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Surfactants and emulsion polymerisation: an industrial perspective
Published in David R. Karsa, Surfactants in Polymers, Coatings, Inks and Adhesives, 2020
A commercial foaming machine is shown schematically in Figure 1.4. Air is metered into a pumped latex stream and then the mixture passes through a series of rotating teeth which break down the large bubbles to a fine, even foam. This foam then passes down a delivery hose. Forcing the foam through the hose causes a pressure to develop in the mixing head; this pressure allows better mixing and in fact there may be a critical pressure below which it is not possible to obtain a satisfactory foam with a given air content. This results in an intermittent flow of foam and air from the end of the pipe, a phenomenon referred to as blowing. The pressure developed is a function of the diameter and length of the pipe and the viscosity of the foam. The viscosity of the foam is dependent on the viscosity of the latex compound, the bubble size and the air content. Too high a back-pressure would cause equipment problems or prevent further air being admitted. Of the common foam generators, potassium oleate gives a lower foam viscosity than sodium lauryl sulfate. Ammonium lauryl sulfate gives higher viscosities than the sodium salt. Some reductions in foam viscosity may be obtained by using salts of shorter chain fatty acids. An indication of the effect of surfactant level on foamability is given in Table 1.2 [43]. These data were obtained by foaming a fixed volume of latex in a domestic food mixer for 15 s. The added surfactant was sodium lauryl sulfate.
Graphene-Based Hybrid Nanofluids and Its Application in Heat Exchangers
Published in K.R.V. Subramanian, Tubati Nageswara Rao, Avinash Balakrishnan, Nanofluids and Their Engineering Applications, 2019
Hooman Yarmand, Nurin Wahidah Binti Mohd Zulkifli, Mahidzal Dahari, S.N. Kazi
Suresh et al. [24,25] prepared alumina-copper hybrid nanoparticles by a thermophysical synthesis technique. They prepared water suspension of soluble nitrates of aluminum and copper. Then they spray dried these solutions to achieve the precursor powder, and after that the sample was heated in air atmosphere to get the powder mixture form of stable Al2O3 and copper oxide. The mixture powder was then put in an alumina boat and placed in a horizontal alumina tube of the furnace. Alumina was kept in its original forms without any change, but CuO was reduced in hydrogen and changed to metallic copper. Then the Al2O3-Cu hybrid nanocomposite was ball milled to get a homogeneous powder. Finally, the prepared sample was dispersed in water by assistance of sodium lauryl sulfate (SLS) as a surfactant and by ultrasonication.
Evaluation Methods for Conditioned Hair
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
Interactions between surfactant anions and the polymeric cation not only influence the solution properties of the two compounds, but also affect the nature of their deposition on the fiber surface. Averages ( 16 measurements each) of advancing wettabilities of fibers treated with 15 solutions of JR-400 containing increasing concentrations of sodium lauryl sulfate show high levels of deposition with low substantivity up to the critical micelle concentration (CMC) of the lauryl sulfate, at which point wettability decreases, especially after the third immersion. This decrease to values below that of the untreated fiber indicates a reorientation of the surfactant-polymer complex resulting in a hydrophobic fiber surface.
Comparison of adsorption equilibrium models and error functions for the study of sulfate removal by calcium hydroxyapatite microfibrillated cellulose composite
Published in Environmental Technology, 2018
Sanna Hokkanen, Amit Bhatnagar, Ari Koistinen, Teija Kangas, Ulla Lassi, Mika Sillanpää
On the other hand, surfactants are the active ingredients of hygiene products and detergents for industrial and household cleaning. They are one of the most common organic pollutants characterized with very high potential to enter the environment due to their wide use in daily life mainly in household applications and as industrial cleaning agents. Surfactants are primarily present in aqueous solutions, which lead to introduction into the environment via wastewater discharges [7]. Sodium lauryl sulfate (SLS) is widely used as anionic surfactant in several products such as shampoos, detergents and toothpaste due to its relatively low cost [8]. It has been shown that SLS causes eye or skin irritation in experiments done on animals and humans [8]. The research suggests that SLS can also cause irritation after extended exposure in some people [8]. Therefore, robust water treatment is necessary in order to remove elevated concentrations of sulfates and surfactant from industrial and domestic wastes to reduce their concentrations.