Adsorption of Anionic Surfactant Mixtures by Polymeric Resins

Abstract

Results concerning the single-solute adsorption of two anionic surfactants were presented in a previous paper; this paper deals with their mixtures. Equilibrium adsorption isotherms of mixtures of sodium lauryl sulfate and sodium dodecylbenzene sulfonate in aqueous solution by Amberlite XAD-4 and XAD-7 polymeric resins at 10 and 30°C have been obtained and are compared to the predictions given by several multicomponent adsorption models that make use of the single solute adsorption data already available. Reasonable agreement has been achieved in some cases, especially when predicting total surfactant adsorption.     

Optimum Coagulant from Acacia mearnsii de Wild for Wastewater Treatment

A novel coagulant agent from Acacia mearnsii de Wild tannin extract was characterized for removal of the anthraquinonic colorant Alizarin Violet 3R and the anionic surfactant sodium dodecylbenzene sulfonate. This coagulant is the result of a previous optimization study. The influence of operative variables such as temperature, coagulant dosage, initial pollutant content, and pH was investigated. The new coagulant demonstrates a high affinity for dye and surfactant and is efficient within a wide range of working conditions. While the temperature does not affect the coagulant ability, an acidic pH seems to increase the contaminant removal from aqueous solutions. Implementation in a pilot plant confirms the feasibility of this coagulant not only at lab scale, but also at higher level.     

Flotation Using Microgas Dispersions for the Removal of Pentachlorophenol from Aqueous Solutions

ABSTRACT

Microgas dispersions called colloidal gas aphrons (CGAs) were generated using cationic, anionic, and nonionic surfactants, and were used in an adsorptive bubble flotation process in a semibatch mode to remove pentachlorophenol (PCP) from the aqueous phase. The aqueous solution was maintained at pH values by using buffers. CGAs generated with Tergitol, which is a nonionic surfactant, were found to be the most efficient for the removal of PCP; the efficiency remained nearly independent of pH. In the case of an anionic surfactant, sodium dodecylbenzene sulfonate (DDBS), the efficiency of removal improved from 15 to 36% with a change in pH from 10.1 to 3.0. For a cationic surfactant, hexadecyltrimethylammonium bromide (HTAB), the removal at pH 10.1 was 81%, which decreased to 68.1% at pH 3.0. The charges on the encapsulating film of CGAs may explain the higher percentage of adsorption of PCP on the CGAs generated using HTAB as compared to CGAs generated using DDBS. For all the surfactants, an increase in concentration improved the removal efficiency. These results were compared with the removal efficiencies using conventional flotation techniques used by other researchers. Solvent sublation appears to be effective in the removal of PCP, but even in the presence of a surfactant it required 300% more air volume per volume of liquid when compared with CGA flotation.     

The effect of builders on the activity of protease enzymes

The effect of builders on the stability of protease enzyme activity was studied in an effort to identify superior builders which are soluble in water and compatible with enzymes formulated into heavy duty laundry powders. Various poly(styrenesulfonate-methacrylate) copolymers, polyacrylate and tripolyphosphate anionic builders, as well as various poly(vinylalcohol-vinylacetate) nonionic copolymers, namely PVAs, were used. Zeolite 4A was also used as a typical nonphosphate particulate builder in the detergents. The protease used is frombacillus stearothermophilus. The calcium content was determined to be 16.7 mole/mole of protease by atomic spectrophotometry. In binary systems composed of a fixed concentration of 10 U/mL protease and varied concentrations of compound, builder or surfacant, it was found that compounds having the larger calcium ion binding capacity (C.B.C.) lowered the relative activity of protease enzyme. The activity of protease enzyme alone was lowered about 20% by addition of 0.02% sodium dodecylbenzene sulfonate (DBS). The anionic builders added to the binary system of fixed 10 U/mL protease and 0.02% DBS reduce the protease enzyme activity in proportion to the magnitude of their C.B.C. Addition of anionic builders further lowered the protease enzyme activity. The nonionic builders and the nonionic surfactant can enhance the protease enzyme activity by protection of protease against the inhibitor, DBS. It is certain that calcium atoms contained in the protease must play an important role for the protease enzyme activity and its stability. Calcium atoms must have a great influence on the formation of protease-substrate complex, protease-compound complex and substrate-compound complex, because the protease, protein substrate and anionic compound would all be negatively charged in alkaline solutions. Builders for enzyme-containing detergents should be constructed to be insensitive to calcium ion.     

利用胶质气体泡沫分离细微颗粒

This paper presents a method of separation of fine particles, of the order of a few microns or less, from aqueous media by flotation using colloidal gas aphrons (CGAs) generated in aqueous solutions. More than 150 experiments were conducted to study the effects of surfactant type, surfactant concentration, CGAs flow rate, and particle concentration on the removal efficiency (fine particles of polystyrene were used as a target compound). The results indicate that CGAs, generated from cationic surfactant of hexdecyltrimethyl ammonicum bromide (HTAB) and anionic surfactant of sodium dodecylbenzne sulfonate (SDBS), are an effective method for the separation off ine particles of polystyrene from wastewater. The flotation yields are higher than 97%.     

An experimental study of interaction between surfactant and particle hydrogels

Polyacrylamide gel was synthesized to study interaction between surfactant and particle hydrogel. Surfactants used in this study include cationic surfactants, n-dodecylpyridinium chloride, (1-hexadecyl) pyridinium bromide; anionic surfactants, sodium salt of dodecylbenzene sulfonic acid, sodium 4-n-octyl benzene sulfonate and sodium branched alcohol propoxylate sulfate; and nonionic surfactants, Igepal^® CO-530, Tergitol^® NP-10 and Neodol^® 25-12. It has been found that, after swelling of the dry particles, surfactant concentration shows a substantial increase. Meanwhile, dynamic modulus (G′ and G") of the gels shows a significant decrease in the surfactant solutions. Based on the experimental results, a mechanism has been proposed to elucidate the reduction of the gel dynamic modulus. Furthermore, this mechanism was discussed through surfactant critical packing parameters (CPP) at the interface of the hydrogel particle and surfactant aqueous solution, and confirmed by recovery of the gel dynamic modulus after removal of the surfactant from the hydrogels.     

Synthesis and Micellization Properties of New Anionic Reactive Surfactants Based on Hydrogenated Cardanol

We report the synthesis, characterization and micellization properties of two anionic reactive surfactants based on 3-pentadecyl phenol obtainable from a renewable resource, cardanol. The synthesis is achieved through simple chemical transformations, first converting the phenol to the acrylate that is sulfonated in a second step. The products were characterized by elemental analysis and spectroscopic techniques. The surfactant properties of the sulfonated acrylates were measured and compared with the standard non-reactive anionic surfactant sodium dodecyl sulfonate. The micellization behavior of aqueous solutions was studied using conductivity, surface tension measurements, and the fluorescence probe technique based on diphenyl hexatriene. Characterization by surface tension measurements facilitated the determination of basic surfactant properties like the critical micelle concentration (CMC), the surface tension at the CMC, surface excess and area per surfactant molecule. The Gibbs free energy of micellization showed a negative value suggesting spontaneous micellization in aqueous solution. The micellization of the surfmer with an ethylene spacer between the phenyl ring and the acrylate group seems to be enhanced as indicated by the lower surface excess and lower free energy. Its CMC was also lower.     

表面活性剂对聚脲甲醛包覆双环戊二烯微胶囊的影响

采用阴离子、非离子和高分子3类表面活性剂及不同浓度的DBS溶液,研究了表面活性剂种类及浓度对聚脲甲醛包覆双环戊二烯微胶囊的物理性能的影响,并通过光学-摄影显微镜对微胶囊表面形貌、粒径尺寸及分布等进行了表征。结果表明,DBS和明胶对微胶囊的形成有积极作用;当DBS浓度接近CMC时,微胶囊表面较光滑;超过CMC后,DBS浓度增加,微胶囊表面粗糙度增大。     

4种阴离子表面活性剂易漂洗性能的比较研究

采用实验室建立的同时测定模拟漂洗硬水条件下泡沫衰减性和织物上表面活性剂的初始/残留吸附量的方法,对家居织物洗涤剂中常用的4种典型的阴离子表面活性剂的易漂洗性能进行了比较研究,并考察了易漂洗性能与表面活性剂的钙离子稳定性之间的关系。实验结果表明,表面活性剂的钙离子稳定性与硬水漂洗液的泡沫性正相关,而与表面活性剂在织物上的初始/残留吸附量负相关。具有适中钙离子稳定性的改性羧酸盐(N-月桂酰基肌氨酸钠)具有最佳易漂洗性,磺酸盐(十二烷基苯磺酸钠)次之,而钙离子稳定性极低的皂类(月桂酸钠)或钙离子稳定性极高的阴-非离子型硫酸酯盐(十二烷基聚氧乙烯醚硫酸钠)均不属于易漂洗表面活性剂。这一研究结果对易漂洗阴离子表面活性剂的分子结构设计以及节水型洗涤剂的研发具有理论指导意义和应用价值。     

硝酸溶液中十二烷基苯磺酸钠对锌的缓蚀作用及吸附热力学研究

采用失重法研究了硝酸介质中烷基磺酸盐类阴离子表面活性剂对锌的缓蚀及吸附作用,考察了在不同温度的3%硝酸中,不同浓度的十二烷基苯磺酸钠对锌的缓蚀作用。实验结果表明,十二烷基苯磺酸钠能很好的抑制锌的腐蚀,当其含量达到一定浓度后,缓蚀作用基本保持不变,而其在锌表面上的吸附是产生缓蚀作用的重要原因。在浓度为0~300 mg/L时,十二烷基苯磺酸钠在锌表面的吸附规律服从Langmuir吸附等温式。用Sekine方法处理实验数据,从而获得了ΔH0、ΔS0和ΔG0等一系列相关的热力学参数。     

罗丹明B光谱探针测定祛斑霜中微量汞

罗丹明B为光谱探针,研究了在三羟甲基氨基甲烷-HCl缓冲溶液(pH=6.5)中,十二烷基苯磺酸钠(SDBS)存在下,分光光度法测定祛斑霜中微量汞离子,得出了测定的优化条件.实验表明,室温下罗丹明B-SDBS-Hg2+形成水溶性三元复合物,最大吸收波长为554 nm,表观摩尔吸光系数ε=2.43×105L·mol-1·cm-1.Hg2+质量浓度在0～3.00μg/mL范围内服从朗伯-比尔定律.检出限为0.021μg/mL,加标回收率为98.5%～100.3%,RSD为1.06%～1.11%.     

Sodium Cardanol Sulfonate Surfactant from Cashew Nut Shell Liquid

Sodium cardanol sulfonate surfactant was synthesized from cardanol from cashew nut shell liquid. Surfactant properties of cardanol sulfonate were determined and compared with dodecylbenzene sulfonate. Surface tension values were determined to be 32.25 mN/m for cardanol sulfonate at 20% w/v and 28.00 mN/m for dodecylbenzene sulfonate at 15% w/v. Critical micelle concentrations of dodecylbenzene sulfonate and cardanol sulfonate were found to be 0.435 and 0.372 mol/L, respectively. In comparison with dodecylbenzene sulfonate, the relative detergency of cardanol sulfonate was calculated to be 93.7% compared to dodecylbenzene sulfonate. Results suggest that cardanol sulfonate can be used as alternative anionic surfactant.

Preparation of organoclay by a precipitation–adsorption method

Organoclay was prepared by a precipitation–adsorption process in which sodium‐montmorillonite (Na‐MMT) suspension was fully mixed with an anionic surfactant, sodium dodecylbenzene sulfonate, and then precipitation agent CaCl₂ was added to produce a precipitate of organophilic montmorillonite (OMMT). The Na‐MMT suspension was obtained by ion‐exchange reaction of bentonite with sodium cation resin. Fourier transform infrared spectroscopy spectral analysis confirmed the adsorption of organic groups on the MMT, and the organic groups content was calculated from the results of thermal gravimetric analysis. X‐ray diffraction results indicated that the OMMT prepared was exfoliated. In this article, the mechanism of the precipitation–adsorption process was discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Phase behavior and hydrated solid structure in lysophospholipid/long-chain alcohol/water system and effect of cholesterol addition

Phase behavior in lysophospholipid/long-chain alcohol/water system at 80°C was investigated using hexanol and oleyl alcohol as the long-chain alcohol. Similarly to hydrophilic surfactant, a micellar phase in a lysophospholipid/water system transitioned to a lamellar liquid-crystalline phase by the addition of long-chain alcohol. In the oleyl alcohol system the lamellar liquid-crystalline phase was observed in wider region compared to the hexanol system. The effect of cholesterol addition on the phase behavior was also studied. The region of liquid-crystalline phase and (reverse micellar + liquid-crystalline + water) phase shifted towards higher lysophospholipid concentrations. The structure of hydrated solid as well as the transition between lamellar liquid-crystalline phase and hydrated solid was analyzed by X-ray scattering measurement and differential scanning calorimetry measurement. It was revealed that the hydrated solid was α-type crystals with lamellar structure. The hydrated solid (gel)-liquid crystal transition temperature gradually decreased with increasing oleyl alcohol concentration and the decrement was enhanced by the addition of cholesterol.     

分光光度法测定水中微量阴离子表面活性剂

在用HCl溶液调节pH=12.0的NaOH溶液中,5-甲基-2-[3-(4-苯基-2-噻唑基)三氮烯基]苯磺酸(MPTTBSA)与氯化十六烷基吡啶(CPC)形成离子缔合物MPTTBSA-CPC。在该溶液中加入阴离子表面活性剂时,能定量置换出离子缔合物中的MPTTBSA,使缔合物在最大吸收波长556 nm处的吸光度下降,阴离子表面活性剂的浓度与溶液的褪色程度呈良好线性关系,从而建立了阴离子表面活性剂光度测定法。实验结果表明,十二烷基磺酸钠(SLS)和十二烷基苯磺酸钠(SDBS)的表观摩尔吸光系数分别为1.24×104 L·mol-1·cm-1和1.07×104 L·mol-1·cm-1,在0～2.5×10-5 mol·L-1范围内服从比尔定律。该方法应用于生活污水中微量阴离子表面活性剂(以SLS计)的测定,结果与亚甲基蓝法测定结果基本一致。     

Solubilization Behavior of Phorbol Esters from Jatropha Oil in Surfactant Micellar Solutions

Phorbol esters (PEs) are important toxic compounds found in Jatropha curcas oil and pressed seeds. These compounds are tumor promoters; thus, their removal prior to further utilization of the pressed seed is important. This work aimed to investigate the solubilization behavior of PEs and Jatropha oil in nonionic [effect of the ethylene oxide number (EON), carbon‐chain length and temperature] and anionic (NaCl addition) surfactant systems. The results reveal that an increase in the EON of the nonionic surfactant molecules, rather than an increase in the carbon‐chain length, enhances PE solubilization. The hydrophile‐lipophile balance (HLB) value was correlated with PE solubilization for nonionic surfactant solutions. The solubilization of PEs decreased slightly with increasing temperature, in contrast to solubilization of the oil. Moreover, the mole fraction of PE solubilized in the micelle decreased with increasing electrolyte concentration in anionic surfactant solutions. The solubilization behavior of PEs in both nonionic and anionic solutions indicates that PE acts more like a polar compound than a nonpolar compound. In addition, the PEs in nonionic micelles are likely located in the palisade region (i.e., between the head group and the first few carbon atoms of the tail), whereas those in anionic micelles are likely near the outer core of the head group. This finding suggests that a nonionic surfactant with a higher EON has a greater potential to extract PE from Jatropha seeds. If an anionic surfactant is combined as co‐surfactant, a small amount of electrolyte should be added to increase PE solubilization.     

Adsorption mechanism of surfactants on nonwoven fabrics

For improved surface properties, nonwoven fabrics of polypropylene and poly(ethylene terephthalate) were treated with several kinds of surfactants, including anionic, cationic, and nonionic types. The adsorption isotherms of the anionic, cationic, and nonionic surfactants on the nonwoven fabrics were different. The adsorption isotherm of the cationic surfactant (dodecyl dimethylbenzyl/ammonium chloride) exhibited a maximum. The adsorption isotherm of the anionic surfactant (sodium dodecylbenzene sulfonate) was in the shape of the fifth Brunauer adsorption isotherm, and that of the nonionic surfactant (alkylphenol/ethylene oxide condensate) was similar to the fourth Brunauer adsorption isotherm. The time of the adsorption equilibrium was constant for the same types of adsorbate and adsorbent, and it was not related to the initial concentration. The specific surface resistance of the nonwoven fabrics decreased substantially after the adsorption of ionic surfactants. The nonwoven fabrics with the surfactants were characterized with scanning electron microscopy and X‐ray photoelectron spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3210–3215, 2003     

表面活性剂对铝酸钠溶液中一水软铝石晶种分解的影响

研究了非离子及阴离子型表面活性剂(聚乙二醇、聚氧乙烯月桂醚和十二烷基苯磺酸钠)对铝酸钠溶液晶种分解制备一水软铝石的影响. 结果表明,十二烷基苯磺酸钠抑制溶液分解及晶体附聚,导致产物粒度细化;聚乙二醇可强化溶液分解,并促进晶体附聚;PEG1000添加量为1 g/L时获得最高分解率(32.39%),较空白提高8.37%;PEG1000添加量为5 g/L时附聚效果最好,产物的中位粒径为23.86 mm,较空白提高4.5%. XRD和热重分析结果表明,添加剂未改变产物晶型,产物均为一水软铝石和三水铝石.     

CLAs制备及其稳定性的实验研究

制备了预分散溶剂萃取所需的胶质液泡(CLAs),探讨了溶质的存在对CLAs稳定性的影响. 结果发现,在表面活性剂浓度相同时[离子型表面活性剂浓度为1 g/L,非离子型表面活性剂浓度为1.0%(j)],溶质(苯甲酸)的存在对CLAs稳定性的影响很大,许多在没有溶质存在的条件下能够制备得到稳定的CLAs的表面活性剂组合,在加入了溶质后,不能再制备得到稳定的CLAs. 对于在溶质存在的条件下仍能制备得到稳定的CLAs的表面活性剂组合,考察了表面活性剂浓度对所制得的CLAs平均直径的影响. 结果发现,随着离子型表面活性剂和非离子型表面活性剂浓度的增大,CLAs平均直径逐渐减小. 另外,考察了离子型表面活性剂的类型对CLAs稳定性的影响. 结果发现,当表面活性剂浓度相同时[离子型表面活性剂浓度为1 g/L,非离子型表面活性剂浓度为1.0%(φ)],阴离子表面活性剂十二烷基硫酸钠和十二烷基苯磺酸钠可制备得到稳定的CLAs,而阳离子表面活性剂十六烷基三甲基溴化铵不能制备得到稳定的CLAs.     

Mixed-surfactant system of dodecylbenzene sulfonate and alpha-olefin sulfonate: Micellar and volumetric studies

Critical micelle concentrations of sodium salts of dodecylbenzene sulfonate, alpha-olefin (C₁₆) sulfonate, and their mixtures have been evaluated by measuring the surface tensions of solutions at 298.15 K. Interaction parameters for mixed monolayer formation (β^σ) and mixed-micelle formation (β^M) have been calculated from the critical micelle concentration data. Densities of solutions of surfactants and their mixtures were measured with a vibrating-tube densimeter at 298.15 K. Apparent and partial molar volumes have been evaluated from solution density data. Results of the micellar properties have been eplained on the basis of a nonideal multicomponent mixed-micelle model. The mixed-surfactant system exhibits synergism in all aspects when the mole fraction of alpha-olefin sulfonate in the mixture is 0.2. Volumetric properties correlate well, as the partial molar volumes also show a minimum at the same composition of the mixture. Formation of a compact mixed micelle at this composition has been envisaged.