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1.
阿尔法凝胶作为一种特殊的液晶结构,能够在清洁或调理皮肤的过程中给皮肤毛发提供更好的湿润感和调理性。由于阿尔法凝胶结构的搭建传统方法需要不少于14个碳原子的烷基表面活性剂,其实际应用一直受到限制。提供了一种由月桂酰肌氨酸钠作为烷基碳链为12个碳原子的氨基酸型表面活性剂搭建阿尔法凝胶的方法,并对其产物进行结构表征和分析。  相似文献   

2.
A simple and accurate method for evaluating skin roughness caused by surfactants has been developed. The intensities of the roughness have been correlated with the chemical structures of surfactants by using this method. Results indicated in general, that the surfactants having 12 carbons in their alkyl chain gave the skin more roughness than did those which had more or less than 12. The results obtained by this method were in good agreement with those from the immersion method usually used.  相似文献   

3.
Modification of the molecular structure of surfactants is an effective method for exploring their self‐assembly. A double‐tailed quaternary ammonium surfactant with a protrudent head group, namely 2‐octyldecyltrimethylammonium bromide (2‐ODTAB) was synthesized, and the solution properties were investigated by surface tension, dynamic light scattering, and cryogenic TEM. A comparative study was also performed on the traditional double‐tailed homologue surfactants dioctyldimethylammonium bromide (8–8), didecyldimethylammonium bromide (10–10), and didodecyldimethylammonium bromide (12–12). The results showed that 2‐ODTAB was more effective at lowering surface tension and in forming stable vesicles than traditional double‐tailed surfactants with similar alkyl chain length. The reason is attributed to the improved structure of 2‐ODTAB, in which the two alkyl tails are connected to the ionic head group by one carbon atom. This structure imparts more freedom to the head group and thus favors formation of more stable aggregates at low concentration. In addition, the lower limit of the alkyl chain length of the double‐tailed surfactants for forming stable vesicles was illustrated.  相似文献   

4.
1H NMR and thin layer chromatography (TLC) were applied to analyze the component of two series of synthesized sulfonated Gemini surfactants with different spacer lengths (2, 4, and 6 carbons) and hydrophobic chain lengths (9, 12 carbons). Gemini surfactants were prepared by reacting alkylphenol with alkyl halide followed by sulfonation with chlorosulfonic acid. The influence of the molar ratio of alkyphenol to alkyl halide on the mono‐ to diether ratio was investigated and the results indicated that the molar ratio is a key factor to minimize impurities in the target material, due to the high reactivity of alkyl halide. In addition, the results showed that alkyl halide with a shorter spacer group length required a higher molar ratio of alkyl halide to alkylphenol. To synthesize the intermediate Gemini product with 80 % diether content, the molar ratios were optimized using n(alkylphenol):n(1,6‐dibromohexane) = 1:0.55, n(alkylphenol):n(1,4‐dibromobutane) = 1:0.7, and n(alkylphenol):n(1,2‐dibromoethane) = 1:2.5, respectively.  相似文献   

5.
The aqueous self-assembly behavior of two homologous series of poly(ethylene oxide) (PEO)-containing nonionic surfactants based on a C10-Guerbet hydrophobe is reported. The two families of surfactants, alkyl ethoxylates and alkyl alkoxylates, are commercially available from BASF under the trade name Lutensol® XP-series and XL-series, respectively. The latter incorporate propylene oxide (PO) units in the surfactant chain. Dye solubilization was used to determine the critical micellization concentration (CMC) of each surfactant at 22 and 50 °C. The PO-containing alkyl alkoxylates displayed lower CMC values, which were also more sensitive to temperature. The Gibbs free energy, enthalpy, and entropy of micellization were computed from the CMC data and used to identify the contribution of each surfactant moiety (alkyl chain, PO unit, and PEO block) in controlling the CMC. The micellization properties are compared with compositionally similar surfactants with linear alkyl chains, yielding information about the effects of the Guerbet alkyl chain on micellization. Isothermal titration calorimetry was also used to characterize the CMC and enthalpy of micellization which generally compare well with the dye solubilization results. Cloud point data reveal nonmonotonic relationships for the Lutensol® surfactants with respect to composition, unlike linear alkyl chain surfactants. Finally, dilute solution viscosity measurements performed on some Lutensol® surfactants show a change in the slope, suggesting a structural change that tends to be more pronounced for surfactants with longer PEO blocks. The data presented herein enhance the understanding of surfactant structure–property relationships required for industrial formulation.  相似文献   

6.
A family of phosphated alkyl oligoglucoside surfactants was prepared by reacting alkyl oligoglucosides with phosphorus oxychloride. The alkyl oligoglucosides were obtained by an usual method in which the glucose is reacted with a fatty alcohol containing 10–18 carbon atoms. These novel phosphated surfactants have been found to exhibit good surface tension, foaming and wetting power. The critical micelle concentration was found to increase with the length of hydrocarbon chain of the surfactant. The surface excess concentration and the interfacial area per surfactant molecule are reported. These phosphated surfactants also exhibit a good performance to improve the whiteness and wetting of cotton fabrics in a hydrogen oxide bleaching system, and they are also found to be more biodegradable than conventional surfactants.  相似文献   

7.
重点介绍了离子液体表面活性剂的熔点与结构的关系。阳离子母体结构越不对称熔点越低,烷基链长增加熔点稍有提高;对阴离子型离子液体表面活性剂,阳离子的半径越大,其熔点越低;双子和Bola型离子液体表面活性剂比单疏水基离子液体表面活性剂的熔点高。室温呈液态的离子液体表面活性剂一般为黏稠液体,密度比一般有机溶剂大,在1 g/cm3左右,其表面张力为25~35 mN/m。  相似文献   

8.
Micellization of four cationic quaternary ammonium gemini surfactants, having a diethyl ether or hexyl spacer with the alkyl chain lengths of 12 and 16 carbon atoms, was studied using isothermal titration microcalorimetry (ITC) and electrical conductivity measurements in the temperature range from 298.15 to 313.15 K. In this temperature range, where surfactants are normally applied, the temperature almost does not influence the critical micelle concentration (CMC) and the degree of micelle ionization (α) values of the gemini surfactants, and the replacement of a hexyl spacer by a diethyl ether spacer leads to a slight decrease in the CMC and α values. However, as the alkyl chain length increases from 12 to 16 carbon atoms, the CMC values significantly decrease from 0.99–1.19 mM to 0.020–0.057 mM. In particular, the enthalpy of micellization (ΔHmic ) and the associated thermodynamic parameters show obvious changes with varying temperature and molecular structure. ΔHmic becomes much more exothermic at higher temperature or for the surfactants with a more hydrophilic spacer. Moreover, the heat capacity change of micellization (ΔC P, mic ) is less exothermic for the surfactants with a more hydrophilic spacer or a longer alkyl chain. The enthalpy–entropy compensation data show that the surfactants with longer alkyl chains have a more stable micellar structure.  相似文献   

9.
以低含氢硅油、α-烯丙基聚醚等为原料,经烷基封端、硅氢加成等反应制备了封端型聚醚改性聚硅氧烷非离子表面活性剂,讨论了温度、催化剂以及聚醚结构等对封端率的影响。结果表明,采用以氢氧化钠和碳酸钠制备的缓释性复合碱为催化剂的一步法封端工艺,在反应温度25~65℃条件下,α-烯丙基聚醚的烷基封端率可达85%以上。封端型聚醚改性有机硅表面活性剂可用于单组分聚氨酯密封胶、高回弹和软质聚氨酯泡沫的泡沫稳定剂。  相似文献   

10.
A series of polyethylene glycol-linked Gemini fatty alcohol phosphate surfactants (GFAP) were prepared with long chain n-alkanol (C = 8, 12, 16, 18), polyethylene glycol (PEG-200, PEG-400, PEG-600, PEG-800, PEG-1000) and phosphorus oxychloride (POCl3). The structure of the prepared surfactants was characterized by Fourier transform infrared spectrometer (FT-IR). The surfactants were employed for the modification of chrome-tanned leather. The morphological changes of chrome-tanned leather and modified chrome-tanned leather were observed by scanning electron microscopy (SEM). The relationship between the alkyl chain length and molecular weight of the PEG and the hydrophobicity, softness, mechanical strength of modified chrome-tanned leather was also discussed. The experimental results showed that the mechanical strength and softness of modified chrome-tanned leather were enhanced with an increase of alkyl chain length, while the hydrophobicity, mechanical strength and softness were decreased with an increase of molecular weight of the PEG. The hydrophobicity, mechanical strength and softness of modified chrome-tanned leather were optimized for an alkyl chain length of 16. Therefore, 16–200 Gemini phosphate surfactants with an alkyl chain length of 16 and a PEG molecular weight of 200 have a good comprehensive modification effect on Chrome-tanned leather, the tensile strength, tear strength and softness of modified chrome-tanned leather are 57.07 N mm−2, 79.49 N mm−1, 9.73 mm, respectively.  相似文献   

11.
A series of novel surfactants have been prepared by the reaction of hydrolyzed soy protein with alkyl succinic anhydride. These novel surfactants exhibit excellent surface active properties including surface tension, foaming, emulsifying, wetting power, and buffer ability. The hydrophobic modified protein exhibit more surface activity than original protein because of the enhanced hydrophobicity in structure. The increase in hydrophobic chain length leads to an increase in the surface activity. The surface tension reduction is correlated to the hydrophobicity of the modified molecule, which was determined by a fluorescent probe. In application on cotton bleaching procedures, these surfactants increase the whiteness of fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3498–3503, 2006  相似文献   

12.
Three cationic surfactants containing amide groups were prepared by quaternization of dimethylaminopropylamine with benzyl chloride. FTIR and 1H-NMR spectroscopy were used to confirm the chemical structure of the prepared cationic surfactants. The surface parameters were estimated using surface tension measurements at three different temperatures. The prepared cationic surfactant showed a lower CMC than conventional cationic surfactants. Thermodynamic parameters of adsorption and micellization depend mainly of alkyl chain length and temperature. The adsorption process is more favorable than micellization. The biological activity of the three surfactants was estimated using inhibition zone showing that amidoamine cationic surfactants have good activity and the surfactants C12Bn is the most effective one.  相似文献   

13.
A series of disodium alkyl monoglucoside citric monoesters (AG‐EC) were synthesized with an indirect method using glucosides, lauryl/decyl/octyl alcohol and citric acid. The structure and composition of the synthesized surfactants were defined by Fourier transform infrared spectroscopy (FTIR) and liquid chromatography–mass spectrometry (LC/MS). The surface properties, foaming ability and wetting ability were investigated. AG‐EC surfactants exhibited excellent water solubility which eliminated the defect of long‐chain alkyl glucoside. All three surfactants showed high surface activities. AG12‐EC and AG10‐EC showed remarkable foaming abilities in distilled water and hard water. Aqueous solutions of AG‐EC surfactants spread slowly on a parafilm surface.  相似文献   

14.
Twenty-six alkyl, alkenyl, cycloalkyl, and substituted alkyl 2-cyanoacrylates were synthesized in the pure state. The purity was determined by gas-liquid chromatography, and a correlation between the log retention time and the number of carbons in the compounds within the homologous series was deduced. Their physical properties such as parachor and molar refraction were determined and the data were fitted to a linear relation to the number of carbons present in the ester within a homologous series of cyanoacrylates. The tensile strengths of the 2-cyanoacrylate bonds between various metal surfaces are also presented. The tensile strength of the adhesive bonds gradually decreased with an increase in the alkyl chain length, beginning from ethyl cyanoacrylate.  相似文献   

15.
A number of surface-active alkoxynaphthalenesulfonates, ROC10H6SO3Na, have been synthesized, and some of their surface properties determined. The synthesis involved a Williamson reaction of an alkyl halide with the disodium salt of a naphtholsulfonic acid. The Krafft points, surface tension-log concentration curves, critical micelle concentrations, and areas/ molecule at the air/liquid interface of the purified and characterized alkoxynaphthalenesulfonates have been determined. Their surface areas/molecule indicate that the oxynaphthalenesulfonate portion of these compounds is lying flat in the air/liquid interface with the alkyl group vertical to the plane of the naphthalene. Their surface tension reduction efficiencies and critical micelle concentrations indicate that an α- or β-naphthoxy gruop in the hydrophobic portion of the molecule at 60 C is equivalent to about eight carbons in a straight alkyl chain and about six carbons at 25 C. These compounds, in contrast to other surfactants without an aryl ether linkage in the molecule, show greater efficiency and effectiveness in surface tension reduction with increase in temperature. Abstracted in part from a thesis for the Master of Arts degree presented by Chang-Chin Kwan to the graduate faculty of Brooklyn College, City University of New York, May 1977.  相似文献   

16.
N-烷基苯并咪唑阳离子表面活性剂的合成及性能   总被引:2,自引:0,他引:2  
以苯并咪唑、不同链长的卤代烷烃、硫酸二甲酯为原料,合成了几种烷基苯并咪唑阳离子表面活性剂。通过IR1、HNMR对产物结构进行表征,测定了所得产物的表面活性和发泡性能,并计算出产物的饱和吸附量及饱和吸附面积。结果表明,合成的N-辛基、癸基、十二烷基、十四烷基苯并咪唑阳离子表面活性剂的最低表面张力随烷基链增长而降低,但N-十六烷基苯并咪唑阳离子表面活性剂的最低表面张力却高于十四烷基苯并咪唑阳离子表面活性剂;合成的表面活性剂中,十二烷基苯并咪唑阳离子表面活性剂的发泡性能较佳,但所有的表面活性剂的泡沫稳定性均较差。  相似文献   

17.
Bis(sulfonate) types of amphipathic compounds with three long- chain alkyl groups were prepared by the reaction ofN- (long- chain acyl)diethanolamine diglycidyl ethers with long- chain fatty alcohols, followed by the reaction with propanesultone. The diglycidyl ethers were easily obtained from the correspondingN- acyldiethanolamines and epichlorohydrin in the presence of a phasetransfer catalyst. The same types of compounds with two longchain alkyl groups were also prepared from Nacetyldiethanolamine according to similar procedures. All these new double- or triple- chain surfactants were soluble in water and showed much better micelle forming and ability to lower surface tension than general types of single- chain surfactants with one sulfonate group. The critical micelle concentration (CMC) and γCMC values of the triple- chain compounds were still much smaller than those of the corresponding double- chain compounds with two common alkyl groups. The efficiency of adsorption at the water/air interface (pC20) of these surfactants was very high. Their foaming properties, wetting ability toward a felt chip, and lime- soap dispersing ability were measured. To whom correspondence should be addressed at Department of Applied Chemistry, Faculty of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565, Japan.  相似文献   

18.
The membrane proteins (MP) α-synuclein (ASYN) and bacteriorhodopsin (BR) were readily incorporated into bicontinuous microemulsions (BμEs) formed by two microemulsion systems: water/heptane/Aerosol-OT (AOT)/CK-2,13 and water/dodecane/sodium dodecyl sulfate (SDS)/1-pentanol. (CK-2,13 is an alkyl ethoxylate possessing two alkyl tail groups of carbon chain length 2 and 13 and an average degree of ethoxylation of 5.6.) MP were encapsulated in BμEs through preparation of Winsor-III systems at optimal salinity, with the anionic surfactants AOT and SDS providing the driving force for extraction. Dissolution of ASYN in BμEs greatly increased the former's α-helicity, similar to ASYN's behavior in the presence of biomembranes, while BμE- and vesicle-encapsulated BR possessed similar secondary structure. Small-angle neutron scattering (SANS) results clearly demonstrated the direct interaction of MP with the surfactants, resulting in a decrease of surface area per volume for surfactant monolayers due to decreased surfactant efficiency. The SANS signal for ASYN was isolated through the use of neutron contrast matching for the surfactants through partial deuteration of water and oil, one of the first reports of contrast matching for BμEs in the literature. The SANS results of the contrast-matched sample reflected similar aggregation for ASYN in BμEs as was reported previously for vesicles and SDS solution. This study demonstrates the potential use of BμEs as MP host systems for conducting biochemical reactions such as the conversion of sunlight into adenosine triphosphate by BR and studying the fundamental behavior of MP, such as the role of ASYN dysfunction in Parkinson's disease, as well as for isolation and purification of MP via Winsor-III-based extraction.  相似文献   

19.
表面活性剂驱油体系中效率与效能定义的应用   总被引:1,自引:0,他引:1  
作者重新界定了效率和效能定义的内涵,并将之应用于驱油用表面活性剂烷基苯磺酸盐降低油水界面张力的表征;通过试验和计算。认为效率和效能可以作为评价和筛选驱油用表面活性剂的两个标尺来使用;而表面活性剂亲油基的碳链长度和亲油基的支化是影响效率和效能的主要结构因素。  相似文献   

20.
烷基四甲基胍双子表面活性剂的合成与性能   总被引:1,自引:1,他引:0  
以十二烷基伯胺和四甲基脲为原料合成了十二烷基四甲基胍及其盐酸盐.后者再与环氧氯丙烷反应制备了十二烷基四甲基胍双子阳离子表面活性剂,通过IR和~1HNMR鉴定了其结构,并考察了其性能.结果表明,十二烷基四甲基胍双子表面活性剂的临界胶束浓度(cmc)为2.5×10~(-4)mol/L,γ_(cmc)为28.5 mN/m,其表面活性明显高于单十二烷基胍盐酸盐.最后以十二烷基四甲基胍双子表面活性剂为模板剂制备了纳米SiO_2粒子.  相似文献   

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