Relevant bibliographies by topics / Surfactants

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Surfactants'

Author: Grafiati
Published: 4 June 2021
Last updated: 31 July 2024

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Journal articles on the topic "Surfactants"

1

Cheng, Chao, and Shi-Yong Ran. "Interaction between DNA and Trimethyl-Ammonium Bromides with Different Alkyl Chain Lengths." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/863049.

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The interaction betweenλ—DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant’s alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60–110 nm at low surfactant concentrations. In contrast, high concentration of surfactants leads to aggregates with increased sizes. Atomic force microscope scanning also supports the above observation. Zeta potential measurements show that the potential of the particles decreases with the increase of surfactant concentration (CTAB, TTAB, DTAB), which contributes much to the coagulation of the particles. For OTAB, the surfactant with the shortest chain in this study, it cannot fully neutralize the charges of DNA molecules; consequently, the complex is looser than other surfactant-DNA structures.
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Benedicto, Elisabet, Eva María Rubio, Diego Carou, and Coral Santacruz. "The Role of Surfactant Structure on the Development of a Sustainable and Effective Cutting Fluid for Machining Titanium Alloys." Metals 10, no. 10 (October 19, 2020): 1388. http://dx.doi.org/10.3390/met10101388.

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In cutting operations of titanium alloys, most of the problems are related to the high consumption of cutting tools due to excessive wear. An improvement of metalworking fluid (MWF) technology would increase the productivity, sustainability, and quality of machining processes by lubricating and cooling. In this research article, the authors varied the surfactant’s charge, the hydrocarbon chain length, and the ethoxylation degree. Surfactants were dispersed at 1.2 mM in water and trimethylolpropane oleate to produce water-based MWF. Infrared reflection absorption spectroscopy and total organic carbon analysis were used to study the influence of surfactant structure on the film forming ability of the emulsion and performance was studied on Ti6Al4V using tapping torque test. The results showed that by changing the molecular structure of the surfactant, it is possible to vary the affinity between the ester and the substrate and reach an optimal combination, which improves the formation of a tribofilm. The mixture with anionic surfactants has good tribology performance, while non-ionic surfactants shorten the tool’s life. Moreover, the increase in the hydrocarbon chain length and the number of ethoxylations of surfactants promotes the adhesion of ester onto the metal surface, improving the lubricity properties of environmentally friendly MWF.
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Deng, Chun Min, Tian Yi Zhong, and Bao Qi Zuo. "Surfactant-Induced Nanofibrous Architecture of Silk Fibroin Hydrogels." Materials Science Forum 745-746 (February 2013): 453–58. http://dx.doi.org/10.4028/www.scientific.net/msf.745-746.453.

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Hydrogels had been prepared by blending four types of surfactants such as alkyl betaine (zwitterion surfactant), tween 60 (non-ionic surfactant), sodium fatty alcohol ether sulfate (anionic surfactant) and silicone quaternary ammonium salt (cationic surfactant) with bombyx mori silk fibroin (SF) solution. Surfactant molecules would interact with SF molecules, resulting in lower critical micelle concentration (CMC). Gelation time measurements showed surfactants had significantly accelerated the hydrogelation process of SF solution, which could be controlled by the type or blend ratio of surfactants. Fourier transform infrared (FTIR) indicated that the addition of surfactants affected the molecular secondary of SF. The results from X-ray diffraction indicated that surfactants and SF were only blended but phase separation with two kinds of crystalline structure. SEM images showed that the surfactants had significantly changed the morphology of hydrogels according to certain rules, especially non-ionic and cationic surfactants could induce silk fibroin solutions into porous and nanofibrous hydrogels. These results indicated that a novel and potential method not only can be used to accelerate hydrogelation process of SF solution but also can be used to alter the structural and morphological of SF hydrogels. Furthermore, the porous and nanofibrous hydrogels of SF induced by surfactants provided a novel strategy to mimic the nanofibrous structure of collagen in extracellular matrix (ECM).
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Li, He Lian, Rong Hui Qu, Xue Mei Han, and Jia Jun Chen. "Surfactant-Enhanced Washing of Aged PAH Contaminated Soils: Comparison between Nonionic Surfactant and Anionic Surfactant." Applied Mechanics and Materials 522-524 (February 2014): 316–21. http://dx.doi.org/10.4028/www.scientific.net/amm.522-524.316.

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Nonionic surfactants Triton X-100 (TX100), Triton X-305 and anionic surfactant SDS were used to desorb PAHs from contaminated soil. The surfactant loss due to sorption/ precipitation and PAH removal efficiency by each surfactant were evaluated. Due to sorption/precipitation, the apparent critical micelle concentration (CMCsoil) values for the 3 surfactants are 1.3-3.8 times their corresponding CMC values in aqueous solutions. The maximal surfactant loss follows the order of SDS>>TX100>TX305. The anionic surfactant SDS is quite different from nonionic surfactants TX100 and TX305 in PAH removal. SDS can effectively remove 3-ring PAHs at very low concentration, but is not so efficient for 5 or 6-ring PAHs. While for nonionic surfactants TX100 and TX305, the removal efficiencies of PAHs increased with increasing surfactant concentration. Nonionic surfactants at low concentration cannot facilitate PAH desorption, but enhance the retardation of PAHs in soil. While anionic surfactant SDS enhanced PAH desorption at all the concentrations.
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Lamch, Łukasz, Weronika Szczęsna, Sebastian J. Balicki, Marcin Bartman, Liliana Szyk-Warszyńska, Piotr Warszyński, and Kazimiera A. Wilk. "Multiheaded Cationic Surfactants with Dedicated Functionalities: Design, Synthetic Strategies, Self-Assembly and Performance." Molecules 28, no. 15 (August 1, 2023): 5806. http://dx.doi.org/10.3390/molecules28155806.

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Contemporary research concerning surfactant science and technology comprises a variety of requirements relating to the design of surfactant structures with widely varying architectures to achieve physicochemical properties and dedicated functionality. Such approaches are necessary to make them applicable to modern technologies, such as nanostructure engineering, surface structurization or fine chemicals, e.g., magnetic surfactants, biocidal agents, capping and stabilizing reagents or reactive agents at interfaces. Even slight modifications of a surfactant’s molecular structure with respect to the conventional single-head–single-tail design allow for various custom-designed products. Among them, multicharge structures are the most intriguing. Their preparation requires specific synthetic routes that enable both main amphiphilic compound synthesis using appropriate step-by-step reaction strategies or coupling approaches as well as further derivatization toward specific features such as magnetic properties. Some of the most challenging aspects of multicharge cationic surfactants relate to their use at different interfaces for stable nanostructures formation, applying capping effects or complexation with polyelectrolytes. Multiheaded cationic surfactants exhibit strong antimicrobial and antiviral activity, allowing them to be implemented in various biomedical fields, especially biofilm prevention and eradication. Therefore, recent advances in synthetic strategies for multiheaded cationic surfactants, their self-aggregation and performance are scrutinized in this up-to-date review, emphasizing their applications in different fields such as building blocks in nanostructure engineering and their use as fine chemicals.
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Urmi, Wajiha Tasnim, M. M. Rahman, K. Kadirgama, D. Ramasamy, M. Samykano, and M. Y. Ali. "Exploring Surfactant-Enhanced Stability and Thermophysical Characteristics of Water-Ethylene Glycol-Based Al2O3-TiO2 Hybrid Nanofluids." WSEAS TRANSACTIONS ON HEAT AND MASS TRANSFER 18 (December 31, 2023): 195–206. http://dx.doi.org/10.37394/232012.2023.18.16.

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This study presents an empirical investigation into the impact of surfactant's enhanced stability and thermophysical characteristics of water-ethylene glycol (60:40) based Al2O3-TiO2 hybrid nanofluids. It aims to shed light on the nanofluid's behavior, mainly how surfactants affect its stability and thermal performance, thus contributing to advancements in heat transfer technology and engineering applications. The growing interest in nanofluids, which involves blending nanoparticles with conventional base fluids, spans diverse sectors like solar energy, heat transfer, biomedicine, and aerospace. In this study, Al2O3 and TiO2 nanoparticles are evenly dispersed in a DI-water and ethylene glycol mixture using a 50:50 ratio with a 0.1 % volume concentration. Three surfactants (SDS, SDBS, and PVP) are utilized to investigate the effect of the surfactants on hybrid nanofluids. The study examines the thermophysical characteristics of these hybrid nanofluids across a temperature range of 30 to 70 0C in 20 0C intervals to understand their potential in various industrial applications. The results show the highest stability period for nanofluids with PVP compared to nanofluids with surfactant-free and other surfactants (SDS, SDBS). The thermal conductivity is slightly decreased (max 4.61%) due to PVP surfactant addition compared to other conditions. However, the nanofluids with PVP still exhibit more excellent thermal conductivity value than the base-fluid and significantly reduced viscosity (max 55%). Hence, the enhanced thermal conductivity and reduced viscosity with improved stability due to PVP addition significantly impact heat transfer performance. However, the maximum thermal conductivity was obtained for surfactant-free Al2O3-TiO2/Water-EG-based hybrid nanofluids that reveal a thermal conductivity that is 17.05 % higher than the based fluid. Instead, the lower viscosity of hybrid nanofluids was obtained at 70 0C with the addition of PVP surfactant. Therefore, adding surfactants positively impacts Al2O3-TiO2/Water-EG-based hybrid nanofluids with higher stability, enhancing thermal conductivity and reducing viscosity compared to the based fluids. The results show that adding surfactants at a fixed volume concentration affects thermal conductivity at low temperatures and viscosity at high temperatures, suggesting that these fluids might be used as cooling agents to increase pumping power in industrial applications.
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Sharma, Gaurav, and Kishore K. Mohanty. "Wettability Alteration in High-Temperature and High-Salinity Carbonate Reservoirs." SPE Journal 18, no. 04 (April 22, 2013): 646–55. http://dx.doi.org/10.2118/147306-pa.

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Summary The goal of this work was to change the wettability of a carbonate rock from mixed-wet toward water-wet at high temperature and high salinity. Three types of surfactants in dilute concentrations (<0.2 wt%) were used. Initial surfactant screening was performed on the basis of aqueous stability at these harsh conditions. Contact-angle experiments on aged calcite plates were conducted to narrow the list of surfactants, and spontaneous-imbibition experiments were conducted on field cores for promising surfactants. Secondary waterflooding was carried out in cores with and without the wettability-altering surfactants. It was observed that most but not all surfactants were aqueous-unstable by themselves at these harsh conditions. Dual-surfactant systems, mixtures of a nonionic and a cationic surfactant, increased the aqueous stability. Some of the dual-surfactant systems proved effective for wettability alteration and could recover could recover 70 to 80% OOIP (original oil in place) during spontaneous imbibition. Secondary waterflooding with the wettability-altering surfactant increased the oil recovery over the waterflooding without the surfactants (from 29 to 40% of OOIP).
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Wang, Ruiguo, Xinxin Xu, Xiaodi Shi, Junjie Kou, Hongjian Song, Yuxiu Liu, Jingjing Zhang, and Qingmin Wang. "Promoting Efficacy and Environmental Safety of Pesticide Synergists via Non-Ionic Gemini Surfactants with Short Fluorocarbon Chains." Molecules 27, no. 19 (October 10, 2022): 6753. http://dx.doi.org/10.3390/molecules27196753.

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Improving the utilization rate of pesticides is key to achieve a reduction and synergism, and adding appropriate surfactant to pesticide preparation is an effective way to improve pesticide utilization. Fluorinated surfactants have excellent surface activity, thermal and chemical stability, but long-chain linear perfluoroalkyl derivatives are highly toxic, obvious persistence and high bioaccumulation in the environment. Therefore, new strategies for designing fluorinated surfactants which combine excellent surface activity and environmental safety would be useful. In this study, four non-ionic gemini surfactants with short fluorocarbon chains were synthesized. The surface activities of the resulting surfactants were assessed on the basis of equilibrium surface tension, dynamic surface tension, and contact angle. Compared with their monomeric counterparts, the gemini surfactants had markedly lower critical micelle concentrations and higher diffusivities, as well as better wetting abilities. We selected a single-chain surfactant and a gemini surfactant with good surface activities as synergists for the glyphosate water agent. Both surfactants clearly improved the efficacy of the herbicide, but the gemini surfactant had a significantly greater effect than the single-chain surfactant. An acute toxicity test indicated that the gemini surfactant showed slight toxicity to rats.
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Ramanathan, Rangasamy. "Surfactants in the Management of Respiratory Distress Syndrome in Extremely Premature Infants." Journal of Pediatric Pharmacology and Therapeutics 11, no. 3 (July 1, 2006): 132–44. http://dx.doi.org/10.5863/1551-6776-11.3.132.

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Respiratory distress syndrome (RDS) is primarily due to decreased production of pulmonary surfactant, and it is associated with significant neonatal morbidity and mortality. Exogenous pulmonary surfactant therapy is currently the treatment of choice for RDS, as it demonstrates the best clinical and economic outcomes. Studies confirm the benefits of surfactant therapy to include reductions in mortality, pneumothorax, and pulmonary interstitial emphysema, as well as improvements in oxygenation and an increased rate of survival without bronchopulmonary dysplasia. Phospholipids (PL) and surfactant-associated proteins (SP) play key roles in the physiological activity of surfactant. Different types of natural and synthetic surfactant preparations are currently available. To date, natural surfactants demonstrate superior outcomes compared to the synthetic surfactants, at least during the acute phase of RDS. This disparity is often attributed to biochemical differences including the presence of surfactant-associated proteins in natural products that are not found in the currently available synthetic surfactants. Comparative trials of the natural surfactants strive to establish the precise differences in clinical outcomes among the different preparations. As new surfactants become available, it is important to evaluate them relative to the known benefits of the previously existing surfactants. In order to elucidate the role of surfactant therapy in the management of RDS, it is important to review surfactant biochemistry, pharmacology, and outcomes from randomized clinical trials.
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Qi, Zi Yuan, Ye Fei Wang, Hai Yang Yu, and Xiao Li Xu. "Study on Wettability Alteration of Quartz Surface by Surfactants." Advanced Materials Research 962-965 (June 2014): 539–43. http://dx.doi.org/10.4028/www.scientific.net/amr.962-965.539.

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In order to study the effect of surfactants on wettability of quartz surface, the dynamic contact angles of different surfactants on water-wet and oil-wet quartz surfaces were measured. The experimental results showed that the advancing contact angles of cationic surfactants, anionic surfactants and nonionic surfactants on oil-wet quartz surfaces decrease with the increase of surfactant concentrations; the wettability of water-wet quartz plates remains water-wet after treated by all three kinds of surfactants. Surfactants can reverse the wettability from oil-wet to water-wet at low concentrations; The electrostatic force, hydrophobic force and the attraction between surfactant and polar components of crude oil are the key interactions in the wettability alteration process.
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Dissertations / Theses on the topic "Surfactants"

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Hines, J. D. "Investigation of surfactants and surfactant mixtures." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337736.

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Stellner, Kevin Lance. "Precipitation of surfactants and surfactant mixtures in aqueous solutions /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1987.

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Kjellin, Mikael. "Structure-Property Relationships of Surfactants at Interfaces and Polyelectrolyte-Surfactant Aggregates." Doctoral thesis, KTH, Chemistry, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3299.

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The first part of this thesis is concerned with thestructure-property relationships in nonionic surfactantsystems. The main aim was to investigate how the surfactantstructure influences the adsorption at interfaces andinteractions between surfactant coated interfaces.Particularly, the effect of the structure of the surfactantheadgroups was investigated. These were sugar-based headgroupwith varying size and flexibility and poly(ethylene oxide)based headgroups with or without an additional amide or estergroup. The hydrophobic part of the surfactant consisted mostlyof straight alkyl chains, except for one type of poly(ethyleneoxide) based surfactant with a dehydroabietic hydrophobe.

The main technique that was used is the surface forcetechnique, with which the forces acting between two adsorbedsurfactant layers on hydrophilic or hydrophobic surfaces can bemeasured. These forces are important for e.g. the stability ofdispersions. The hydrophilic surfaces employed were glass andmica, whereas the hydrophobic surfaces were silanized glass andhydrophobized mica. The adsorption behavior on hydrophilicsurfaces is highly dependent on the type of headgroup andsurface, whereas similar results were obtained on the two typesof hydrophobic surfaces. To better understand how the surfaceforces are affected by the surfactant structure, measurementsof adsorbed amount and theoretical mean-field latticecalculations were carried out. The results show that the sugarsurfactant layers and poly(ethylene oxide) surfactant layersgive rise to very different surface forces, but that the forcesare more similar within each group. The structure-propertyrelationships for many other physical properties have beenstudied as well. These include equilibrium and dynamicadsorption at the liquid-vapor interface, micelle size, micelledynamics, and wetting.

The second part in this thesis is about the aggregationbetween cationic polyelectrolytes and an anionic surfactant.The surface force technique was used to study the adsorption ofa low charged cationic polyelectrolyte on mica, and theaggregation between the adsorbed polyelectrolyte with theanionic surfactant. The aggregation in bulk was studied withturbidimetry, small angle neutron scattering (SANS), and smallangle x-ray scattering (SAXS). An internal hexagonal aggregatestructure was found for some of the bulk aggregates.

Keywords:nonionic surfactant, sugar surfactant,poly(ethylene oxide), amide, ester, polyelectrolyte, SDS,hydrophobic surface, glass surface, mica, adsorption,aggregation, micelle size, surface forces, wetting, dynamicsurface tension, NMR, TRFQ, SANS, SAXS, mean-field latticecalculations.

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Nusselder, Jan Jacob Hendrik. "Surfactant structure and aggregation behavior 1-alkyl-4-alkylpyridinium iodide surfactants /." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 1990. http://irs.ub.rug.nl/ppn/29074184X.

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Bleta, Rudina. "Systèmes fluorés pour la conception de matériaux poreux : Matrices pour la physisorption de biomolécules." Thesis, Nancy 1, 2007. http://www.theses.fr/2007NAN10111/document.

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Les propriétés d’auto organisation de tensioactifs ainsi que celles de la chimie de la silice ont permis de préparer des matériaux mésoporeux organisés selon une symétrie hexagonale, cubique ou lamellaire dont la taille des pores varie de 2 à plus de 10 nm. Ils sont depuis quelques années le centre d’intérêt d’universitaires et d’industriels qui développent des recherches fondamentales et appliquées. La compréhension globale des mécanismes de synthèse et la maîtrise des propriétés structurales et texturales des matériaux mésoporeux sont nécessaires pour envisager leur utilisation dans un quelconque procédé industriel. Dans ce cadre, nous avons étudié les relations entre les propriétés physico-chimiques d’un tensioactif fluoré C7F15C2H4(OC2H4)8OH et les caractéristiques des silices mésoporeuses. Malgré l’existence d’une phase micellaire, les canaux poreux des matériaux obtenus avec ces solutions micellaires ne sont pas organisés. En revanche, l’addition de la perfluorodécaline provoque une structuration du matériau selon une symétrie hexagonale. L’utilisation de divers fluorocarbures, ayant des structures moléculaires différentes, montre que le phénomène est associé au déplacement de la courbe de point de trouble vers les hautes températures. De plus, il a été montre que la préparation de matériaux à porosité hiérarchisée à partir d'émulsions de type huile dans eau est corrélée à la température d’inversion de phase du système eau/huile/tensioactif. Enfin, les matériaux mésoporeux ont été mis à profit pour immobiliser des enzymes et les résultats montrent que les lipases physisorbées conservent une activité catalytique
The self-assembly properties of surfactants and those of silica chemistry have led to the preparation of ordered mesoporous materials with hexagonal, cubic or lamellar symmetry and with pore sizes varying from 2 to more than 10 nm. Recently, they have aroused of great deal of interest to academics and industrialists for the development of fundamental and applied research. However, their use in any industrial process needs a careful consideration of the total comprehension of the synthesis mechanism as well as the control of their structural and textural properties. In this work, the relation between the physicochemical properties of a fluorinated surfactant, C7F15C2H4(OC2H4)8OH, and the characteristics of mesoporous silica was investigated. In spite of the existence of a micellar phase, only wormlike mesoporous materials were obtained. On the other hand, the addition of the perfluorodecalin led to the organisation of the channels according to a hexagonal symmetry. The use of various fluorocarbons of different molecular structures evidenced that this phenomenon is associated to the shift of the cloud point curve towards higher temperatures. Hierarchically porous silica were also prepared from oil-in-water emulsions and their characteristics were correlated to the phase inversion temperature of the surfactant/water/oil system. Finally, the mesoporous materials were used as hosts for the physisorption of enzymes and the results showed that the catalytic activity of the immobilised lipases is preserved
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Sherratt, A. E. "Polymeric surfactants." Thesis, Lancaster University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282410.

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Neimert-Andersson, Kristina. "Synthesis of Novel Polyhydroxyl Surfactants. Influence of the Relative Stereochemistry on Surfactant Properties." Licentiate thesis, KTH, Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1687.

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This thesis deals with the synthesis and characterization ofnovel polyhydroxyl surfactants. The first part describes thesynthesis of a number of stereoisomers of a polyhydroxylsurfactant, and the second part concerns surface chemicalcharacterization.

A stereodivergent route for preparation of the hydrophilichead group was developed, featuring consecutive stereoselectivedihydroxylations of a diene. This afforded in total fourdifferent polyhydroxyl head groups. These surfactant headgroups were natural and unnatural sugar analogues, and wereused for the coupling with two different hydrophobic tailgroups.

Three of these surfactants were used to investigate thechiral discrimination in Langmuir monolayers at an air-waterinterface. The isotherms showed a remarkable difference incompressibility between surfactants of diastereomericrelationship and also a pronounced chiral discriminationbetween racemic and enantiomerically pure surfactants favoringheterochiral discrimination.

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ALENCAR, Bruna Cabral de. "Influência da dinâmica de sorção/dessorção na biodegradação anaeróbia do alquilbezeno linear sulfonado." Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/17246.

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Made available in DSpace on 2016-07-01T14:17:21Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação Versão em PDF.pdf: 1393964 bytes, checksum: 9f6914af2635718fc925ce4690531587 (MD5) Previous issue date: 2015-01-30
CAPES
O LAS é um tensoativo usado na fabricação de produtos de limpeza, sendo sua degradação no tratamento aeróbio altamente eficaz. Todavia, em ambientes anaeróbios, sua biodegradação depende de vários fatores, como a composição e concentração de alguns compostos dos esgotos. Por isso, as eficiências de degradação do LAS neste ambiente são distintas, variando de 0 a 78%. No Brasil, devido a uma carência na área do saneamento, alternativas mais baratas para o tratamento de esgoto estão sendo amplamente utilizadas. Os reatores anaeróbios do tipo UASB são um exemplo destas alternativas, devido a sua alta eficiência de remoção de matéria orgânica. Entretanto, atualmente em uma estação de tratamento de esgoto, o objetivo não é apenas a matéria orgânica de fácil degradação, mas também compostos recalcitrantes e nutrientes. Este trabalho teve como objetivo aplicar em um reator contínuo, alimentado com esgoto real, um modelo de otimização, realizado em laboratório com regime em batelada, para verificar reprodutibilidade da influência de alguns parâmetros na dinâmica de sorção/dessorção do LAS em reatores utilizados em estações de tratamento de esgoto convencionais. Foram realizados dois experimentos. O experimentoI foi o monitoramento de um reator UASB em escala de laboratório. Este reator era alimentado com esgoto de uma estação de tratamento real, ETE Mangueira. Alterações no afluente foram realizadas para proporcionar a adsorção do LAS na biomassa. O pH foi ajustado para 6. Seguindo um planejamento fatorial 2K, o reator foi operado em 4 fases alterando a concentração de óleo, entre 0 e 5 g/L e a oxigenação ou não do LAS. O experimento II foi um teste de laboratório de adsorção e de dessorção, utilizando a mesma biomassa do reator do primeiro experimento. Foram submetidas diferentes concentrações de LAS (10, 20 e 100 mg/L), e diferentes tempos de mistura. Durante o período de operação, observou-se a ocorrência de adsorção e dessorção do LAS no lodo, bem como biodegradação, quando a adsorção foi baixa; as eficiências de degradação do LAS total nas diversas fases experimentais variaram de 0 a 33%. Os homólogos C12 e C13 foram os que sofreram maior degradação durante todo período de operação, com eficiências de 42 e 57% de sua massa inicial, respectivamente, na fase com alteração apenas do pH; o C13 foi o homólogo de maior taxa de adsorção, 97% de sua massa inicial. Isto ocorreu quando a concentração de óleo foi de 5 g/L e não foi realizado aeração do LAS. No teste de adsorção, os resultados obtidos mostraram que a adsorção na biomassa seca depende da disponibilidade de LAS no líquido. No teste de dessorção o comportamento de liberação de LAS no meio aquoso foi lento. Os testes mostraram capacidade reversível da adsorção do LAS, comprovando que a dinâmica de adsorção e dessorção do LAS no reator depende da composição do meio líquido e da forma de operação do reator, e que sua indisponibilidade no meio solúvel impede a degradação. Logo, o processo de adsorção inibe a degradação do LAS em ambientes anaeróbios e os resultados obtidos no teste de otimização em laboratório foram também observados em reatores operados com esgoto real.
LAS is a surfactant used in the manufacture of cleaning products, and its degradation in the highly efficient aerobic treatment. However, in anaerobic environments, biodegradation depends on several factors, including the composition and concentration of certain compounds of sewage. Therefore, the LAS this environmental degradation efficiencies are different, ranging from 0 to 78%. In Brazil, due to a lack in the sanitation area, cheaper alternatives for the treatment of sewage are being widely used. The anaerobic reactor of the UASB type are an example of these alternatives, due to its high removal efficiency of organic matter. However, currently a sewage treatment plant, the aim is not only the organic matter degradation easily, but also nutrients and recalcitrant compounds. This study aimed to apply in a continuous reactor, fed with real wastewater, an optimization model, conducted in laboratory batch system to check reproducibility of the influence of some parameters on dynamic sorption / desorption of LAS reactors used in stations Conventional sewage treatment. Two experiments were conducted. The first was a monitoring of a UASB reactor at laboratory scale. This reactor was fed with sewage a real treatment plant, ETE hose. Changes in the influent were performed to provide the adsorption of LAS biomass. The pH was adjusted to 6. By following a factorial design 2K, the reactor was operated at four stages by changing the concentration of oil, between 0 and 5 g / L and oxygenation or not the LAS. The second experiment was a laboratory test adsorption and desorption using the same biomass from the first reactor experiment. They underwent different concentrations of LAS, 10, 20 and 100 mg / L, and different mixing times. During the operation period, it was observed the occurrence of adsorption and desorption of LAS in the sludge as well as biodegradation when adsorption was low; The degradation efficiency of the total LAS in the different experimental phases ranging from 0 to 33%. The C12 and C13 homologues have suffered the greatest degradation during the entire operating period, efficiency 42 and 57% of their initial mass, respectively, in phase with the pH change only; the C13 was the counterpart of higher adsorption rate, 97% of its initial mass. This occurred when the oil concentration was 5 g / L and aeration was not performed LAS. In the adsorption test, the results showed that adsorption of dry biomass depends on the availability of LAS in the liquid. In desorption test the LAS release behavior in aqueous media was slow. The tests showed reversible adsorption capacity of the LAS, proving that the dynamics of adsorption and desorption of LAS in the reactor depends on the composition of the liquid medium and form of reactor operation, and that their unavailability in the middle soluble prevents degradation. Therefore, the adsorption process inhibits the degradation of LAS in anaerobic environments and the results obtained in laboratory test optimization are also observed in reactors operated with real sewage.
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Brown, Paul. "Magneto-responsive surfactants." Thesis, University of Bristol, 2012. http://hdl.handle.net/1983/41cd19c9-3d4d-47c9-a6a6-dfcab12586f2.

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Surfactants comprise one of the largest volume commodity chemicals in the world and have multifarious uses from pharmaceuticals, agrochemicals, food, fuel and lubricant additives, paints and inks as well as detergents and cleaning agents. The ability to control surfactants once they are in solution is of great importance not only for scientific reasons but also because of environmental and economic interest. To this end, surfactants sensitive to changes in pH, temperature, C02, light and redox have already been developed. This thesis investigates a new class of surfactants designed to be magnetically active, whereby the composition and physico-chemical properties of a system may be perturbed simply by the switching "on" and "off" of a magnetic switch and with no significant energy input. The thesis demonstrates that these new magneto-responsive surfactants behave like conventional surfactants but are now bifunctional allowing for new magnetic approaches where previously magnetic nanoparticles have been employed. For example, the magnetic properties makes it easier to round up and remove the surfactant from a system once it has been added. By developing the first nanoparticle-free magnetic emulsions the potential for further applications in environmental clean ups (e.g. oil spills), water treatment or drug delivery have been demonstrated. In addition to this, the combination of surfactant adsorption and intrinsic magnetism has allowed for the control and manipulation of biomolecules without the need for magnetic nanoparticles. This work explores both the fundamental properties of these novel surfactants and also takes significant steps to optimize the surfactants for potential applications.
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Neimert-Andersson, Kristina. "Synthesis of Polyhydroxylated Surfactants : Comparison of Surfactant Stereoisomers and Investigation of Haemolytic Activity." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-461.

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Books on the topic "Surfactants"

1

Rooney, Seamus A. Lung surfactant: Cellular and molecular processing. Austin, TX: Landes Bioscience, 1998.

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Rieger, Martin M. Surfactants. New York: Society of Cosmetic Chemists, 1997.

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Hayes, Teresa L., Wendy F. Marley, and Kelly Misch. Surfactants. Cleveland, OH: Freedonia Group, 1998.

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Hollis, Gordon L., ed. Surfactants Europa. Cambridge: Royal Society of Chemistry, 2007. http://dx.doi.org/10.1039/9781847551979.

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Saxena, Neha, and Ajay Mandal. Natural Surfactants. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-78548-2.

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Sayyed, R. Z., and Hesham All El-Enshasy. Microbial Surfactants. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003247739.

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Sayyed, R. Z. Microbial Surfactants. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003260165.

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Robb, I. D., ed. Specialist Surfactants. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1557-2.

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Porter, M. R. Handbook Surfactants. Boston, MA: Springer US, 1991. http://dx.doi.org/10.1007/978-1-4615-3676-5.

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Kim, Se-Kwon, and Kyung-Hoon Shin. Marine Surfactants. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003307464.

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Book chapters on the topic "Surfactants"

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Florence, A. T., and D. Attwood. "Surfactants." In Physicochemical Principles of Pharmacy, 173–227. London: Macmillan Education UK, 1988. http://dx.doi.org/10.1007/978-1-349-16558-2_6.

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Bährle-Rapp, Marina. "Surfactants." In Springer Lexikon Kosmetik und Körperpflege, 539. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_10238.

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Bisht, Anu Singh. "Surfactants." In Commercial Surfactants for Remediation, 17–23. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-0221-3_4.

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Tadros, Tharwat. "Surfactants." In Encyclopedia of Colloid and Interface Science, 1242–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-20665-8_40.

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Shao, Bing. "Surfactants." In Analysis of Endocrine Disrupting Compounds in Food, 305–24. Oxford, UK: Wiley-Blackwell, 2012. http://dx.doi.org/10.1002/9781118346747.ch13.

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Sagir, Muhammad, Muhammad Mushtaq, M. Suleman Tahir, Muhammad Bilal Tahir, and Abdul Ravoof Shaik. "Surfactants." In Surfactants for Enhanced Oil Recovery Applications, 1–11. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-18785-9_1.

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Khaled, Elmorsy, and Hassan Y. Aboul-Enein. "Surfactants." In Environmental Analysis by Electrochemical Sensors and Biosensors, 905–30. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-1-4939-1301-5_10.

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Schmiermund, Torsten. "Surfactants." In The Chemistry Knowledge for Firefighters, 605–12. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-64423-2_50.

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Yan, S., B. Subramanian, S. Barnabe, R. D. Tyagi, and R. Y. Surampalli. "Surfactants." In Contaminants of Emerging Environmental Concern, 279–314. Reston, VA: American Society of Civil Engineers, 2009. http://dx.doi.org/10.1061/9780784410141.ch08.

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de Gennes, Pierre-Gilles, Françoise Brochard-Wyart, and David Quéré. "Surfactants." In Capillarity and Wetting Phenomena, 191–213. New York, NY: Springer New York, 2004. http://dx.doi.org/10.1007/978-0-387-21656-0_8.

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Conference papers on the topic "Surfactants"

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Gbonhinbor, Jeffrey, Ann Obuebite, George Kuradoite, and Augustine Agi. "Characteristic Curvature Assessment of Some Natural Surfactants for Chemical Enhanced Oil Recovery Applications in Nigeria." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/211996-ms.

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Abstract Chemical enhanced oil recovery (CEOR) application of natural surfactants is based on potential interfacial tension (IFT) alterability and eco-friendly considerations. The reduced IFT is associated with microemulsion formation in relation to a surfactant’s characteristic curvature. Lately, surface activities of natural surfactants have gained interest in Nigerian laboratory studies with no attention given to their hydrophilicity/hydrophobicity. This research focuses on molecular weight determination, micelle formation, and characteristic curvature evaluation of readily available natural surfactants. Four plants that are known to possess relevant surfactant properties were selected for this evaluation. Freezing point dipping method was used to determine the average molecular weight of each surfactant. Critical micelle concentration (CMC) was ascertained by electric conductivity tests. Characteristic curvature was evaluated from microemulsion formulations of toluene and aqueous surfactant mixtures. Formulated aqueous surfactant mixture consists of a combination of selected natural surfactant and a reference surfactant. Sodium dodecylsulphate (SDS) was adopted as the reference surfactant throughout this work. The analysis was configured in line with the hydrophilic-lipophilic deviation (HLD) model set to 0. Results yielded average molecular weights of examined surfactants between 128.3 g/mol to 186.7 g/mol. Critical micelle concentrations values of 0.45 to 0.60 were derived for all natural surfactants. Estimated characteristic curvature values suggested hydrophobicity with values from 0.116 to 0.194. As a consequence, these natural surfactants possess a tendency to form reverse micelles due oleic phase attraction. Their low positive values make them suitable for lowering IFT in order to mobilise trapped formation oil.
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Bian, Yu, and Pinn-Tsong Chiang. "Effect of Hydrophobic/Hydrophilic Groups of Surfactants on Wax Deposition Studied by Model Waxy Oil System." In SPE International Conference on Oilfield Chemistry. SPE, 2023. http://dx.doi.org/10.2118/213821-ms.

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Abstract It is well known that surfactants can be used as a wax dispersant, however, with properly adjusted ratios between the hydrophobic and hydrophilic groups of non-ionic surfactants, they can not only reduce the waxy oil pour point, but also reduce the detected wax appearance temperature (DWAT) and thus reduce wax deposition. Non-ionic surfactants with different numbers of hydrophobic/hydrophilic groups were studied as wax inhibitors using a model waxy oil system. Two model oils with different amounts and distribution of wax in dodecane were used in this study. High temperature gas chromatography (HTGC) was used to analyze the wax distributions. Surfactants with varying levels of ethoxylation and saturation were studied to find the most efficient structures for wax inhibition. A pour point tester was employed as an initial screening tool to determine the oil pour point and DWAT. A Turbiscan was used to evaluate the wax dispersing capabilities of the surfactants. Capillary flow through (CFT) wax deposition tests were then performed to verify the wax deposition reduction efficiency and to study the effect of the test parameters on wax deposition. The results showed that a surfactant with a moderate number of linear saturated alkane chains at an optimized dosage level can interact with the wax in dodecane, and thus reduce the pour point and DWAT. More alkane chains make the surfactants perform as a wax inhibitor (WI) but cause the solubility issues. Hydrophilic groups on the surfactants improve their solubility and interfere with the formation of wax crystals; however, having too many results in the surfactant self-assembling. The interaction between surfactants and wax changes with wax molecular weight (MW) and content. By optimizing the balance of hydrophobic and hydrophilic groups, the surfactant's wax inhibition performance can be improved. From this systematic study on the kinetic and dynamic behaviors of wax deposition, it was demonstrated that surfactants can be optimized to inhibit wax crystallization. By better understanding the relationship between their chemical structures and their performance, surfactant selection can be optimized with purpose-designed lab screening tests. Surfactants which are effective at wax inhibition could further mitigate wax deposition and keep the formulated WI package cost effective.
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Xu, Limin, Ming Han, Dongqing Cao, and Alhasan Fuseni. "New Synergistic Surfactant Mixtures for Improving Oil Production in Carbonate Reservoirs." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2022. http://dx.doi.org/10.2118/200182-ms.

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Abstract The paper presents the development of new surfactant formulations composed of various low-cost and low-performance surfactants to make them high performance products for high temperature and high salinity carbonate reservoirs. The objective of this study is to optimize the surfactant chemistry by mixing different kinds of surfactants (ionic, nonionic, and amphoteric), which results in significant synergistic effects in interfacial properties to improve oil production at the given harsh conditions. The optimal mixing surfactant ratios were determined according to the brine-surfactant compatibility, microemulsion phase behavior, and the interfacial tension (IFT) between oil and surfactant solutions in high salinity brine and at 90˚C. Comprehensive performance of the surfactants was evaluated, including adsorption of the surfactants onto the carbonate rocks and the long-term stability at 95˚C. The coreflooding displacement experiments were performed using carbonate core plugs at 95˚C to evaluate the potential of the optimal mixing surfactants in improving oil production. Three formulations composed of two types of low-cost surfactants were developed in this study. The mixing surfactants were chosen based on moderate electrostatic interaction among the surfactants. It appeared the synergistic effect between the mixing surfactants was enhanced with increasing temperature. Although the IFT of the individual surfactants with crude oil was in the range of 100mN/m, a significant IFT reduction in the magnitude of 10−2 - 10−3 mN/m was observed by mixing the surfactants. A salinity scan showed that the IFT values maintained a value of 10−2 mN/m in a wide salinity range, which demonstrated the robustness of the surfactants mixtures. In microemulsion phase behavior studies, these mixed surfactant solutions in the presence of crude oil exhibited Winsor Type III emulsions. The static adsorptions of the mixed surfactants were lower than the individual surfactant adsorption. All this indicated the feasibility of these formulations for their applications in the harsh reservoir conditions. The results of coreflooding displacement tests demonstrated significant oil production improvement beyond water flooding. This work provides an efficient way to get surfactant formulations by mixing low-performance and low cost surfactants to obtain high performance in improving oil production under the harsh conditions.
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Pandey, Rishabh, Ali Ousseini Tinni, and Chandra Shekhar Rai. "Experimental Investigation of Amphoteric and Microbial Surfactants for Enhanced Oil Recovery in Shaly Sandstones." In SPE Oklahoma City Oil and Gas Symposium. SPE, 2023. http://dx.doi.org/10.2118/213102-ms.

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Abstract To meet the increasing demand for oil and gas, surfactants have been used to increase hydrocarbon recovery. Use of surfactants reduces the Interfacial Tension (IFT) at fluid/fluid interface and wettability at rock/fluid interface and mobilizes trapped oil out of the pores. However, there are two main limitations of the surfactant flooding process—first, high reservoir temperature & salinity, and second, adsorption of surfactants on the rock surface. Surfactant adsorption alters wettability of reservoir rock from oil-wet to water-wet. However, it may not increase oil recovery, especially in conventional reservoirs with high Total Dissolved Solids (TDS) and temperature due to excess surfactant adsorption. This study tested two synthetic amphoteric surfactants, one nonionic biosurfactant, and a base case with produced brine to understand wettability, IFT, surfactant adsorption, and their effect on oil recovery in shaly sandstone formation. Produced brine has a TDS of 238,000 ppm. First, surfactant stability tests were performed on the three surfactants. Then, IFT measurements were performed between crude oil and surfactant solutions along with produced brine. Next, wettability alteration was studied by measuring contact angle on oil saturated rock samples before and after being exposed with surfactants and produced brine. Then, surfactant adsorption experiments were performed using UV-Vis spectrophotometer to calculate the amount of surfactant adsorbed on the rock sample. Next, surfactants and produced brine imbibition experiments were performed on plug samples at 145°F and 500 psi pressure, and oil recovery was quantified using 12MHz Nuclear Magnetic Resonance (NMR) spectrometer. Results showed that all three surfactants reduced IFT and altered wettability, but biosurfactant showed most reduction of IFT, much lower surfactant adsorption, and made the sample most water wet as compared to amphoteric surfactants. Imbibition experiments showed that biosurfactant have the highest oil recovery, while amphoteric surfactants have oil recovery even lower than produced brine. This study shows that surfactant adsorption effects oil recovery, which can lead to loss of surfactants from solution to the rock surface. This study suggests that biosurfactants with glycolipids can be effectively used in shaly sandstone at high TDS and temperature.
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Eady, Shawn. "Oleo-furan surfactants as fully biorenewable, carcinogen-free drop-in replacements for commercial anionic surfactants." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/avmo1700.

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Surfactants are versatile and ubiquitous chemical compounds that find application in everything from laundry detergents to pharmaceuticals. Commercial production of anionic surfactants, which provide the foaming and soil removal properties consumers have come to enjoy in their cleaning and personal care products, is at the highest production volumes focused on several surfactants. These include the petrochemical-derived surfactant linear alkylbenzene sulfonate (LAS), as well as the partially biorenewable surfactant sodium lauryl ether sulfate (SLES) which has recently been the target of regulations due to the carcinogenic byproduct 1,4-dioxane. Oleo-furan sulfonate surfactants developed by Sironix Renewables provide a fully biorenewable anionic surfactant alternative without the carcinogenic byproducts, with performance in application testing which rivals or exceeds that of LAS and SLES, particularly in challenging application conditions such as with hard water. Recent developments in Sironix’s research have identified unique and finely-tuned surfactant structures that provide a combination of desired properties with application across a wide range of applications, including exhibiting superior foaming compared to LAS or SLES with a less irritating effect on the skin. Oleo-furan surfactants have exceptional solubility, allowing for formulation of more concentrated consumer products; the surfactants can also be produced and shipped in powder form, allowing for reduced fuel use during transportation and a resulting decrease in product cost and lifecycle carbon emissions. Herein, we provide an overview of the properties for oleo-furan surfactants with comparison to commercial anionic surfactants and take a closer look at how costs and carbon emissions can be reduced by their substitution. We also discuss ongoing research at Sironix to produce oleo-furan surfactants from domestic and abundant biomass sources, including sources that are non-food competitive and those derived from agricultural waste.
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Bello, Ayomikun, Alexander Rodionov, Anastasia Ivanova, and Alexey Cheremisin. "Synergistic Effects of Binary Surfactant Systems for Enhanced Oil Recovery in Carbonates." In SPE Improved Oil Recovery Conference. SPE, 2024. http://dx.doi.org/10.2118/218271-ms.

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Abstract This study investigates the use of binary surfactant systems for enhancing oil recovery (EOR) in carbonate formations, which have complex surface charges and harsh conditions (high temperature, high salinity) that limit the effectiveness of single surfactants. Binary surfactants form mixed micelles with lower interfacial tension (IFT) and higher solubilization capacity than single surfactants, thus improving their performance and synergism. We measured the critical micelle concentrations (CMCs) of various binary surfactant ratios and applied Rubingh's Regular Solution Theory (RST) to analyze their behavior and interactions. We found that the binary surfactants had lower CMCs than their individual components, which means less surfactant is needed to achieve optimal surface activity, reducing costs and environmental impact. The nonionic surfactant concentration was a key factor for synergism. We also conducted static adsorption and spontaneous imbibition tests to examine the effects of binary surfactants on oil recovery. We observed that the nonionic surfactant reduced the adsorption of the anionic and cationic surfactants by 53% and 28%, respectively, and increased the recovery factor to nearly 60%. Our results demonstrate the potential of binary surfactant systems for EOR in carbonate formations, as well as for CO2 sequestration and filtration optimization.
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Bello, Ayomikun, Alexander Rodionov, Anastasia Ivanova, and Alexey Cheremisin. "Experimental Investigation and Molecular Dynamics of the Fluid-Fluid Interactions Between Binary Surfactant Systems for EOR." In GOTECH. SPE, 2024. http://dx.doi.org/10.2118/219237-ms.

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Abstract This work aims to explore the properties and interactions between binary surfactant systems. We employed a methodology comprising experimental analysis, mathematical modeling, and molecular dynamics simulations. In the experimental study, we examined eight individual surfactants and six binary surfactant systems at various ratios to determine their critical micelle concentrations (CMCs), using reservoir oil and performing experiments at reservoir conditions. Then, Rubingh's Regular Solution Theory (RST) was applied to evaluate interactions within the binary surfactant mixtures. Finally, using molecular dynamics simulations, we characterized the microscopic interactions to comprehend how hydrophilic and hydrophobic parts of the surfactants interact with surrounding media, and how they self-assemble into aggregates such as micelles or bilayers. The key findings of our work showed that the occurrence of synergism or antagonism in lowering the CMC of binary surfactant mixtures depend on both the concentration of the individual surfactant and the type of surfactant used. Nevertheless, we noted a prevalent synergistic phenomenon in all binary surfactant systems, notably influenced by the concentration of the non-ionic surfactant. Increased concentrations of non-ionic surfactants notably enhanced synergistic interactions, fostering lowered CMC values when combined with anionic, cationic, and zwitterionic surfactants. On the other hand, an excessive concentration of cationic surfactants demonstrated relatively ‘weak’ synergistic effects, attributed to their comparatively smaller hydrophobic tail. Moreover, the formation of mixed micelles in binary surfactant systems led to a more negative free energy of micellization, thereby achieving synergistic effects between surfactants and resulting in lower CMC values. This emphasizes the crucial role of surfactant concentration in achieving synergistic outcomes within mixed systems. Generally, binary surfactant systems demonstrated lower CMC values compared to single surfactants, suggesting the potential for their use at lower concentrations to achieve desired interfacial and recovery outcomes, thereby reducing operational costs.
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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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"Wettability Alteration on Sandstone Reservoirs Containing Clay Minerals By The Addition Anionic Alkyl Ethoxy Carboxylate Surfactant." In Indonesian Petroleum Association - 46th Annual Convention & Exhibition 2022. Indonesian Petroleum Association, 2022. http://dx.doi.org/10.29118/ipa22-e-298.

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With the increasing number of maturing fields, surfactant injection as an alternative EOR technique is essential to mobilize the remaining oil. The presence of clay in the sandstone causes the polar components in the oil to be adsorbed on the rock surface, causing a tendency towards wettability towards oil-wet. Therefore, the oil potential remaining in the reservoir, which is the target of surfactant injection, is more significant in oil reservoirs with oil-wet characteristics. For this reason, surfactants are needed that can alter the surface properties of oil-wet to water-wet and the ability of these surfactants to reduce IFT. The wettability alteration mechanism is one thing that needs to be understood more deeply, considering the critical function of surfactant injection in the EOR method. Studies on the effect of adding surfactants on sandstones containing clay minerals of certain types and concentrations need to be developed to assist the application of the oil recovery process at an advanced stage. Laboratory experiments are carried out by measuring the contact angle of sandstone samples conditioned according to reservoir characteristics with several concentrations of clay interacting with fluid. The measurement results show that the initial condition of the sandstone containing montmorillonite clay is water-wet, while the sandstone containing kaolinite clay is oil-wet. The presence of surfactant solutions gives a wettability alteration effect on sandstones containing montmorillonite clay to become more water-wet and sandstones containing kaolinite to be water-wet. Surfactant solution with a concentration of 1wt% gives a more significant wettability alteration effect than surfactants with the attention of 2wt%. The interaction of sandstones containing clay minerals with surfactant solution shows that the addition of surfactants can reduce the interfacial tension between oil and water. In contrast, surfactants with a concentration of 2wt% can reduce IFT greater than surfactants with the attention of 1wt%.
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Fernandez, Jose Alejandro, Daniela Martinez, Franklin Salazar-Rodríguez, and Johnny Bullon. "Determination of the Concentration of Commercial Cationic Surfactants in Aqueous Solutions by the Colloidal Titration Method." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/kwwz9816.

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Cationic Surfactant's quantification in aqueous solution is relevant in fundamental and applied research, as well as for quality control in processes in the chemical industry. Colloidal titration is a commonly used method for surface charge determination in colloidal systems such as polyelectrolytes, macromolecules and solid particles, but it can also be applied for the detection of ionic surfactants in aqueous solution. It is a simple technique, easy to implement in a laboratory and its principle is based on the stoichiometric neutralization between two species of opposite charge, potassium polyvinylsulfonate (standard PVSK) and a cationic polyelectrolyte or cationic surfactant. When the stoichiometric ratio is exceeded, the excess polyelectrolyte reacts with a cationic indicator (crystal violet) forming an electrically neutral pair that modifies the solutions' absorbance value which is determined by spectrophotometry at 587 nm. To assess the feasibility of this technique, the colloidal titration method was normalized by titration between two standard polyelectrolytes (PDADMAC and PVSK), also with analytical grade cationic surfactants (DDBAB, CTAB and HDBAC) and finally with some commercial ones (Praepagen WK, Dodigen 1828, Empygen BAC 50). High molecular weight surfactants showed stoichiometric proportionality between their concentration and the amount of tritant added for concentration between 10-100 mN. This proportionality was not observed for low molecular weight surfactants. Finally, it was also observed that for commercial surfactants the presence of 0.01 M sodium chloride does not affect the titration results.
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Reports on the topic "Surfactants"

1

Weiss and Xie. WVJB8LP Smart Gas - Using Chemicals to Improve Gas Deliverability. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2008. http://dx.doi.org/10.55274/r0010902.

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Each year, more than 17,000 gas storage wells in the United States lose from 3�5% of their storage capacity and deliverability. In addition, the gas storage industry spends $80�100 million annually to revitalize existing wells; thus, there is an economic incentive to develop new stimulation methods. Limited laboratory information suggests that using surfactants to alter the wettability of the reservoir rock could increase deliverability of gas storage wells. The objective of this project was to develop new technology to improve deliverability from gas storage wells. Two cost-effective surfactants were selected from 11 candidates through preliminary screening tests for additional reservoir core tests. Reservoir cores from three gas storage facilities including sandstone and dolomite reservoirs were used to evaluate surfactant-gas-core systems. The imbibition and core flood tests showed that gas deliverability and storage capacity were improved in surfactant-treated sandstone cores. However, the surfactants had a very limited effect on dolomite cores. An engineering analysis was conducted to develop an analytical method to evaluate future field tests of the new technology. The aquifer storage facilities are candidates for field testing.
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2

Weiss. PR-318-08700-R01 Smart Gas-Using Chemicals to Improve Gas Deliverability-Phase II. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2009. http://dx.doi.org/10.55274/r0010944.

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In water-wet gas storage reservoirs, the imbibition force promotes the retention of water in the pore space, which curtails the deliverability of gas to the wellbore during periods of high demand. Similarly, the injection of gas during the fill cycle is restricted. In addition, the pore space occupied by irreducible water is not available to hold gas. The objective of this Phase II project was to demonstrate in the field the new technology developed in the laboratory during Phase I. Wettability alteration was evaluated as a technique to improve gas deliverability from gas storage wells during Phase I. During the first year, two cost-effective surfactants were selected from 11 candidates through various laboratory screening and reservoir core tests. Reservoir cores from three gas storage facilities including sandstone and dolomite reservoirs were used to evaluate the two surfactants. The imbibition and core flood tests showed that gas deliverability and storage capacity were improved in surfactant-treated sandstone cores. However, these surfactants had a very limited effect on dolomite cores. An engineering analysis was conducted to develop an analytical method for evaluating future field tests of the new technology. It was concluded that the aquifer storage facilities are candidates for field testing. Results from Phase I provided the foundation for this Phase II project.
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3

Viers, Brent D., Alan Esker, and Katie Farmer. Polyhedral Oligomeric Silsesquioxanes Surfactants. Fort Belvoir, VA: Defense Technical Information Center, January 2001. http://dx.doi.org/10.21236/ada410399.

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4

Morgan, Matthew Earle. Solubilization of pentanol by cationic surfactants and binary mixtures of cationic surfactants. Office of Scientific and Technical Information (OSTI), January 1993. http://dx.doi.org/10.2172/10146350.

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5

Lebone T. Moeti and Ramanathan Sampath. Characterization of Phase and Emulsion Behavior, Surfactant Retention, and Oil Recovery for Novel Alcohol Ethoxycarboxylate Surfactants. Office of Scientific and Technical Information (OSTI), May 1998. http://dx.doi.org/10.2172/1623.

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6

Lebone T. Moeti and Ramanathan Sampath. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS. Office of Scientific and Technical Information (OSTI), September 2001. http://dx.doi.org/10.2172/833446.

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LEBONE MOETI and RAMANATHAN SAMPATH. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS. Office of Scientific and Technical Information (OSTI), November 1998. http://dx.doi.org/10.2172/7479.

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8

Miller, D. D., and D. F. Evans. Aggregation Behavior of Mixed-Counterion Double-Chained Surfactants. Fort Belvoir, VA: Defense Technical Information Center, January 1991. http://dx.doi.org/10.21236/ada257206.

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9

Laura Wesson, Prapas Lohateeraparp, Jeffrey Harwell, and Bor-Jier Shiau. Next Generation Surfactants for Improved Chemical Flooding Technology. Office of Scientific and Technical Information (OSTI), May 2012. http://dx.doi.org/10.2172/1070067.

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10

Miranda, Paulo B. Nonlinear vibrational spectroscopy of surfactants at liquid interfaces. Office of Scientific and Technical Information (OSTI), December 1998. http://dx.doi.org/10.2172/6502.

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