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E Santacesaria - One of the best experts on this subject based on the ideXlab platform.
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the evolution of the fed batch Ethoxylation reactors to produce the non ionic surfactants
Frontiers in Chemical Engineering, 2021Co-Authors: Martino Di Serio, E Santacesaria, Vincenzo Russo, Riccardo TesserAbstract:The most recent reactor technology to produce non-ionic surfactants via Ethoxylation reaction is illustrated in the present work. The most advanced reactors are deeply illustrated for what concerns the working principle and the main performance. In detail, Venturi Loop Reactor (VLR), Spray Tower Loop Reactor (STLR) and Enhanced Loop Reactor (ELR) are depicted, and the related performance compared. ELR shows the highest flexibility, to reach the desired Ethoxylation degree, and at the same time good performances comparable with the VLR. Moreover, ELR allows to reach high Ethoxylation degree, as in this condition, a good mixing, in the case of high liquid expansion, is difficult to be achieved with the other reactors. Thus, it is possible to work at higher Ethoxylation degree respecting safety issues. Finally, a comprehensive model was proposed to describe quantitatively the mentioned reactors. The model is characterized by a general validity and can be easily adapted to each specific reactor configuration.
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the evaluation of risks of Ethoxylation reactors
Process Safety Progress, 2007Co-Authors: Ernesto Salzano, Martino Di Serio, E SantacesariaAbstract:Alkoxylations are commonly performed in industry for the production of surfactants and polyglycols by means of a simple semi-batch liquid-stirred reactor. More recent processes use semi-batch Venturi Loop Reactors (VCR) or Spray Tower Loop Reactors (SLR), where liquid phase is dispersed into the gaseous oxides through recirculation loops. In this article, a risk analysis is made on the recirculation loops to compare these three reactor types. More specifically, the analysis of consequences for the Ethoxylation of dodecanol with different ethylene oxide partial pressures and process temperatures are studied. The atmospheric wind velocity was varied for a range of releases from the recirculation loop or from small releases from flanges and valves along the same pipeline. This article shows that the risks of the VLR and SLR are lower than the semi-batch reactor. The higher risks for recirculation loops are only related to toxicity in the proximity of reactor. Explosions give high overpressures only in the case of near-instantaneous releases of the reactor contents (large releases). Although this analysis was specifically made for alkoxylation reactors, the methods and conclusions can also be used for comparing the risks of other semi-batch reactors to loop reactors. © 2007 American Institute of Chemical Engineers Process Saf Prog 26, 2007
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kinetics of Ethoxylation and propoxylation of ethylene glycol catalyzed by koh
Industrial & Engineering Chemistry Research, 2002Co-Authors: M Di Serio, Riccardo Tesser, And A Dimiccoli, E SantacesariaAbstract:In the present paper the kinetics of Ethoxylation and of propoxylation of ethylene glycol catalyzed by KOH have been studied. The Ethoxylation of ethylene glycol occurs with a rate that initially i...
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kinetics of Ethoxylation and propoxylation of 1 and 2 octanol catalyzed by koh
Industrial & Engineering Chemistry Research, 1996Co-Authors: M Di Serio, G Vairo, P Iengo, F Felippone, E SantacesariaAbstract:Ethoxylation and propoxylation reactions are often performed together or in alternation to obtain surfactants with particular properties or random and block copolymers. Both reactions are normally performed in the same reactor, in the presence of an alkaline catalyst, at relatively low temperature, 120−130 °C, to avoid the intervention of the side reactions that are typical of the propoxylation. The propoxylation of a primary fatty alcohol is slower than the corresponding Ethoxylation and gives place to a secondary hydroxyl terminal group that is still less reactive. On the contrary, Ethoxylation restores more reactive primary hydroxyl terminal groups. Therefore, it is important for optimizing the described industrial operations to know the reactivity of ethylene and propylene oxide with, respectively, primary and secondary hydroxyls, in the presence of the most used KOH catalyst. In this paper, the kinetics of both the Ethoxylation and propoxylation of 1- and 2-octanol catalyzed by KOH have been studied ...
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role of ethylene oxide solubility in the Ethoxylation processes
Catalysis Today, 1995Co-Authors: E Santacesaria, M Diserio, Riccardo TesserAbstract:Abstract The role of ethylene oxide solubility in the Ethoxylation processes has been studied for what concerns: the influence on the kinetics of the reaction and the behaviour in the different kinds of normally employed reactors, in particular the influence on the reactor instability. The conclusions of the work are: (i) Henry's law, is a rough and unreliable model to describe ethylene oxide solubilities in a large range of pressures and temperatures, (ii) the predictive UNIFAC model can be applied to a few number of situations, (iii) the employment of NRTL (non random two liquids theory) and Wilson's models seem to be more reliable, but many experimental data are necessary to evaluate the correct parameters of the mentioned models. As it will be seen it is difficult to collect and interpret experimental data. Nevertheless, the precision in the evaluation of ethylene oxide solubilities is fundamental for reactor design, simulation and safety.
R K Thomas - One of the best experts on this subject based on the ideXlab platform.
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nature of the intermicellar interactions in ethoxylated polysorbate surfactants with high degrees of Ethoxylation
Langmuir, 2016Co-Authors: J Penfold, Peixun Li, Jordan T. Petkov, I. Tucker, R K Thomas, R PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant...
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Tuning Polyelectrolyte-Surfactant Interactions: Modification of Poly(ethylenimine) with Propylene Oxide and Blocks of Ethylene Oxide
'American Chemical Society (ACS)', 2016Co-Authors: Penfold J, R K Thomas, Li P, Sn Batchelor, Im Tucker, Aw BurleyAbstract:Significantly enhanced adsorption at the air-water interface arises in polyelectrolyte/ionic surfactant mixtures, such as poly(ethylenimine)/sodium dodecyl sulfate (PEI/SDS), down to relatively low surfactant concentrations due to a strong surface interaction between the polyelectrolyte and surfactant. In the region of charge neutralization this can result in precipitation or coacervation and give rise to undesirable properties in many applications. Ethoxylation of the PEI can avoid precipitation, but can also considerably weaken the interaction. Localization of the Ethoxylation can overcome these shortcomings. Further manipulation of the polyelectrolyte-surfactant interaction can be achieved by selective Ethoxylation and propoxylation of the PEI amine groups. Neutron reflectivity and surface tension data are presented here which show how the polyelectrolyte-surfactant interaction can be manipulated by tuning the PEI structure. Using deuterium labeled surfactant and polymer the neutron reflectivity measurements provide details of the surface composition and structure of the adsorbed layer. The general pattern of behavior is that at low surfactant concentrations there is enhanced surfactant adsorption due to the strong surface interaction; whereas around the region of the SDS critical micellar concentration, cmc, the surface is partially depleted of surfactant in favor bulk aggregate structures. The results presented here show how these characteristic features of the adsorption are affected by the degree of Ethoxylation and propoxylation. Increasing the degree of propoxylation enhances the surfactant adsorption, whereas varying the degree of Ethoxylation has a less pronounced effect. In the region of surfactant surface depletion increasing both the degree of Ethoxylation and propoxylation result in an increased surface depletion
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Nature of the Intermicellar Interactions in Ethoxylated Polysorbate Surfactants with High Degrees of Ethoxylation
2016Co-Authors: J Penfold, I. Tucker, R K Thomas, J. Petkov, R. E. PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant micelles. Unlike the intermicellar interaction in ionic surfactant micellar solutions, which results from the charge on the micelle arising from the partial binding of counterions, the interaction between ethoxthylated polysorbate surfactant micelles is unaffected by the addition of electrolyte
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Nature of the intermicellar interactions in ethoxylated polysorbate surfactants with high degrees of Ethoxylation
'American Chemical Society (ACS)', 2016Co-Authors: Penfold J, R K Thomas, Li P, Petkov J, R. E. PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant micelles. Unlike the intermicellar interaction in ionic surfactant micellar solutions, which results from the charge on the micelle arising from the partial binding of counterions, the interaction between ethoxthylated polysorbate surfactant micelles is unaffected by the addition of electrolyte
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sodium dodecyl sulfate ethoxylated polyethylenimine adsorption at the air water interface how the nature of Ethoxylation affects the pattern of adsorption
Langmuir, 2014Co-Authors: Stephen N Batchelor, Jordan T. Petkov, I. Tucker, J Penfold, R K ThomasAbstract:The strong interaction between ionic surfactants and polyelectrolytes of opposite charge results in enhanced surface adsorption at the air–water interface down to low surfactant concentrations and in some cases in the formation of ordered surface structures. A notable example which exhibits such properties is the mixture of polyethylenimine, PEI, and sodium dodecyl sulfate, SDS. However, the electrostatic interaction, around charge neutralization, between the surfactant and polymer often results in precipitation or coacervation. This can be mitigated for PEI–surfactant mixtures by Ethoxylation of the PEI, but this can also result in a weaker surface interaction and a significant reduction in the adsorption. It is shown here that by localizing the Ethoxylation of the PEI into discrete regions of the polymer precipitation upon the addition of SDS is suppressed, the strong surface interaction and enhanced adsorption of the polymer–surfactant mixture is retained. The adsorption of SDS in the presence of ethox...
Nathan S. Lewis - One of the best experts on this subject based on the ideXlab platform.
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a mechanistic study of the oxidative reaction of hydrogen terminated si 111 surfaces with liquid methanol
Journal of Physical Chemistry C, 2017Co-Authors: Noah T. Plymale, Mita Dasog, Bruce S. Brunschwig, Nathan S. LewisAbstract:H–Si(111) surfaces have been reacted with liquid methanol (CH3OH) in the absence or presence of a series of oxidants and/or illumination. Oxidant-activated mEthoxylation of H–Si(111) surfaces was observed in the dark after exposure to CH3OH solutions that contained the one-electron oxidants acetylferrocenium, ferrocenium, or 1,1′-dimethylferrocenium. The oxidant-activated reactivity toward CH3OH of intrinsic and n-type H–Si(111) surfaces increased upon exposure to ambient light. The results suggest that oxidant-activated mEthoxylation requires that two conditions be met: (1) the position of the quasi-Fermi levels must energetically favor oxidation of the H–Si(111) surface and (2) the position of the quasi-Fermi levels must energetically favor reduction of an oxidant in solution. Consistently, illuminated n-type H–Si(111) surfaces underwent mEthoxylation under applied external bias more rapidly and at more negative potentials than p-type H–Si(111) surfaces. The results under potentiostatic control indicate...
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A Mechanistic Study of the Oxidative Reaction of Hydrogen-Terminated Si(111) Surfaces with Liquid Methanol
2017Co-Authors: Noah T. Plymale, Mita Dasog, Bruce S. Brunschwig, Nathan S. LewisAbstract:H–Si(111) surfaces have been reacted with liquid methanol (CH3OH) in the absence or presence of a series of oxidants and/or illumination. Oxidant-activated mEthoxylation of H–Si(111) surfaces was observed in the dark after exposure to CH3OH solutions that contained the one-electron oxidants acetylferrocenium, ferrocenium, or 1,1′-dimethylferrocenium. The oxidant-activated reactivity toward CH3OH of intrinsic and n-type H–Si(111) surfaces increased upon exposure to ambient light. The results suggest that oxidant-activated mEthoxylation requires that two conditions be met: (1) the position of the quasi-Fermi levels must energetically favor oxidation of the H–Si(111) surface and (2) the position of the quasi-Fermi levels must energetically favor reduction of an oxidant in solution. Consistently, illuminated n-type H–Si(111) surfaces underwent mEthoxylation under applied external bias more rapidly and at more negative potentials than p-type H–Si(111) surfaces. The results under potentiostatic control indicate that only conditions that favor oxidation of the H–Si(111) surface need be met, with charge balance at the surface maintained by current flow at the back of the electrode. The results are described by a mechanistic framework that analyzes the positions of the quasi-Fermi levels relative to the energy levels relevant for each system
Jordan T. Petkov - One of the best experts on this subject based on the ideXlab platform.
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nature of the intermicellar interactions in ethoxylated polysorbate surfactants with high degrees of Ethoxylation
Langmuir, 2016Co-Authors: J Penfold, Peixun Li, Jordan T. Petkov, I. Tucker, R K Thomas, R PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant...
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sodium dodecyl sulfate ethoxylated polyethylenimine adsorption at the air water interface how the nature of Ethoxylation affects the pattern of adsorption
Langmuir, 2014Co-Authors: Stephen N Batchelor, Jordan T. Petkov, I. Tucker, J Penfold, R K ThomasAbstract:The strong interaction between ionic surfactants and polyelectrolytes of opposite charge results in enhanced surface adsorption at the air–water interface down to low surfactant concentrations and in some cases in the formation of ordered surface structures. A notable example which exhibits such properties is the mixture of polyethylenimine, PEI, and sodium dodecyl sulfate, SDS. However, the electrostatic interaction, around charge neutralization, between the surfactant and polymer often results in precipitation or coacervation. This can be mitigated for PEI–surfactant mixtures by Ethoxylation of the PEI, but this can also result in a weaker surface interaction and a significant reduction in the adsorption. It is shown here that by localizing the Ethoxylation of the PEI into discrete regions of the polymer precipitation upon the addition of SDS is suppressed, the strong surface interaction and enhanced adsorption of the polymer–surfactant mixture is retained. The adsorption of SDS in the presence of ethox...
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impact of the degree of Ethoxylation of the ethoxylated polysorbate nonionic surfactant on the surface self assembly of hydrophobin ethoxylated polysorbate surfactant mixtures
Langmuir, 2014Co-Authors: Jeff Penfold, Nick Hedges, Peixun Li, Jordan T. Petkov, I. Tucker, Robert K. Thomas, John R. P. Webster, Maximilian W. A. SkodaAbstract:Neutron reflectivity measurements have been used to study the surface adsorption of the polyethylene sorbitan monostearate surfactant, with degrees of Ethoxylation varying from 3 to 20 ethylene oxide groups, with the globular protein hydrophobin. The surface interaction between the ethoxylated polysorbate nonionic surfactants and the hydrophobin results in self-assembly at the air–solution interface in the form of a well-defined layered surface structure. The surface interaction arises from a combination of the hydrophobic interaction between the surfactant alkyl chain and the hydrophobic patch on the surface of the hydrophobin, and the hydrophilic interaction between the ethoxylated sorbitan headgroup and the hydrophilic regions on the surface of the hydrophobin. The results presented show that varying the degree of Ethoxylation of the polysorbate surfactant changes the interaction between the surfactant and the hydrophobin and the packing, and hence the evolution in the resulting surface structure. The ...
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Sodium Dodecyl Sulfate–Ethoxylated Polyethylenimine Adsorption at the Air–Water Interface: How the Nature of Ethoxylation Affects the Pattern of Adsorption
2014Co-Authors: Stephen N. Batchelor, Jordan T. Petkov, Ian Tucker, Jeffrey Penfold, Robert K. ThomasAbstract:The strong interaction between ionic surfactants and polyelectrolytes of opposite charge results in enhanced surface adsorption at the air–water interface down to low surfactant concentrations and in some cases in the formation of ordered surface structures. A notable example which exhibits such properties is the mixture of polyethylenimine, PEI, and sodium dodecyl sulfate, SDS. However, the electrostatic interaction, around charge neutralization, between the surfactant and polymer often results in precipitation or coacervation. This can be mitigated for PEI–surfactant mixtures by Ethoxylation of the PEI, but this can also result in a weaker surface interaction and a significant reduction in the adsorption. It is shown here that by localizing the Ethoxylation of the PEI into discrete regions of the polymer precipitation upon the addition of SDS is suppressed, the strong surface interaction and enhanced adsorption of the polymer–surfactant mixture is retained. The adsorption of SDS in the presence of ethoxylated PEI is greatly enhanced at low SDS concentrations compared to the adsorption for pure SDS. The adsorption is equally pronounced at pH 7 and 10 and is largely independent of the degree of Ethoxylation. Surface ordering, more than monolayer adsorption, is observed over a relatively narrow range of SDS concentrations and is most pronounced at pH 10 and for the polymers with the lower degree of Ethoxylation. The results show that ethoxylated PEI’s reported here provide a suitable route to enhanced surfactant adsorption while retaining favorable solution properties in which precipitation effects are minimized
J Penfold - One of the best experts on this subject based on the ideXlab platform.
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nature of the intermicellar interactions in ethoxylated polysorbate surfactants with high degrees of Ethoxylation
Langmuir, 2016Co-Authors: J Penfold, Peixun Li, Jordan T. Petkov, I. Tucker, R K Thomas, R PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant...
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Nature of the Intermicellar Interactions in Ethoxylated Polysorbate Surfactants with High Degrees of Ethoxylation
2016Co-Authors: J Penfold, I. Tucker, R K Thomas, J. Petkov, R. E. PetkovaAbstract:Ethoxylated polysorbate Tween nonionic surfactants are extensively used as foam and emulsion stabilizers and in aqueous solution form globular micelles. The ethoxylated polysorbate surfactants with higher degrees of Ethoxylation than the Tween surfactants exhibit some interesting self-assembly properties. Small-angle neutron scattering, SANS, measurements have revealed intermicellar interactions which are more pronounced than the hard-sphere excluded volume interactions normally associated with nonionic surfactant micelles. The interactions are interpreted as arising from the partial charge on the ether oxygen of the ethylene oxide groups. This gives rise to an effective net negative charge on the micelles, which has been determined from the SANS data and zeta potential measurements. For degrees of Ethoxylation of ⩽20, the effect is relatively small. The interaction increases with increasing Ethoxylation such that for a degree of Ethoxylation of 50 the interaction is comparable to that of ionic surfactant micelles. Unlike the intermicellar interaction in ionic surfactant micellar solutions, which results from the charge on the micelle arising from the partial binding of counterions, the interaction between ethoxthylated polysorbate surfactant micelles is unaffected by the addition of electrolyte
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sodium dodecyl sulfate ethoxylated polyethylenimine adsorption at the air water interface how the nature of Ethoxylation affects the pattern of adsorption
Langmuir, 2014Co-Authors: Stephen N Batchelor, Jordan T. Petkov, I. Tucker, J Penfold, R K ThomasAbstract:The strong interaction between ionic surfactants and polyelectrolytes of opposite charge results in enhanced surface adsorption at the air–water interface down to low surfactant concentrations and in some cases in the formation of ordered surface structures. A notable example which exhibits such properties is the mixture of polyethylenimine, PEI, and sodium dodecyl sulfate, SDS. However, the electrostatic interaction, around charge neutralization, between the surfactant and polymer often results in precipitation or coacervation. This can be mitigated for PEI–surfactant mixtures by Ethoxylation of the PEI, but this can also result in a weaker surface interaction and a significant reduction in the adsorption. It is shown here that by localizing the Ethoxylation of the PEI into discrete regions of the polymer precipitation upon the addition of SDS is suppressed, the strong surface interaction and enhanced adsorption of the polymer–surfactant mixture is retained. The adsorption of SDS in the presence of ethox...