共查询到20条相似文献,搜索用时 15 毫秒
1.
主要探讨了在泡沫体系内,表面活性剂对泡沫稳定性的影响,以表活剂浓度为主要研究点,总结了不同表活剂浓度下气泡的聚并过程,还分析了液膜的排液过程,指出界面流变学因素以及表活剂高浓度情况下的胶束分层现象是影响泡沫稳定的主要因素.表活剂浓度低于CMC时,界面流变学因素起主要决定作用;表活剂浓度高于CMC时,胶团分层起主要决定作用. 相似文献
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A novel xanthan gum-g-itaconic acid/bentonite (XG-g-PIA/BET) hydrogel composite was synthesized using free radical polymerization in the presence of ammonium persulfate as initiator and N,N’-methylenebis(acrylamide) as crosslinker. The Fourier transform infrared spectroscopy spectra of XG-g-PIA/BET composite before and after adsorption gave strong evidence of the successful adsorbance of copper ions with COOH groups. Influence of the presence of three typical salts (NaCl, CaCl2, and FeCl3) and three types of surfactants including anionic (Brij 35), cationic (N-Cetyl-N,N,N-trimethyl ammonium bromide), anionic (sodium dodecyl sulfate), and their two-term interactions on copper ions adsorption capacity were investigated using 32 experiments with fractional factorial experimental design. The analysis of variance (ANOVA) showed that the fitted model had a significant p value (<0.0001), and except FeCl3, all other variables present in the aqueous solution increased the copper adsorption capacity. In addition, there was no significant two-term interaction between different variables. 相似文献
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Although the biosurfactant rhamnolipid has been previously characterized as having low foam ability, its fermentation is largely impeded by severe foaming. Hence, the investigation of this paradox is critically important for improving the mass production of rhamnolipid. Unexpectedly, the hydrophobic cell, instead of rhamnolipid, has been claimed to explain such severe foaming in rhamnolipid fermentation. This study tried to systematically investigate the severe foaming in fermentation, aiming to propose an effective strategy for foam control. The overflowing foam sustained a super high stability in terms of half‐time for over 30 min. The major product of rhamnolipid largely contributed to the severe foaming in the fermentation process whereas other products like cells elicited much more limited effects. Furthermore, the foam stability of the fermentation broth increased with rhamnolipid concentration and noticeably increased with agitation speed. In the classic Bikerman foam test system without stirring, rhamnolipid showed foam stability as low as Tween 20 which is well known for its poor foam stability. However, in a stirring Bikerman system, rhamnolipid exhibited a foam stability almost as high as sodium dodecyl sulfate (SDS) at 10 g/L and even surpassed SDS at a higher concentration of 20 g/L. Hence, the extraordinarily increased foam stability of rhamnolipid with both agitation and concentration could explain the severe foaming at its late‐stage fermentation when rhamnolipid‐rich solution is mechanically agitated. 相似文献
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《分离科学与技术》2012,47(7):1544-1561
Abstract The purpose of this study was to investigate the recovery of surfactants using a multistage foam fractionator for three types of surfactants: cationic (cetyl pyridinium chloride, CPC); anionic (sodium dodecyl sulfate, SDS); and nonionic (polyoxyethylene(20) sorbitan monolaurate, Span80). The studied system was operated at a constant temperature of 25°C with a surfactant concentration in the range of 50 to 100% of CMC (critical micelle concentration). For any surfactant system, the enrichment ratio of surfactant increased with increasing foam height and number of stages but decreased with increasing effects of the air flow rate and feed concentration. For all studied surfactants, the removal efficiency of the surfactant was not significantly affected by changing the air flow rate, foam height, and feed concentration in the studied ranges. An increase in the number of stages showed a great improvement of both the enrichment ratio and the removal fraction for all three types of surfactants. In a comparison among the three studied surfactants, the separation performance, in terms of the enrichment ratio and removal was found to lie in the following order: CPC >Span80 > SDS, which can be explained by the foamability and foam stability of each surfactant. 相似文献
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Byung Joo Jeon Young Ho Kim Kyung Soo Lee Gi Joon Nam Chan Yong Park 《Polymer-Plastics Technology and Engineering》2013,52(8):785-790
In modern industries, the development of communication mediums requires high-frequency communication networks in which signal reduction by dielectric loss is increased. Accordingly, the need for an insulator with low permittivity also has grown, making the production of highly foamed insulators now necessary. Considering the mechanical and electrical properties of such insulators, benefits can be seen in multiresponse problems with higher densities of uniform-specific cell size. In this paper, we describe the applicability of a highly foamed polyolefin extrusion process to the manufacturing of insulation for coaxial cable. Moreover, a combination of axiomatic design and the Taguchi method was utilized for solving the multiresponse problem. Through this technique, we propose a new method for optimizing multiresponse problems. Development of manufacturing processes for insulating coaxial cable, and responses for each process variable, become possible with this method. 相似文献
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Hakima Azira Amel Tazerouti Jean Paul Canselier 《Journal of surfactants and detergents》2008,11(4):279-286
Using different reaction conditions of photosulfochlorination of n-dodecane, two samples of anionic surfactants of sulfonate type are obtained. Their micellar behavior has been already reported
and the relationship between their isomeric distribution and their chemical structures and micellar behaviors have been more
thoroughly explored. In this investigation, we screened the foaming properties (foaming power and foam stability) by a standardized
method very similar to the Ross–Miles foaming tests to identify which surfactants are suitable for applications requiring
high foaming, or, alternatively, low foaming. The results obtained for the synthesized surfactants are compared to those obtained
for an industrial sample of secondary alkanesulfonate (Hostapur 60) and to those of a commercial sample of sodium dodecylsulfate
used as reference for anionic surfactants. The foam formation and foam stability of aqueous solutions of the two samples of
dodecanesulfonate are compared as a function of their isomeric distribution. These compounds show good foaming power characterized
in most cases by metastable or dry foams. The highest foaming power is obtained for the sample rich in primary isomers which
also produces foam with a relatively high stability. For the sample rich in secondary isomers we observe under fixed conditions
a comparable initial foam height but the foam stability turns out to be low. This property is interesting for applications
requiring low foaming properties such as dishwashing liquid for machines. The best results are observed near and above the
critical micellar concentrations and at 25 °C for both the samples.
相似文献
Amel TazeroutiEmail: |
8.
Florence Chantraine Marylène Viana Christelle Pouget Nelly Brielles Olivier Mondain-Monval Paul Branlard Gilles Rubinstenn Dominique Chulia 《Journal of surfactants and detergents》2009,12(1):59-71
The aim of this study is to limit the hurdles generated by the presence of a surfactant, i.e., sodium dodecyl sulfate (SDS),
in effervescent detergent tablets containing a chlorine provider. The results are highlighted by investigating the tablet’s
functional characteristics (mechanical strength, disintegration time). A second objective is to increase the surfactant content
of the tablet in order to improve the cleaning properties of the detergent formula without retaining the previous drawbacks.
For low tablet porosity, mechanical properties are damaged by the presence of 2% of SDS and while disintegration through an
erosion mechanism is slowed down. Experimental evidence indicated that these phenomena are associated with the coexistence
of SDS and sodium dichloroisocyanurate (DCCNa). Their separation by locating SDS in the tablet core was encouraging but had
limited value due to the slow dissolution of the SDS core. The problem was solved when 2% SDS was concentrated on one face
of the tablet; however, a higher concentration induced a delayed disintegration due to the progressive erosion of SDS, which
behaved as a massive solid. The coating of the tablet with SDS was beneficial because the dissolution of the film delayed
effervescence and consequently disintegration. Neither coating the SDS particles with cellulosic film nor including them in
zeolite was an appropriate solution. On the other hand, segregating SDS and DCCNa by placing them in separate layers of the
tablet produced very conclusive results when microcrystalline cellulose and an effervescent system were added to the SDS.
Furthermore, this bilayer tablet allowed the SDS content to be increased while a satisfactory tensile strength and a low disintegration
time were retained.
相似文献
Marylène VianaEmail: |
9.
制备凝胶色谱在聚氨酯匀泡剂组成分析中的应用 总被引:1,自引:0,他引:1
用制备凝胶渗透色谱分离聚氨酯匀泡剂的混合组分,并对分离的组分进行了凝胶色谱、红外光谱等分析。对两个混合组分的聚氨酯匀泡剂的剖析结果进行了讨论。 相似文献
10.
Salih Hakan Yetkin Huseyin Unal Fehim Findik 《Polymer-Plastics Technology and Engineering》2013,52(5):433-439
In this study, PP and Talc/EPDM/PP composite materials are used. Foaming process is achieved by a conventional injection molding method. The influence of injection pressure and melting temperature on the average cell dimension, cell number, skin layer thickness, foam density and mechanical properties of investegated foam materials were evaluated. It is observed that cell density is increased by the increment of injection pressure. However, the values of skin layer thickness, density, cell diameter and charpy impact strength are decreased. In addition, the values of skin layer thickness, cell density, density and impact strength are increased with the increment of melting temperature. 相似文献
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采用GB/T 13173-2008《表面活性剂洗涤剂实验方法》中7洗涤剂中总活性物含量的测定方法,对已知配比的有机酸、无机酸、表面活性剂等复配的卫生洁具清洗剂进行表面活性剂含量的检测,测量值均远高于配方理论值,文章分析了检测误差的原因,提出了优化检测方案.结果表明,改进后的方法测量误差低,检测结果稳定可靠. 相似文献
12.
通过冲击试验,应力-应变试验研究了表面活性剂用量,液体石蜡用量,注体石蜡用量,橡胶含量对PVC/SBR共混材料力学性能的影响。同时对表面活性剂增容PVC/SBR共混材料的形变机理进行了初步探讨。 相似文献
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对影响聚氯乙烯/木粉复合材料性能的因素,包括PVC树脂分子结构、木粉处理工艺、加工润滑剂的选择等,进行了分析。指出木粉的加入对该复合材料起一定阻燃作用。 相似文献
17.
PVC(PW)/木粉复合材料的研制?生产和应用对于寻求实体木材的替代品和利用木材加工残余物具有重要意义,也是塑料回收再生利用的有效途径之一。PVC(PW)/木粉复合材料的优点主要是力学强度高、耐强酸碱腐蚀性强和经济环保。对复合材料的性能影响因素进行了分析,并对PVC/木粉复合材料研究和探索的方向和趋势进行概述。 相似文献
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以牛血清白蛋白(BSA)和鸡蛋白蛋白(albumin)为模型蛋白,研究了热变性对蛋白质起泡性能和分子结构的影响. 结果表明,热变性后的BSA起泡能力下降,泡沫稳定性有增强的趋势. 热变性使BSA分子表面巯基含量下降,分子之间发生缔合,表面疏水性下降. 而albumin在热变性后的起泡能力及泡沫稳定性都大大提高,热变性使albumin分子展开,表面巯基含量增加. 实验证明,蛋白质分子的表面疏水性是决定其起泡能力的重要因素之一,蛋白质分子之间的相互作用对泡沫的稳定性有很大的影响. 相似文献
19.
Na Qi Ziyun Chen Hui Zhao Qiaozhi Wang Heng Chen Hao Yuan Ying Li 《Journal of surfactants and detergents》2020,23(2):347-358
In the wide application of foam products, the effect of oil additive on foam property is a critical issue that has gained increasing attention; the effect on foam induced by various flavor oils is still a puzzling question, and relative study is rare. In this article, a series of typical flavor oils were studied for their effects on the foam properties of sodium dodecylsulfate. Measurements of foamability, foam stability, foam elasticity, and surface activity were taken; meanwhile, molecular dispersion and interfacial arrangement behavior of surfactant and oil molecules were explored by molecular dynamics simulation. Through a combination of macroscopic phenomenon and microscopic information, how flavor oils with different chemical structures affected the foaming properties of surfactants was demonstrated, and an evaluation scheme for predicting the level of influence on foam properties by different flavor oils was constructed. This investigation may help better understand the role of flavor oils in foam systems and provide a theoretical foundation for optimizing the application of flavor oils in relevant industries. 相似文献
20.
《分离科学与技术》2012,47(12):2463-2478
Abstract The critical aggregation concentration (cac) in surfactant–polymer mixtures approximates a lower limit to the surfactant concentration in the permeate (surfactant leakage) in polyelectrolyte micellar‐enhanced ultrafiltration. Here, the cac was measured at different salinities by using surface tension measurements. It was found that the cac increases slightly with the addition of simple salt, then the cac value decreases at higher salt concentration. The critical micelle concentration (CMC), which approximates surfactant leakage in micellar systems (no polymer), decreases monotonically with increasing salinity for ionic surfactants. The surfactant leakage in colloid‐enhanced ultrafiltration (CEUF) processes is investigated by using a dialysis method in the presence of three phenolic solutes with various degrees of chlorination: 2‐monochlorophenol (MCP), 2,4‐dichlorophenol (DCP), and 2,4,6‐trichlorophenol (TCP). Cetylpyridinium chloride (CPC) or n‐hexadecylpyridinium chloride is used as a cationic surfactant; and sodium poly(styrenesulfonate) (PSS) is used as an anionic polyelectrolyte. The effect of salinity and type of colloid is focused on here. In the absence of added salt, the cac can be over an order of magnitude less than the CMC, as can be surfactant leakage with added polymer. The added salt reduces the surfactant leakage in the micellar solution due to CMC reduction in the presence of electrolyte. In the surfactant–polymer mixture, the surfactant leakage is dramatically affected by salinity. 相似文献