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%。     

Effects of surfactants on hydrodynamics and mass transfer in a split‐cylinder airlift reactor

Effects of various concentrations (0–5 ppm) of anionic (sodium dodecyl sulfate, SDS) and non‐ionic (Tween‐80 and Triton X‐405) surfactants on gas hold‐up and gas–liquid mass transfer in a split‐cylinder airlift reactor are reported for air–water. Surfactants were found to strongly enhance gas hold‐up. Non‐ionic surfactants were more effective in enhancing gas hold‐up compared to the anionic surfactant SDS. An enhanced gas hold‐up and a visually reduced bubble size in the presence of surfactants implied an enhanced gas–liquid interfacial area for mass transfer. Nevertheless, the overall gas–liquid volumetric mass transfer coefficient was reduced in the presence of surfactants, suggesting that surfactants greatly reduced the true liquid film mass transfer coefficient and this reduction outweighed the interfacial area enhancing effect. Presence of surfactants did not substantially affect the induced liquid circulation rate in the airlift vessel.     

Effect of surfactants on phenol removal by the method of polymerization and precipitation catalysed by Coprinus cinereus peroxidase

The removal of phenol by peroxidase‐catalysed polymerization was examined using Coprinus cinereus peroxidase in the presence of surfactants. The non‐ionic surfactants with poly(oxyethene) residues, Triton X‐100, Triton X‐405 and Tween 20, enhanced the phenol removal efficiency at a level similar to high relative molecular mass poly(ethylene glycol) (relative molecular mass 3000). Although the improvement in the removal efficiency was less than that of Triton X‐100, Span 20, sodium lauryl sulfate (SDS) and lauryl trimethylammonium bromide (DTAB) also enhanced the removal efficiency. The requirement of the enzyme for almost 100% removal of 100 mg dm^?3 phenol decreased to one‐fourth by the addition of 30 mg dm^?3 Triton X‐100. Triton X‐100, Triton X‐405, Tween 20 and DTAB could reactivate the enzyme precipitated with the phenol polymer, leading to the restarting of the phenol removal reaction. Copyright © 2003 Society of Chemical Industry     

Solubilization of bituminous and lignite coals by chemically and biologically synthesized surfactants

Tween 80 (polyoxyethylene sorbitan monooleate), Triton X-100 (nonaethylene glycol octylphenol ether), and SDS (sodium dodecyl sulfate) solubilized several components of Mississippi Wilcox lignite and Illinois No. 6 bituminous coal. Tween 80 extraction of alkali-soluble Ugljevik lignite resulted in an increase in hydrogen content and decreases in the nitrogen and sulfur contents of undissolved coal solids. Biosurfactant-containing cell-free extracts of Bacillus licheniformis solubilized a 53 000 Da coal component of Mississippi Wilcox lignite. The results suggest that solubilization of coal organic components by chemically- and biologically-synthesized surfactants has potential in terms of upgrading coals.     

PAH biodegradation in surfactant‐water systems based on the theory of cohesive energy density (CED)

The influence of two non‐ionic surfactant additives (Triton X‐100 and Brij 35) on polycyclic aromatic hydrocarbon (PAH) biodegradation was evaluated using the chemical molecular interaction method, which is based on the theory of cohesive energy density (CED). The results indicated that PAHs have relatively higher CED values because aromatic compounds with labile π are more polarized and this encourages molecular attractions involving induced dipole force. Under different PAH‐surfactant compositions, similar CED values, which facilitated their intermolecular attractions through π–π electron interactions, gave rise to a similar biodegradation pattern. For example, when induced enzymes were able to target the same molecular bonding on the PAH and Triton X‐100, rapid degradation rates were observed in both systems. The distribution of the PAH in the monomer or micelle surfactant bulk affected the rate of PAH biodegradation. Quantification of the bacterial activity by applying specific oxygen uptake requirements (SOUR) identified an effect involving chemical molecular interaction. Changes in the physiological characteristics as measured by BioLog GN microplate measurements were identifiable and also could be related to the chemical structure of the dual substrates. Community‐level physiological profiling (CLPP) changed when PAH biodegradation took place in the presence of the different surfactants. Cluster analysis using matching coefficient and carbon degradation potential values also varied with the different PAH‐surfactant compositions. Copyright © 2007 Society of Chemical Industry     

Spectroscopic and conductometric studies on the interactions of thionine with anionic and nonionic surfactants

In this study, the interaction of thionine, a cationic dye, with anionic [sodium dodecyl sulphate (SDS), lithium dodecyl sulphate (LiDS), and sodium dodecylbenzene sulphonate (SDBS)], nonionic (Tween 20 and Triton X‐100), and binary mixtures of anionic and nonionic surfactants was studied by conductometric and spectrophotometric measurements. The degree of ionisation, the counterion binding parameters, and the equilibrium constants in the premicellar region were obtained from conductivity data. Binding constants of thionine to anionic, nonionic, and mixtures of anionic and nonionic micelles were determined by spectrophotometric measurements. The binding tendency of thionine to anionic micelles followed the order SDBS > SDS > LiDS. The presence of nonionic surfactants increased significantly the binding affinity of thionine to anionic micelles, and the highest binding constant was calculated in the presence of Tween 20. The results obtained from conductometric studies correlated with those obtained from spectroscopic studies. Data concerning dye–surfactant interaction are important for a fundamental understanding of the performance of single and mixed surfactants and for their industrial application.     

Influence of Quartz,Kaolin, and Organic Matter on the Critical Micelle Concentration of Tween Surfactants and their Application in Diesel-Contaminated Soil Washing

Surfactant solutions are commonly used for the remediation of petroleum-contaminated soil due to their good petroleum removal performance, time-saving capability, and cost effectiveness. However, applying surfactants in excess concentrations could make oil recovery difficult. Moreover, residual surfactants in soil are toxic to microorganisms and plants. Thus, it is crucial to identify a suitable surfactant concentration for soil washing applications. The main objective of this study was to evaluate the effect of soil minerals (quartz and kaolin) and organic matter (OM) on the critical micelle concentration (CMC) of polyethoxylated sorbitan ester surfactants (Tween 20, 40, 60, and 80) and its effect on diesel removal from diesel-contaminated soil by soil washing. The results showed that Tween surfactants with shorter carbon chain lengths required higher CMC for diesel removal from quartz, while those with longer chains needed higher CMC for kaolin cleanup. FTIR results illustrated that oxygenated functional groups of Tween surfactants played an important role in their adsorption on quartz, while alkyl chains of Tween surfactants were responsible for their adsorption on kaolin. At a certain OM concentration, quartz and OM exhibited antagonistic effects, resulting in CMC reduction. In soil washing application, maximum diesel removal could be achieved from kaolin, in the presence of which surfactants exhibited the highest CMC. Based on FTIR results, the adsorbed surfactant could reduce the hydrophobicity of the kaolin surface, thus preventing the re-deposition of detached diesel.     

Bacterial Bio-Resources for Remediation of Hexachlorocyclohexane

In the last few decades, highly toxic organic compounds like the organochlorine pesticide (OP) hexachlorocyclohexane (HCH) have been released into the environment. All HCH isomers are acutely toxic to mammals. Although nowadays its use is restricted or completely banned in most countries, it continues posing serious environmental and health concerns. Since HCH toxicity is well known, it is imperative to develop methods to remove it from the environment. Bioremediation technologies, which use microorganisms and/or plants to degrade toxic contaminants, have become the focus of interest. Microorganisms play a significant role in the transformation and degradation of xenobiotic compounds. Many Gram-negative bacteria have been reported to have metabolic abilities to attack HCH. For instance, several Sphingomonas strains have been reported to degrade the pesticide. On the other hand, among Gram-positive microorganisms, actinobacteria have a great potential for biodegradation of organic and inorganic toxic compounds. This review compiles and updates the information available on bacterial removal of HCH, particularly by Streptomyces strains, a prolific genus of actinobacteria. A brief account on the persistence and deleterious effects of these pollutant chemical is also given.     

Effect of pH on the flotation performance of incinerator fly ash

Flotation was proved to be effective for decarburization and removal of dioxins from hospital solid waste (HSW) incinerator fly ash, but weathering makes it difficult. The effects of three types of surfactants including nonionic (Tween 80), anionic (SDS), and cationic (CTAB) at different pulp pH values on the flotation performance of weathered HSW incinerator fly ash were investigated. Results showed that the corresponding optimal pH values of Tween 80, CTAB, and SDS were 7, 5, and 9 in terms of decarburization performance, respectively, which were validated by the measurement of Zeta potential. The total dioxins and carbon removal efficiencies showed good correlation at various pulp pH values with surfactant of Tween 80. The optimum surfactant type and pH value should be selected as Tween 80 and pH = 7 from the standpoints of the dioxin removal. Under the optimum condition, the lowest content of dioxins (2.7 ng I-TEQ/g) in the tailings was obtained. The content of heavy metals in the froths exhibited higher with addition of SDS compared with that with Tween 80 and CTAB.     

表面活性剂与离子液体对β-葡萄糖苷酶的协同影响

为考察表面活性剂和离子液体1-乙基-3-甲基咪唑磷酸二乙酯盐（[EMIM]DEP）对类芽孢杆菌sp. LLZ1 β-葡萄糖苷酶活性的影响,在酶活测定体系中加入一定浓度的表面活性剂和[EMIM]DEP。结果表明：添加5%的[EMIM]DEP使β-葡萄糖苷酶的活性增强了12.00%,进一步添加0.1%鼠李糖脂、Span20、PEG4000和Tween80分别使酶活增强了21.85%、12.07%、8.57%和5.25%,而Triton X-100和SDS分别使酶活降低了4.59%和10.63%。动力学曲线和动力学参数表明随着表面活性剂和5%[EMIM]DEP对β-葡萄糖苷酶活性的增强,米氏常数K_m随之减小。圆二色谱（CD）分析表明分别经0.1%鼠李糖脂、Span20、PEG4000和Tween80处理后,β-葡萄糖苷酶的α-螺旋分别增加1.00%、0.78%、0.72%和0.80%,添加SDS导致α-螺旋减少5.72%。荧光光谱表明同时添加表面活性剂和5%[EMIM]DEP改变了β-葡萄糖苷酶的最大发射波长。差示扫描量热法(DSC)表明0.1%鼠李糖脂和5%[EMIM]DEP提高了β-葡萄糖苷酶的中点温度和平均展开焓。使用0.1%鼠李糖脂协同5%[EMIM]DEP水解纤维二糖,转化率提高了21.93%。     

不同表面活性剂对单相微乳液特性的影响

表面活性剂是影响微乳液特性的关键因素之一。本文选取聚氧乙烯脱水山梨醇单油酸酯（Tween 80）、烷基糖苷1214（APG 1214）、十二烷基苯磺酸钠（SDBS）、脂肪醇聚氧乙烯醚硫酸钠（AES）、十二烷基硫酸钠（SDS）和95%纯度鼠李糖脂（R-95%）这6种表面活性剂,通过对其乳化性能和临界胶束浓度进行筛选,结合其形成微乳液的拟三元相图、粒径分布和界面张力分析其特性,并提出微乳液增溶油能力和增溶油成本。研究表明：APG 1214、SDBS、Tween 80乳化性能好、临界胶束浓度低具有更易形成微乳液的优势;5种表面活性剂（Tween 80、SDBS、APG 1214、SDS、AES）均可与正丁醇、水和3号白油自发形成单相微乳液,单相区面积大小为AES型>SDS型>APG 1214型>Tween 80型>SDBS型,最大增溶油能力大小为SDS型>AES型>APG 1214型>Tween 80型>SDBS型,最低增溶油成本大小为AES型相似文献   

Adsorption of nonionic surfactants at fluid-fluid interfaces: Importance in the coalescence of bubbles and drops

Major industrial applications of surfactants are related to the stability of emulsions and foams, which is directly dependent on the rate of coalescence of drops and bubbles. Surfactant molecules adsorb at the liquid-liquid and gas-liquid interfaces and prevent the drops and bubbles from coalescing with one another. Therefore, it is important to correlate the adsorption of surfactant with the time required for coalescence. In this work, we have studied the adsorption of three nonionic surfactants, Tween 20, Triton X-100 and Span 80 at air-water and water-toluene interfaces. The variation of surface and interfacial tension with the concentration of surfactant was studied and the data were fitted using a surface equation of state derived from the Langmuir adsorption isotherm. We have studied binary coalescence of water drops in toluene in presence of these three surfactants. Coalescence of air bubbles at flat air-water interface was studied in presence of the water-soluble surfactants, Tween 20 and Triton X-100. A stochastic model for coalescence was used to fit the coalescence time distributions. The significance of the model parameters was discussed.     

Tween 80强化-活化过硫酸钠氧化修复多环芳烃污染土壤

考察了在典型非离子表面活性剂Tween 80辅助增溶作用下,活化过硫酸钠（SPS）对多环芳烃（PAHs）污染土壤的氧化修复性能。研究结果表明,室温下10%（20 g·L^-1）的Tween 80对PAHs的平均洗脱效率达到37.8%,连续淋洗样品4次,PAHs平均解吸率可达89.5%以上。当使用柠檬酸（CA）络合硫酸亚铁为活化剂时,在84 mmol·L^-1 SPS浓度条件下,将反应Fe （Ⅱ）浓度由0.84 mmol·L^-1增加至4.2 mmol·L^-1,PAHs的平均去除率可从64.3%提高至73.5%。但当Fe （Ⅱ）浓度继续增大时,PAHs的去除率反而降低。固定SPS与Fe （Ⅱ）摩尔比为20：1,当SPS浓度持续增加至168 mmol·L^-1时,总PAHs的平均去除率可提高到86.1%,之后SPS浓度对PAHs的去除率无显著影响。在活化SPS体系中添加0.25%的Tween 80后,与不加Tween 80的反应系统相比,PAHs平均去除率提高约14%。最终优化结果显示,在0.25% Tween80,42 mmol·L^-1 SPS,2.1 mmol·L^-1 Fe （Ⅱ）浓度条件下,受污染土壤中PAHs平均去除率可达到90.0%。因此,Tween 80强化过硫酸钠可作为PAHs污染场地氧化修复的有效手段。     

有机相变乳液中HCFC–141b水合物生成及稳定性

为了促进水合物形成，在HCFC–141b、有机相变材料（正癸酸和十二醇）和水体系中添加表面活性剂Tween 80和Span 80作为乳化剂，采用高速搅拌的方法制备了有机相变材料-表面活性剂-制冷剂-水乳液体系，增大水分子与制冷剂的接触面积。实验研究了静态条件下有机相变材料和表面活性剂添加量对水合物形成的影响。研究结果表明添加乳化剂可以有效提高水合物的蓄冷量，减少水合物形成诱导时间，降低水合物生成的随机性；温度越低，水合物促进效果越好。水合物生成/分解循环实验表明，添加Tween 80的乳液体系的稳定性好，有机相变乳液提高了水合物生成/分解循环过程的稳定性。     

Effects of surface-active agents on mass transfer of a solute into single buoyancy driven drops in solvent extraction systems

Numerical simulation was made of transient mass transfer to a surfactant contaminated buoyancy-driven drop controlled by appreciable resistance in both liquid phases. For this purpose, the momentum equations were formulated and solved in a boundary-fitted orthogonal coordinate system. On the basis of resolved hydrodynamics of the contaminated drop, the transient mass transfer was formulated and solved in the same coordinate system. In order to check the applicability of the numerical scheme, single drop extraction experiments were conducted in a totally closed droplet file column with the terminal effect efficiently eliminated. The MIBK-acetic acid-water system was used with small quantities of SDS (sodium dodecyl sulphate), Triton X-100, or Tween 80 introduced into the continuous phase. For these experimental cases, the flow field and the drag coefficient of a contaminated drop were simulated first. The numerical prediction of the drag coefficient is found in good agreement with the corresponding experimental data. It illustrates that the behavior of a drop approaches that of a rigid sphere and that about 100 times higher bulk concentration of SDS than that of Triton X-100 is required for the same extent contamination of a MIBK drop of the same size. Then the information of the flow field of a contaminated MIBK drop was used in simulating the transient mass transfer of solute into the drop. The resulted extraction fraction and overall mass transfer coefficient are in reasonable coincidence with the experimental data. Both numerical results and experimental data show that overall mass transfer coefficient of a heavily contaminated drop is only about one third of that in the pure system. This can be explained well by the distribution of the local Sherwood number, which drops down abruptly along the rear stagnant surface. Also the interfacial resistance of adsorbed surfactant was incorporated in the mass transfer model and then estimated by the least square fitting the simulation with data. The numerical results also show that Tween 80 presents obvious interfacial resistance on the acetic acid diffusing across the interface, whereas SDS and Triton X-100 show no interfacial resistance. It is suggested that the numerical simulation can be resorted in some solvent extraction systems containing surfactants to conduct numerical experiments and parametric study.     

Suspension thiol-ene photopolymerization: Effect of stabilizing agents on particle size and stability

The impact of several surfactant species employed in the suspension photopolymerization of water-borne thiol-ene polymer microspheres is reported. The focus of analysis was on how different surfactant species and the surfactant concentrations affected particle size and particle size distributions. Surfactants used included sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), and hexadecyltrimethylammonium bromide (HTAB), Tween 20, Tween 40, Tween 60, Tween 80, Lutensol XL 70, Lutensol XP 70, Pluronic PE 6400, and Pluronic F108 Pastille. Using stabilizing agents or surfactants is necessary to prevent extensive aggregation and agglomeration of crosslinked thiol-ene polymer. All surfactants used in this study for particle stabilization and development produced spherical thiol-ene polymer particles. The chemical structure and concentration of the surfactants influenced the final particle size and size distribution of particles obtained. In general, it was found that smaller particles are obtained with higher concentrations of stabilizing agent, especially for ionic surfactants.     

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.     

Primary aerobic biodegradation of cationic and amphoteric surfactants

The primary aerobic biodegradation of several cationic and amphoteric surfactants has been studied by using the shaking-flask degradation test and orange II spectrophotometric analysis. The results show that cationic and amphoteric surfactants can be readily biodegraded, with their degradation exceeding 94%. The degradation kinetics can be accurately described by the Boltzmann model. The relationship between structure and biodegradability is discussed. The presence of hydrophobic groups has a strong effect on the biodegradability of these surfactants. Biodegradability decreases with increasing chain length. The presence of hydrophilic groups mainly affects the degradation rate of these surfactants, but not their ultimate biodegradeability. Bio-degradability is deterred and degradation is slowed as steric hindrance increases. Degradation rates increase markedly when hydrophilic groups containing an amide bond are pres-ent.     

表面活性剂在污染土壤生物修复中的应用

评述了表面活性剂在疏水性有机物污染土壤生物修复中的应用。从表面活性剂、污染物、土壤及微生物之间相互作用的角度讨论了表面活性剂的作用机制。指出导致污染土壤生物修复效率低的一个很重要原因是传递问题,而表面活性剂的加入可以加快疏水性有机物污染物从土壤表面到水相的传质过程。目前已经发现某些表面活性剂能够促进疏水性有机污染物的生物降解,但并未发现一致的规律。     

制备球形KDNBF的新方法

介绍了一种制备球形KDNBF的新方法。通过使用PVA、吐温80、司盘、NaCMC、糊精、Triton X等表面活性剂，可以控制KDNBF的结晶形状，在这些表面活性剂中，吐温80的效果最好。制备出的KDNBF用FT-IR、DSC和元素分析等方法进行了表征。