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Academic literature on the topic 'CATIONIC MICELLES'

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Published: 10 March 2023

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Journal articles on the topic "CATIONIC MICELLES"

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Wasylishen, Roderick E., Jan C. T. Kwak, Zhisheng Gao, Elisabeth Verpoorte, J. Bruce MacDonald, and Ross M. Dickson. "NMR studies of hydrocarbons solubilized in aqueous micellar solutions." Canadian Journal of Chemistry 69, no. 5 (May 1, 1991): 822–33. http://dx.doi.org/10.1139/v91-122.

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Information concerning the solubilization of hydrocarbons in ionic surfactant micelles was obtained from 2H NMR relaxation, 1H NMR chemical shifts, and 1H NMR paramagnetic relaxation measurements. The rotational motion of deuterated hydrocarbons, which is related to the micellar microviscosity at the location of the hydrocarbons, was probed by 2H NMR relaxation. The relaxation data are interpreted using both the two-step and the single-step models, and the results are discussed in terms of the micellar microviscosity and the location of the hydrocarbons in micelles. The location of the hydrocarbons in micelles was further investigated by determining the aromatic ring current-induced 1H chemical shifts along the surfactant alkyl chain and by comparing the 1H spin-lattice relaxation enhancement of the hydrocarbons and the surfactant alkyl chain, induced by Mn2+ on the micellar surface. The hydrocarbons used include benzene, naphthalene, acenaphthalene, triphenylene, cyclohexane, cyclododecane, and tert-butylcyclohexane and the surfactants studied are hexadecyl-, tetradecyl-, and dodecyltrimethylammonium bromide; hexadecyl-, tetradecyl-, and dodecylpyridinium halide; and sodium dodecyl sulfate. The results indicate that the micellar microviscosity at the location of saturated hydrocarbons is approximately 5 cP for both the cationic and anionic micelles, whereas the micellar microviscosity at the location of unsaturated hydrocarbons is much higher. The unsaturated hydrocarbons are found to reside primarily near the surfactant headgroup in the cationic micelles, but are distributed evenly throughout the anionic SDS micelles. The saturated hydrocarbons appear to be located in the interior of the micelles. Key words: NMR, relaxation, solubilization, surfactant, micelle.
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Kumar, Abanish. "SN2 Mechanism of Cationic Micelles on the Hydrolysis of Bis-p-Methoxyphenyl Phosphate Ester." Pakistan Journal of Scientific & Industrial Research Series A: Physical Sciences 58, no. 3 (October 26, 2015): 117–21. http://dx.doi.org/10.52763/pjsir.phys.sci.58.3.2015.117.121.

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Hydrolysis of bis-p-methoxyphenyl phosphate ester (bis-p-MPPE) was studied in micellar solutions of cityltrimethylammoniumbromide n-C16H33N+(CH3)3Br- (CTABr) at pH-9.0. The hydrolysis followed first order kinetics with respect to bis-p-MPPE concentration. At the concentration of critical micelle concentration (CMC) the rate of hydrolysis increased with increasing CTABr concentration. Surfactant with cationic or polar head group form micelles in water with hydrocarbon like interior or polar groups at the surface and bind cationic solute. The binding constant of micelle for bis-p-MPPE and the rate constant in micellar pseudo phase were determined from kinetic data using the pseudophase model.
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Hosseinzadeh, Reza, Mohammad Gheshlagi, Rahele Tahmasebi, and Farnaz Hojjati. "Spectrophotometric study of interaction and solubilization of procaine hydrochloride in micellar systems." Open Chemistry 7, no. 1 (March 1, 2009): 90–95. http://dx.doi.org/10.2478/s11532-008-0078-4.

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AbstractThe interaction of Procaine hydrochloride (PC) with cationic, anionic and non-ionic surfactants; cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and triton X-100, were investigated. The effect of ionic and non-ionic micelles on solubilization of Procaine in aqueous micellar solution of SDS, CTAB and triton X-100 were studied at pH 6.8 and 29°C using absorption spectrophotometry. By using pseudo-phase model, the partition coefficient between the bulk water and micelles, Kx, was calculated. The results showed that the micelles of CTAB enhanced the solubility of Procaine higher than SDS micelles (Kx = 96 and 166 for SDS and CTAB micelles, respectively) but triton X-100 did not enhanced the solubility of drug because of weak interaction with Procaine. From the resulting binding constant for Procaine-ionic surfactants interactions (Kb = 175 and 128 for SDS and CTAB surfactants, respectively), it was concluded that both electrostatic and hydrophobic interactions affect the interaction of surfactants with cationic procaine. Electrostatic interactions have a great role in the binding and consequently distribution of Procaine in micelle/water phases. These interactions for anionic surfactant (SDS) are higher than for cationic surfactant (CTAB). Gibbs free energy of binding and distribution of procaine between the bulk water and studied surfactant micelles were calculated.
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Jeyarajan, Helen Ratna Monica. "PHOTOPHYSICAL ASPECTS OF POLARITY SENSITIVE FLUOROPHORE IN CATIONIC REVERSE MICELLES." Journal of Advanced Scientific Research 13, no. 01 (February 10, 2022): 340–47. http://dx.doi.org/10.55218/jasr.202213140.

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In recent years, the field of reverse micelles has witnessed a significant growth of interest, partly due to the finding that proteins, other biopolymers, and even bacterial cells can be solubilized in the reverse micellar systems. Among surfactants capable of forming water in oil microemulsion, the cationic surfactant cetyltrimethylammonium bromide (CTAB) has received particular attention because of its ability to solubilize relatively large amount of water in a variety of hydrophobic organic solvents. Due to versatile photochemical and photophysical properties of Ru(II) complexes, Ru(II)- phenanthroline and its derivatives were used in this present work to form CTAB cationic reverse micelles and studied to characterise their photophysical properties such as absorption, emission and excited state life time. The findings from the spectral data observed in the present study proves that the excited state properties of Ru(II)-phenanthroline complexes are dramatically altered in the presence of reverse micelle. Specifically reverse micelle encapsulation of [Ru(dpphen)3]2+ complex in restricted environment causes blue shift in the emission maximum as well as have longer radiative lifetime. The blue shift in the emission maximum in the case of [Ru(dpphen)3]2+ indicates that the probes are near the water in oil reverse micellar interface, tightly bound and are not displaced towards the water pool of the micelle even at the highest water loading W0=50, which reveals the increased hydrophobicity. This highest fluorescence lifetime can serve as an excellent indicator to point out the location of the probe in a microheterogeneous system/environment.
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Wang, Jing, Xueqing Xing, Xiaocui Fang, Chang Zhou, Feng Huang, Zhonghua Wu, Jizhong Lou, and Wei Liang. "Cationic amphiphilic drugs self-assemble to the core–shell interface of PEGylated phospholipid micelles and stabilize micellar structure." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371, no. 2000 (October 13, 2013): 20120309. http://dx.doi.org/10.1098/rsta.2012.0309.

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Since polymeric micelles are promising and have potential in drug delivery systems, people have become more interested in studying the compatibility of polymeric carriers and drugs, which might help them to simplify the preparation method and increase the micellar stability. In this article, we report that cationic amphiphilic drugs can be easily encapsulated into PEGylated phospholipid (PEG–PE) micelles by self-assembly method and that they show high encapsulation efficiency, controllable drug release and better micellar stability than empty micelles. The representative drugs are doxorubicin and vinorelbine. However, gemcitabine and topotecan are not suitable for PEG–PE micelles due to lack of positive charge or hydrophobicity. Using a series of experiments and molecular modelling, we figured out the assembly mechanism, structure and stability of drug-loaded micelles, and the location of drugs in micelles. Integrating the above information, we explain the effect of the predominant force between drugs and polymers on the assembly mechanism and drug release behaviour. Furthermore, we discuss the importance of p K a and to evaluate the compatibility of drugs with PEG–PE in self-assembly preparation method. In summary, this work provides a scientific understanding for the reasonable designing of PEG–PE micelle-based drug encapsulation and might enlighten the future study on drug–polymer compatibility for other polymeric micelles.
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Ezhilrani, V. C., Vigneshwari R, and Sasmita Dash. "Comparison Between Interaction of Hydrophobic-anionic and Hydrophobic-cationic Mixed Micellar System with Drug Ciprofloxacin." Oriental Journal Of Chemistry 37, no. 6 (December 30, 2021): 1376–86. http://dx.doi.org/10.13005/ojc/370616.

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The interaction studies of drug ciprofloxacin with two mixed micellar systems are reported. The mixed micelles comprise a nonionic hydrophobic surfactant, pluronic L-81, an anionic surfactant, Ammonium dodecyl sulfate (ADS); and a cationic surfactant, Cetylpyridinium bromide (CPB). The various combinations chosen were L-81-ADS and L-81-CPB. The properties of both the mixed micelles were compared. Spectrophotometric, conductometric, co-solvent effect, and Infrared studies were used for the investigations. The studies were carried out in a wide range of mixed micellar concentrations in the post micellar region of the individual surfactants. The solubilization of drug CPX in the L-81-ADS was higher than that in L-81-CPB mixed micelle, as evidenced by UV studies. Ethanol and ethylene glycol were found to be effective co-solvents for both the mixed micellar systems. The conductivity studies of CPX with ADS and CPB surfactants, displayed a higher value of conductance for CPX and ADS, from 0.37µs-1 to 0.74µs-1 compared to CPX and CPB. The drug-mixed micelle displayed a higher molecular weight complex formation as seen from the IR spectra.
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Favaro, Yvette L., and Vincent C. Reinsborough. "Micellar catalysis in mixed anionic/cationic surfactant systems." Canadian Journal of Chemistry 72, no. 12 (December 1, 1994): 2443–46. http://dx.doi.org/10.1139/v94-310.

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Dye solubility and stopped-flow kinetic studies were conducted in sodium dodecylsulfate/dodecyltrimethylammonium bromide and sodium dodecylsulfate/decyltrimethylammonium bromide micellar solutions with excess anionic surfactant. The enhanced rate in the presence of anionic micelles of the Ni2+(aq)/pyridine-2-azo-p-dimethylaniline (PADA) complexation reaction was used as a probe of the mixed micellar situation. PADA solubilities and the kinetic parameters derived through the Robinson model for micellar catalysis were consistent with a complete incorporation of the cationic surfactant into the sodium dodecylsulfate micelles.
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Pilgrová, Tereza, and Miloslav Pekař. "Interaction between Cationic Micelles and Hyaluronan." Materials Science Forum 851 (April 2016): 26–31. http://dx.doi.org/10.4028/www.scientific.net/msf.851.26.

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Micelles are particles of colloidal dimension and it is known that in an aqueous phase can solubilize water insoluble molecules (hydrophobic biologically active substances) in their inner core. However surfactants may have adverse effects on biological structures. Association of micelles with suitable bioacceptable molecules (e.g. hyaluronan) may lead to enhance their biocompatibility, decrease the nanoparticles cytotoxicity and also to target to the specific receptors in a human body. In this study, results of the research of electrostatic coating of cationic micelle with hyaluronan are reported. The cationic micelle/hyaluronan complexes were studied using turbidimetry and dynamic light scattering method and were evaluated to determine their structure, average size and zeta potential as a function of the amount of the both component in the system. Turbidimetric titration was chosen as indicator of the loss of intensity of transmitted light due to the scattering effect of particles associated from hyaluronan and surfactant in it. Dynamic light scattering measurement provided information about size distribution and zeta potential during mixing of component. Pilot solubilization experiments were performed to evaluation of stability and solubilization ability of the complexes. Results of turbidimetry revealed that aggregates formation (turbidity increasing) depends especially on hyaluronan concentration while surfactant concentration (above critical micelle concentration) affects interaction insignificantly. Dynamic light scattering experiments indicate that hyaluronan molecular weight has insignificant effect on isoelectric point of the systems. It was found that solubilization ability of the complexes is influenced by molecular weight of hyaluronan.
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Kim, B. K., K. Baek, and J. W. Yang. "Simultaneous removal of nitrate and phosphate using cross-flow micellar-enhanced ultrafiltration (MEUF)." Water Science and Technology 50, no. 6 (September 1, 2004): 227–34. http://dx.doi.org/10.2166/wst.2004.0380.

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The feasibility of cross-flow micellar-enhanced ultrafiltration (MEUF) was investigated to remove nitrate and phosphate simultaneously. At the above critical micelle concentration (CMC), a cationic surfactant added in wastewater forms micelles, which have positive charge on their surface. Anionic contaminants such as nitrate and phosphate can be bound on the micelles by electrostatic interaction, and the micelle-pollutants complex is removed effectively by ultrafiltration. In this study, a cross-flow MEUF system was designed and investigated the feasibility of MEUF for field application. A cationic surfactant, cetylpyridinium chloride (CPC), was used, and the synthetic wastewater was treated by the polyacrylonitrile membranes with molecular weight cut-off (MWCO) of 30,000 Da and 10,000 Da. With the molar ratio of CPC to total pollutants of > 3, > 86% of nitrate and > 91% of phosphate were removed, respectively, and > 97% of CPC was also rejected. The flux was maintained 20Ð30% of the flux of distilled water. Therefore, it is feasible to remove nitrate and phosphate simultaneously using the cross-flow MEUF system.
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Wang, Tingyi, Hui Yan, Li Lv, Yingbiao Xu, Lingyu Zhang, and Han Jia. "Computational Investigations of a pH-Induced Structural Transition in a CTAB Solution with Toluic Acid." Molecules 26, no. 22 (November 19, 2021): 6978. http://dx.doi.org/10.3390/molecules26226978.

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In this work, molecular dynamics simulations were performed to study the pH-induced structural transitions for a CTAB/p-toluic acid solution. Spherical and cylindrical micelles were obtained for aqueous surfactants at pH 2 and 7, respectively, which agrees well with the experimental observations. The structural properties of two different micelles were analyzed through the density distributions of components and the molecular orientations of CTA+ and toluic acid inside the micelles. It was found that the bonding interactions between CTA+ and toluic in spherical and cylindrical micelles are very different. Almost all the ionized toluic acid (PTA−) in the solution at pH 7 was solubilized into the micelles, and it was located in the CTA+ headgroups region. Additionally, the bonding between surfactant CTA+ and PTA− was very tight due to the electrostatic interactions. The PTA− that penetrated into the micelles effectively screened the electrostatic repulsion among the cationic headgroups, which is considered to be crucial for maintaining the cylindrical micellar shape. As the pH decreased, the carboxyl groups were protonated. The hydration ability of neutral carboxyl groups weakened, resulting in deeper penetration into the micelles. Meanwhile, their bonding interactions with surfactant headgroups also weakened. Accompanied by the strengthen of electrostatic repulsion among the positive headgroups, the cylindrical micelle was broken into spherical micelles. Our work provided an atomic-level insights into the mechanism of pH-induced structural transitions of a CTAB/p-toluic solution, which is expected to be useful for further understanding the aggregate behavior of mixed cationic surfactants and aromatic acids.
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Dissertations / Theses on the topic "CATIONIC MICELLES"

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Schnee, Vincent Patrick. "The characterization of cationic pseudostationary phases for electrokinetic chromatography." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-05222008-102001/.

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Zhou, Xing Zhi. "Cationic polypeptide-based micelles for camptothecin delivery in lung cancer therapy." Thesis, University of Macau, 2018. http://umaclib3.umac.mo/record=b3952141.

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Faivre, Valérie. "Étude des propriétés esterolytiques de complexes hydrophobes 2-hydroxymethylbenzimidazole-zn+² en présence de micelles cationiques (CTAB)." Vandoeuvre-les-Nancy, INPL, 1993. http://www.theses.fr/1993INPL008N.

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On décrit la préparation de deux séries de 2-hydroxymethylbenzimidazoles substitués par une chaine n-alkyle (1 a 14 carbones) en position 5(6) (série I) ou 1 (série II) ainsi que la mise au point de la synthèse de nouveaux picolinates de 4-nitrophenyle (série III) porteurs d'un groupe alkoxy hydrophobe de 1 a 18 atomes de carbone. L'activité esterolytique des systèmes ligands I ou II-Zn2+ vis-à-vis des esters actives III en présence de micelles cationiques (CTAB) est comparée à celle d'un système hydrosoluble de même nature. L'étude cinétique montre l'intervention d'un seul complexe actif 2/1 pour la série I, mais de deux complexes actifs 1/1 et 2/1 pour la série II alors qu'en l'absence de micelles n'existe que le complexe 1/1. Le pouvoir esterolytique global de ces complexes est beaucoup plus élevé qu'une solution moléculaire. L'étude plus détaillée d'un ligand I montre sa complexation quasi totale; cependant la constante de vitesse apparente liée au complexe ainsi que les constantes spécifiques rapportées à la pseudo-phase micellaire sont plus faibles qu'en l'absence de micelle. Cette forte diminution de réactivité peut être attribuée à la formation plus difficile du complexe ternaire ligand/-Zn++/ester, intermédiaire dans la réaction d'esterolyse
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Ergican, Erdogan. "Molecular level separation of arsenic (V) from drinking water using cationic micelles and ultrafiltration membrane." abstract and full text PDF (free order & download UNR users only), 2005. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3210067.

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Skoglund, Sara. "Self-assembly in mixtures of an anionic and a cationic surfactant: A comparison between static light scattering and cryotransmission electron microscopy." Thesis, KTH, Skolan för kemivetenskap (CHE), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34032.

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Surfactants self-assemble into aggregates above a certain concentration. In this work mixtures of the cationic surfactant cetyltrimetylammonium bromide (CTAB) and the anionic surfactant sodium octyl sulfate (SOS) were investigated systematically. The measurements were accomplished by combining the two complimentary techniques static light scattering (SLS) and cryo-transmission electron microscopy (CRYO-TEM). It was found that CTAB-rich samples contain large threadlike micelles rather close to mole fractions where vesicles start to form. The mole fraction x of the surfactant in excess in the aggregates was calculated and it was found that it differs a lot from the mole fraction in the bulk, and the transition from micelles to vesicles occurs when x is about 0.7. In the SOS-rich samples small globular micelles were observed that transform into vesicles upon dilution. Some of the samples rich in SOS were found to contain open vesicles with CRYO-TEM and the reasons for this behavior have been discussed. One question that needs to be further investigated is whether or not these structures are the result of some kind of distortion of the equilibrium process during sample preparation in connection with CRYO-TEM measurements. In most cases the two methods showed consistent results and trends, but for some samples differences could be observed.
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Kashapov, Ruslan R., Tatiana N. Pashirova, Sergey V. Kharlamov, Albina Yu Ziganshina, Elena P. Ziltsova, Svetlana S. Lukashenko, Lucia Ya Zakharova, Wolf D. Habicher, Shamil K. Latypov, and Alexander I. Konovalov. "Novel self-assembling system based on resorcinarene and cationic surfactant." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-138802.

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Mixed association of calix[4]resorcinarene with ethyl sulfonate groups on the lower rim and dimethylaminomethyl groups on the upper rim (CR) and cationic surfactant 4-aza-1-hexadecyl-azoniabicyclo[2.2.2]octane bromide (DABCO-16) is studied by methods of tensiometry, conductometry, potentiometry and NMR spectroscopy at fixed CR concentration and varied surfactant concentration. Beyond ca. 0.4 mM of DABCO-16, mixed aggregates enriched by CR are proved to be formed due to electrostatic forces, while beyond ca. 5 mM, aggregates enriched by surfactant occur due to the hydrophobic effect. Spectrophotometry monitoring of the solubilization of a hydrophobic dye, Orange OT, demonstrated that only the second type of mixed aggregate enriched by DABCO-16 is capable of binding the organic probe, while the mixed system where the surfactant is a minor component shows no binding capacity towards Orange OT. This finding can be used for the design of nanocontainers with controllable binding/release properties
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Kashapov, Ruslan R., Tatiana N. Pashirova, Sergey V. Kharlamov, Albina Yu Ziganshina, Elena P. Ziltsova, Svetlana S. Lukashenko, Lucia Ya Zakharova, Wolf D. Habicher, Shamil K. Latypov, and Alexander I. Konovalov. "Novel self-assembling system based on resorcinarene and cationic surfactant." Royal Society of Chemistry, 2011. https://tud.qucosa.de/id/qucosa%3A27782.

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Mixed association of calix[4]resorcinarene with ethyl sulfonate groups on the lower rim and dimethylaminomethyl groups on the upper rim (CR) and cationic surfactant 4-aza-1-hexadecyl-azoniabicyclo[2.2.2]octane bromide (DABCO-16) is studied by methods of tensiometry, conductometry, potentiometry and NMR spectroscopy at fixed CR concentration and varied surfactant concentration. Beyond ca. 0.4 mM of DABCO-16, mixed aggregates enriched by CR are proved to be formed due to electrostatic forces, while beyond ca. 5 mM, aggregates enriched by surfactant occur due to the hydrophobic effect. Spectrophotometry monitoring of the solubilization of a hydrophobic dye, Orange OT, demonstrated that only the second type of mixed aggregate enriched by DABCO-16 is capable of binding the organic probe, while the mixed system where the surfactant is a minor component shows no binding capacity towards Orange OT. This finding can be used for the design of nanocontainers with controllable binding/release properties.
Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
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Pires, Paulo Augusto Rodrigues. "Síntese e propriedades de soluções de tensoativos catiônicos derivados de (3-dimetilaminopropil)amidas de ácidos carboxílicos." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-06102003-163601/.

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Duas séries homólogas de tensoativos foram sintetizadas, os cloretos de benzil-(3-acilaminopropil)dimetilamônio, RCONH(CH'ind.2')3N'pot.+'(CH'ind.3')]pot.2'CH'pot.2'C'pot.6'H'pot.5'Cl'pot.-'e (3-acilaminopropil)trimetilamônio, RCONH[(CH'pot.2')]'ind.3'N'pot.+'(CH'ind.3')'pot.3'Cl'ind. -' , onde RCO = C'ind.10' a C'ind.16'. A síntese foi realizada a partir de precursor comum, RCONH(CH'ind.2')'pot.3'N'(CH'ind.3')ind.2', sendo a quaternização feita pela reação com cloreto de benzila e iodeto de metila (seguido de troca iônica), respectivamente. Investigou-se a adsorção na interface solução/ar, a micelização e a estrutura dos agregados formados. Os resultados foram comparados com os de tensoativos catiônicos. Algumas das propriedades micelares das séries estudadas (ex: concentrações micelares críticas, graus de dissociação, números de agregação) tem valores na mesma faixa de grandeza dos outros tensoativos catiônicos com o mesmo tamanho de cadeia hidrofóbica. Outras, por exemplo, a energias livres de Gibbs de adsorção e micelização são diferentes (mais favoráveis). Os resultados apontam para o fato de que o grupo 3-amidopropila, [-CO-NH-CH'ind.2'-CH'ind.2'-CH'ind.2'-], quando inserido na molécula do tensoativo, acaba constituindo parte do seu grupo hidrofílico e facilita a micelização do mesmo. A polaridade microscópica da água interfacial foi determinada usando sondas solvatocrômicas e mostra que a água interfacial é menos polar que água 'bulk'.
The following surfactants have been synthesized: benzyl-(3-acyl-aminopropyl)dimethylammonium chloride, RCONH(CH'ind.2')'ind.3'N'pot.+'(CH'ind.3')'ind.2'CH'ind.2'C'ind.6'H'ind.5' Cl'pot.-' and (3-acylaminopropyl) trimethylammonium chloride, RCONH(CH'ind.2')'ind.3'N'pot.+'(CH'ind.3')'ind.3' Cl'ind.-', where RCO = C'ind.10' to C'ind.16'. The two series have been synthesized from the precursor RCONH(CH2)3N(CH3)2, by quaternization with benzyl chloride, and/or methyl iodide (followed by ion exchange), respectively. Adsorption at solution/air interface and micellization in aqueous solution has been studied, and the results compared with those of other cationic surfactants. Some properties, e.g., critical micelle concentrations, degrees of micelle dissociation, and aggregation numbers are similar to those of other cationic surfactants of equivalent hydrophobic chain length. The Gibbs free energies of adsorption at solution/air interface, and of micellization are, however, more favorable. The group [-CO-NH-CH'ind.2'-CH'ind.2'-CH'ind.2'-] is a part of the interface, and lead to favorable micellization. The microscopic polarity of interfacial water has been measured by appropriate solvatochromic probes, and is less than that of bulk water.
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Ashrafizadeh, Seyed Nezameddin. "Cation exchange with reverse-micelles." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=61109.

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Experimental and theoretical studies on the extraction of the cation K$ sp+$ and Mg$ sp{++}$ from a bulk aqueous phase to an organic phase using the water/dinonylnaphthalene sulfonic acid (HD)/heptane reverse-micellar system was conducted. The counter ion of the surfactant, H$ sp+$, was exchanged with the alkali metal cations in the aqueous phase. Two different types of experiments were conducted. The first set involved a constant total normality of ions while the second investigated the effect, of varying the normality of ions. Electrolyte solutions with molarities ranging from 0 to 1 were contacted with a reverse-micellar organic containing different concentrations of surfactant with different types of counter ions.
The HD reverse-micellar extraction system exhibited behavior similar to that of conventional ion-exchange resin systems. A preferential extraction for Mg$ sp{++}$ over K$ sp+$ was observed. The efficiency of the extraction was high for low salt concentrations and it was independent of surfactant concentration. The amount of water uptake was low, with W$ sb{o}$ ranging between 4 and 10. For a wide range of salt and surfactant concentrations W$ sb{o}$ was independent of surfactant concentration. The HD surfactant showed a low solubility in the aqueous phase.
The results of the equilibrium partition experiments were correlated using a thermodynamic model. Interaction parameters determined from binary system experimental data were used to predict the ternary system partition behavior. The ternary system predictions were compared with experimental results and found to be satisfactory.
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Gélinas, Stéphanie. "Micellar-enhanced ultrafiltration using a twin-head cationic surfactant." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23262.

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In Micellar-Enhanced Ultrafiltration (MEUF), a surfactant is added to a wastewater stream containing an organic solute. Most of the solute is solubilized in micelles, which are aggregates of surfactant molecules, formed in the feed solution. Separation is achieved through retention of the micelles by an ultrafiltration membrane. Since much of the solute is within the micelles, a membrane with a molecular weight cut off (MWCO) much larger than the molecular weight of the solute is used. Although some unsolubilized solute and surfactant monomers pass through the membrane, the use of a surfactant with a low critical micelle concentration (CMC) ensures little contamination of the permeate by surfactant monomers.
Solubilization tests and MEUF experiments were performed with an aqueous feed solution of benzoic acid (molecular weight 122) and Rhodameen T12/90 (molecular weight 798), a twin-head, cationic tertiary amine surfactant. This surfactant has an 18 carbon hydrophobic tail and two hydrophilic polyoxyethylene heads. The equilibrium solubilization of benzoic acid by surfactant solutions was measured by semiquilibrium dialysis. The maximum solubilization was nearly one mole of benzoic acid per mole of Rhodameen.
MEUF was carried out in hollow fiber polysulfone membrane units with MWCO of 5,000 and 30,000. The permeate flux and overall rejection of benzoic acid and surfactant were measured for different initial feed compositions and initial surfactant concentrations under varying transmembrane pressures (TMP). The flux increased with TMP and decreased with Rhodameen concentration, but was not affected by the benzoic acid concentration. The highest rejections of benzoic acid (90%) and Rhodameen (95%) were obtained when the molar ratio of surfactant to solute in the feed was 1.2.
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Books on the topic "CATIONIC MICELLES"

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R, Hill Aubrey, and Orgel Leslie E, eds. Catalysis of the oligomerization of o-phospho-serine, aspartic acid, or glutamic acid by cationic micelles. [Washington, D.C: National Aeronautics and Space Administration, 1997.

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Anionic polyelectrolyte binding to mixed cationic-zwitterionic surfactant micelles: A molecular perspective from [2]H NMR spectroscopy. Ottawa: National Library of Canada, 1995.

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Book chapters on the topic "CATIONIC MICELLES"

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Ripoll, Manon, Patrick Neuberg, Jean-Serge Remy, and Antoine Kichler. "Cationic Photopolymerized Polydiacetylenic (PDA) Micelles for siRNA Delivery." In Nanotechnology for Nucleic Acid Delivery, 101–22. New York, NY: Springer New York, 2019. http://dx.doi.org/10.1007/978-1-4939-9092-4_7.

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Wright, Sally, Clifford A. Bunton, and Paul M. Holland. "Binding of Bromide Ion to Mixed Cationic—Nonionic Micelles." In Mixed Surfactant Systems, 227–33. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0501.ch013.

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Sivarajasekar, N., S. Ramasubbu, J. Prakash Maran, and B. Priya. "Cationic Dyes Sequestration from Aqueous Phase Using Biosurfactant Based Reverse Micelles." In Recent Advances in Chemical Engineering, 67–74. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1633-2_8.

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Marangoni, D. Gerrard, Andrew P. Rodenhiser, Jill M. Thomas, and Jan C. T. Kwak. "Interaction of Alcohols and Ethoxylated Alcohols with Anionic and Cationic Micelles." In Mixed Surfactant Systems, 194–209. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0501.ch011.

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Song, Cun Xian, Man Yan Wang, Jing Yang, Xu Jin, Lin Mei, Xigang Leng, Hong Fan Sun, and R. J. Levy. "Anti-DNA Antibody/Cationic Lipid Micelles for Plasmid DNA Gene Delivery." In Advanced Biomaterials VI, 105–8. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-967-9.105.

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Rodenas, E., F. Ortega, S. Vera, C. Otero, and S. Maestro. "Discussion of Different Kinetic Models for Explaining Experimental Results in Cationic Micelles." In Surfactants in Solution, 211–27. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4613-0839-3_16.

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Falsini, Sara, and Sandra Ristori. "Lipoplexes from Non-viral Cationic Vectors: DOTAP-DOPE Liposomes and Gemini Micelles." In Methods in Molecular Biology, 33–43. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3718-9_3.

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Baglioni, Piero, Luigi Dei, Larry Kevan, and Elisabeth Rivara-Minten. "Interface of Mixed Micelles Formed of Anionic—Cationic and Ionic—Nonionic Surfactants." In Mixed Surfactant Systems, 180–93. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0501.ch010.

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Yang, Yi, Shuai Shi, and Zhiyong Qian. "Preparation and Application of MPEG-PCL-g-PEI Cationic Micelles in Cancer Therapy." In Biomaterial Engineering, 1–16. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-6198-0_7-1.

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Yang, Yi, Shuai Shi, and Zhiyong Qian. "Preparation and Application of MPEG-PCL-g-PEI Cationic Micelles in Cancer Therapy." In Biomaterial Engineering, 121–36. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-5419-0_7.

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Conference papers on the topic "CATIONIC MICELLES"

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Roy, Ved Prakash, and Kevin J. Kubarych. "Hydration Dynamics at Water-Surfactant Interface in Cationic Reverse and Regular Micelles using 2D-IR." In International Conference on Ultrafast Phenomena. Washington, D.C.: OSA, 2016. http://dx.doi.org/10.1364/up.2016.uw4a.21.

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Zakin, Jacques L., Yunying Qi, and Ying Zhang. "Recent Experimental Results on Surfactant Drag Reduction." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45654.

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Certain surfactant solutions are drag reducing in turbulent shear flows. Because they “self-repair” after mechanical degradation, they are very attractive for reducing pumping energy losses in recirculating water applications such as district heating and cooling systems. Some surfactant systems reduce drag below the Virk limiting drag reduction asymptote for high polymers. The surfactant asymptote is 40% below that for polymers and the limiting velocity profile slope for highly drag reducing surfactant systems is about twice that for polymers. Like polymers, surfactants show low turbulence intensities normal to the wall and may exhibit zero Reynolds stresses requiring the postulation of an “elastic” stress to satisfy the total stress balance. The influences of counterion chemical structure and shear on microstructures, rheology and therefore drag reduction of cationic surfactant solutions are also addressed. Viscoelasticity, high extensional/shear viscosity ratios and threadlike microstructures have been proposed as necessary physical criteria for surfactant drag reduction. Recently, however, several non-viscoelastic drag reducing surfactant solution systems (zero first normal stress differences, no recoil and no stress overshoot) have been reported. Most drag reducing surfactant solutions have extensional to shear viscosity ratios of 100 or more. However, two solutions with a low ratio in the shear/extensional rate range of 20∼1000 s−1 have been observed. The ratio tends to increase at higher extensional rates, however, so the second criterion may be valid. Finally, cryo-TEM images of some drag reducing surfactant micelle microstructures which lacked threadlike structures in the quiescent state have been observed. However, Zheng et al. [1] showed that vesicle microstructures in the quiescent state can change to threadlike micelles under shear, supporting the third criterion.
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Friesen, Dawn, Brian Seymour, and Aaron Sanders. "A Novel Gemini Cationic Viscoelastic Surfactant-Based Fluid for High Temperature Well Stimulation Applications." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206297-ms.

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Abstract Viscoelastic surfactant (VES)-based fracturing fluids can reduce the risk of formation damage when compared with conventional polymer-based fracturing systems. However, many VES systems lose viscoelasticity rapidly under high-temperature conditions, leading to high fluid leakoff and problems in proppant placement. A gemini cationic VES-based system offering thermal stability above 250°F and its efficiency in friction reduction is presented in this paper. Rheology measurements were conducted on viscoelastic cationic gemini surfactant fluids as a function of temperature (70 – 300°F) and surfactant concentration. The length of surfactant alkyl chain was varied to investigate the impact of surfactant chain length on VES fluid viscosity at elevated temperatures. The effect of flow rate on friction reduction capability of the surfactant fluid was measured on a friction flow loop. Foam rheology measurements were conducted to evaluate the VES fluid's ability to maintain high temperature viscosity with reduced surfactant concentration. A gemini cationic surfactant was used to prepare a viscoelastic surfactant system that could maintain viscosity over 50 cP at a shear rate of 100 s−1up to at least 250°F. With this system, viscoelastic gel viscosity was maintained without degradation for over 18 hours at 250°F, and the fluid showed rapid shear recovery throughout. Decreasing the average alkyl chain length on the surfactant reduced the maximum working temperature of the resulting viscoelastic gel and showed the critical influence of surfactant structure on the resulting fluid performance. The presence of elongated, worm-like micelles in the fluid provided polymer-like friction reduction even at low surfactant concentrations, with friction reduction of over 70% observed during pumping (relative to fresh water) up to a critical Reynolds number. Energized fluids could also be formulated with the gemini surfactant to give foam fluids suitable for hydraulic fracturing or wellbore cleanouts. The resulting viscoelastic surfactant foams had viscosities over 50 cP up to at least 300°F with both nitrogen and carbon dioxide as the gas phase. The information presented in this paper is important for various field applications where thermal stability of the treatment fluid is essential. This will hopefully expand the use of VES-based systems as an alternative to conventional polymer systems in oilfield applications where a less damaging viscosified fluid system is required.
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Baccile, Niki, Alexandre Poirier, and Chloe Seyrig. "Biosurfactants and biopolymers: Between interactions, orthogonality and mutual responsivity." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/taly8346.

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Polymer-surfactant systems have many applications in everyday life, but their petrochemical origin is not only controversial but soon submitted to regulatory restrictions. In a more environmentally friendly approach, but also to forecast regulations in both EU and USA, biopolymer-biosurfactant systems are an interesting alternative. There exists a large family of both biobased surfactants and polymers, which possess a huge potential, however currently limited, because both the solution behaviour of the former and their interactions are not established, yet. [1] This presentation shows the first set of work where biosurfactants (sophorolipids, glucolipids) are studied together with biopolymers (chitosan, alginate, gelatin, collagen, silk fibroin) (Figure 1). The results are astonishing, as they depend on the biosurfactant's self-assembled state, but also its charge and the charge of the biopolymer. Complex coacervates are often formed at basic pH when biosurfactants are within their micellar state and charges are opposite. [2] At acidic pH, orthogonality seems to prevail when the biosurfactant reorganizes into crystalline fibers, [3] but new phases, derived from mutual electrostatic interactions, can also appear, when the biosurfactants forms a vesicular phase. [4] These data are important to design biosurfactant-biopolymer-based nanocarriers or stimuli-responsive hydrogels. [1] Baccile N, Seyrig C, et al. Self-assembly, interfacial properties, interactions with macromolecules and molecular modelling and simulation of microbial bio-based amphiphiles (biosurfactants). A tutorial review. Green Chem. 2021, 3842[2] G. Ben Messaoud, Baccile N, et al. Complex coacervation of natural sophorolipid bolaamphiphile micelles with cationic polyelectrolytes. Green Chem. 2018, 3371[3] Seyrig C, Kignelman G, Thielemans W, Griel P Le, Cowieson N, Perez J, Baccile N et al. Stimuli-induced non-equilibrium phase transitions in polyelectrolyte-surfactant complex coacervates. Langmuir. 2020, 8839[4] Seyrig C, Baccile N et al. Synthesis of multilamellar walls vesicles polyelectrolyte-surfactant complexes from pH-stimulated phase transition using microbial biosurfactants. J Colloid Interface Sci. 2020, 493
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Qin, Wen-Long, Lei Yue, Li-Pan HuangPu, Xiao Qu, Jiang Yang, and Wen-Long Qin. "Rheology of a Long Chain Cationic Surfactant Micelle Solution with Multi-Walled Carbon Nanotubes." In 2015 International Conference on Energy, Environmental & Sustainable Ecosystem Development (EESED 2015). WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814723008_0046.

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Setiawan, Ely, Karna Wijaya, and Mudasir Mudasir. "Generic QSPR study for predicting critical micelle concentration of gemini cationic surfactants using the online chemical modeling environment (OCHEM)." In 4TH INTERNATIONAL SEMINAR ON CHEMISTRY. AIP Publishing, 2021. http://dx.doi.org/10.1063/5.0051623.

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Bahl, Manish, Juntao Zhang, and Raj M. Manglik. "Measurement of Dynamic and Equilibrium Surface Tension of Surfactant Solutions by the Maximum Bubble Pressure Method." In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47137.

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Surfactant solution systems are encountered in many different applications, including as a method to enhance the nucleate boiling performance of water. Characterizing the attendant interfacial phenomena requires precise predictions of their surface tension relaxation behavior. In this study, both the dynamic and equilibrium surface tension behavior of aqueous surfactant solutions has been investigated using the maximum bubble pressure method. The surface tension is measured as a function of concentration at room (23°C) and elevated (80°C) temperatures. The critical micelle concentration (c.m.c.) of each surfactant is calculated from their respective equilibrium adsorption isotherms. The dynamic surface tension measurements are obtained at a surface age of 50 ms, which simulates conditions typically encountered during nucleate boiling of water. Two anionic surfactants, Sodium Dodecyl Sulfate (SDS) and Sodium Lauryl Ether Sulfate (SLES), two cationic surfactants Dodecyl Trimethyl Ammonium Chloride (DTAC) and Ethoquad O12/PG, and one non-ionic surfactant Triton X-100 have been used. SLES, Ethoquad O12/PG and Triton X-100 have, respectively, 3, 2, and 9–10 degrees of ethoxylation, which tends to alter the interfacial rheology. The σ–C isotherms show marked variation based on the surfactant ionic nature and the number of ethoxy groups present, along with the effects of temperature, with considerably less surface relaxation under dynamic conditions compared to those at equilibrium.
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Khan, Mohammad Niyaz, May-Ye Cheong, Azhar Ariffin, Mohamad Rusop, and Tetsuo Soga. "An Empirical Kinetic Approach To Study The Occurrence Of Ion-Exchange At The Aqueous Cationic Micellar Surface: Alkaline Hydrolysis Of N-Benzylphthalimide." In NANOSCIENCE AND NANOTECHNOLOGY: International Conference on Nanoscience and Nanotechnology—2008. AIP, 2009. http://dx.doi.org/10.1063/1.3160169.

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Lokanathan, Manojkumar, Himanshu Sharma, Mostafa Shabaka, Vaibhav Bahadur, and Kishore Mohanty. "Comparing Electrowettability and Surfactants As Tools for Wettability Enhancement on a Hydrophobic Surface." In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10483.

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Abstract Wettability alteration has significant applications in microfluidics, energy production and process engineering. Surfactants have been widely used for wettability alteration on surfaces. More recently, electrowetting (EW) has emerged as a powerful microfluidic technique to dynamically alter wettability. EW relies on the application of an electrical potential difference across a dielectric layer on which the fluid rests. This work analyzes the extent of wettability enhancement of water droplets on a hydrophobic surface (in air) via the use of surfactants and EW. Nine surfactants were chosen from the categories of anionic, cationic and zwitterionic surfactants. The critical micelle concentration (CMC) of these surfactants, and the wettability of surfactant-infused water droplets was measured at post and pre-CMC concentrations. Next, experiments were conducted to quantify the wettability enhancement of water droplets (with surfactants) via EW. Many interesting insights on the interplay between surfactants and electric fields are uncovered in this work. As expected, adding surfactants enhances wettability up to the CMC. EW can further enhance wettability of surfactant solutions and further reduce the contact angle by as much as 30°. Interestingly, it is seen that the influence of EW in enabling CA reduction is reduced by the addition of surfactants at pre-CMC levels. Conversely, surfactants strengthen the influence of EW at higher concentrations. It is noted that the extent of wettability alteration via EW is limited by the phenomena of contact angle saturation, wherein the contact angle saturates beyond a certain voltage. Interestingly, it is seen that at post CMC concentrations, the saturation contact angles are independent of surfactant concentrations.
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Shi, Xundan, Choongyong Han, Christian Wolfsteiner, Yih-Bor Chang, and Baris Güyagüler. "Methods to Improve Accuracy and Performance in a Fully Implicit Surfactant Flood Simulator." In SPE Improved Oil Recovery Conference. SPE, 2022. http://dx.doi.org/10.2118/209447-ms.

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Abstract Saturation distributions exhibiting unphysical "checkerboard" patterns, time-step size sensitivity, and slow convergence in certain instances are observed in a fully implicit surfactant simulator that is based on an industry-wide accepted formulation. In this paper, we discuss methods to address each of the above conditions and hereby achieve a robust algorithm with favorable convergence characteristics. The proposed remedies are result of in-depth studies of the physics of micro-emulsion appearance and disappearance as well as detailed analysis of the numerical convergence difficulty. Our method considers wide ranges of solution variables in a typical surfactant flood simulator and critical key parameters identified by flash algorithm [Han, et al. 2017] and general non-linear solver. The details of the improved formulation are provided and should enable readers to replicate all these results. Identifying grid cells in a reservoir model where and when the micro-emulsion phase appears is a key capability in the modeling of surfactant phase behavior. The Critical Micelle Concentration (CMC) is the commonly accepted triggering criterion for forming the micro-emulsion phase. We have observed unphysical "checkerboard" saturation patterns for several cases where water mobility is greater than oil mobility when using the conventionally accepted CMC calculation method. We have analyzed the reasons for this unphysical solution and propose a new CMC definition to ensure physically consistent simulation results. Typical CMC values for surfactant flood are in the range of 10-5 to 10-3. This requires surfactant concentration to be solved more accurately relative to other component concentrations as it directly affects micro-emulsion phase disappearance. The simulation results may vary with time-step sizes not only from the time-truncation errors but, more importantly, from the accuracy of the solved surfactant concentration for each time-step. Special treatments are introduced to reduce the time-step size sensitivity in our simulator. For cases with cation exchange, slow convergence is observed as the corresponding governing equations form an ill-conditioned matrix for cells with small surfactant concentration. An extra term is introduced into the formulation to speed up the convergence rate without changing the model behavior.
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Reports on the topic "CATIONIC MICELLES"

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Gerstl, Zev, Thomas L. Potter, David Bosch, Timothy Strickland, Clint Truman, Theodore Webster, Shmuel Assouline, Baruch Rubin, Shlomo Nir, and Yael Mishael. Novel Herbicide Formulations for Conservation-Tillage. United States Department of Agriculture, June 2009. http://dx.doi.org/10.32747/2009.7591736.bard.

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The overall objective of this study was to develop, optimize and evaluate novel formulations, which reduce herbicide leaching and enhance agronomic efficacy. Numerous studies have demonstrated that CsT promotes environmental quality and enhances sustainable crop production, yet continued use of CsT-practices appears threatened unless cost effective alternative weed control practices can be found. The problem is pressing in the southern portion of the Atlantic Coastal Plain region of the eastern USA where cotton and peanut are produced extensively. This research addressed needs of the region’s farmers for more effective weed control practices for CsT systems. HUJI: CRFs for sulfentrazone and metolachlor were developed and tested based on their solubilizion in cationic micelles and adsorption of the mixed micelles on montmorillonite. A better understanding of solubilizing anionic and nonionic organic molecules in cationic micelles was reached. Both CRFs demonstrated controlled release compared to the commercial formulations. A bioassay in soil columns determined that the new sulfentrazone and metolachlor CRFs significantly improve weed control and reduced leaching (for the latter) in comparison with the commercial formulations. ARO: Two types of CRFs were developed: polymer-clay beads and powdered formulations. Sand filter experiments were conducted to determine the release of the herbicide from the CRFs. The concentration of metolachlor in the initial fractions of the effluent from the commercial formulation reached rather high values, whereas from the alginate-clay formulations and some of the powdered formulations, metolachlor concentrations were low and fairly constant. The movement of metolachlor through a sandy soil from commercial and alginate-clay formulations showed that the CRFs developed significantly reduced the leaching of metolachlor in comparison to the commercial formulation. Mini-flume and simulated rainfall studies indicated that all the CRFs tested increased runoff losses and decreased the amount of metolachlor found in the leachate. ARS: Field and laboratory investigations were conducted on the environmental fate and weed control efficacy of a commercially available, and two CRFs (organo-clay and alginate-encapsulated) of the soil-residual herbicide metolachlor. The environmental fate characteristics and weed control efficacy of these products were compared in rainfall simulations, soil dissipations, greenhouse efficacy trials, and a leaching study. Comparisons were made on the basis of tillage, CsT, and conventional, i.e no surface crop residue at planting (CT). Strip-tillage (ST), a commonly used form of CsT, was practiced. The organo-clay and commercial metolachlor formulations behaved similarly in terms of wash off, runoff, soil dissipation and weed control efficacy. No advantage of the organo-clay over the commercial metolachlor was observed. Alginate encapsulated metolachlor was more promising. The dissipation rate for metolachlor when applied in the alginate formulation was 10 times slower than when the commercial product was used inferring that its use may enhance weed management in cotton and peanut fields in the region. In addition, comparison of alginate and commercial formulations showed that ST can effectively reduce the runoff threat that is commonly associated with granular herbicide application. Studies also showed that use of the alginate CRF has the potential to reduce metolachlor leaching. Overall study findings have indicated that use of granular herbicide formulations may have substantial benefit for ST-system weed management for cotton and peanut production under Atlantic Coastal Plain conditions in the southeastern USA. Commercial development and evaluation at the farm scale appears warranted. Products will likely enhance and maintain CsT use in this and other regions by improving weed control options.
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