双水相微胶束萃取对苯二酚研究

采用非离子型表面活性剂辛基酚聚氧乙烯醚(Triton X-114)组成的双水相系统(ATPS)萃取对苯二酚,依据胶束分相和分配,实现对苯二酚的萃取和分离。讨论表面活性剂浓度对萃取率的影响,尝试用反萃取方法回收进入微胶束相的对苯二酚。结果表明:双水相微胶束对对苯二酚的萃取率取决于Triton X-114的浓度,双水相微胶束对对苯二酚的萃取率随Triton X-114浓度的增加而增大;反萃取时溶液的pH值等因素对反萃取率的影响很大,通过调节pH值可以使反萃取率增大。     

B-藻红蛋白在表面活性剂中的光谱性质

对标题化合物在3种不同类型的表面活性剂中的可见吸收光谱进行了研究.实验条件下,阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)使B-藻红蛋白的最大吸收峰由545 nm蓝移至506 nm,随CTAB浓度增加,最大吸收值显著下降.阴离子表面活性剂十二烷基硫酸钠(SDS)在低浓度时对B-藻红蛋白的特征吸收峰形影响不大,当SDS的浓度2.0×10-3mol/L时,B-PE在564 nm的吸收峰消失.非离子表面活性剂Triton X-100对B-藻红蛋白的吸收峰形没有产生明显影响,并使吸收峰强度均有所增加.还初步探讨了B-藻红蛋白在3种表面活性剂中光谱变化的机理.     

表面活性剂对水过冷池沸腾特性影响实验研究

以Tween20、Span20及两者复配物为表面活性剂,实验研究了其对水过冷池沸腾传热特性影响。基于实验结果与表面张力、接触角、临界胶束浓度等基础物性分析发现,单一表面活性剂对沸腾传热的影响由其添加种类、浓度及热通量共同决定。一方面,不同于饱和沸腾情形,过冷状态下Tween20能够有效降低沸腾起始点温度与壁面过热度,但其沸腾强化效果在高热通量下减弱;另一方面,Span20只在低浓度下表现出强化效果,其浓度增大将引起壁面过热度大幅攀升。此外,尽管Tween20与Span20都具有强化沸腾传热的潜力,但两者复配表面活性剂在实验研究浓度范围内均恶化了沸腾传热过程。研究结果可为传热强化复合工质过冷池沸腾传热特性分析提供基础依据,并为其配制提供指导。     

非离子表面活性剂在浊点萃取及光度分析中的应用研究

对浊点萃取以及光度分析中非离子型表面活性剂的增效作用进行研究,通过红外光谱、相对粘度和可见吸收吸分光光度法等方法对表面活性剂聚乙二醇叔辛基苯基醚(Triton X-114和Triton X-100)进行表征和研究。结果表明,在可见吸收分光光度法中,TX-114比TX-100具有更高的增效作用,能够有效提高有色金属络合物在水中的溶解度和灵敏度;对于浊点萃取过程的增效作用研究表明,TX-114与TX-100相比具有不同的相对粘度,对浊点萃取和光度分析具有显著的差异,相对粘度高的TX-114表现出更高的增效作用,能够提高分析方法中的灵敏度并降低检出下限。     

表面活性剂对木薯秆酶水解的影响

采用纤维素酶促水解的方法,以木薯秆为底物,研究了5种表面活性剂(SDS、Tween 20、Tween 80、Triton x-100、Triton x-114)及其用量对木薯秆酶水解得率的影响。结果表明,除SDS外,其他4种表面活性剂对木薯秆酶水解有不同程度的促进作用,Tween 20的效果最为显著。添加2.5 g/L的Tween 20水解72 h和5.0 g/L的Triton x-114水解60 h,酶水解得率分别达到了49.23%、49.48%,比空白样提高了33.45%和34.13%。     

TritonX-114残留量检测方法的建立及验证

目的建立测定生物制品中Triton X-114残留量的方法,并进行验证及初步应用。方法先对Triton X-114进行光谱扫描,用所得到的特异吸收峰来初步检测Triton X-114的残留量,再根据Triton X-114与苯酚发生反应并产生具有一定浊度的复合物,且浊度与Triton X-114的浓度成正比的原理,通过测定340 nm处吸光度值,建立测定Triton X-114残留量的方法,并对方法进行稳定性、准确性、精密性验证。考察核酸和蛋白对Triton X-114含量测定的影响,并分别采用紫外吸光法和建立的方法检测样品中的Triton X-114含量。结果 Triton X-114在280 nm左右有特异吸收峰,可通过测定280 nm处的吸光度值来初步测定Triton X-114的残留量;利用Triton X-114与苯酚发生反应后产物的A340值来测定Triton X-114含量的方法的线性范围为0.001%~0.007%,检测下限为0.001%;建立标准曲线后,每间隔5 min测定1次A340值,各浓度标准品A340值的变异系数(CV)均小于5%;低(0.001%)、中(0.003%)、高(0.006%)浓度Triton X-114溶液连续测定3次,每个浓度平行测定9组的CV值均<5%,回收率均>100%;核酸和蛋白对该方法测定Triton X-114的含量无影响;4份样品经两种方法检测的试验内CV值均<10%。结论可采用280 nm紫外吸收法初步测定Triton X-114的含量,但该法灵敏度低,易受干扰;而采用Triton X-114与苯酚反应后检测其产物浊度的方法来测定Triton X-114的残留量,稳定性、精密性良好,准确性高,可用于生物制品中Triton X-114残留量的检测。     

微乳液中四氯化硅水解制备二氧化硅微球

利用阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)和非离子表面活性剂聚乙二醇辛基苯基醚(Triton X-100)配制微乳体系,并利用工业生产单晶硅副产物四氯化硅制备粒径分别为45 nm和60~120 nm的二氧化硅微球。探讨了加水量、氨水浓度、四氯化硅用量、搅拌转速、反应温度对微球粒径及表面形貌的影响。研究表明,在CTAB乳液体系中,微球粒径随含水量的增加而减小,随通入四氯化硅气体量的增加而增大,且只有在碱性条件下才能得到硅球;在Triton X-100乳液体系中,微球粒径随含水量的增加呈现先减小后增大的趋势,随四氯化硅液体加入量的影响较小,碱性越高颗粒成球度越好、分散性能越好。微乳液反应过程不宜搅拌,且反应温度不易高于四氯化硅沸点。     

Research progress of physical properties of surfactant solutions

认知表面活性剂溶液物理特性是揭示表面活性剂强化沸腾换热机理的基础。本文以表面活性剂强化沸腾换热为背景,阐述了与沸腾换热密切相关的表面活性剂溶液相关物理特性的研究进展,包括表面活性剂溶液的静态表面张力、动态表面张力、黏度、润湿性能和溶解度等物理特性。最后,指出了目前表面活性剂溶液物理特性的研究不足,并对表面活性剂溶液物理特性的研究方法和研究内容进行了展望。     

i影响换热器用多孔表面管沸腾换热的主要因素

综述了换热器用多孔表面管沸腾传热的各种影响因素,既介绍了如孔穴直径、多孔层厚度及孔隙率等多孔层的特征参数的特性;也介绍了材料物性、加工工艺、工质物性、压力与温度等对沸腾传热的影响。同时对各种因素对沸腾换热的具体影响进行了分析归纳,对今后多孔表面强化沸腾传热的研究提出了一些自己的建议。     

影响换热器用多孔表面管沸腾换热的主要因素

综述了换热器用多孔表面管沸腾传热的各种影响因素,既介绍了如孔穴直径、多孔层厚度及孔隙率等多孔层的特征参数的特性;也介绍了材料物性、加工工艺、工质物性、压力与温度等对沸腾传热的影响.同时对各种因素对沸腾换热的具体影响进行了分析归纳,对今后多孔表面强化沸腾传热的研究提出了一些自己的建议.     

Extraction of anionic dyes with ionic liquid–nonionic surfactant aqueous two-phase system

The cloud point of nonionic surfactant (Triton X-114) in ionic liquid ([Bmim]Cl) aqueous solution exhibits as increase and then decrease and increase again with the increase of ionic liquid (IL) content, which is the origin of an IL–nonionic surfactant aqueous two-phase system. The nonionic surfactant-rich phase coexists with a high content of IL aqueous solution phase in the IL–nonionic surfactant aqueous two-phase system. The partitioning of various ionic dyes indicates that anionic species exhibit a high partitioning coefficient between the IL-rich phase and the nonionic surfactant-rich phase.     

Partitioning equilibria in multicomponent surfactant systems for design of surfactant-based extraction processes

Aqueous biphasic systems based on nonionic surfactants have perspective applications in extraction processes, in particular, cloud point extraction of hazardous compounds or high valued products, especially biomolecules. Additives (e.g., ionic surfactants, salts) and variations in pH can significantly affect the surfactant-based separation processes, representing an additional degree of freedom for their optimization. However, there are few systematic studies of phase and partition behavior for these multicomponent surfactant systems.In this study we examined the clouding, phase compositions and partitioning equilibria for aqueous mixed surfactant systems of a nonionic surfactant (Triton X-114), ionic surfactants (cetyltrimethylammonium bromide or sodium dodecyl sulfate) and NaCl, in order to improve the extraction efficiency. Vanillin was used as a model substance at three different pH values, specifically in (partly) dissociated or non-dissociated states. The partition coefficients obtained in the batch experiments were compared to the predictions by the thermodynamic model COSMO-RS. Based on this knowledge a continuous multistep extraction process was carried out.To the best of our knowledge this is the first demonstration of using a mixed surfactant system for continuous countercurrent cloud point extraction.     

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.     

EFFECTS OF FLOW RATE AND TEMPERATURE ON THE DISSOLUTION OF POLYCYCLIC AROMATIC HYDROCARBONS TRANSFERRING FROM A NONAQUEOUS PHASE LIQUID TO NONIONIC SURFACTANT SOLUTIONS

The effects of flow rate and temperature on the dissolution of two polycyclic aromatic hydrocarbon (PAH) compounds, naphthalene and phenanthrene, transferring from a synthesized nonaqueous phase liquid (NAPL) comprised of hexadecane and the 2 PAHs into different nonionic surfactant solutions were investigated using a reactor with a spinning cell. The variation of the flow rate was possible by changing the angular velocity of the spinning cell. The flow rate generally increased the values of the mass transfer coefficients and the rates of mass transferred for both aromatics in the absence and presence of a surfactant in the aqueous phase. In comparison to the pure aqueous solution the results suggest that the addition of a surfactant at all doses investigated enhanced the rates of mass transfer for both PAHs. As the temperature increased the rates of mass transfer for both PAHs in the solutions of surfactants increased. The increase in the temperature has a much greater effect on the rates of mass transfer for both PAHs in solutions of the surfactant Triton X-100 than in Brij 35. In solutions of the surfactant Triton X-100 a decrease in the mass transfer coefficient for both PAHs with surfactant concentration was observed for the temperatures investigated.     

Pulsed electrodeposition of Zn in the presence of surfactants

The preparation of Zn deposits has been performed by galvanostatic pulsed electrolysis, from acidic zinc sulphate solutions, on a stainless steel substrate. The influence of the surfactants (cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS) and octylphenolpoly(ethyleneglycolether)_n, n = 10, Triton X-100) on the voltammetric behaviour, structural and morphological characteristics of the deposits have been investigated. The characterization of the samples was made by X-ray diffraction (XRD) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS). The experimental data shows that the presence of surfactants affects the zinc deposition process. The electrodeposits are mainly composed by Zn with different texture, crystal shape and size (grain size ranging from 40 to 20 nm). The obtained results led us to conclude that the Zn deposits prepared in the absence of surfactants and in the presence of SDS are more crystalline and with a higher grain size than the ones obtained in the presence of CTAB and Triton X-100. These facts may be justified by the increase on the overpotential deposition as the electrochemical studies confirm.The XRD results show that the deposits prepared, in the absence of surfactant and in the presence of SDS, contain ZnSO₄ and Zn₄SO₄(OH)₆ as oxidation products. ZnO is also detected on the deposits obtained in the presence of CTAB and Triton X-100.     

Aqueous Surfactant Two‐Phase Systems for the Continuous Countercurrent Cloud Point Extraction

Aqueous nonionic surfactant solutions split into two phases if the temperature is increased beyond a certain temperature, the so‐called cloud point temperature. Presently many different types of nonionic surfactants are produced commercially, out of these numerous have been considered as potential solvent for the cloud point extraction. In this work the crucial thermophysical properties of nonionic surfactants are investigated to determine the potential of surfactant systems for extraction processes. Phase equilibria of the binary system Triton X‐114/water and the ternary system Triton X‐114/water/phenol were measured. Based on these data the cloud point extraction was implemented in a continuous stirred extraction column. It was found, that increasing temperature within the column reduces the loss of surfactant and leads to an increasing enrichment factor. This work demonstrates that surfactant/water systems represent a suitable alternative to conventional solvents and can effectively be processed in continuous extraction columns.     

添加剂对非离子表面活性剂浊点的影响

研究了醇类、聚合物、离子型表面活性剂、有机复配物等添加剂对非离子表面活性剂浊点的影响,总结出几类添加剂对非离子表面活性剂浊点的影响规律。结果表明,有机醇对浊点的影响比较复杂,聚合物随着分子链的长短对浊点的影响而不同,离子型表面活性剂的加入会有效提高非离子表面活性剂的浊点。