CO2/N2 Triggered Switchable Surfactants with Imidazole Group

In order to overcome the hydrolysis of 2-alkyl-1-hydroxyethyl imidazoline and its unsatisfactory emulsification–demulsification switchability to water-alkane, the long-chain N-alkylimidazole compounds were synthesized by n-octyl bromide, n-decyl bromide, n-dodecyl bromide, n-tetradecyl bromide and n-hexadecyl bromide with imidazole, respectively and characterized by MS, ¹H NMR and FTIR. The long-chain N-alkylimidazole compounds can be reversibly transformed into charged surfactants by exposure to CO₂. Surface tension values indicated that N-alkylimidazolium bicarbonates had excellent surface activity compared with corresponding conventional surfactants with a lower γ _CMC. The surface behaviors of the five surfactants can be illustrated by A _min. Five conductivity cycles by bubbling CO₂ and N₂ alternately indicated that these surfactants could be switched by CO₂ reversibly and repeatedly. Emulsions were repeatedly stabilized for five cycles by N-alkylimidazolium bicarbonate and broken by bubbling N₂ through the solutions to reverses the reaction, releasing CO₂.     

阳离子咪唑啉表面活性剂的合成

以脂肪酸和二乙烯三胺为原料 ,经过酰化和环化制得中间体 2 烃基酰胺乙基咪唑啉 ,进而利用硫酸二甲酯活泼的甲基对咪唑啉环上的氮原子进行季铵化反应 ,生成季铵盐型阳离子咪唑啉表面活性剂。对合成路线和工艺条件进行了探讨 ,对目标产物作了分析和测定 ,证实它具有良好的性能。     

咪唑啉型Gemini表面活性剂合成与应用进展

从合成和应用两个方面综述了近些年咪唑啉型Gemini表面活性剂的进展,包括归纳现有的咪唑啉型Gemini表面活性剂的合成方法及路线,按照不同的结构特点进行分析比较,并整理了目前咪唑啉型Gemini表面活性剂在金属防腐、乳化、材料制备等方面的应用,并将其与单体咪唑啉表面活性剂进行了对比,体现了其结构变化导致性能的优越性。同时,对目前咪唑啉型Gemini表面活性剂发展过程中存在的问题进行了分析,并对今后咪唑啉型Gemini表面活性剂的发展方向与应用前景进行了展望。     

Synthesis, Characterization and Surface Properties of Series Sulfobetaine Surfactants

A series of surface active sulfo-propane betaines and sulfo-butane betaines were synthesized with high yields by the reaction of an appropriate N,N-dimethyl alkylamine with an excess of 1,3-propane sultone and 1,4-butane sultone. The structures were characterized by ¹H-NMR spectroscopy and elemental analysis. The micellar properties of these compounds were determined by surface tension methods. Surface tension measurements also provide information about the dependence of the surface tension at the CMC (??_cmc), pC₂₀ (negative logarithm of the surfactant molar concentration C₂₀ required to reduce the surface tension by 20 mN/m), the surface excess (??_max) at air/solution interface, the minimum area per surfactant molecule at the air solution interface (A).     

Synthesis of Unsymmetrical Bolaform Surfactants with a Sulfonate Group and a Carboxyl Group

Three unsymmetrical bolaform surfactants with different aromatic rings and a ω-carboxyalkyl chain were synthesized and their molecular structures were characterized by ESI–MS and ¹H NMR. The percentages of conversion of alkylation were judged by the iodine value measurements and the effect of reaction temperature on sulfonate content of synthesized products has also been discussed.

咪唑啉型表面活性剂及其应用

介绍了咪唑啉型表面活性剂的合成及改性方法，综述了咪唑啉型表面活性剂在日用化工、纺织印染、化纤、石油采矿等领域的应用。     

Synthesis and Properties of Dicephalic Cationic Surfactants Containing a Quaternary Ammonium and a Guanidine Group

Novel dicephalic surfactants containing a quaternary ammonium and a guanidine group were synthesized, and the effect of the alkyl chain length on micellization and antimicrobial activity were investigated. Surface tension and conductivity were applied to study the self-aggregation of the amphiphilic molecule in aqueous solution. The results indicated that these compounds reduce the surface tension to a level of 30–36 mN/m at the air/water interface and that there is a characteristic chain length dependence of the micellization process of surfactants. The antimicrobial activity was evaluated against Gram-negative, Gram-positive bacteria and fungi, indicating strong antibacterial activity against tested strains.     

以金刚烷为联接链的Gemini表面活性剂的合成及性能

以1,3-金刚烷二甲酸为起始原料,合成了3种以金刚烷为联接链的具有不同疏水链长的Gemini表面活性剂(n P-Ad-Pn,n=12,14,16)。用FTIR、1HNMR、ESI-MS对目标化合物的结构进行了表征。采用表面张力法、电导率法和稳态荧光光谱法测定了金刚烷Gemini表面活性剂的表面活性、胶束化热力学参数和胶束微极性。结果显示:白金环法测得n P-Ad-Pn在25℃下的临界胶束浓度分别为6.0×10-4、1.0×10-4和2.5×10-5mol/L,ΔG0m和ΔH0m均为负值说明表面活性剂胶束形成是一个自发且放热的过程。化合物对金黄色葡萄球菌、枯草杆菌、大肠杆菌、绿脓杆菌、副溶血性弧菌抑菌活性的测定结果表明,12P-Ad-P12对5种菌株的MIC值在0.2~4.2mg/L,显示出很强的抑菌活性。     

Recovery and Recycling of CO2/N2‐Switchable Anionic Surfactants in Emulsions

To develop a mild, effective, and clean strategy for recovery and recycling of anionic surfactants in CO₂/N₂‐switchable emulsions, a CO₂/N₂‐switchable anionic surfactant, which is a combination of dodecyl seleninic acid (DSA) and N,N,N′,N′‐tetramethyl‐1,2‐ethylenediamine (TMEDA), here referred to as DSA–TMEDA, was used to stabilize an oil‐in‐water (O/W) emulsion. Upon stimulation with CO₂, DSA–TMEDA was switched off to form insoluble DSA and the water‐soluble TMEDA bicarbonate. Upon N₂ bubbling and heating, the OFF state of DSA–TMEDA was restored to the surfactant of DSA–TMEDA. In this manner, O/W emulsions stabilized by DSA–TMEDA can be switched reversibly between demulsification (phase separation) and re‐emulsification (recovered emulsion) by triggering with CO₂/N₂ over ten times. After breakage of the emulsion, nearly all of the OFF state surfactant could be separated conveniently away from the oil phase, thus facilitating recovery and recycling of the surfactant afterward in emulsifying oil. No obvious adverse changes in the dispersed oil particles size and the relative stability of the regenerated emulsions were observed over five cycles, and the surfactant loss can be neglected during the recycling.     

非环状乙缩醛表面活性剂的合成

非环状乙缩醛表面活性剂是一类可分解的表面活性剂。本文以氯化氢为催化剂，脂肪醇与三聚甲醛醚化得到脂肪基氯甲基醚，再与环氧氯丙烷烷基化后加聚乙二醇缩合得到非环状乙缩醛表面活性剂，并考察了其在纺织印染助剂中的应用。     

咪唑啉还原开环反应在表面活性剂合成中的应用

综述了应用咪唑啉还原开环反应合成乙二胺衍生物及数种新型多功能表面活性剂,至表面活性剂的应用性能作了分析,并报道了部分表面活性剂的物化性能。还报道了把咪唑啉还原开环反应于双阳离子表面活性剂Ｎ,Ｎ,Ｎ’,Ｎ’,Ｎ’－五羟乙基－Ｎ－十二锘乙二胺合成中的方法。     

以金刚烷为联接链的Gemini表面活性剂合成与性能

以1,3-金刚烷二甲酸为起始原料,合成了3种以金刚烷为联接链的具不同疏水链长的Gemini表面活性剂（nP-Ad-Pn,n=12,14,16）。用FTIR、1HNMR、ESI-MS对目标化合物的结构进行了表征。采用表面张力、电导率和稳态荧光光谱测定了金刚烷Gemini表面活性剂的表面活性、胶束化热力学参数和胶束微极性。结果显示：白金环法测得nP-Ad-Pn在25℃下的临界胶束浓度分别为6×10-4、1×10-4和2.5×10-5 mol·L-1,∆G0m和∆H0m均为负值说明表面活性剂胶束形成是一个自发且放热的过程。化合物对金黄色葡萄球菌、枯草杆菌、大肠杆菌、绿脓杆菌、副溶血性弧菌抑菌活性的测定结果表明,12P-Ad-P12对5种菌株的MIC值在0.2～4.2 mg/L,显示出很强的抑菌活性。     

Synthesis and Surface Active Properties of a Gemini Imidazoline Amphoteric Surfactant

The gemini imidazoline amphoteric surfactant was prepared in two steps. We first reacted lauric acid and triethylenetetramine to obtain the intermediate called bisalkyl-bis-imidazoline. We analyzed it by ¹H NMR, and the yield was 82.45 % according to perchloric acid non-aqueous titration. The intermediate was then quaternized using sodium 2-chloroethanesulfonic acid in a mixture of isopropyl alcohol and water, during which we controlled the pH between 8 and 9 and the temperature between 80 and 90 °C to prepare C12-bis-imi. The air–liquid surface tension was measured by a tensiometer at 298 ± 0.1 K. The results show that the critical micelle concentration (CMC) was 2.25 × 10^?3 mol/L and the surface tension at the CMC (γ _CMC) was 30.42 mN/m. C12-bis-imi showed a synergistic effect in combination with lauric alcohol with nine ethylene oxide groups (AEO9). The synergistic effect is most striking when the mole ratio of C12-bis-imi/AEO9 was 1/1, and the corresponding CMC was 9.79 × 10^?5 mol/L and the γ _CMC was 37.61 mN/m.     

双磷酸酯表面活性剂的合成与性能

以三氯氧磷、二元醇(酚)、正十二醇为原料,合成了4种双十二烷基双磷酸酯(HDP,DGDP,BDP,PDP)。产物经无水乙醇重结晶提纯后,通过IR、1HNMR、质谱和电位滴定进行了结构表征。25℃时,它们的电离常数分别为:2.76×10-5mol/L(HDP),3.940×10-4mol/L(DGDP),1.595×10-4mol/L(BDP),4.255×10-3mol/L(PDP)。20℃时,它们的临界胶束浓度分别为:3.5×10-4mol/L(HDP),9.0×10-4mol/L(DGDP),1.1×10-3mol/L(BDP),1.3×10-3mol/L(PDP);在临界胶束浓度处的表面张力分别为:30.38 mN/m(HDP),34.49 mN/m(DGDP),35.31 mN/m(BDP),36.14 mN/m(PDP)。差热分析表明,4种产物的分解温度分别为:231℃(BDP),251℃(HDP),227℃(PDP),249℃(DGDP);初熔温度分别为:87℃(BDP),80℃(HDP),97℃(PDP),72℃(DGDP)。     

双子咪唑啉季铵盐的合成及其乳化性能

首先,以二丁胺和环氧氯丙烷为原料合成N-丁基-N,N-二(3-氯-2-羟丙基)丁烷-1-铵盐;然后,利用其与长链烷基咪唑啉进行季铵化反应合成双子咪唑啉季铵盐,并通过FTIR和1HNMR验证了目标产物的结构;最后,利用合成的双子咪唑啉季铵盐和秦皇岛AH-70重交道路沥青制备乳化沥青,进行双子咪唑啉季铵盐乳化性能的考察。结果表明,在皂液p H=5.0、沥青温度为135℃、皂液温度为55℃、乳化剂加量为1.5%(占乳化沥青总质量的百分数)的条件下制备的乳化沥青达到交通部JTG F40-2004的质量要求。     

Synthesis and Performance Evaluation of CO2/N2 Switchable Tertiary Amine Gemini Surfactant

A type of switchable tertiary amine Gemini surfactant, N,N′‐di(N,N‐dimethyl propylamine)‐N,N′‐didodecyl ethylenediamine, was synthesized by two substitution reactions with 3‐chloro‐1‐(N,N‐dimethyl) propylamine, bromododecane and ethylene diamine as main raw materials. The structure of the product was characterized by FTIR and ¹H‐NMR. We also investigated the surface tension when CO₂ was bubbled in different concentrations of surfactant solution and the influence of different CO₂ volumes on surface tension under a constant surfactant concentration. Finally the surface tension curve and the related parameters were acquired by surface tension measurements. The experimental results showed that the structure of the synthesized compounds were in conformity with the expected structure of the surfactant, and displayed a better surface activity after bubbling CO₂. The critical micelle concentration (CMC) surface tension at CMC (γ_cmc) pC₂₀ (negative logarithm of the surfactant's molar concentration C₂₀, required to reduce the surface tension by 20 mN/m) surface excess (Γ_max) at air/solution interface and the minimum area per surfactant molecule at the air/solution interface (A_min) were determined. Results indicate that the target product had good surface activity after bubbling CO₂.     

2-Ethylhexanol Derivatives as Nonionic Surfactants: Synthesis and Properties

The synthesis and basic properties of 2‐ethylhexanol based innovative nonionic surfactants are described in this paper. 2‐Ethylhexanol as an available and relatively inexpensive raw material was used as the hydrophobe source modified by propoxylation and followed by polyethoxylation. As the result, six series of 2‐ethylhexyl alcohol polyalkoxylates (EHP_mE_n) were obtained with three steps of propoxylation, each followed by polyethoxylation and two series only with polyethoxylation (EHE_n). Two different catalysts were used, a dimetalcyanide and KOH. Values of average conversion rates and chemical content of the obtained products (GC, TG and GPC techniques) were compared. The influence of the applied catalyst and polyaddition degree on the homologue distribution, reactant conversion and amount of byproducts is discussed. The basic physicochemical parameters including refractive index, solubility in polar media, foaming properties and wettability were investigated and compared. Furthermore, surface activity parameters, i.e. surface tension (γ_CMC) and critical micelle concentrations were determined. Results are compared to C_12–14 alcohol ethoxylates (LaE_n). Accordingly, it was found that the studied 2‐ethylhexyl alcohol based compounds are effective, low foaming nonionic surfactants.     

Synthesis of Siloxane Polyether Surfactants and Their Solubility in Supercritical CO2

Four siloxane polyether surfactants were synthesized from allyl bromide, polyethylene glycol methyl ether and heptamethyltrisiloxane (HMTS) to explore their solubility in CO₂. The dissolving pressures of these surfactants were measured using a high‐pressure view cell at 318–343 K to calculate their solubility in CO₂. The results show that, the silicone‐containing surfactants exhibit excellent solubility in CO₂. The shorter the polyethylene glycol group, the better the solubility in CO₂. Of the five compounds tested, HMTS showed the best solubility in CO₂ which was around 2.4% as a mole percentage. The surfactants show much better solubility than the commonly used surfactants. Moreover, by investigating the effects of the pressure and temperature on the solubility, it was found that an increase in pressure benefits solubility of the compound in CO₂, while an increase in temperature within the experimental range does the opposite. In addition, a linear correlation in the logarithmic values of the solubility data and the density of CO₂ was found, which means the solubility follows density more directly and not the pressure.     

Synthesis and Properties of Dissymmetric Gemini Surfactants

A series of novel dissymmetric gemini cationics surfactants was synthesized by three-step reactions. The dissymmetric gemini surfactants contain a dodecanoic acid dimethylethylamine ester as the constant cationic part on one side of the hydroxypropyl center and a similar other cationic part, but with a different acid length (from octanoic to palmitic), on the other side. The critical micelle concentration (CMC) and the effectiveness of surface tension reduction (γ _CMC) were determined. The surface tension measurements of dissymmetric gemini surfactants showed good water solubility, and low CMC had great efficiency in lowering the surface tension and a strong adsorption at the air/water interface. The CMC was observed to increase initially with the increase of the ester bond alkyl group. They also showed good foaming properties and wetting capabilites.     

羧酸盐Gemini表面活性剂合成及性能

以脂肪醇聚氧乙烯醚为原料,合成了羧酸盐阴-非Gemini表面活性剂,针对胜利油田某区块的油水,进行了表面活性剂的耐温抗盐性能、聚表配伍性能试验。结果表明,其耐盐可达50000mg/L、抗钙镁离子达到1000mg/L、耐温性能达90℃,聚表配伍性能良好,具有应用于三次采油(EOR)先导试验的前景。