Relevant bibliographies by topics / Surfactant

Academic literature on the topic 'Surfactant'

Author: Grafiati
Published: 4 June 2021
Last updated: 22 June 2024

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Journal articles on the topic "Surfactant"

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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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Kurnia, Rani, Dian Asfriany Nurfalah, Deana Wahyuningrum, Taufan Marhaendrajana, and Utjok W.R Siagian. "Lessons Learned in Interfacial Tension Prediction Using a Mixture of Sulfonate- and Ethoxylate-based Surfactants in a Waxy Oil-brine System." Journal of Engineering and Technological Sciences 55, no. 6 (December 31, 2023): 627–38. http://dx.doi.org/10.5614/j.eng.technol.sci.2023.55.6.1.

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The chemical-enhanced oil recovery (CEOR) method is applied to change reservoir rock or fluid characteristics by injecting alkaline, surfactant, and polymer or a combination of two or three of the compounds. Surfactant flooding improves oil recovery by reducing the interfacial tension between oil and water. Selecting reservoir surfactants, especially microemulsions, requires careful screening. This study predicted waxy oil system interfacial tension using surfactant mixtures at below- and above-optimum salinity. To predict the interfacial tension, microemulsion types, HLB, ideal salinity, and HLD were used. The study predicted oil-surfactant-water interfacial tension using SAE, FEO, and their mixtures. We improved the Huh equation by adding a fitting parameter, β, to accommodate the transition from type III to type II microemulsions as salinity increases. With increasing salinity, anionic surfactant’s hydrophilic-hydrophobic interactions change, affecting the values and surfactant layer thickness. This study improved hydrophilic-lipophilic deviation (HLDN) by establishing a fixed interval for nonionic surfactants. Van der Waals attraction, values and interface surfactant layer thickness are connected, reflecting the fact that lower values reduce interfacial tension better. This study also found that surfactant packing at the oil-water interface increases the order of the oil-solution ratio and the microemulsion values with polarity.
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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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Ikegami, Machiko, Yotaro Agata, Tarek Elkady, Mikko Hallman, David Berry, and Alan Jobe. "Comparison of Four Surfactants: In Vitro Surface Properties and Responses of Preterm Lambs to Treatment at Birth." Pediatrics 79, no. 1 (January 1, 1987): 38–46. http://dx.doi.org/10.1542/peds.79.1.38.

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Natural sheep surfactant, rabbit surfactant, human surfactant, and surfactant TA were compared for in vitro surface properties and for responses of preterm lambs to treatment. Equivalent amounts of sheep, rabbit, and human surfactants were needed to lower the surface tension to less than 10 dynes/cm, whereas four times less surfactant TA similarly lowered the surface tension. Surface-spreading rates were similar for the surfactants. The surface adsorption of the batch of human surfactant tested was much slower than was adsorption of the other surfactants. Ventilation was significantly improved in all surfactant-treated lambs relative to the control lambs, indicating the general efficacy of the surfactant treatments. Overall, surfactant TA had the best in vitro characteristics, yet the preterm lambs treated at birth with surfactant TA had lower Po2 values and higher ventilatory requirements than did the sheep surfactant-treated lambs. The in vivo responses to rabbit surfactant were intermediate between the responses to sheep surfactant and to surfactant TA. Human surfactant resulted in the least effective clinical response. More of the phosphatidylcholine associated with human surfactant and surfactant TA was lost from the alveoli and lung tissue after four hours of ventilation than was lost from sheep or rabbit surfactant-treated lambs. More intravascular radiolabeled albumin leaked into the alveoli of the surfactant TA-treated lambs than sheep or rabbit surfactant-treated. lambs. The four surfactants also had different sensitivities to the effects on minimum surface tensions of the soluble proteins present in alveolar washes. The study demonstrates that the range of clinical responses was not predictable based on the in vitro surface properties that we measured. The surfactants behaved differently with respect to loss from the lungs and sensitivity to soluble proteins. Factors other than surface properties are important for the in vivo responses to surfactant treatments.
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Bernhard, Wolfgang, Andreas Gebert, Gertrud Vieten, Gunnar A. Rau, Jens M. Hohlfeld, Anthony D. Postle, and Joachim Freihorst. "Pulmonary surfactant in birds: coping with surface tension in a tubular lung." American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 281, no. 1 (July 1, 2001): R327—R337. http://dx.doi.org/10.1152/ajpregu.2001.281.1.r327.

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As birds have tubular lungs that do not contain alveoli, avian surfactant predominantly functions to maintain airflow in tubes rather than to prevent alveolar collapse. Consequently, we have evaluated structural, biochemical, and functional parameters of avian surfactant as a model for airway surfactant in the mammalian lung. Surfactant was isolated from duck, chicken, and pig lung lavage fluid by differential centrifugation. Electron microscopy revealed a uniform surfactant layer within the air capillaries of the bird lungs, and there was no tubular myelin in purified avian surfactants. Phosphatidylcholine molecular species of the various surfactants were measured by HPLC. Compared with pig surfactant, both bird surfactants were enriched in dipalmitoylphosphatidylcholine, the principle surface tension-lowering agent in surfactant, and depleted in palmitoylmyristoylphosphatidylcholine, the other disaturated phosphatidylcholine of mammalian surfactant. Surfactant protein (SP)-A was determined by immunoblot analysis, and SP-B and SP-C were determined by gel-filtration HPLC. Neither SP-A nor SP-C was detectable in either bird surfactant, but both preparations of surfactant contained SP-B. Surface tension function was determined using both the pulsating bubble surfactometer (PBS) and capillary surfactometer (CS). Under dynamic cycling conditions, where pig surfactant readily reached minimal surface tension values below 5 mN/m, neither avian surfactant reached values below 15 mN/m within 10 pulsations. However, maximal surface tension of avian surfactant was lower than that of porcine surfactant, and all surfactants were equally efficient in the CS. We conclude that a surfactant composed primarily of dipalmitoylphosphatidylcholine and SP-B is adequate to maintain patency of the air capillaries of the bird lung.
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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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LIU, HAO-YANG, XIAN-WU ZOU, YIN-QUAN YUAN, and ZHUN-ZHI JIN. "EFFECTS OF INTERACTION WITH SOLVENT AND CHAIN CONFORMATION OF SURFACTANTS ON EMULSIFICATION." Modern Physics Letters B 15, no. 24 (October 20, 2001): 1061–68. http://dx.doi.org/10.1142/s0217984901002853.

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The details of the emulsification process has been investigated by discontinuous molecular dynamic simulation. The surfactants help to bring about emulsification. The emulsification can be divided crudely into two stages: splitting and uniting process. The splitting and uniting of oil droplets occurs in this position, where surfactants at the interface is rather scarce. The effects of the conformation of surfactant chain and the strength of surfactant–water and surfactant–oil interactions on emulsification were also studied. The surfactants with longer tail and stronger surfactant–water and surfactant–oil interactions promote the emulsification more.
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Zhao, Hong Mei, Yong Li Liang, and Wen Yan Zhao. "Influence of Triton X-100 and SDBS on the Sorption of Streptomycin Sulfate from Soil." Advanced Materials Research 610-613 (December 2012): 186–89. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.186.

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Although surfactants have been considered in surfactant-aided soil washing systems, there is little information on the adsorption of the impact of surfactant on the adsorption of antibiotic, and this may have significant implications for the soil. In this study, Triton X-100 and SDBS were selected to study its effect on the sorption of Streptomycin sulfate from soil under equilibrium sorption. The adsorption of Streptomycin sulfate on soils in surfactant free and surfactant solutions of different critical micelle concentrations (CMCs) has been studied .The applied surfactant concentrations (X) ranged from below the (nominal) CMC to 5 times the CMC. For relatively water-soluble Streptomycin sulfate, the distribution coefficients with anionic surfactant (Kd*) deceeded those without surfactant (Kd), while non-ionic (Kd*) all exceeded those without surfactant (Kd). The Kd*/Kd ratios were used to evaluate the efficiency of surfactants and it was found that anionic surfactant is a better choice for remediation of contaminated soils whereas non-ionic surfactants leads to poor remediation efficiency.
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Straight, Paul D., Joanne M. Willey, and Roberto Kolter. "Interactions between Streptomyces coelicolor and Bacillus subtilis: Role of Surfactants in Raising Aerial Structures." Journal of Bacteriology 188, no. 13 (July 1, 2006): 4918–25. http://dx.doi.org/10.1128/jb.00162-06.

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ABSTRACT Using mixed-species cultures, we have undertaken a study of interactions between two common spore-forming soil bacteria, Bacillus subtilis and Streptomyces coelicolor. Our experiments demonstrate that the development of aerial hyphae and spores by S. coelicolor is inhibited by surfactin, a lipopeptide surfactant produced by B. subtilis. Current models of aerial development by sporulating bacteria and fungi postulate a role for surfactants in reducing surface tension at air-liquid interfaces, thereby removing the major barrier to aerial growth. S. coelicolor produces SapB, an amphipathic peptide that is surface active and required for aerial growth on certain media. Loss of aerial hyphae in developmental mutants can be rescued by addition of purified SapB. While a surfactant from a fungus can substitute for SapB in a mutant that lacks aerial hyphae, not all surfactants have this effect. We show that surfactin is required for formation of aerial structures on the surface of B. subtilis colonies. However, in contrast to this positive role, our experiments reveal that surfactin acts antagonistically by arresting S. coelicolor aerial development and causing altered expression of developmental genes. Our observations support the idea that surfactants function specifically for a given organism regardless of their shared ability to reduce surface tension. Production of surfactants with antagonistic activity could provide a powerful competitive advantage during surface colonization and in competition for resources.
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Doong, Ruey-an, Ya-Wen Wu, and Wen-gang Lei. "Surfactant enhanced remediation of cadmium contaminated soils." Water Science and Technology 37, no. 8 (April 1, 1998): 65–71. http://dx.doi.org/10.2166/wst.1998.0309.

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An investigation involving the addition of surfactant to remediate cadmium-contaminated soils was performed to determine the optimal surfactant enhanced remediation system. Anionic (sodium dodecyl sulfate, SDS), nonionic (Triton X-100, TX100) and cationic (cetyltrimethylammonium bromide, CTAB) surfactants were used to elucidate the extraction efficiency of surfactant. EDTA and diphenylthiocarbazone (DPC) were also added to enhance the extraction efficiencies of surfactants. Moreover, the pH effect was examined to determine the optimal surfactant systems. The addition of anionic and nonionic surfactants can enhance the desorption rates of cadmium, lead and zinc, whereas the addition of cationic surfactant decreased the desorption efficiency of heavy metals. The desorption efficiency was found to increase linearly with the increasing surfactant concentration below critical micelle concentration (CMC) and remained relatively constant above the CMC. Moreover, the addition of EDTA can significantly enhance the desorption efficiency of heavy metals. Cationic surfactant was shown to be a more effective surfactant than nonionic and anionic surfactants in extracting heavy metals under acidic environment. The desorption efficiency of heavy metal in the surfactant/EDTA mixture system was in the order of Cd > Pb > Zn. However, the addition of DPC lowered the heavy metal removals by 2 to 4 times. Also, increasing pH value can decrease the extraction capabilities of nonionic and anionic surfactants. The results of this study demonstrate that surfactant in combination with complexing agents can be effectively used as chemical amendments to flush cadmium-contaminated soil by proper selection of type and concentration of surfactant and complexing agent at different pH values.
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Dissertations / Theses on the topic "Surfactant"

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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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Senra, Tonimar Domiciano Arrighi. "N,N,N-trimetilquitosana e N-(2-hidróxi)-propil-3-trimetilamônio quitosana: preparação, caracterização e estudo de suas interações com decanossulfonato de sódio." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-20052015-154551/.

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O presente trabalho estudou duas vias reacionais para a preparação de derivados cationizados de quitosana (QCat), sendo que a N-metilação extensiva via reação de quitosana com iodometano (CH3I) resultou em N,N,N-trimetilquitosana (TMQ) enquanto que a reação de quitosana com cloreto de glicidiltrimetilamônio (CGTMA) produziu N-(2-hidroxi)-propil-3-trimetilamônio quitosana (HPTAQ). Planejamento fatorial completo 23 foi aplicado para analisar os efeitos das condições reacionais sobre o rendimento das reações (R) e as características de TMQ e HPTAQ. As características estruturais da quitosana de partida e seus derivados foram analisadas por espectroscopias na região de infravermelho (FTIR) e de ressonância magnética nuclear de hidrogênio (RMN-1H), sendo que esta última também foi utilizada para determinar os graus médios de acetilação (GA), de quaternização (GQ) e de substituição (GS) de quitosana, TMQ e HPTAQ, respectivamente. Viscosimetria capilar foi utilizada para determinar a viscosidade intrínseca ([η]) de quitosana, TMQ e HPTAQ, permitindo estimar a ocorrência de despolimerização e sua relação com as condições reacionais. Todas as amostras de TMQ foram solúveis em água e o valor de GQ variou no intervalo 21,0 - 67,0%; a [η] variou entre 13,7 mL/g - 213,0 mL/g e o rendimento da reação atingiu até 82,0%, sendo que entre as variáveis analisadas a concentração de hidroxido de sódio e excesso de CH3I são as mais relevantes. Quanto às amostras de HPTAQ, apenas aquelas com GS > 12,0% foram solúveis em água,GS ficou no intervalo 1,0 % - 45,5%; [η] variou entre 283,0 mL/g - 446,0 mL/g e o rendimento não foi superior a 33,0%, e entre as variáveis analisadas, temperatura e excesso de CGTMA foram as mais importantes na produção de HPTAQ. As amostras TMQ2 GQ = 46,0%; [η] = 290,0 mL/g) e HPTAQ6 GS = 33,0%; [η] = 293,0 mL/g) foram empregadas em estudo visando a formação de complexos surfactante/polieletrólito (CSP) com decanossulfonato de sódio (DS). As propriedades condutimétricas e tensiométicas dos TMQ2, HPTAQ6 e CSP\'s foram estudadas e mostraram que todos apresentam atividade interfacial (γ <= 52,0 mN.m-1), além de elevado valor de módulo de elasticidade (E >= 31,0 mN.m-1), indicando que as espécies analisadas geram filmes interfaciais com boas propriedade mecânicas e por isso podem ser aplicados como agentes estabilizantes de emulsões. As emulsões do tipo óleo/água preparadas pela incorporação de QCat (TMQ ou HPTAQ) ou de CSP (TMQ/DS ou HPTAQ/DS) foram estáveis por mais de 4 meses, conforme avaliado por medidas de fluorescência e de turbidez.
In this work were studied two different methods for preparing cationized derivatives of chitosan (ChCat), a consisted extensive N-methylation by chitosan reaction with iodomethane (CH3I) resulted in N,N,N-trimethylchitosan (TMCh), and other a reaction of chitosan with chloride glycidyltrimethylammonium (GTMAC) resulted in N-(2-hydroxy)-propyl-3-trimethylammonium chitosan (HPTACh). A complete factorial design (23) was used to analyze the influence of reaction conditions on the yield of the reaction (R) as well as the characteristics of TMCh and HPTACh produced. The structure of chitosan pattern and its derivatives were characterized by infrared spectroscopy (IR) and nuclear magnetic resonance (1H-NMR), considering that the latter was also used to determine the average degree of acetylation (DA), quaternization (DQ) and substitution (DS) of chitosan, TMCh and HPTACh, respectively. Capillary viscometry was used to determine the intrinsic viscosity ([η]) of chitosan, TMCh and HPTACh, allowing to estimate the occurrence of depolymerization and its relationship with the reaction conditions. All samples of TMCh were soluble in water and it was found that DA ranged as 21.0% - 67.0%; the [η] ranged as 13.7 mL/g - 213.0 mL/g and the yield reaction was up to 82.0%, among the variables studied, the concentration of sodium hydroxide and excess CH3I were the most relevant. The HPTACh samples were soluble in water with DS > 12.0%, DS ranged as 1.0% - 45.5%; the [η] ranged as 283.0 mL/g - 446.0 mL/g and the yield was lower than 33.0%, among the variables studied temperature and excess CGTMA were the most important in the production of HPTACh. Among the reaction conditions studied for the synthesis of TMCh the best condition was 2, while for HPTACh the best condition was 6. The samples TMCh2 DQ = 46.0%, [η] = 290.0 ml/g) and HPTACh6 DS = 33.0%, [η] = 293.0 mL/g) were used in a study aiming at the formation of surfactant/polyelectrolyte complex (SPEC) with sodium 1-decanessulfonate (SD). The conductivity and surface tension properties of TMCh2, HPTACh6 and SPEC\'s have been studied and show that all have interfacial activity (γ <= 52.0 mN.m-1), and high value of elasticity modulus (E >= 31.0 mN.m-1), indicating that all species generate interfacial film with good mechanical property and thus can be applied as a stabilizing agent in emulsions emulsions oil/water that were prepared by incorporating ChCat synthesized and SPEC\'s in their formulations, they were stable for more than 4 months, as evaluated by fluorescence and turbidity measurements.
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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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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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Valstar, Ank. "Protein-surfactant interactions." Doctoral thesis, Uppsala University, Department of Physical Chemistry, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-1070.

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Protein-surfactant interactions in aqueous media have been investigated. The globular proteins lysozyme and bovine serum albumin (BSA) served as model proteins. Several ionic and non-ionic surfactants were used.

Fluorescence probe measurements showed that at low sodium dodecyl sulfate (SDS) concentration (< 0.1 M) one micelle-like SDS cluster is bound to lysozyme. From dynamic light scattering (DLS) results it was observed that lysozyme in the complex does not correspond to the fully unfolded protein. At high SDS concentration (> 0.1 M) one compact and one more extended lysozyme-SDS complex coexist.

The influence of surfactant alkyl chain length and headgroup on BSA-surfactant complex formation was investigated. In these studies, binding isotherms were determined by nuclear magnetic resonance (NMR), DLS was used to measure the hydrodynamic radii of the complexes and the size of the micelle-like aggregates on BSA was determined using fluorescence probe methods.

It was observed from fluorescence measurements that the number of bound SDS molecules does not depend on the presence of the disulfide bridges. Reduced proteins wrap more efficiently around the micelle-like structures, resulting in somewhat smaller complexes, as observed with DLS.

Concentrated BSA-SDS solutions and the corresponding heat-set gels were investigated using DLS and fluorescence probe methods. Correlation lengths in the gel were determined and it was concluded that SDS forms micelle-like aggregates on BSA in concentrated solution and gel phase. The gel region in the ternary phase diagram BSA-SDS-3.1 mM NaN3 has been determined at room temperature.

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Warner, Mark Robert Edward. "Surfactant driven films." Thesis, Imperial College London, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415666.

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Lewis, R. W. "Pulmonary surfactant metabolism." Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332108.

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Books on the topic "Surfactant"

1

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

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von, Wichert P., and Müller B. 1952-, eds. Basic research on lung surfactant. Basel: Karger, 1990.

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Swisher, R. D. Surfactant biodegradation. 2nd ed. New York: M. Dekker, 1987.

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Clint, John H. Surfactant Aggregation. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2272-6.

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Rieger, Martin M. Surfactant encyclopedia. 2nd ed. Carol Stream, IL: Allured Pub. Corp., 1996.

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Clint, John H. Surfactant aggregation. Glasgow: Blackie, 1992.

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Scamehorn, John F., and Jeffrey H. Harwell, eds. Surfactant-Based Separations. Washington, DC: American Chemical Society, 1999. http://dx.doi.org/10.1021/bk-2000-0740.

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Holland, Paul M., and Donn N. Rubingh, eds. Mixed Surfactant Systems. Washington, DC: American Chemical Society, 1992. http://dx.doi.org/10.1021/bk-1992-0501.

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Lachmann, Burkhard, ed. Surfactant Replacement Therapy. Berlin, Heidelberg: Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-73305-5.

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Walker, Long, ed. Surfactant replacement therapy. Philadelphia: Saunders, 1993.

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Book chapters on the topic "Surfactant"

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Soll, Roger F., Gautham Suresh, Douglas Willson, Edmund F. Egan, and Robert Notter. "Surfactant." In Pediatric and Neonatal Mechanical Ventilation, 761–807. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-01219-8_28.

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Gooch, Jan W. "Surfactant." In Encyclopedic Dictionary of Polymers, 723. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_11450.

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Heppner, John B., David B. Richman, Steven E. Naranjo, Dale Habeck, Christopher Asaro, Jean-Luc Boevé, Johann Baumgärtner, et al. "Surfactant." In Encyclopedia of Entomology, 3634. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6359-6_4482.

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Gooch, Jan W. "Surfactant." In Encyclopedic Dictionary of Polymers, 926. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_14902.

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Thiriet, Marc. "Surfactant." In Tissue Functioning and Remodeling in the Circulatory and Ventilatory Systems, 789–804. New York, NY: Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4614-5966-8_13.

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Schwarz, G., and E. Vaeth. "Analysis of Surfactants and Surfactant Formulations." In Surfactants in Consumer Products, 440–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71545-7_7.

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Thomas, Neal J., Robert F. Tamburro, Douglas F. Willson, and Robert H. Notter. "Surfactant Therapy." In Pediatric Critical Care Medicine, 195–213. London: Springer London, 2014. http://dx.doi.org/10.1007/978-1-4471-6356-5_11.

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Gooch, Jan W. "Cationic Surfactant." In Encyclopedic Dictionary of Polymers, 125. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_2055.

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Knepper, Thomas P., and Peter Eichhorn. "Surfactant Metabolites." In Organic Pollutants in the Water Cycle, 211–50. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/352760877x.ch9.

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Tadros, Tharwat. "Polymeric Surfactant." In Encyclopedia of Colloid and Interface Science, 964–95. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-20665-8_35.

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Conference papers on the topic "Surfactant"

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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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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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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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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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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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Ahmad Wazir, Norhidayah, Shazleen Saadon, and Anita Ramli. "New Formulation of Ultra-Low Ift Surfactant for Potential Eor Application." In Offshore Technology Conference Asia. OTC, 2022. http://dx.doi.org/10.4043/31449-ms.

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Abstract The paper discussed the development of an Ultra-Low Interfacial Tension (IFT) foaming surfactant based on a combination of improved as-synthesized surfactant (CBH) consist of as-synthesized oleic amido propyl betaine with mixtures of co-solvents and PETRONAS’ in-house patented foaming-based surfactant (IVF) which consist of amphoteric and anionic surfactant; as well as the performance evaluation of the surfactant in Enhanced Oil Revery (EOR) application. CBH and PETRONAS (IVF) foam-based surfactants were used in the formulation as ultra-low IFT and foaming components, respectively. The surfactant's development has been highlighted, and the findings have been discussed in detail. Due to the good foaming and IFT output at ultra-low levels, the combination of 0.3wt.% IVF and CBH at a ratio of 2: 8 was suggested. The addition of a non-ionic scleroglucan polymer from the polysaccharide group was chosen to study the stabilizing effect to the foam and the ultra-low IFT value of the formulation. Based on the findings, the presence of scleroglucan in the formulation has a significant effect on the performance of IFT and foam of the formulation when compared to the original formulation.
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Katiyar, Amit, Troy Knight, Adam Grzesiak, Pete Rozowski, and Quoc Nguyen. "Low Adsorbing CO2 Soluble Surfactants for Commercially Viable Implementation of CO2 Foam EOR Technology." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206361-ms.

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Abstract Several gas Enhanced Oil Recovery (EOR) pilots enhanced with aqueous-foam based conformance solutions have been implemented in the last 30 years. While these pilots were technically successful, there were economic challenges limiting their commercial viability. Many of these pilots were implemented with water-soluble foaming surfactants that can get adversely affected by near wellbore gas-water gravity segregation and adsorption loss up to 90% of the injected surfactant. Novel, gas-soluble surfactants can be injected with the gas phase where these surfactants are carried with the gas to thief zones faster and deeper with relatively lower adsorption to the rock surface. However, the conventional foam modeling approach relied only on the surfactant concentration in brine to determine foam strength, which adversely predicted the performance of gas soluble surfactants. With proven laboratory evaluations and multiple successful field implementations, the advantages of low adsorbing and gas soluble surfactants cannot be ignored. In this paper, the advantages of surfactant partitioning to the gas phase are confirmed by correcting the conventional foam modeling approach while simulating 1D transport of CO2-foam displacing brine in porous media. An empirical foam model was developed from the lab scale core flooding work of CO2foam transport through porous media using a novel gas-soluble foaming surfactant. While investigating the performance of gas soluble surfactants, global surfactant concentration was used to determine foam strength as the surfactant can transport to the gas-water interface from both the phases. Lab experiments and simulations with an improved foam modeling approach confirmed that a higher gas phase partitioning surfactant generated robust foam and deeper foam propagation while injecting surfactant with CO2in a water saturated core. In addition, comparing three partition coefficient scenarios around 1 on mass basis, the higher gas phase partitioning surfactant showed the larger delay in gas breakthrough. Overall, the simulation results with our better modeling approach do support the advantages of the higher gas phase surfactant partitioning in deeper foam transport and conformance enhancement for the gas-EOR technology.
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AlRadhwan, Azizah, Mohammed Al Hamad, and Wael Abdallah. "Superactive Surfactant for Enhanced Oil Recovery." In Middle East Oil, Gas and Geosciences Show. SPE, 2023. http://dx.doi.org/10.2118/213480-ms.

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Abstract After primary and secondary oil recovery, a large amount of oil is left behind in the reservoir. Enhanced oil recovery (EOR) techniques are introduced to recover additional oil from the reservoir. Chemical EOR is one of the commonly used EOR techniques. It involves the use of chemical substances such as surfactants. Surfactants are commonly used in the petroleum industry because they have the ability to change the water-oil interface as well as the properties of the rock surface. The use of such surfactants depends on technical, financial, and environmental factors. In this study, the performance of a new superactive surfactant is evaluated for use as an oil recovery agent for carbonate and sandstone formations. The surfactant showed high stability in deionized water and seawater, with strong ability to lower the interfacial tension of different crude oils (light, medium, and heavy) at a very low concentration (i.e., 0.05 wt%). The maximum reduction in interfacial tension reached 99.5%. The surfactant also showed significant surface wettability alteration toward water-wet at the tested concentration, with maximum reduction of 87%. From the interfacial tension and wettability experiment results, the optimum system was obtained for the medium crude oil and seawater at surfactant concentration of 0.05 wt%. Therefore, the coreflooding experiments on carbonate and sandstone samples were carried out using this system. Results showed a significant additional oil recovery by the surfactant injection. Additional oil of 43% was recovered from the carbonate core samples, while 16% recovered from the sandstone sample. With these results, this new surfactant can be potentially considered as a new agent for enhancing oil recovery from carbonate and sandstone formations.
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Adila, Ahmed S., Mahmoud Aboushanab, Ahmed Fathy, and Muhammad Arif. "An Experimental Investigation of Surface Chemistry of Rocks in the Presence of Surfactants." In GOTECH. SPE, 2024. http://dx.doi.org/10.2118/219143-ms.

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Abstract Surfactant flooding is a well-known chemical enhanced oil recovery (cEOR) technique. However, surfactant surface chemistry and the associated interactions with rock surfaces are complex and have not been fully investigated. Here, we experimentally investigate the surface chemistry of 15 rock surfaces (10 carbonate and 5 sandstones) upon interaction with different types of surfactants, including cationic, anionic, non-ionic, and zwitterionic surfactants at different concentrations (before, at, and after the critical micelle concentration, CMC). The rock samples were examined using Scanning Electron Microscopy (SEM) to investigate their structure and surface morphology. To understand the interactions at the surfactant-mineral interface and surfactant behavior, the zeta potential measurements of surfactant-brine-rock emulsions were performed, while surface chemical functional groups were identified by Fourier-transform infrared (FTIR) spectroscopy. The zeta potential results show that both anionic (SDS) and cationic (CTAB) surfactants depict better stability, in carbonates and sandstones, compared to the non-ionic (Triton X-100) and zwitterionic (3- (N, N-Dimethylmyristylammonio) surfactants, which is due to the nature of the charge of each surfactant. Also, the FITR results indicate the existence of different chemical bonds and functional groups at different concentrations for each surfactant type, and the magnitude of these bonds differs as a function of rock type and mineralogy. For instance, the rock samples treated with CTAB cationic surfactant reveal the presence of C-O, Mg-C, and Ca-C groups at all concentrations. However, despite being present at all concentrations, these responses show different magnitudes at different surfactant concentrations. The results of this study provide valuable data set to understand the surfactant surface chemistry interactions with different carbonate and sandstone rock surfaces and thus have direct implications for chemical enhanced oil recovery.
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Saputra, I. Wayan Rakananda, and David S. Schechter. "A Temperature Operating Window Concept for Application of Nonionic Surfactants for EOR in Unconventional Shale Reservoirs." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/206346-ms.

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Abstract Surfactant performance is a function of its hydrophobic tail, and hydrophilic head in combination with crude oil composition, brine salinity, rock composition, and reservoir temperature. Specifically, for nonionic surfactants, temperature is a dominant variable due to the nature of the ethylene oxide (EO) groups in the hydrophilic head known as the cloud point temperature. This study aims to highlight the existence of temperature operating window for nonionic surfactants to optimize oil recovery during EOR applications in unconventional reservoirs. Two nonylphenol (NP) ethoxylated nonionic surfactants with different EO head groups were investigated in this study. A medium and light grade crude oil were utilized for this study. Core plugs from a carbonate-rich outcrop and a quartz-rich outcrop were used for imbibition experiments. Interfacial tension and contact angle measurements were performed to investigate the effect of temperature on the surfactant interaction in an oil/brine and oil/brine/rock system respectively. Finally, a series of spontaneous imbibition experiments was performed on three temperatures selected based on the cloud point of each surfactant in order to construct a temperature operating window for each surfactant. Both nonionic surfactants were observed to improve oil recovery from the two oil-wet oil/rock system tested in this study. The improvement was observed on both final recovery and rate of spontaneous imbibition. However, it was observed that each nonionic surfactant has its optimum temperature operating window relative to the cloud point of that surfactant. For both nonionic surfactants tested in this study, this window begins from the cloud point of the surfactant up to 25°F above the cloud point. Below this operating window, the surfactant showed subpar performance in increasing oil recovery. This behavior is caused by the thermodynamic equilibrium of the surfactant at this temperature which drives the molecule to be more soluble in the aqueous-phase as opposed to partitioning at the interface. Above the operating window, surfactant performance was also inferior. Although for this condition, the behavior is caused by the preference of the surfactant molecule to be in the oleic-phase rather than the aqueous-phase. One important conclusion is the surfactant achieved its optimum performance when it positions itself on the oil/water interface, and this configuration is achieved when the temperature of the system is in the operating window mentioned above. Additionally, it was also observed that the 25°F operating window varies based on the characteristic of the crude oil. A surfactant study is generally performed on a single basin, with a single crude oil on a single reservoir temperature or even on a proxy model at room temperature. This study aims to highlight the importance of applying the correct reservoir temperature when investigating nonionic surfactant behavior. Furthermore, this study aims to introduce a temperature operating window concept for nonionic surfactants. This work demonstrates that there is not a "one size fits all" surfactant design.
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Reports on the topic "Surfactant"

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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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Vane, Leland, A. L. Wood, Gary A. Pope, and Edwin E. Tucker. Surfactant Enhanced DNAPL Removal. Fort Belvoir, VA: Defense Technical Information Center, August 2001. http://dx.doi.org/10.21236/ada607317.

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Weiss. L52296 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/r0010658.

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The objective of this effort was to demonstrate in the field the new wettability altering technology developed in the laboratory during Phase 1. 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 was improved in surfactant-treated sandstone cores. 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. The Waverly Storage Facility operated by Southern Union/Panhandle Energy was selected as the site for a field test of the surfactant process. Waverly is an 1800-ft sandstone aquifer gas storage reservoir located near Springfield, lllinois. Expansion and contraction of a spherical gas bubble provided pressure support as gas was injected and withdrawn from 37 individual wells. Three wells were selected for treatment with 1000 bbl of ~4% surfactant solution. An additional three nearby wells were selected as control wells. A field mixing procedure similar to that used in the laboratory to avoid phase separation of the microemulsion was developed and successfully used during the third week of October 2007 when the wells were treated. Rates and pressures were measured at the wellhead; fluid levels were not recorded. Since the initial rate-pressure data collected during the project year including the well treatments were sparse, it was decided to extend the project to the end of 2008 to acquire more field data.
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Harwell, J., and J. Scamehorn. Surfactant enhanced volumetric sweep efficiency. Office of Scientific and Technical Information (OSTI), October 1989. http://dx.doi.org/10.2172/5534509.

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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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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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Kishore K. Mohanty. Dilute Surfactant Methods for Carbonate Formations. Office of Scientific and Technical Information (OSTI), March 2004. http://dx.doi.org/10.2172/910178.

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Kishore K. Mohanty. Dilute Surfactant Methods for Carbonate Formations. Office of Scientific and Technical Information (OSTI), June 2004. http://dx.doi.org/10.2172/910179.

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Kishore K. Mohanty. Dilute Surfactant Methods for Carbonate Formations. Office of Scientific and Technical Information (OSTI), October 2005. http://dx.doi.org/10.2172/890025.

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