Novel glucose-derived gemini surfactants with a 1,1′-ethylenebisurea spacer: Preparation, thermotropic behavior, and biological properties

In the search for environmentally safe surfactants made from inexpensive and renewable sources, the interest has mainly been focused on new saccharide derivatives. This report describes the synthesis of newly designed nonionic gemini compounds comprising two reduced sugar headgroups, two alkyl tails, and a 1,1′-ethylenebisurea entity as the spacer linking two amphiphilic glucose-derived moieties. Thus, the series of N,N′-bis[(3-alkyl-3-deoxy-d-glucitol)ureido]ethylenediamines (bis(C_nGT), with C_n=n-C₉H₉, n-C₆-H₁₃, n-C₈H₁₇, n-C₁₀H₂₁, or n-C₁₂H₂₅), were prepared using a convenient procedure starting from easily accessible reagents such as d-glucose, n-alkylamines, urea, and ethylenediamine. Their structure and purity were confirmed by means of elemental analysis, electrospray ionization mass spectrometry, and ¹H and ¹³C nuclear magnetic resonance spectroscopy. Additionally, the present contribution introduces selected properties of these surfactants, including their thermotropic behavior and biological properties. The presence of two phase transition points, determined using the differential scanning calorimetry method, indicates liquid-crystalline mesophase formation upon heating. Furthermore, using the closed-bottle test (OECD Guideline 301D) as well as the biological oxygen demand test for insoluble substances for biodegradability measurements, it has been concluded that the tested glucose-derived gemini structures achieve more than 60% biodegradation after 64–75 test days. All tested surfactants were practically nontoxic to bacteria, yeast, and molds. Owing to their fitting aggregation ability as well as their nontoxicity, they constitute an interesting group of surfactants for various applications.     

A correlation for the estimation of critical micellization concentrations and temperatures of polyols in aqueous solutions

An empirical correlation is presented for the estimation of critical micellization concentrations (CMC) and critical micellization temperatures (CMT) for poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers in aqueous solutions. The CMC and CMT are expressed as a function of the polyol molecular weight, composition, and temperature (for CMC determination) or concentration (in the case of CMT). The correlation was developed from experimental CMT data for a set of 12 polyols that covered a wide range of molecular weights (2900–14600) and poly(ethylene oxide) contents (30–80 wt%) and is based on a simple expression for the standard free energy of micellization. Such a correlation should be useful to practitioners of the field as it allows easy prediction of CMC and CMT for a wide range of polyols with a minimal number of input parameters.     

Rheological investigation on the interaction of a fluorocarbon and hydrocarbon comodified PAA with a nonionic surfactant in the presence of salt

Derivatives of poly(acrylic acid) hydrophobically modified with hydrocarbon group (PH) and both hydrocarbon and fluorocarbon groups (PHF) were synthesized and the association of these copolymers with nonionic surfactant Np7.5 in 0.1M NaCl aqueous solutions was investigated. Microdomains formed in the system of PHF/Np7.5 consist of both hydrocarbon (HC) and fluorocarbon (FC) groups, which is similar to Winnik's mixed model (Kujawa, P. C.; Goh, C. E.; Calvet, D.; Winnik, F. M. Macromolecules 2001, 34, 6387). The hybrid structure of FC and HC groups on the polysoap backbone was proposed to interpret why the miscibility between FC and HC groups was improved. The effect of salt and Np7.5 on PHF and PH solutions was carried out and compared. When the concentration of Np7.5 reaches 0.1 wt % in 0.3 wt % polymer solution especially, physical network junctions become greatly stabilized. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1279–1285, 2004     

Synthesis and surface properties of new dicephalic saccharide-derived surfactants

A new group of nonionic dicephalic saccharide amides, N-dodecyl-N,N-bis[(3-d-gluconylamido)propyl]-amine, N-dodecyl-N,N-bis[(3-d-glucoheptonylamido)propyl]-amine, and N-alkyl-N,N-bis[(3-lactobionylamido)propyl]amines (alkyl: n-C₁₂H_25′ n-C₁₆H_33′, n-C₁₈H₃₇) were synthesized and characterized. Their structure and purity were confirmed by means of ¹H and ¹³C nuclear magnetic resonance analysis and electrospray ionization mass spectrometry. Carbon spectra were verified using a DEPT experiment. The surface and interfacial properties such as critical micelle concentration (CMC), standard free energy of micellization, ΔG _CMC, surface excess concentration, Γ_CMC, and surface area demand per molecule, A _CMC, were determined. The tertiary nitrogen atom seems to have a surprising effect on surfactnat packing at the interface.     

微乳液的增溶、相态及微乳液/中空纤维膜萃取钕

通过考察非离子型微乳液体系（OP-4+OP-7）/ 苯甲醇/D2EHPA/煤油/盐酸中的混合表面活性剂OP-4［壬基酚聚氧乙烯（4）醚］和OP-7［壬基酚聚氧乙烯（7）醚］配比、盐酸浓度、温度和NaCl对盐酸增溶量的影响以及D2EHPA［二（2-乙基己基）磷酸］和盐酸浓度对体系相态的影响，制备了适合作为液膜分离介质的微乳液体系，同时提出了新的膜萃取过程：微乳液/中空纤维膜萃取，并用于稀土钕的萃取.结果表明，微乳液中盐酸的增溶量随混合表面活性剂HLB值以及盐酸浓度的增大而增大，随温度的升高、NaCl浓度的增大而减小;D2EHPA的加入有利于WinsorⅡ体系的形成;盐酸浓度小于6 mol•dm^-3时也可形成WinsorⅡ体系，而盐酸浓度为7 mol•dm^-3和8 mol•dm^-3时则分别形成WinsorⅢ体系或WinsorⅠ体系;将W/O非离子型微乳液通过中空纤维膜从浓度为300 mg•dm^-3的料液中萃取钕时，采用3个中空纤维膜器串连一次萃取即可使萃取率达95.3%，内相富集倍数18.1.该新膜萃取体系同时具有液膜与固膜萃取的优点，不需进行反萃操作.     

O/W型微乳的制备及其对皮肤刺激性的检测

通过拟三元相图微乳区大小筛选微乳制备组分的较佳配比,电导率法检测微乳的类型,研究了以十四酸异丙酯、十六酸异丙酯、大豆油为油相,吐温80和卵磷脂质量比以及乙醇、1,2-丙二醇为助表面活性剂对微乳形成区域的影响。结果表明:选用十六酸异丙酯作油相,吐温80和卵磷脂质量比为2∶1作混合表面活性剂,乙醇为助表面活性剂时能形成较大的O/W型微乳区。经动物实验证实能够满足药用无毒、无刺激性要求,适合作为透皮吸收药物载体。     

改性聚乙烯醇水性憎水剂的研究

研制了一种以聚乙烯醇、2种非离子表面活性剂——Span-20和Tween-20、水溶性缓蚀剂等为原料的水性憎水剂;考察了聚乙烯醇的聚合度和醇解度、2种非离子表面活性剂之间的配比、聚乙烯醇含量、乳化剂含量、水溶性缓蚀剂含量、预处理和后处理工序等因素对憎水剂憎水效果及稳定性的影响。试验结果表明,该憎水剂处理的钢材试样的各项指标优良,有望替代某些溶剂型憎水剂。     

改性松香基非离子表面活性剂的合成及性能

以松香和聚甘油为原料,合成了一种松香基非离子表面活性剂,得到不同甘油聚合度的产物。得到的松香基非离子表面活性剂的表面物化性能为:表面张力44 2～49 6mN/m;临界胶束浓度8 0×10-4～25 6×10-4mol/L;钙皂分散指数13 5%～21 5%;界面张力11 7～18 9mN/m;乳化力44～85s;泡沫性能6～46mm;润湿力87～121s。并对甘油聚合度和产物表面性能的关系进行了考察。     

新型非离子水性聚氨酯表面活性剂的制备及性能

采用甲苯-2,4-二异氰酸酯(TDI)、蓖麻油和聚乙二醇(PEG)等为主要原料,通过逐步聚合得到一种新型非离子水性聚氨酯表面活性剂,并利用红外光谱对其结构进行了表征。实验结果表明,当蓖麻油∶TDI∶PEG-4000=1∶9∶11时,采用依次加入蓖麻油、TDI、PEG的加料方式,能够合成得到综合性能较好的非离子水性聚氨酯表面活性剂。对该表面活性剂在水相中的表面活性进行了测试,结果表明,所制得的非离子水性聚氨酯表面活性剂的临界胶束浓度约为22 g/L,水溶液的最低表面张力可达53 mN/m。     

Brij97／IPM／蔗糖溶液体系的相行为和流变性质

测定了Brij97／IPM／蔗糖溶液体系在37℃相图,并利用TA－2000ex旋转流变仪测定了组成和温度对Brij97／IPM／蔗糖溶液体系流变性质的影响,结果表明,当蔗糖溶液含量一定时,随Brij97／IPM比例的增大体系依次形成六角状液晶和层状液晶。动态流变性质测量表明,该两种液晶均显示较高的弹性性质。