Utilization of acid oils in making surface-active compounds by lipase-catalyzed hydrolysis and esterification reactions

Nonionic surface-active molecules were made from acid oils such as mustard, sunflower, rice bran, soybean, coconut, and polyethylene glycols (PEG) of varying molecular weights (200, 300, 400, 600), using processes based on lipasecatalyzed hydrolysis with Candida cylindracea lipase and esterification with Mucor miehei lipase. Both the PEG molecular weight and the acid oil influence the yield of ester. Molar concentration of reatants also influences the rate and yield of ester. Surface tension values of ester products reveal that maximal lowering of surface tension of water occurs in the case of PEG 600 and coconut acid oil ester. This work demonstrates an important technological advance in the synthesis of nonionic surfactants of the alkyl ethoxylate type from a variety of acid seed oils in high yields by using lipase technology involving first hydrolysis and then esterification with another lipase.     

Emulsification of Chemically Modified Vegetable Oils for Lubricant Use

Oil in water emulsions of several vegetable oils were studied in order to prepare a useful lubrication fluid. Several previously uncharacterized systems were studied in this paper, including those made from epoxidized vegetable oils. A series of different surfactants were studied in order to obtain emulsions suitable for lubrication applications. The epoxidized oils were found to form stable oil in water emulsions using several different surfactant systems. Only the (4) lauryl ether dodecyl polyethoxylated nonionic surfactant and a modified palm stearin methoxy ester ethoxylate were able to stabilize ordinary soybean oil for 1 week under our test conditions. Overall, the best surfactants were those with an HLB value slightly above 9. The droplet size of emulsions made with surfactants formed submicron droplets, whereas only droplets of larger diameter were obtained when surfactants were not added. Most importantly, a lubrication study was performed showing that even a 1% emulsion of the vegetable oils used in this study can reduce friction nearly as well as using the base oil alone.     

The characteristic curvature (Cc) definition and its use in assessing Cc for single ionic surfactants

The hydrophilic–lipophilic-difference (HLD) is a set of empirical equations that correlate the formulation conditions at phase inversion (HLD = 0). Based on partition studies for nonionic surfactants, the HLD can be interpreted as a normalized chemical potential difference between the surfactant dissolved in water and oil. The net-average curvature (NAC) model extrapolates this interpretation into a curvature form that has been used to fit and predict the phase behavior of surfactant-oil–water (SOW) systems. The curvature interpretation led to renaming the HLD surfactant parameter, sigma (σ), as the characteristic curvature (Cc). This work tests the validity of the curvature interpretation of the HLD, and the Cc concept, for single ionic surfactants and the use of this concept as a method to assess the Cc without the use of reference surfactants or alcohols. To this end, the net curvature of six anionic and two cationic surfactants was evaluated from solubilization data at the characteristic condition of 25°C, no added cosolvent, in the presence of an oil mixture with equivalent alkane carbon number (EACN) of zero, and as a function of salinity. These studies showed that the original HLD equation for ionic surfactant could not be interpreted as chemical potential or curvature because a salinity prefactor (coefficient) “bi” was missing. The revised equation, HLD_bi = bi∙ln(S)-k_bi∙EACN+Cc_bi -a_Tbi∙(T-25°C), could now be interpreted as a curvature expression, and it was demonstrated that Cc could be obtained from curvature using the expression Cc = Cc_bi/bi. This single surfactant method produces uncertainties that, for most surfactants, ranged from 0.2 to 1 Cc units, similar to the uncertainty obtained with the conventional method of Cc determination using mixtures of test and reference surfactants.     

Biodegradability and aquatic toxicity of glycoside surfactants and a nonionic alcohol ethoxylate

The environmental properties of three glycoside surfactants and one alcohol ethoxylate were examined by standardized laboratory methods. All of the surfactants biodegraded extensively in aerobic screening tests and may be assumed to approach 100% removal in aerobic wastewater treatment plants, except in cases of high loadings or otherwise exceptional conditions. Anaerobic biodegradability tests showed that an ethyl glycoside monoester (EGE) and a linear alkyl polyglycoside (APG) were both mineralized (>70%) under methanogenic conditions. In contrast, a branched APG resisted anaerobic degradation, while the alcohol ethoxylate was partially mineralized by anaerobic bacteria. The EGE surfactant was most rapidly mineralized in aerobic and anaerobic biodegradability tests. None of the surfactants inhibited respiration in activated sludge at the highest concentration tested (200 mg/L). Tests with aquatic organisms showed increasing toxicity in the following order: branched APG<EGE<linear APG<alcohol ethoxylate. Negligible aquatic toxicity was observed for the branched APG, while the alcohol ethoxylate was highly toxic to examined organisms. This evaluation demonstrates that considerable variation in biodegradability and toxicity responses can be seen within structurally related glucose-based surfactants.     

On the Characteristic Curvature of Alkyl-Polypropylene Oxide Sulfate Extended Surfactants

The hydrophobicity of alkyl-polypropylene oxide sulfate surfactants was evaluated via their characteristic curvature (Cc) using the hydrophilic-lipophilic difference (HLD) framework. A close examination of the relationship between the molecular structure of the surfactants considered (structure of the alkyl group and the number of propylene oxide groups in each surfactant) and their Cc led to a group contribution model that, for the first time, takes into consideration the geometry of the alkyl tail group. Based on this group contribution model, branching at the C2 (beta-carbon) position of the alkyl group produces the largest increase in characteristic curvature. This observation is consistent with the notion that the Cc is associated with the packing factor for anionic surfactants. Branching at the C2 position tends to produce cylindrical or inverse cone shape packing, typical of more hydrophobic (positive Cc) surfactants. This study also confirms previous observations that, different from conventional anionic surfactants, the phase behavior of alkyl polypropylene oxide sulfates is less sensitive to electrolyte concentration and that these formulations turn hydrophobic with increasing temperature, akin to the behavior of nonionic surfactants.     

Synthesis and properties of novel alkyl sulfate gemini surfactants

Four anionic gemini surfactants of the sulfate type C₁₂C_nC₁₂, where n is the spacer chain length (n = 3, 4, 6, and 10) were synthesized. The structures of these surfactants were confirmed by FT‐IR, ¹H NMR, ESI mass spectra (ESI‐MS), and elemental analysis. The surface‐active properties of these compounds were investigated by means of surface tension, electrical conductivity, and fluorescence measurements. Premicellar aggregations were found for the four gemini surfactants, as revealed by the conductivity measurement. The formation of premicellar aggregates may account for the discrepancy between the critical micelle concentration (cmc) obtained by the surface tension and conductivity measurement. The cmc values of these gemini surfactants were much lower than that of sodium dodecylsulfate (SDS) and decreased monotonously with the increase of spacer chain length from 3 to 10. The effect of spacer chain length on the performance properties like foaming, emulsion stability, and lime soap dispersing ability were also studied and discussed. Practical applications : Alkyl sulfate surfactants are one of the most widely used surfactants. The new alkyl sulfate gemini surfactants synthesized in our study are more surface‐active than sodium dodecylsulfate. These gemini surfactants possess low critical micelle concentrations, high emulsion stability, and excellent lime soap dispersing ability. They have potential applications in the fields of cosmetics, detergents, etc.     

Enzyme-based detergent formulas for fatty soils and hard surfaces in a continuous-flow device

The present work analyzes the effect of incorporating a lipolytic enzyme (Lipolase^® 100L) into detergent formulas for washing fatty soils on hard surfaces. The experimental device, which is called a “bath-substrate-flow” device, uses a continuous flow on a substrate (glass spheres) soiled with triolein. Washing tests were done using only the enzyme and changing both its concentration and the temperature of the process. The results showed that, in the presence of lipase, soil removal was achieved through three consecutive mechanisms: (i) fundamental devoval of the soil by the bath flow through the experimental device; (ii) emulsion of the soil in the washing medium; and (iii) enzymatic hydrolysis of the dispersed soil. Different commercial surfactants were used, and detergency was evaluated in the absence and presence of lipase. The use of surfactant formulas with the lipolytic enzyme showed a positive effect of the enzyme on the detergency values registered with the fatty alcohol ethoxylate surfactants Findet^® 10/15 and Findet 1214N/23, and with the anionic surfactant linear alkylbenzene sulfonate. The commercial surfactants Glucopon^® 600, Glucopon 650, Findet 10/18, and Findet Q/21.5NF alone each presented high detergency values for fatty soils, and the effect of the incorporation of the lipase was not significant.     

Effect of alkyl groups in anionic surfactants on solution properties of anionic-nonionic surfactant system

The effect of different alkyl chains of anionic surfactants on properties of binary anionic-nonionic mixed surfactant systems was studied. These systems included ocytldodecyl-, and cetylsulfoacetates mixed with isooctyl phenol nonyl ethoxylate. The critical micelle concentration of mixed surfactants shifted to lower values compared to those of the single anionic surfactants. Effectiveness values increased with decreases in the mole fraction of anionic surfactants. The negative values of interaction parameter (β) increased with increases in the chain length of anionic surfactants.     

Prediction of Cloud Point Curves of Alkyl Ethoxylates with the Hydrophilic–Lipophilic-Difference and Net-Average-Curvature (HLD-NAC) Framework

Understanding and predicting cloud point phenomena is important for the formulation of nonionic surfactant systems, and the design of cloud-phenomena-associated separation processes. There have been several approaches to fit and predict the cloud point phenomena, in most cases using bulk thermodynamic approaches. In this work, we introduced the hydrophilic–lipophilic-difference and net-average-curvature (HLD-NAC) as an interfacial (curvature) approach to predict cloud point values at different surfactant concentrations (cloud point curve). The HLD-NAC method could fully predict the cloud point of alkyl ethoxylate of pure surfactants, typically within 4 °C of the experimental values, using published HLD constants, and the molecular structure of the surfactants. For commercial (polydispersed) surfactants, the same level of accuracy can be achieved if the experimental cloud point at 1 wt.% is used to adjust the HLD values. One additional benefit of using the HLD framework is the ability to predict changes in the cloud point curve with the introduction of electrolytes. While other models can fit the experimental data within 1 °C, the greater uncertainty of the HLD-NAC (~4 °C) is a reasonable compromise given the simplicity of the approach.     

凝胶渗透色谱法测脂肪醇聚氧乙烯醚产品的相对分子质量分布

应用高效液相色谱技术 ,采用凝胶色谱柱 ,用示差折光检测器 ,对 AEO产品进行了分析 ,测出了产物的相对分子质量 ,并得到分布图 ,成功地实现了对产品的质量控制和中间控制     

Micellization and Adsorption Behaviors of New Reactive Polymerizable Surfactants Based on Modified Nonyl Phenol Ethoxylates

The synthesis and characterization of a series of polymerizable surfactants based on alkyl phenol ethoxylate backbone and carboxylic or anhydride chain ends were investigated. Surface activities of these polymerizable surfactants were investigated to correlate their structure and their performances. The new bifunctional surfmers were prepared by reacting polyoxyethylene 4-nonyl-2-propylene-phenol nonionic reactive surfactants with maleic anhydride. The chemical structure of the prepared surfactants was characterized by ¹³C and ¹H NMR analyses. The surface activities of the modified polymerizable surfactants were measured from the adsorption isotherm measurements which were determined from the relationship between the concentrations and surface tension of surfactants in aqueous medium at different temperatures. Critical micelle concentration (CMC) values were determined for water soluble surfactants. It was found that CMC decreases with the incorporation of the anhydride and acid groups in the chemical structure of polyoxyethylene 4-nonyl -2-propylene-phenol nonionic surfactant. surface-active parameters such as area per molecule at the interface (A _min), surface excess concentration (Γ_max) and the effectiveness of surface tension reduction (π_CMC) were measured from the adsorption isotherms of the modified surfactants. Some thermodynamic data for the adsorption process were calculated and discussed. The data indicated that the new surfmers are more reactive than the simple polyoxyethylene 4-nonyl-2-propylene-phenol and more adsorbed at interfaces. We have performed a preliminary experiment to explore the emulsification efficiency of the newly synthesized reactive surfactants in equal volume oil–water emulsions. Different emulsion types and stabilities were obtained.     

Synthesis and characterization of TRITON™ X‐based surfactants with carboxylic or amino groups in the oxyethylene chain end

This paper describes the synthesis and characterization of a series of TRITON™ X‐based surfactants with a predominantly alkyl phenol ethoxylate (APE) backbone and carboxylic or amino chain ends. Three carboxylic acid‐containing TRITON X (or APE)‐derivatives, [OPE2‐COOH], [OPE5‐COOH], and [OPE10‐COOH], were prepared from commercially available octyl phenol ethoxylate (OPE) of different oxyethylene units (i.e., n = 2, 5, and 10) and ethyl bromoacetate via a simple etherification reaction followed by saponification. Two amine‐containing TRITON X ‐derivatives, [NPE10‐NH₂] and [NPE10‐imidazole], were prepared based on modifications of mesylate of nonyl phenol ethoxylate (NPE) of 10 oxyethylene units reacted with ammonia and imidazole, respectively. Depending on their composition and chain length of oxyethylene units used in the reaction, the surfactants show different thermal degradation behaviors. The carboxylic acid‐containing surfactants give no char at high temperatures under air condition. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 162–170, 2007     

Effect of homolog distribution on the toxicity of alcohol ethoxylates

Previous work established a high correlation between the potential environmental toxicity of oxyethylenated nonionic surfactants and the average degree of ethoxylation. For this reason, it was considered of interest to determine whether a narrow- or broad-range homolog distribution of polydisperse commercial alcohol ethoxylates would influence toxicity. Ethoxylated fatty alcohols, both linear and branched, were synthesized with sodium hydroxide or an unconventional calcium-based catalyst. Toxicity tests were run onDaphnia magna and luminescent marine bacteria. Toxicity of ethoxylated alcohols as a function of type of ethoxylate homolog distribution (narrow or broad) and average degree of polyaddition is analogous for both test species. However, narrow-range ethoxylates show lower toxicity values than conventional ethoxylates. Differences in toxicity values between broad- and narrow-range ethoxylates depend on the degree of ethoxylation.     

The Characteristic Curvature of Ionic Surfactants

Characterizing the hydrophilic-lipophilic nature of a surfactant molecule has been a challenge for colloid scientists and technologists. The hydrophilic-lipophilic balance (HLB), the packing factor, the phase inversion temperature (PIT) and the natural curvature of the surfactant are all terms that seek to address this issue. In this article we build on the hydrophilic–lipophilic difference concept (HLD) (Salager et al. Langmuir, 16, 5534–5539, 2000) to develop a methodology to determine a characteristic curvature (Cc) for ionic surfactants based on the phase behavior of mixed ionic surfactant microemulsions. In essence, the method consists of evaluating the shift in optimal electrolyte concentration as a function of the mole fraction of the test surfactant in a mixture with a reference surfactant, sodium dihexyl sulfosuccinate (SDHS) and applying the appropriate HLD equation for ionic surfactant mixtures to determine Cc. The values of Cc were determined for a range of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), sodium naphthenate, and others. The method was also extrapolated to nonionic additives and hydrophilic linkers. It was observed that the calculated values of Cc were similar to those predicted by group contribution models, however the proposed method can be used even for complex surfactant mixtures. Finally, when Cc values were compared to apparent packing factor and HLB values, it was found that Cc is correlated with the apparent packing factor of ionic surfactants, and that Cc correlates with the HLB value for nonionic amphiphiles. The physical interpretation of Cc, and its potential application in the Net-Average Curvature equation of state for oil-surfactant-water systems is discussed.

Effect of oil type on stability of high internal phase water-in-oil emulsions with super-cooled internal phase

This study considered the stability and rheology of a type of high internal phase water-in-oil emulsions (W/O) emulsion. The aqueous phase of the emulsions is a super-cooled inorganic salt solution. The oil phase is a mixture of industrial grade oils and stabilizer. Instability of these systems manifests as crystallization of the metastable dispersed droplets with time. This work focused on the effects of oil polarity and oil viscosity on the stability of these emulsions. Ten types of industrial oils, covering the viscosity range 1.4–53.2?cP, and with varying polarity, were used in combination with polymeric poly(isobutylene) succinic anhydride (PIBSA) and sorbitan monooleate (SMO)-based surfactants. The effect of oil relative polarity on rheological parameters of the emulsion was evident mainly in the emulsions stabilized using polymeric surfactant, whereas the oil viscosity did not show any significant effect. The optimum stability of the emulsions stabilized with SMO was achieved using high polar oils with a viscosity of 3?±?0.5?cP. However, when using the PIBSA surfactant, the best emulsion stability was achieved with low polar, high viscosity oils.     

Melting-point determination of fat products

A variety of methods exist for the determination of the melting point (mp) of fats. These include the Wiley mp (AOCS Method Cc 2–38), open capillary slip point, softening point and Mettler dropping point. The conditions under which the tests are performed influence the values obtained. Several of these methods were compared using a variety of fats, including margarine and soft margarine oils, lard, butter and hydrogenated Canola oils. The Mettler dropping-point values were found to coincide with the extrapolated solid fat curves obtained using wide-line NMR for all fats except butterfat. The reproducibilities of the Mettler dropping point and softening point were excellent; that of the slip point was poor. Presented at the 73rd AOCS annual meeting, Toronto, 1982.     

How to Efficiently Remove tert-butylhydroquinone from Commercial Soybean Oils to Obtain Stripped Oils: Eliminating tert-butylhydroquinone's Influence on Oxidative Stabilities of Model Oil-in-Water Emulsions

The present study proposes an efficient method to effectively strip tert-butylhydroquinone (TBHQ) from commercial soybean oils. Ethanol, a typically common and relatively safe organic solvent, can successfully strip TBHQ by employing a liquid-liquid extraction strategy. The results show that the volume ratio of ethanol to oil is a key factor for stripping efficiency (SE), and 4:1 (v/v) is considered the optimal parameter. When compared with traditional stripping methods via adsorbing materials (such as activated charcoal or alumina powder), the proposed ethanol extraction method can more effectively strip TBHQ from commercial oils with lower adsorption loss and higher SE. Moreover, the model O/W emulsion systems prepared using ethanol stripped oils showed the highest degree of lipid oxidation. The method can completely strip TBHQ from commercial soybean oils, thereby eliminating its influence on oxidative stabilities of model oil-in-water emulsions. Practical Applications : The ethanol stripping method can be applied as a pretreatment method to completely strip TBHQ from commercial soybean oils, and subsequently eliminate the influence of TBHQ on lipid oxidation in model O/W emulsion systems during storage.     

Synthesis, Characterization, Biodegradation and Evaluation of the Surface Active Properties of Nonionic Surfactants Derived from Jatropha Oil

Four nonionic surface active agents were synthesized using the fatty acids obtained from the hydrolysis of Jatropha oil. The fatty acids obtained contained different fatty acids including: palmitic, stearic, oleic, linoleic and linolenic acids in different proportions. The chemical structures of the obtained surfactants were characterized using elemental analysis and FTIR spectroscopy. The surface activities of the different surfactants were determined using surface and interfacial tension measurements. The surfactants showed good surface and interfacial activities, which are dependent on their chemical structures. Thermodynamic parameters of adsorption and micellization confirmed these results. The biodegradation tests in river water showed that the surfactants are readily biodegradable, and reached the European standards after 24 days. Surfactants containing longer nonionic chains formed stable emulsions with paraffin oil, while shorter chains exhibit a lower emulsion stability performance.     

Rapid Quantitative Determination of Squalene in Shark Liver Oils by Raman and IR Spectroscopy

Squalene is sourced predominantly from shark liver oils and to a lesser extent from plants such as olives. It is used for the production of surfactants, dyes, sunscreen, and cosmetics. The economic value of shark liver oil is directly related to the squalene content, which in turn is highly variable and species‐dependent. Presented here is a validated gas chromatography‐mass spectrometry analysis method for the quantitation of squalene in shark liver oils, with an accuracy of 99.0 %, precision of 0.23 % (standard deviation), and linearity of >0.999. The method has been used to measure the squalene concentration of 16 commercial shark liver oils. These reference squalene concentrations were related to infrared (IR) and Raman spectra of the same oils using partial least squares regression. The resultant models were suitable for the rapid quantitation of squalene in shark liver oils, with cross‐validation r² values of >0.98 and root mean square errors of validation of ≤4.3 % w/w. Independent test set validation of these models found mean absolute deviations of the 4.9 and 1.0 % w/w for the IR and Raman models, respectively. Both techniques were more accurate than results obtained by an industrial refractive index analysis method, which is used for rapid, cheap quantitation of squalene in shark liver oils. In particular, the Raman partial least squares regression was suited to quantitative squalene analysis. The intense and highly characteristic Raman bands of squalene made quantitative analysis possible irrespective of the lipid matrix.     

Clinoptilolites of western anatolia as detergent builders

The use of clinoptilolites of Western Anatolia in detergents as phosphate substitutes was investigated. The cations present in the clinoptilolite samples were first exchanged with sodium ions. The washing characteristics of detergent mixtures containing surfactants, clinoptilolite, sodium carbonate and sodium sulphate were analysed. The stains of coffee, tea and tomato paste were tested. The washing tests were repeated for different surfactants, i.e. linear alkyl benzene sulphonate, sodium alkyl sulphate and alcohol ethoxylate and for different co-builders, i.e. sodium carbonate and EDTA. In addition, the effects of detergent dose and detergent formulation on washing were investigated. Other factors affecting the degree of soil removal such as shaking time, temperature and water hardness were also studied. The contribution of clinoptilolite to the washability was compared with zeolite A, zeolite X and sodium tripolyphosphate. Increasing the shaking time and temperature improves the degree of cleaning. LAS was the most effective surfactant for use with clinoptilolite. The washing performance of the detergent mixtures used in the present work was found to be comparable with that of commercial detergents at low washing temperatures.