Synthesis and Surface Activity of Novel Triazole—based Cationic Gemini Surfactants

Gemini surfactants, which contain two hydrophilic groups and two hydrophobic groups in the molecule, are considered as a new generation of surfactants. These surfactants are about 3 orders of magnitude more efficient at reducing surface tension and more than 2 orders of magnitude more efficient at forming micelles than conventional surfactants1. During recent years, many gemini surfactants have been synthesized, and a considerable number of investigations have been reported on their unusua…     

Novel Piperazine-based Gemini and Bola Surfactants

Gemini surfactants, containing several hydrophilic and hydrophobic groups in the molecules, are considered as a new generation of surfactants. It is extensively used in both material science and biotechnology. Bola-amphiphiles generally contain two ionic …     

Synthesis of Hydrophobically Modified Poly（acrylic acid） gels and Interaction of the gels with Cationic／Anionic Surfactants

Poly(acrylic acid)(PAA) gel network with only chemical crosslinking and hydorophobically modified PAA(HM-PAA)gels with both chemical and physical crosslinking were synthesized by radical polymerization in tert-butanol,using ethylene glycol dimethacrylate (EGDMA) as crossliker,and 2-(N-ethylperfluorooctanesulfoamido)ethyl methacrylate (FMA),stearyl acrylate (SA) or lauryl acrylate (LA) as Hydrophobic comonomer respectively.The effcet of the fractions and the species of the hydrophobes on swelling properties of HM-PAA gels and the interaction of gels and surfactants were studied.The results showed that the swelling ratio of HM-PAA gels exhibited a sharp decrease with increasing hydrophobic comomomer comcentration,Which Could be sacribed to the formation of strong hydrophobic association among hydrophobic groups.It was proved that two kinds of binding mechanisms of surfactan/gel and different kinds of hydrophobic clusters existed in gels containing both physical and chemical networks.     

Molecular Exchanging Energy of Anionic／Cationic Surfactants System on the Surface of Solution

In order to study synergism of the mixed surfactants system with molecular exchanging energy ( ε ), the Lennard-Jones formula has been firstly introduced to evaluate the ε of the mixed system, CH3(CH2)nOSO 3^- /CH3(CH2)nN^ (CH3)3, directly from their molecular structure. The comparison of the calculated and the observed results showed that this method is practical.     

Synthesis of γ-Substituted Alcohol with Polymer-bound Amide

With solid phase organic synthesis method(SPOS), polymer-bound N-enoylprolinol(4) was prepared by the attachment of N-enoylprolinol(3) to Merrifield resin and was used for asymmetric Michael additions for the first time. The enantiomeric excess obtained by this method is increased as compared with that obtained by the corresponding solution phase reactions.     

Synthesis of Novel Anionic Receptors with （Thio）urea and Amide Binding Sites and the Recognition Properties for Anions

IntroductionSincemoreandmoreanionsplayanimportantroleinbiologicalandchemicalprocesses ,thedesignandsynthe sisofreceptorsforon lineandrealtimedetectionofbio logicallyimportantanions ,andforenvironmentalmonitor ingofharmfulanionpollutantshaveattractedparticularat tentioninsupramolecularchemistry .1Thebasicstrategyfortheconstructionofanion bindingreceptorsistoexploitthereceptorsthathaveelectrostatic ,2 hydrogenbonding ,3orLewisacidiccentralinteraction .4 Amongavarietyofnon covalentinteractions ,h…     

Biphasic Catalytic Hydroformylation of 1-Dodecene in Micellar System with Cationic Gemini Surfactants

The promotion effect of cationic gemini surfactants for the hydroformylation of 1-dodecene in the organic/aqueous biphasic catalytic system is reported. The hydroformylation reaction in the presence of gemini surfactant occurred with higher turnover frequency and higher selectivity for linear aldehyde than using conventional monomeric surfactant CTAB.     

Synthesis and Characterization of Zirconia Nanocrystallites by Cationic Surfactant and Anionic Surfactant

1 INTRODUCTION Zirconia is a kind of metallic oxide with high mel- ting point. It is highly corrosion-resistant for acid fu- sant and neutral fusant, thus it can be used as refrac- tory material, and it can also be utilized as acid acy- loxy bi-functional catalystic material owing to hav- ing both acid and alkali surface centers[1]. Moreover, zirconia has superior ion-exchange capacity as well as chemical and mechanical stability, therefore, it can also be applied as a catalyst carrier. …     

Synthesis and Absorption Properties of Calix[6]amides—based Polymers

Reacting calix[6]arene hexaesters with poly(ethyleneimine),a series of calix[6]amidesbased polymers were obtained for the first time.It is found that they show high absorption capacities towards soft cations comparing to hard cations,and the absorption abilities enhanced with the increasing of calixarene content,which may indicates the cavity of calixarene plays crucial role in absorption.Polymer 2c shows good selective absorption capability towards Ag^ among the tested cations.     

Synthesis and Properties of Novel Cationic Maleic Diester Polymerizable Surfactants

The surfactants used in the emulsion polymerization can be thereafter the source of many problems for the application, such as adhesives and coatings. To overcome these negative aspects essentially related to their mobility in the final polymer, surfactants can be covalently linked to the particle surface through incorporation into the polymer chains. Recent years, polymerizable surfactants (surface active monomer or surfmer) are widely reported and used in the emulsion polymerization, many po…     

含有酰胺基或酯基的可降解阳离子Gemini表面活性剂在水溶液中的聚集行为

In the last thirty years, Gemini surfactants with various structures have been designed, synthesized, and demonstrated to show superior physicochemical properties. However, the utilization of non-degradable surfactants, including these Gemini surfactants, poses a threat to the environment; hence, degradable Gemini surfactants are desirable. Herein, biodegradable cationic Gemini surfactants with amide or ester groups in the hydrophobic chains or the spacer were synthesized. A monomeric surfactant containing an amide group and a Gemini surfactant with amide groups both in the hydrophobic chains and the spacer were synthesized for comparison. The effects of amide group location on the aggregation behavior of Gemini surfactants were studied systematically. The differences between the Gemini surfactants with amide groups and Gemini surfactants with ester groups were evaluated by comparing their aggregation behavior and hydrogen bonding formation. The Gemini surfactants with amide groups (C₁₂A-C_n-AC₁₂) in the chains showed much larger exothermic ΔH_mic and more negative ΔG_mic values than those of the corresponding monomeric surfactant C₁₂A; besides, their critical micelle concentration (cmc) was more than one order of magnitude lower than that of C₁₂A. The amide groups located in the hydrophobic alkyl chains promoted hydrogen bonding formation and self-assembly of the Gemini surfactants C₁₂A-C_n-AC₁₂. Moreover, ¹H NMR spectra revealed that the co-effect of a short spacer and hydrogen bonding leads to slow exchange of the C₁₂A-C₂-AC₁₂ molecules between the monomer and the aggregate. For the Gemini surfactant series C₁₂-AC_nA-C₁₂, the amide groups notably increased the spacer length, and largest cmc value and smallest exothermic ΔH_mic value were observed for C₁₂-AC₂A-C₁₂ instead of C₁₂-AC₆A-C₁₂. In C₁₂-AC₁₂A-C₁₂, the spacer was long and sufficiently flexible to adopt a "U"-shaped conformation above the cmc, and it acted as the hydrophobic part of the surfactant, as confirmed by ¹H NMR spectra. Among the Gemini surfactant with amide groups in both the spacer and the hydrophobic alkyl chains, C₁₂A-AC₆A-AC₁₂ had a smaller cmc and I₁/I₃ ratio as well as more exothermic ΔH_mic values than those of C₁₂A-C₆-AC₁₂ and C₁₂-AC₆A-C₁₂. ¹H NMR spectra indicated that an ester-alcohol structural equilibrium exists during aggregation for the Gemini surfactants with ester groups. In addition, the Gemini surfactants with ester groups formed water-mediated hydrogen bonds in the aggregates. This water-mediated hydrogen bonding between ester groups was weaker than the direct hydrogen bonding between amide groups. Therefore, the Gemini surfactants with ester groups, C₁₂E-C₆-EC₁₂ and C₁₂-EC₆E-C₁₂, exhibited lower surface activity, a larger micelle ionization degree, higher micropolarity, and smaller exothermic ΔH_mic and less negative ΔG_mic values than their counterparts with amide groups, C₁₂A-C₆-AC₁₂ and C₁₂-AC₆A-C₁₂.     

阴离子孪连表面活性剂的合成及其表/界面活性研究

合成了疏水链长度不同和连接基长度不同的7种系列阴离子孪连表面活性剂,研究了它们的表/界面活性。结果表明,它们有较低的表面张力和临界胶束浓度(CMC),有很好的表面活性。它们的CMC都在10-5~10-6mol/L之间,表面张力在26·5~34mN/m之间。它们有非常好的抗一价、二价盐的能力。除了C16-C2-C16在高于5%的NaCl溶液中会产生析出外,其余孪连表面活性剂都能耐盐20%以上。随着盐浓度的增加,孪连表面活性剂与烷烃间的界面张力逐渐降低,能达到10-3mN/m。与中原油田原油间的界面张力能降低到10-3~10-4mN/m,表明它们可应用于特高矿化度油藏提高采收率。     

系列阳离子双子表面活性剂的合成及其表面活性的研究

合成了一系列新型的阳离子双子表面活性剂二溴化-N,N'-二(二甲基烷基)乙二铵(12-2-m', m'＝4, 8, 12, 16), 初步研究了其水溶液的表面活性和电导率性质. 结果表明, 此类表面活性剂的表面活性与所含疏水尾基的碳数密切相关.     

含酰胺基Gemini阳离子表面活性剂的合成

含酰胺基Gemini阳离子表面活性剂的合成     

Synthesis and Properties of Novel Cationic Triazolium Gemini Surfactants

New type of triazolium Gemini surfactants were synthesized by reaction of epichlorohydrine with long-chain fatty alcohols namely cetyl alcohol and oleyl alcohol furnishing product 2-(alkoxymethyl)oxirane followed by the their subsequent treatment with triazole resulting in the formation of 1-(1,2,4-triazole)-3-alokoxypropane-2-ol which on reaction with 1,6-dibromohexane resulted in the formation of triazolium-based cationic Gemini surfactant. Their formation was confirmed by IR spectroscopy. Surface tension values were used to determine the critical micelle concentration (CMC), minimum area per molecule (A_min) at air?water interface, Gibbs free energy of adsorption (ΔG_ads), the maximum surface excess concentration (Γ_max), and other parameters. The inhibition behavior of dimeric surfactant on the corrosion of carbon steel (CS) in 1 N H₂SO₄ aqueous medium was studied at 30°C. Performance tests like dispersion capability, foaming power and stability, emulsifying power, and wetting ability were determined. The obtained results show that dispersion capability, foaming power, foaming stability, and emulsifying ability are very good. The wetting power of synthesized surfactants is quite better.     

Synthesis and Surface Properties of Novel N-Alkyl Quinoline-Based Cationic Gemini Surfactants

Two series of cationic dimeric (gemini) surfactants are prepared with respect to key surfactants properties, such as surface activity and solubilization. The influence of both the dimerization and the spacer group is examined in order to establish structure-property relationships. The surface tension and critical micelle concentration can be markedly reduced compared to the monomeric surfactants in the pure state. The critical micelle concentration (cmc) of each series has been determined using equilibrium surface tension measurements. Furthermore, air/water interface parameters including effectiveness (π_cmc), efficiency (P_C20), maximum surface excess (Γ _max ), and minimum surface area (A _min ) have been also derived using Gibb's adsorption equation at 25°C. Standard free energies of micellization and adsorption were calculated. Solubilization behaviors of the synthesized surfactants were measured towards paraffin oil as solubilized material using light transmission technique.     

荧光探针法研究双子型阳离子表面活性剂与明胶的相互作用

利用荧光探针法研究了双子型阳离子表面活性剂与明胶的相互作用,考察了此类表面活性剂的分子结构和明胶对临界胶团浓度(cmc)、胶团聚集数(N_agg)和胶团微极性的影响.结果表明,当双子型阳离子表面活性剂的疏水基增长时,cmc减少,N_agg增加,胶团的微极性降低;加入明胶后,双子型阳离子表面活性剂的N_agg减少,cmc和胶团微极性增加.     

含对苯氧基联接链的羧酸盐Gemini表面活性剂合成及胶团化特性

合成了含对苯氧基联接链的羧酸盐Gemini表面活性剂,研究了其胶团化特性.结果表明,该羧酸盐Gemini表面活性剂具有很低的cmc值,给出了cmc-T(温度)以及lncmc-(m+1)(烷烃链长)的回归方程.计算了胶团化的热力学函数变化,证实胶团化过程来自熵驱动,并表现出焓/熵补偿现象,在所考察的系列中,以(m+1)=11的胶团最为稳定.     

新型Gemini咪唑表面活性剂的合成及表面性能

以2,2-双(溴甲基)-1,3-丙二醇为连接基合成了新型的连接基为枝状的Gemini咪唑表面活性剂2,4-二(溴化-3-烷基咪唑)-1,3-丙二醇([Cn-P-Cnim]Br2,n=10,12,14).产物经核磁共振氢谱(1H NMR)、红外(IR)光谱和元素分析等进行了分析,证明所得产物即为目标产物.通过表面张力法和电导法测量其表面活性并计算胶束形成热力学参数(ΔG m—0,ΔH m—0,ΔS m—0).结果表明,25℃时3种表面活性剂均具有很高的表面活性,胶束的形成是自发的熵驱动过程.