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1.
Interactions of a widely used commercial anionic surfactant, linear alkylbenzene sulfonate, with zein protein, a water insoluble protein, was studied to better understand the effects of the counterion on skin irritation of anionic surfactants. The neutralizing ions used were inorganics: Li+, Na+, K+, Mg2+, and NH4+ and organics: monoethanolamine, diethanolamine, and triethanolamine. According to the results obtained, the influence of counterions of anionic surfactants on zein solubilization is significant; with magnesium counterions showing lower zein solubilization. In aqueous solutions, zein solubilization by anionic surfactant is related to the effect of the counterion on the critical micelle concentration of the surfactant for the inorganic counter‐ions; for the organic counter‐ions, effects of tighter anionic binding in the micelle also contribute to zein solubilization trends.  相似文献   

2.
The solution characteristics of the system linear alkylbenzene sulfonate (LAS)/Ca++/builder were studied using a dynamic surface tension technique. The results showed that the rate of CA++/LAS interaction is slower than the CA++ binding rate of zeolite A. Consequently, zeolite A is effective in preventing precipitation of LAS by calcium ions. The data obtained from the study of Ca++ binding detergent builders on solubilization of Ca(LAS)2 showed that zeolite A was effective but the rate of solubilization was much slower than that for STPP. Incorporation of a small amount of phosphate with zeolite A in a detergent significantly increases the rate of solubilizing of Ca(LAS)2.  相似文献   

3.
The aim of this work was to explore the feasibility of preparing thermoplastic films from commercial zein by film blowing technology. Zein, a cereal protein extracted from maize, was plasticized directly in the extruder, without the time‐consuming and expensive solubilization step, usually utilized in literature for this material. Four different batches of zein were investigated, for it has been observed that properties such as the film‐forming ability of natural polymers strongly depend on several factors such as sources, extraction, and drying conditions. Thermal, rheological, and macromolecular structural characteristics were evaluated for the different materials to establish a correlation among molecular structure, rheological behavior in uniaxial elongation, and film blowing processability. Results indicate that the best films were made by using thermoplasticized zein characterized with a pronounced strain hardening and a large content of α‐helices. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

4.
In this study, a novel film structure of corn zein coated on polypropylene (PP) synthetic films for food packaging applications was developed, and the mechanical properties of the resulting coated film, as affected by the coating formulation, were investigated. Composite structures of PP films coated with corn zein were obtained through a simple solvent casting method. Different amounts of corn zein (5 and 15%) were dissolved in 70 and 95% aqueous ethanol solution at 50°C. Solutions of corn zein plasticized with poly(ethylene glycol) and glycerol (GLY) at various levels (20 and 50%) were applied on corona‐discharge‐treated PP. A statistical analysis based on full factorial design was performed to examine the influence of the coating formulation on the final properties of the corn‐zein‐coated PP films. A significant (p < 0.05) improvement in the coated film's mechanical properties was observed compared to those of the uncoated PP. The effect of the plasticization of the coating solutions was also quite significant. In general, GLY provided better improvements in the mechanical properties of the corn‐zein‐coated PP films. The statistical analysis of the results showed that the corn‐zein and plasticizer concentrations and plasticizer type used in the coating formulations were more effective parameters and had significant effects on the mechanical behavior of the coated PP films. In conclusion, corn‐zein coatings could have potential as alternatives to conventional synthetic polymers used in composite multilayer structures for food packaging applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

5.
实验将一种阴离子表面活性剂(AOT)和一种阳离子表面活性剂(Aliquat336)分别溶于异辛烷(isooctane)中,构成了两种不同的反胶团体系.通过用两种不同的反胶团溶液萃取六种蛋白质的实验,研究了水相pH值及离子强度对反胶团体系中水含量Wo和蛋白质萃取率影响的规律.实验发现不论哪种反胶团体系,水相pH值对Wo的影响都不大,但pH值却对蛋白质萃取率有很大的影响,对AOT反胶团体系而言,随着pH值的降低,蛋白质的萃取率升高;对Aliquat336反胶团体系而言,随着水相pH值的降低,蛋白质的萃取率下降.随着离子强度的增大,AOT反胶团体系的水含量大幅度地降低;而对Aliquat336体系水含量的影响很小,但水相离子强度对蛋白质萃取率的影响是相同的,随着离子强度的增大,两种体系对蛋白质的萃取率均下降。  相似文献   

6.
Advanced oxidation processes (AOP) are able to degrade pollutants into harmless substances. To demonstrate the successful application of AOP to real, polluted effluents, ozonation has been applied for the removal of linear alkylbenzene sulfonates (LAS), a surfactant mixture commonly used in detergent formulation. LAS can be identified in a wide range of concentrations, i.e., in domestic wastewater or in the raw effluent of detergent-processing plants. The strongly tensoactive nature of LAS results in a foaming effect that eventually discourages AOP application, especially in the case of ozonation. The primary goal of this research is to analyze the LAS ozonation kinetics, considering the simultaneous effect of foam formation, by the development of a semiempirical model that is mainly based on the foaming phenomenon. Along with foaming, the proposed model also considers LAS removal by ozonation and the inverse phenomenon of LAS formation by redissolution of LAS. To the best of our knowledge, such a finding has not been previously reported. The proposed foaming model has been developed within various pH and LAS concentration values, primarily examining the initial pH value of the effluent due to its significant effect on foaming. The developed model adequately predicts the LAS concentration profiles measured in the liquid during ozonation. Moreover, this approach makes it possible to quantify the incidence of foaming and LAS redissolution during ozonation comparatively, leading to being able to propose the most desirable operating conditions for LAS removal.  相似文献   

7.
采用乳化剂聚氧乙烯脱水山梨醇油酸酯(Tw-80)和壬基酚聚氧乙烯醚(Tx-10)乳化助溶,利用正交试验法对聚六亚甲基胍(PHMG)与阴离子表面活性剂十二烷基苯磺酸钠(LAS)的复配物进行助溶实验.结果表明,Tw-80和Tx-10在单一使用时对助溶效果均没有作用,但2者配合使用对助溶效果存在高度显著的交互作用.Tw-80...  相似文献   

8.
添加剂对非离子表面活性剂浊点的影响   总被引:3,自引:1,他引:3  
研究了十二烷苯磺酸钠(LAS)、正丁醇、仲丁威对非离子表面活性剂TX-10浊点的影响。LAS与TX-10形成混合胶束,使TX-10增溶能力提高,浊点也提高;正丁醇对其影响比较复杂,少量正丁醇对浊点没有影响,当正丁醇量较大时,使单独TX-10体系浊点降低,使混合体系浊点略有升高;仲丁威使其浊点下降。正丁醇、仲丁威对TX-10浊点的影响与它们在胶束中的增溶位置有关。  相似文献   

9.
Linear alkylbenzene sulfonates (LAS) are anionic surfactants, which are found in relatively high amounts in domestic and industrial wastewaters. The effectiveness of using sonochemical reactor for the degradation of LAS from effluent of wastewater treatment plant has been investigated. In this study, experiments of LAS solution were performed using methylene blue active substances (MBAS) method. The effectiveness of sonochemical reactor for LAS degradation is evaluated with emphasis on the effect of sonication time and initial LAS concentration. Experiments were carried out at initial concentrations of 0.2 mg/L, 0.5 mg/L, 0.8 mg/L and 1 mg/L, frequency of 130 kHz, acoustic power value of 400 W, temperature of 18-20 °C and pH value of 6.8-7. This study showed that LAS degradation was found to increase with increasing sonication time. In addition, as the concentration is increased, the LAS degradation rate decreases in the sonochemical reactor.  相似文献   

10.
Electrospinning processing can be applied to fabricate fibrous polymer mats composed of fibers whose diameters range from several microns down to 100 nm or less. In this article, we describe how electrospinning was used to produce zein nanofiber mats and combined with crosslinking to improve the mechanical properties of the as‐spun mats. Aqueous ethanol solutions of zein were electrospun, and nanoparticles, nanofiber mats, or ribbonlike nanofiber mats were obtained. The effects of the electrospinning solvent and zein concentration on the morphology of the as‐spun nanofiber mats were investigated by scanning electron microscopy. The results showed that the morphologies of the electrospun products exhibited a zein‐dependent concentration. Optimizing conditions for zein produced nanofibers with a diameter of about 500 nm with fewer beads or ribbonlike nanofibers with a diameter of approximately 1–6 μm. Zein nanofiber mats were crosslinked by hexamethylene diisocyanate (HDI). The tensile strength of the crosslinked electrospun zein nanofiber mats was increased significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:380–385, 2007  相似文献   

11.
Shake flask experiments were conducted to determine the biodegradability of aqueous linear alkylbenzene sulfonate (LAS) and LAS (1600 mg dm?3) subjected to wet air oxidation (WAO), to assess the suitability of WAO as a pre‐treatment for biological degradation. The effects of WAO temperature (180–240 °C) and the concentration of the orthophosphoric acid catalyst (0–1.0 mol dm?3) were investigated. Results showed that a higher WAO temperature increased the biodegradability of the WAO effluent. This was due to a greater removal of both recalcitrant sulfonated organics and organic concentration (TOC and COD). Conversely, greater orthophosphoric acid concentrations decreased the biodegradability of the WAO effluents. This was because the higher acid concentration increased the ionic strength and changed the WAO intermediate and product distribution, inhibiting microbial action. Nevertheless, the effluents from both variations of WAO were still more biodegradable than LAS at equivalent concentrations. However, since higher WAO temperatures can substantially increase capital costs, future work should focus on developing a WAO catalyst that both desulfonates and mildly oxidises LAS at moderate temperatures (200 °C). © 2002 Society of Chemical Industry  相似文献   

12.
The development of new food preservatives is essential to prevent foodborne outbreaks or food spoilage due to microbial growth, enzymatic activity or oxidation. Furthermore, new compounds that substitute the commonly used synthetic food preservatives are needed to stifle the rising problem of microbial resistance. In this scenario, we report herein, as far as we know, for the first time the use of the zein protein as a gating moiety and its application for the controlled release of essential oil components (EOCs). The design of microdevices consist of mesoporous silica particles loaded with essential oils components (thymol, carvacrol and cinnamaldehyde) and functionalized with the zein (prolamin) protein found in corn as a molecular gate. The zein protein grafted on the synthesized microdevices is degraded by the proteolytic action of bacterial enzymatic secretions with the consequent release of the loaded essential oil components efficiently inhibiting bacterial growth. The results allow us to conclude that the new microdevice presented here loaded with the essential oil component cinnamaldehyde improved the antimicrobial properties of the free compound by decreasing volatility and increasing local concentration.  相似文献   

13.
Hydrolysis and solubilization of corn gluten were performed using a commercial protease preparation Neutrase. The effects of substrate concentration, enzyme concentration, temperature, pH and hydrolysate amount on the degree of hydrolysis and solubility of corn gluten were investigated depending on processing time. Trials were conducted in a batch reactor and degrees of hydrolysis were computed using a pH‐stat method. Results show that solubility and degree of hydrolysis were almost linearly related in all process conditions applied except in the case of hydrolysate addition. Optimum conditions for hydrolysis and solubilization were obtained as 10 g L?1 protein concentration, 4 mL L?1 enzyme concentration, 45 °C and pH 6.5. The mechanism of the kinetics was explained by taking into consideration association binding between the enzyme and substrate. The kinetics of hydrolysis and solubilization for all experiments performed were represented by exponential association equations that have not been used in the literature before. Also, to illustrate the effect of process variables on hydrolysis and solubilization, some modelling studies were performed. Copyright © 2007 Society of Chemical Industry  相似文献   

14.
已经测出直链烷基苯磺酸镁盐在水溶液中的许多特性,例如:表面张力,临界胶速浓度,比电导率,粘度,溶解性,生物降解性,毒性和对硬水的稳定性等,同时与相应的钠盐作用了对比。  相似文献   

15.
对直链烷基苯磺酸镁盐(LAS2 Mg) 与钠盐水溶液中诸多性质的对比做了大量研究。例如, 表面张力、临界胶束浓度、比电导、粘度、溶解性、生物降解性、毒性及耐硬水性等。同时, 对LAS2 Mg 的其它性能如Zein 试验( 一种皮肤刺激性试验) , 润湿性及在盥洗用品和餐具洗涤剂中的应用性能也进行了测试。镁盐的一些特殊性质及其在洗涤剂和化妆品领域中新的应用的可能性得到了证实或确认。  相似文献   

16.
Three methods of quantifying total phenolic compounds in marine brown algae were compared for their ability to measure accurately known concentrations of phloroglucinol in the presence of a protein, bovine serum albumin (BSA). These methods were: (1) a Folin-Ciocalteu assay for compounds dissolved in 80% methanol, (2) a Folin-Ciocalteu assay for compounds dissolved in 75% methanol-25% trichloroacetic acid, and (3) an assay in which polyvinylpolypyrrolidone (PVPP) was used to remove phenolic compounds in order to quantify nonphenolic, Folin-Ciocalteu-reactive materials. The Folin-Ciocalteu assay used with compounds dissolved in 80% methanol was the method that produced the most consistent results. It was also the assay in which the presence of proteins interfered least with the measurements of phloroglucinol and the assay that was easiest to conduct. The presence of TCA decreased the pH of the extracting solution and increased the amounts of proteins in solution. These proteins later interfered with the Folin-Ciocalteu reaction. TCA effectively bound proteins when protein concentrations were low but not when protein concentrations were high. The amount of phloroglucinol removed by PVPP varied widely and was dependent on phloroglucinol concentration, making this an unreliable method for quantifying phenolic concentrations. The Folin-Ciocalteu assay will measure some nonphenolic substances when brown algae are extracted in 80% methanol; however, inFucus gardneri, nonphenolic substances were at most 5% of the material quantified by the assay.  相似文献   

17.
用玉米醇溶蛋白测试表面活性剂的刺激性   总被引:2,自引:0,他引:2  
表面活性剂的刺激性不同,使醇溶蛋白水解出的氨基酸数量有所差别。zein测试方法就是通过测定zein值,即表面活性剂溶液中有醇溶蛋白时测得的氮含量和无醇溶蛋白时测得的氮含量之差,判断表面活性剂刺激性的强弱。使用自制的玉米醇溶蛋白,利用zein测试法,对月桂醇硫酸酯盐、月桂醇聚氧乙烯醚硫酸酯盐和不同碳链的烷基硫酸镁等表面活性剂的刺激性进行了评价。其实验结果与文献完全吻合,表明zein测试法具有很好的重复性和可信度。  相似文献   

18.
主要考察了烷基苯磺酸钠(LAS)与十六烷基二苯醚双磺酸盐(D8390)复配体系在不同复配比、不同浓度、不同水硬度、不同温度条件下对不同种类污布的洗涤能力。结果表明:(1)对于碳黑、皮脂两种污布,单独D8390的洗涤能力不及LAs,LAS/D8390复配体系在w(LAS):w(D8390)=8:2—7:3范围内洗涤能力最高;(2)对于蛋白污布,单独D8390的洗涤能力明显高于LAS,且在两者复配体系中,随着D8390含量的增加,洗涤能力先快速增大,在w(LAS):W(D8390)=3:7时达到最高点,之后略降低。(3)在W(LAS):W(D8390)=7:3的复配体系中,活性物总质量浓度在0.10%-0.20%范围内,质量浓度对碳黑、皮脂两种污布的洗涤能力影响不明显,但随着浓度的降低,对蛋白污布的洗涤能力明显降低;(4)采用LAS与D8390进行复配,可以明显改善体系在高硬度、低温下的洗涤能力。  相似文献   

19.
The effect of the concentration of linear alkylbenzene sulfonate (LAS) on soil removal efficiency at various water hardnesses was studied. The present investigation indicates that: (i) For each LAS concentration, a calcium ion concentration interval exists, defined by 0.78<(Log(LAS)/Log(Ca))<0.85, where the detergency reaches a maximum; (ii) 24 h after having been prepared, the solutions present either clear solutions (water appearance), milky solutions (without precipitate in the bottom of the bottle), or clear solutions with precipitate in the bottom of the bottle. The milky solutions correspond to the defined interval. The solutions where the relationship LAS/Ca is defined are located, surprisingly in a precise zone of the LAS-calcium solubility diagram. The study has been carried out with and without ionic strength buffering, and the addition of electrolyte moves the maximum detergency performance interval to higher calcium concentrations.  相似文献   

20.
Foam height and foam stability of solutions of a linear alkylbenzene sulfonate (LAS) were measured according to the Ross-Miles test to establish their relationship with ionic concentrations in the solution. The anionic concentration and water hardness were varied alternatively. The results obtained show different behavior for both parameters depending on the concentration of LAS and calcium. However, the results are in line with the proposed theoretical model based on the LAS-calcium precipitation boundary diagram. These tests were aimed at providing a scientific explanation to the complex foaming phenomena. Also, these tests emphasize how essential it is to know the position of the points tested within the LAS-calcium solubility diagram when evaluating the foam properties of an anionic surfactant.  相似文献   

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