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1.
Compost humic acid-like (cHAL) polymeric matter (MW = 15610), isolated in 12% yield from food and green waste compost, exhibits very good surfactant properties in aqueous solution: i.e., critical micelle concentration (cmc) = 403 mg/L and surface tension at cmc = 36.1 mN/m. Values of cmc are confirmed also by conductivity and phenanthrene solubility measurements. These results, compared with those for other major commercial and research surfactants, propose cHAL as a competitive low-cost biosurfactant.  相似文献   

2.
[目的]为解决水溶性香精爆珠的稳定成型问题,通过反滴法制备毫米级中空海藻酸钙载水胶囊(水润珠),研究液滴的表面张力对水润珠成型的影响.[方法]采用Tween 80、Poloxamer 407和APG 0810三种非离子表面活性剂调控氯化钙/羧甲基纤维素钠(CaCl2/CMC)液滴的表面张力,考察液滴表面张力对水润珠形貌...  相似文献   

3.
The removal of dense nonaqueous phase liquid mixtures (DNAPLs) from rocks and subsurface soils is an ongoing remedial challenge. Very often the wetting preferences of the system are not altered by exposure to the DNAPL. However, there are systems where the wetting properties of the solid phase have been altered from strongly water wetting by exposure to the DNAPL. In these cases some technique is necessary for reducing the work of adhesion between the DNAPL and the mineral surface. The focus of this report is the problems posed by coal tar in unconsolidated sands. It is shown that coal tar can alter the wetting properties of quartz, the principal component of sands, and is thus capable of adhering to the surface. In this investigation the ability of several members of the poloxamine family of polymeric surfactants to aid in the removal of coal tar from sand was evaluated. The poloxamines are tetrafunctional block copolymeric surfactants, which contain four poly(ethylene oxide)-block-poly(propylene oxide) chains joined to a central ethylenediamine moiety via the nitrogen atoms. Contact angle measurements of coal tar on a quartz surface immersed in aqueous surfactant solution and the interfacial tension between coal tar and aqueous surfactant solution have been measured. Coal tar/water interfacial tensions are reduced to values in the region of 2 mN m(-1) at surfactant concentrations of approximately 0.1 w/v %. Poloxamine surfactant impact on the static contact angle is more complex. In some cases the polymeric surfactants alter the wetting behavior from strongly water wetting to weakly water wetting. However, other poloxamines appear to have little if any impact on the contact angle, which remains strongly water wetting. The foregoing measurements have then been used to calculate the work of adhesion of the coal tar to quartz and the results qualitatively compared with the concentration of surfactant solution required to visually demonstrate the complete de-adhesion of coal tar to the quartz. It is shown that at surfactant concentrations below the critical micelle concentration (cmc) of the surfactant, the work of adhesion can be reduced sufficiently to ensure complete removal of coal tar from both quartz and sand.  相似文献   

4.
反丁烯二酸蔗糖甲酯的功能特性研究   总被引:7,自引:0,他引:7  
基于防腐防霉剂的构效关系和乳化剂的分子结构特点,合成了反丁烯二酸蔗糖甲酯。抑菌实验表明:对几种常见微生物,酯化度为5.5的反丁烯二酸蔗糖甲酯的最低抑菌浓度比山梨酸的低而接近于富马酸二甲酯,说明其具有较高的抗菌活性;反丁烯二酸蔗糖甲酯的抗菌半衰期要长于山梨酸和富马酸二甲酯,说明其抗代谢性能好,具有一定的开发应用价值。乳化实验表明:酯化度为5.5的反丁烯二酸蔗糖甲酯的HLB值为6.8、临界胶束浓度为0.7g,L、浓度为0.3%溶液的表面张力为28.5mN/m,都接近于span-80,说明反丁烯二酸蔗糖甲酯具有一定的表面活性。有关反丁烯二酸蔗糖甲酯的抗菌特性及乳化特性在食品、日化及涂料等工业领域的应用有待于进一步研究。  相似文献   

5.
Recent field studies have indicated synergistic effects of coupling microbial reductive dechlorination with physicochemical remediation (e.g., surfactant flushing) of dense nonaqueous phase liquid (DNAPL) source zones. This study explored chlorinated ethene (e.g., tetrachloroethene [PCE]) dechlorination in the presence of 50-5000 mg/L Tween 80, a nonionic surfactant employed in source zone remediation. Tween 80 did not inhibit dechlorination by four pure PCE-to-cis-1,2-dichloroethene (cis-DCE) or PCE-to-trichloroethene (TCE) dechlorinating cultures. In contrast, cis-DCE-dechlorinating Dehalococcoides isolates (strain BAV1 and strain FL2) failed to dechlorinate in the presence of Tween 80. Bio-Dechlor INOCULUM (BDI), a PCE-to-ethene dechlorinating consortium, produced cis-DCE in the presence of Tween 80, further suggesting that Tween 80 inhibits dechlorination by Dehalococcoides organisms. Quantitative real-time PCR analysis applied to BDI revealed that the number of Dehalococcoides cells decayed exponentially (R(2) = 0.85) according to the Chick-Watson disinfection model (pseudo first-order decay rate of 0.13+/-0.02 day(-1)) from an initial value of 6.6 +/-1.5 x 10(8) to 1.3+/-0.8 x 10(5) per mL of culture after 58 days of exposure to 250 mg/L Tween 80. Although Tween 80 exposure prevented ethene formation and reduced Dehalococcoides cell numbers, Dehalococcoides organisms remained viable, and dechlorination activity pist cis-DCE was recovered following the removal of Tween 80. These findings suggest that sequential Tween 80 flushing followed by microbial reductive dechlorination is a promising strategy for remediation of chlorinated ethene-impacted source zones.  相似文献   

6.
Surfactant- (hexadecyltrimethylammonium, HDTMA) modified zeolite (SMZ)/zero-valent iron (ZVI) pellets having high hydraulic conductivity (9.7 cm s(-1)), high surface area (28.2 m2 g(-1)), and excellent mechanical strength were developed. Laboratory column experiments were conducted to evaluate the performance of the pellets for perchloroethylene (PCE) sorption/reduction under dynamic flow-through conditions. PCE reduction rates with the surfactant-modified pellets (SMZ/ZVI) were three times higher than the reduction rates with the unmodified pellets (zeolite/ZVI). We speculate that enhanced sorption of PCE directly onto iron surface by iron-bound HDTMA and/or an increased local PCE concentration in the vicinity of iron surface due to sorption of PCE by SMZ contributed to the enhanced PCE reduction by the SMZ/ZVI pellets. Trichloroethylene and cis-dichloroethylene production during PCE reduction increased with the surfactant-modified pellets, indicating that the surfactant modification may have favored hydrogenolysis over beta-elimination. PCE reduction rate constants increased as the travel velocity increased from 0.5 to 1.9 m d(-1), suggesting that the reduction of PCE in the column systems was mass transfer limited.  相似文献   

7.
Surfactant sorption is of considerable importance to environmental applications, including surfactant flushing to mobilize hydrophobic contaminants; effects of surfactants on the transport of dissolved contaminants, microorganisms, and colloids through porous media; and bioremediation of hydrophobic organic compounds, as well as understanding the fate and transport of surfactants as environmental contaminants themselves. Although most sorption studies consider pure surfactants, commercial detergent formulations typically consist of mixtures of nonionic and anionic surfactants. In this study, the effects of varying concentrations of the anionic surfactant linear alkylbenzene sulfonate (LAS) on micelle formation and sorption behavior of the two commonly used nonionic surfactants Brij 30 and Brij 35 onto aquifer sand were examined. A strong linear relationship was observed between the critical micelle concentration (CMC) of the Brij surfactants and the concentration of LAS in the mixture, with the CMC decreasing with increasing concentration of LAS. The relative change in CMC as a function of the LAS concentration was identical forthe two Brij surfactants, indicating that LAS interacted with their common alkyl chains. Sorption isotherms were developed for Brij 30 and Brij 35 present as single surfactants in an aqueous solution as well as when present with LAS. Although LAS had minor effects on the maximum sorption plateaus of the Brij surfactants, Brij sorption at was significantly enhanced as a function of the LAS concentration for Brij aqueous concentrations below the CMC. Application of a multi-interaction isotherm model indicated that the formation of surface aggregates (e.g., hemimicelles) decreased with increasing LAS concentration. Overall, these results provide insight into the complex sorption behavior of surfactant mixtures.  相似文献   

8.
The research in this paper was aimed at finding a treatment method for recovery of fruit candy (fruit leathers) wastes. Fruit leather wastes were dissolved in water to investigate the efficacy of activated carbon adsorption to remove food colorants, which reduce recycling possibilities. The effects of initial pH (2.5-9), food colorant concentration (10-110 g fruit leather/L) and adsorbent dosage (1-12 g/L) on the adsorption process were investigated. Maximum adsorption was obtained at the original pH value of dissolved fruit candy waste in water. Maximum adsorbent capacities for red, yellow and blue food colorants were 4.4; 11.7 and 2 mg/g at pH 3.5 respectively. Regeneration of food colorant loaded activated carbon can be effected at 400 °C. Cost estimates indicate that red color removal would seem to be an economical proposition, costing about $19/ton fruit candy waste, yellow marginal at $70/ton waste, and blue uneconomical at $245/ton waste.  相似文献   

9.
The effects of phenolic-rich extracts from avocado peels (AP) and seeds (AS) on the colloidal and the lipid oxidative stability of oil-in-water (O/W) emulsions/nanoemulsions were evaluated. For this purpose, the interfacial tension (IFT) of avocado oil droplets in the presence of extracts and surfactants (low methoxyl pectin, LMP; Tween 80, T80), individually or combined, was assessed. Individually, T80 led to the lowest IFT values (4.25 ± 0.02 mN/m), followed by AS and AP extracts (9.27 ± 0.86 mN/m and 12.31 ± 0.10 mN/m, respectively) and LMP (14.88 ± 0.05 mN/m). Regarding particle size, the emulsions containing AP and AS extracts were smaller (1.45 ± 0.10 μm and 1.11 ± 0.03 μm, respectively), and stabler, than blank emulsions (4.05 ± 0.51 μm). Conversely, the extracts, especially AS extract, reduced the stability of nanoemulsions causing a 24-fold particle size increase. Nevertheless, AP and AS extracts reduced the formation of secondary oxidation products in emulsions/nanoemulsions. These findings provide novel insights into the potential use of avocado waste.  相似文献   

10.
氨基葡萄糖盐酸盐与三乙胺在乙醇-水相条件下生成氨基葡萄糖(GA),GA再与癸酸反应,合成了一种氨基葡萄糖为反离子的脂肪羧酸盐表面活性剂——氨基葡萄糖癸酸盐(GAD)。采用红外光谱和N元素含量分析对GAD进行了结构表征,并测试了其表面性能。结果表明:25℃下,GAD的临界胶束浓度(CMC)为8.51×10-4mol/L,临界胶束浓度所对应的表面张力(γCMC)为30.1 mN/m,饱和吸附量(Γmax)为4.33×10-10mol/cm2,饱和吸附分子面积(Amin)为0.38 nm2;GAD具有一定的泡沫性能,并对液体石蜡具有较好的乳化能力;与Tween 80、十二烷基二甲基甜菜碱(BS-12)和十六烷基三甲基氯化铵(1631)等助剂配伍良好,无分层现象。  相似文献   

11.
以废弃聚酯、乙二醇、氯化亚砜、十二烷基二甲基叔胺为原料,合成了含有酯基的季铵盐Gemini型表面活性剂。用正交试验法对试验条件进行优化,得出较优的合成工艺条件为:n(中间体):n(十二烷基二甲基叔胺)=1:2.1,反应温度为57 ℃,反应时间为12 h。用红外光谱及显色反应对产物结构进行表征,同时测试了表面活性剂的表面张力、熔点、泡沫性能、溶解性能等。测试结果显示其临界胶束浓度值为1.47×10-4 mol/L,表面张力为28.56 mN/m,其表面活性明显低于工业常用的表面活性剂。  相似文献   

12.
采用白金板法对Surfactin的表面活性进行研究,并用浊度法和离心法对其乳化性进行研究。结果表明:Surfactin的临界胶束浓度为9.03×10-5 mol/L,可将水的表面张力由73.98 mN/m降至最低27.48 mN/m。在浓度为1×10-3~1.2×10-2 mol/L的NaCl溶液中,Surfactin溶液的表面张力随盐浓度升高逐渐降低并最终稳定在34 mN/m;Surfactin在121 ℃处理20 min后,其表面张力仍能保持在37.10 mN/m;在pH值为2~12范围内,其表面活性稳定并良好;表明Surfactin具有较强的NaCl浓度、温度、pH值的耐受性。浊度法测得Surfactin亲水亲油平衡(hydrophilelipophilic balance,HLB)值为14,对所需HLB值为12~16的油相乳化性能良好。  相似文献   

13.
14.
Whey is the main waste by-product from dairy industry and at the same time is the major source of globular proteins. These proteins are concentrated mainly through spray drying, but high temperatures affect the foaming properties of globular protein. The addition of surfactants can have a protective role against thermal effects. The aim of this work was to optimize the spray-drying condition and surfactant concentration to obtain a whey protein concentrate (WPC) to be used in hot beverages according to the industry criteria for foaming stability. Three temperatures and three surfactant concentrations were applied, and the optimization was conducted using response surface analysis. Sensory analysis was applied to the WPC obtained under optimal conditions. The results showed that the foaming stability according to industrial criteria was attained when the spray drying was performed at 210 °C with surfactant concentration of 1.50 g/100 g. This resulted in foaming capacity of 3.80 mL, moisture content of 1.82 g/100 g and apparent density of 0.181 g/cm3. The sensory analysis suggested that aroma was related to dairy, cooked and whey and taste was related to sweet and dairy notes. In conclusion, temperature and surfactant concentration played an important role in the foaming capacity and stability of WPC.  相似文献   

15.
A new method for the preparation of aminated lignin(AEL) through etherification and amination reaction was presented. Chlorine atoms were firstly introduced into lignin through its etherification with epichlorohydrin. Then, hydrophilic amine groups were grafted to the modified lignin structure through amination with ethylenediamine to obtain AEL. Subsequent acidification of AEL led to the ionized aminated lignin(IAEL). The results of our analyses showed that the nitrogen content of AEL was 6.9%. Foaming and emulsifying experiments indicated that AEL had better foamability and emulsifying properties than IAEL. Surface tension tests showed that AEL and IAEL had similar critical micelle concentration(CMC). However, IAEL had lower surface tension(36.33 mN/m) than AEL(42.89 mN/m) at CMC. These results demonstrate the promising applicability of AEL as an emulsifier and that of IAEL as feedstock in the production of detergent and dispersant.  相似文献   

16.
Three novel gemini cationic surfactants were synthesized and their structures confirmed by 1H-NMR analysis. The interaction of C.I. Acid Violet 1 dye with gemini cationic surfactants in aqueous solution was investigated by UV-Vis spectroscopy at the λmax of the acid dye–cationic surfactants. The dyeing behavior of the acid dye–cationic surfactants and their fastness properties were investigated. It was observed that the aggregation of surfactant and dye takes place at low concentrations far below 1 g/l. The further addition of surfactant resulted in an absorption spectrum characteristic of fully saturated acid dye in the cases of the 16–2-16 and 16–3-16 surfactants at 1 g/l, and in the case of the 10–3-10 surfactant 1.2 g/l. The results also showed bathochromic shifts for the acid dye followed by significant increase in the λmax at the optimum concentrations of these surfactants. The dyeability of linen fabric with acid dye–gemini cationic surfactants increased as the electrostatic interactions between the surfactant head groups and the anionic nature of the acid dye increased, but the hydrophobic interactions decreased at higher temperature. The fastness to washing and rubbing improved by increasing the alkyl length of the gemini surfactants from 10–3-10 to 16–2-16 and 16–3-16, although the spacer length had no effect.  相似文献   

17.
烷基糖苷APGs作为新一代绿色表面活性剂,以其优异的表面特性在各个领域的应用开发受到了广泛的关注。文章深入研究了不同链长的烷基糖苷水溶液的表面张力、胶束化行为以及电解质的加入对其的影响。结果表明,APGs溶液的CMC主要取决于其分子疏水端的结构。随着疏水链的增长,APGs溶液的CMC随之减小。相对离子型表面活性剂而言,硫酸钠的加入对溶液的影响较小,主要是通过对疏水链的盐析作用来实现的。在强碱体系下,APGs分子亲水端部分去质子化使得所形成的胶束带负电性,从而导致氢氧化钠的盐析效应相对较弱。  相似文献   

18.
Control of low-concentration pollutants from a semiconductor process vent stream using a wet-scrubbing technique is a challenging task to meet Taiwan environmental emission standards. An efficient wet-scrubber is designed on a pilot scale and tested to control low concentration acid and base waste-gas emission. The scrubber system consisted of two columns, i.e., a fine spray column [cutoff diameter (based on volume), Dv(50) = 15.63 microm; Sauter mean diameter (SMD) = 7.62 microm], which is especially efficient for NH3 removal as the pH of the spraying liquid is approximately 7 followed by a packed column with a scrubbing liquid pH approximately 9.0 mainly for acids removal. It is observed that use of the surfactants in low concentration about 10(-4) M and 10(-7) M in the spray liquid and in the scrubbing liquid, respectively, remarkably enhances the removal efficiency of the system. A traditional packed column (without the spray column and the surfactant) showed that the removal efficiencies of NH3, HF, and HCl for the inlet concentration range 0.2 to 3 ppm were (n = 5) 22.6+/-3.4%, 43.4+/-5.5%, and 40.4+/-7.4%, respectively. The overall efficiencies of the proposed system (the spray column and the packed column) in the presence of the surfactant in the spray liquid and in the scrubbing liquid forthese three species were found to increase significantly (n = 5) from 60.3+/-3.6 to 82.8+/-6.8%, 59.1+/-2.7 to 83.4+/-4.2%, and 56.2+/-7.3 to 81.0+/-6.7%, respectively. In this work, development of charge on the gas-liquid interface due to the surfactants has been measured and discussed. It is concluded that the presence of charge on the gas-liquid interface is the responsible factor for enhancement of the removal efficiency (mass-transfer in liquid phase). The effects of the type of surfactants, their chain length, concentration in liquid, etc. on the removal efficiency are discussed. Since the pilot tests were performed under the operating conditions similar to most of the wet-scrubbers operated in semiconductors manufacturing facilities for inorganic pollutants, this study can be applied to modify the existing wet-scrubbers to enhance the removal efficiencies, especially for low-concentration pollutants.  相似文献   

19.
The aim of this study was to evaluate the effects of the addition of surfactants sodium stearoyl lactate (SSL) and sucrose ester (SE) on the functional properties of films produced with polysaccharides mixtures (methylcellulose/glucomannan/pectin in 1/4/1 ratio, respectively) and gelatin. The films were produced by the casting method and characterized for their water vapor permeability (WVP), mechanical (tensile strength and elongation to break point), morphological and optical properties. Films with low WVP were obtained with surfactants. Addition of SE to the films with polysaccharide/gelatin ratio of 90/10 showed improved mechanical properties. Films presented smooth surfaces with micro voids and lumpiness, depending on the surfactant tested. Surfactants increased the opacity of the films by a factor of 1–3%. All film properties were dependent on the surfactant affinity for the biopolymer matrix. SE presented more affinity for biopolymer matrix containing high polysaccharide proportion, and SSL presented more affinity for polymer matrix containing high gelatin proportion. The addition of surfactants decreased the water vapor permeability of the films, increasing their hydrophobic character.  相似文献   

20.
Colloids such as surfactant micelles can act as transport facilitators for highly lipophilic, generally immobile contaminants in soil. Following a fire at a pesticide facility, this study investigated vertical and lateral migration of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in heterogeneous soil beneath bunded ponds, where contaminated wastewater containing high surfactant loads was stored until remediation. Initially, surface and subsurface soil was obtained during excavation, and subsequently intact cores to 5.7 m were collected. ΣPCDD/F concentrations were elevated in the wastewater (15-81 ng/L) and correspondingly in pond surface soils (6.1-61 ng/g). Maximum ΣPCDD/F concentrations were, however, observed at 2-2.5 m depth (68-130 ng/g), far below their expected mobility range based on physicochemical properties. Congener specific analysis further indicated that PCDD/F mobility was reversed, with the least water-soluble congener migrating to the greatest extent. The presence of higher chlorinated PCDD/Fs throughout a core collected in the direction of groundwater flow indicated subsequent lateral transport. These results provide field evidence for rapid vertical migration (2.4 m in <4 months) of highly lipophilic PCDD/Fs and suggest surfactant facilitated transport as the dominant transport mechanism. Quantification and evaluation of such fundamental changes in contaminant transport and fate in the presence of surfactants is required to identify areas at risk of groundwater contamination.  相似文献   

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