6~0.7附近,说明对于CMC后胶团的形成正负电性作用占主导。     

连接基长度对GSS/TX-100复配体系表面性质的影响

研究了不同连接基的琥珀酸酯磺酸盐型双子表面活性剂(GSS)与辛基苯基聚氧乙烯醚(TX-100)复配体系(GSS/TX-100)在水溶液中的表面性质和胶团化行为,对混合胶团和表面吸附层的组成和相互作用参数进行了计算。结果发现:复配体系水溶液在形成胶团和表面吸附时无明显甚至不存在正加和增效,但是TX-100的加入可明显降低GSS的临界胶束浓度,混合胶团中TX-100占胶团的主要成分,GSS与TX-100具有较弱的相互作用,连接基较短的GSS更易形成胶束,也更易与TX-100形成混合胶束。     

十二烷基酰胺丙基磷酸酯甜菜碱的复配性能研究

在298 K,0.1 mol/L NaCl水溶液中,分别研究了十二烷基酰胺丙基磷酸甜菜碱(C_(12)-APA)/十二烷基硫酸钠(SDS)和十二烷基酰胺丙基磷酸甜菜碱(C_(12)-APA)/脂肪醇聚氧乙烯醚9(AEO_9)混合表面活性剂体系在不同摩尔比下的表面化学性质,通过常规溶液理论计算了混合体系的协同作用参数。结果表明,SDS/C_(12)-APA混合体系具有比单一表面活性剂更好的表面活性,当摩尔比n(SDS)/n(C_(12)-APA+SDS)为0.5时,混合物的协同作用最强;由SDS/C_(12)-APA和AEO_9/C_(12)-APA复配体系的微极性和胶束聚集数,可简单判定SDS/C_(12)-APA复配体系具有协同效应,而AEO_9和C_(12)-APA形成的混合体系没有协同效应,并且混合体系形成了比原来更小更稳定的胶束结构。     

琥珀酸二异辛酯磺酸钠/月桂醇聚氧乙烯醚-7混合体系在水中的溶液行为研究

研究了琥珀酸二异辛酯磺酸钠(062)和月桂醇聚氧乙烯醚-7(AEO-7)混合体系在水中的表面性质和胶团化行为,并对理想混合胶团临界胶束浓度(CMC)~(dea)和混合体系中各组分在表面吸附层和胶团中的组成、相互作用参数和热力学参数进行分析计算。结果表明,062/AEO-7混合体系在水中不存在协同效应,但是AEO-7的加入明显降低了062的临界胶束浓度,混合胶团的形成为自发过程,胶团中062与AEO-7分子具有较弱的相互作用,表面吸附层和胶团中均富含非离子表面活性剂AEO-7。     

阴阳离子表面活性剂复配体系的聚集行为

用芘(Py)荧光探针法测定了添加少量十六烷基三甲基溴化胺(CTAB)后,十二烷基硫酸钠(SDS)的临界胶束浓度(CMC)和胶束聚集数(Nm)。在一定范围内,SDS的CMC与CTAB的添加量〔x=c(CTAB)/c(SDS)〕有如下定量关系:ln〔CMC/(mmol/L)〕=0.69-10.48x。当x=1/80时,SDS的胶束聚集数为92。x=1/40时,SDS的胶束聚集数为122。SDS的胶束聚集数随着CTAB的添加量迅速增加。因此,阴阳离子混合表面活性剂作为合成介孔催化剂的模板剂,可以调控介孔催化剂的孔径大小。     

Formation mechanism for hexagonal-structured self-assemblies of nanocrystalline titania templated by cetyltrimethylammonium bromide

Hexagonal-structured self-assemblies of nanocrystalline (anatase) titania templated by cetyltrimethylammonium bromide (C(16)H(33)N(CH(3))(3)Br; CTAB) (Hex-ncTiO(2)/CTAB Nanoskeleton) were formed after mixing of aqueous solutions containing CTAB spherical micelles and titanium oxysulfate acid hydrate (TiOSO(4).xH(2)SO(4).xH(2)O) as a titania precursor in the absence of any other additives. Formation mechanism of the Hex-ncTiO(2)/CTAB Nanoskeleton was examined in terms of the reaction temperature, titania precursor/CTAB mixing ratio, surfactant type, electrostatic interaction, micelle formation and molecular component. We found that crystal growth of crystalline (anatase) titania (polymorphic crystallization) was promoted with higher temperature and lower titania precursor content in aqueous solutions. In addition, we revealed that the crystalline (anatase) titania was formed in polycation, poly(allylamine hydrochloride ([CH(2)CH(CH(2)NH(2))HCl](n); PAH), and formamide (HCONH(2)) solutions. On the other hand, no titania formation was observed in anionic systems such as sodium dodecyl sulfate (CH(3)(CH(2))(11)OSO(3)Na; SDS) and poly(sodium 4-styrenesulfonate ([C(8)H(7)SO(3)Na](n); PSSS). This indicates that hydrolysis reaction of the titania precursor is initiated by not only cations but also nitrogen atoms in molecules and polymers. Hexagonally structure was formed in only cationic surfactant micellar solutions but not in polycation solutions and formamide.     

粘度法研究邻-苯二甲酸氢钾/CTAB胶束体系的相互作用

研究了十六烷基三甲基溴化胺(CTAB)和邻-苯二甲酸氢钾在水溶液中的相互作用,考察了正丁醇对该胶束体系粘度的影响。结果表明,CTAB/邻-苯二甲酸氢钾胶束体系的相对粘度与邻-苯二甲酸氢钾和CTAB的物质的量之比(ξ)有密切的关系。当ξ由0逐渐增大时,体系的相对粘度也由1显著增大,ξ=2.0时粘度达到最大,以后又逐渐减低。正丁醇对该胶束体系粘度的影响,在盐浓度小于0.02mol/dm3时不明显,而在盐浓度大于0.02mol/dm3时体系粘度随正丁醇体积分数()的增加而迅速减少。     

Protein structural change in a mixed system of ionic and zwitterionic surfactants

The secondary structure of bovine serum albumin (BSA) in the binary surfactant system of anionic sodium dodecyl sulfate (SDS) and zwitterionic N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS) was examined at 25°C. The helicity of BSA decreased from 66% to 55% in a solution of DDAPS alone and decreased to 50% in a solution of SDS alone. However, the late addition of DDAPS reformed the helical structure of BSA, which was initially disrupted by SDS. The reformation required higher DDAPS concentrations as the initial SDS concentration increased. A maximum helicity of 63% was attained by this reformation. On the other hand, the helical structure of the protein, which was first affected by DDAPS denaturation, was also reformed to the same degree by the late addition of certain amounts of SDS. Although attention was paid to the additive order of these two surfactants to BSA, the final helicity of the protein depended on the final concentrations of these two surfactants, irrespective of the additive order. These phenomena may be attributed to the predominance of mixed micelle formation over complex formation between BSA and the two surfactants below the mixing ratio of DDAPS ([DDAPS]/([DDAPS]+[SDS])) of 0.95. The predominance of the mixed micelle formation distinctly appeared in mixing ratios between 0.50 and 0.75. In this range, the mixed micelle formation accompanied the removal of dodecyl sulfate (DS) ions bound to BSA upon the late addition of DDAPS to the BSA-SDS mixture, whereas, upon the late addition of SDS to the BSA-DDAPS mixture, the mixed micelle formation was accelerated by the coexistence of DDAPS which disturbed the binding of DS ions to the protein.     

Rheo-kinetics of bovine serum albumin in catanionic surfactant systems

The effects of catanionic surfactant systems consisting of mixtures of cationic cetyltrimethylamonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) on the rheological properties and kinetics of bovine serum albumin (BSA) were investigated. The ionic strength of the solution was varied by using different mixing ratio of SDS and CTAB. Gelation curves observed in dynamic viscoelastic measurements were fitted with gelation kinetics models to describe the gelation under isothermal and non-isothermal conditions. Overall, the gelation of BSA in cationic-rich solutions was found to be more energetically favorable when compared with BSA solvated in anionic-rich solutions. Consequently, highest gel temperature (T_gel) and time (t_gel) were observed for anionic-rich solutions with SDS/CTAB molar ratio of 4.0 (i.e., SDS/CTAB=4.0), while lowest gel temperature and time were found for cationic-rich solutions with SDS/CTAB molar ratio of 0.25 (SDS/CTAB=0.25). BSA in equal molar ratio of the mixed surfactants (SDS/CTAB=1.0) showed a gel temperature and time in the halfway between the anionic and cationic-rich regions. Interestingly, under isothermal and non-isothermal conditions, BSA in equimolarly mixed and anionic-rich solutions showed a heat-dependent protective effect against thermal denaturation and gelation. The protective effect on BSA gelation in equimolar and anionic-rich solutions was diminished by increasing the catanionic concentration under non-isothermal conditions, while under isothermal conditions, protective effect on BSA gelation increased with catanionic concentration. On the other hand, cationic-rich solutions did not protect BSA from thermal denaturation and gelation, and therefore the gelation rate increased with catanionic concentration in all heating conditions examined.     

Synergistic Rheological Behavior of Mixed Micellar Solutions of Surfactin and Cetyl Trimethyl Ammonium Bromide

This paper investigated the rheological properties of novel viscoelastic thickening micelle system formed by surfactin and cetyl trimethyl ammonium bromide (CTAB). The total concentration of surfactin and CTAB was maintained at 12 wt%. The rheological behavior of the surfactin/CTAB synergistic micelles with different mass ratio and pH was systematically investigated. For the surfactin/CTAB micellar system with a mass ratio varied from 1/11 to 4/8, the viscosity of the micelles rose to a maximum with increasing pH, and then decreased with a further increase of pH. When the mass ratio was surfactin:CTAB = 2.5:9.5 (pH 5.72), the maximum viscosity of the micelle solution reached 8170 mPa. s. Meanwhile, the viscosity curve of the surfactin/CTAB systems was described by the nonlinear co-rotational Jeffreys model. This work sets a rheological foundation for the application of surfactin/CTAB systems. The thixotropic loop area of the micelles was basically zero. Through viscoelasticity measurements, the results demonstrated that the appropriate surfactin/CTAB mass ratio would favor the stability of the network structure of the synergistic thickening system. The value of G″(viscous modulus) is always higher than the value of G′ (elastic modulus).     

Effect of cefoperazone sodium on the physicochemical properties of surfactants

The effects of cefoperazone sodium (CS), a pharmaceutical compound, on the critical micelle concentration (CMC) of surfactants with different charges [cetyl trimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Triton X-100], the cloud point of Triton X-100, and the Krafft temperatures of SDS and CTAB were studied. The interaction of CS with differently charged surfactants was determined by ultraviolet and fluorescence spectrophotometry. The results show that with increasing CS concentration, the Krafft temperature increases and the CMC decreases in the SDS/H₂O system, whereas the opposite results are obtained in the CTAB/H₂O system. Both the cloud point and the CMC of Triton X-100 increase with the addition of CS. The above results are attributed to the different micellar interactions between CS and surfactants with different charges.     

In vitro solubilization of antibiotic drug sulfamethazine: An investigation on drug–micelle aggregate formation by spectroscopic and scattering techniques

Micellar solubilization has been used extensively for the dissolution of sparingly soluble drugs for effective drug delivery. Apart from improving the solubility and bioavailability, micelles can help reduce toxicity and improve permeability in the system. In this article, solubilization of a well-known antibiotic, sulfamethazine (SMZ) upon micellization, is studied by employing various spectroscopic and scattering techniques like, ultraviolet–visible, fluorescence, small angle neutron scattering (SANS), and zeta potential (ZP) studies. The size(s) and charge(s) of the micelles were monitored by SANS and ZP. A positively charged/cationic surfactant, cetyl trimethyl ammonium bromide (CTAB) and a negatively charged/anionic surfactant, sodium dodecyl sulfate (SDS) are used for micelle formation. Regardless of the surfactant type, the solubility of SMZ increases linearly with the increase in the surfactant concentration, as a result of association between the drug and micelles. However, the solubility of SMZ is found to be better with CTAB than SDS. Upon interaction with SMZ, we observed that the critical micelle concentration of CTAB occurred at a lower concentration than that of SDS surfactant. As fitted in the ellipsoidal core–shell model, SANS results also show the formation of charged micelles. This comparative study can help us to select an appropriate medium for SMZ solubilization to improve selective drug delivery in biomedical applications.     

DMSO对CTAB胶束形成影响的实验研究

通过表面张力法和负染色电镜法分别从两个方面研究了二甲基亚砜 ( DMSO)对十六烷基三甲基溴化铵 ( CTAB)胶束形成的影响。研究结果表明 ,DMSO的加入使得 CTAB水溶液表面张力曲线出现双 CMC;从负染色电镜实验可以观察到 ,在 DMSO影响下 CTAB体系的第二 CMC区域出现了棒状胶束     

油水比对阴离子型微乳液相行为的影响

微乳液由水、油、盐、表面活性剂及助表面活性剂组成,其相行为及增溶情况受各组分的影响。研究发现,在SDBS（SDS、SLS）/航空煤油/水/正丁醇/氯化钠体系中,随着NaCl含量的不断增多,微乳液体系发生Winsor Ⅰ型→Winsor Ⅲ型→Winsor Ⅱ型的相态转变。固定水的用量,通过油扫实验不断改变体系中的油水比,利用相图研究油水比对微乳液相行为的影响,并通过冷冻电镜对不同相态下微乳液的微观形貌进行了表征。随着油水比的增加,在低盐度下,体系由胶团溶液转变为Winsor Ⅰ型;而在高盐度下,体系发生由胶团溶液→Winsor Ⅱ型→Winsor Ⅲ型→Winsor Ⅰ型的相态转变。盐度一定时,微乳液的中相形成及消失所需的油量会随着表面活性剂浓度的增多而增多,且三种表面活性剂中,表面活性剂的增溶能力的大小顺序为SDBS>SDS>SLS,对煤油的敏感程度顺序为SLS>SDS>SDBS。