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Journal articles on the topic 'Surfactants'
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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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Wagner, Martin, and H. Johannes Pöpel. "Surface active agents and their influence on oxygen transfer." Water Science and Technology 34, no. 3-4 (August 1, 1996): 249–56. http://dx.doi.org/10.2166/wst.1996.0438.
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Oxygen transfer rates of fine bubble aeration systems in uniform arrangement are reduced down to 40% to 70% in wastewater compared to clean water conditions. Surfactants in wastewater are the main reason for the inferior and therefore uneconomic performance. The influence of different types of surfactants (anionic and nonionic) and of their concentration on oxygen transfer is investigated at various properties of pure water (content of electrolytes, hardness) by means of extensive experiments. The main results of the investigations are:in dependence of the type of surfactant, its concentration and the types of water:– the aeration coefficient kLa decreases (down to 55%)– the specific interfacial area (a) increases (up to 350%)– the oxygen transfer coefficient (kL) decreases (down to 20%)nonionic surfactants reduce the oxygen transfer more strongly than anionic surfactantsat the same surface tension, but different types of surfactant α-values can vary over a range of 0.12. Therefore α-values can not be calculated from surface tension measurementsα-values of approximately 0.55 should be taken for designing fine bubble aeration systemsIn new guidelines for the measurement of oxygen transfer rates, addition of 5 gm−3 of an arbitrary surfactant into clean water to simulate wastewater conditions must be abandoned.
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Tiwari, Mehul, and Divya Bajpai Tripathy. "Soil Contaminants and Their Removal through Surfactant-Enhanced Soil Remediation: A Comprehensive Review." Sustainability 15, no. 17 (September 1, 2023): 13161. http://dx.doi.org/10.3390/su151713161.
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This review provides a comprehensive analysis of the effectiveness of surfactants in enhancing the remediation of contaminated soils. The study examines recent and older research on the use of effluent treatment techniques combined with synthetic surface-active agents, bio-surfactants, and various categories of surfactants for soil reclamation purposes. The main purpose of this review is to evaluate the effectiveness of surfactants in enhancing the remediation of contaminated soils. The research question is to explore the mechanisms through which surfactants enhance soil remediation and to assess the potential benefits and limitations of surfactant-based remediation methods. This review was conducted through an extensive literature search of relevant articles published in scientific databases. The articles were selected based on their relevance to the topic and their methodological rigor. Types of possible soil pollutants and the requirements of specific surfactants were discussed. Structural relationships between pollutant and surfactants were described thoroughly. Extensive study revealed that surfactants have shown great potential in enhancing the remediation of contaminated soils. Surfactants can improve the solubility and mobility of hydrophobic contaminants and facilitate their removal from soil. However, the effectiveness of surfactant-based remediation methods depends on several factors, including the type of contaminant, the soil properties, and the surfactant concentration and type. Surfactant-enhanced soil remediation can be an effective and sustainable method for addressing soil contamination. However, the optimal conditions for using surfactants depend on the specific site characteristics and contaminant properties, and further research is needed to optimize the use of surfactants in soil remediation.
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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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Desai, Tejas R., and Sharad G. Dixit. "Adsorption from Mixtures of Cationic/Non-Ionic Surfactants on to a Polystyrene Surface." Adsorption Science & Technology 15, no. 5 (May 1997): 391–405. http://dx.doi.org/10.1177/026361749701500507.
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The adsorption of cetyltrimethylammonium bromide (CTAB) and nonyl phenyl ethoxylates (NP-n, where n = 13, 20 and 30) on to polystyrene powder has been studied. Concentrations of surfactant solutions ranging from below CMC to well above CMC were investigated. In a single surfactant system, only the cationic surfactant (CTAB) was found to adsorb appreciably while nonionic surfactants showed negligible adsorption. In mixed surfactant systems, the cationic surfactant was found to induce significant co-adsorption of non-ionic surfactants. The increased adsorption of non-ionic surfactants has been attributed to the formation of non-ideal mixed hemimicelles due to intercomponent lateral interactions. However, non-ionic surfactants with longer hydrophilic chains did not form mixed hemimicelles with CTAB. In general, zeta potential measurements support the adsorption results.
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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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Kamal, Muhammad Shahzad, Syed Muhammad Shakil Hussain, and Lionel Talley Fogang. "Role of Ionic Headgroups on the Thermal, Rheological, and Foaming Properties of Novel Betaine-Based Polyoxyethylene Zwitterionic Surfactants for Enhanced Oil Recovery." Processes 7, no. 12 (December 3, 2019): 908. http://dx.doi.org/10.3390/pr7120908.
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Long-term thermal stability of surfactants under harsh reservoir conditions is one of the main challenges for surfactant injection. Most of the commercially available surfactants thermally degrade or precipitate when exposed to high-temperature and high-salinity conditions. In this work, we designed and synthesized three novel betaine-based polyoxyethylene zwitterionic surfactants containing different head groups (carboxybetaine, sulfobetaine, and hydroxysulfobetaine) and bearing an unsaturated tail. The impact of the surfactant head group on the long-term thermal stability, foam stability, and surfactant–polymer interactions were examined. The thermal stability of the surfactants was assessed by monitoring the structural changes when exposed at high temperature (90 °C) for three months using 1H-NMR, 13C-NMR, and FTIR analysis. All surfactants were found thermally stable regardless of the headgroup and no structural changes were evidenced. The surfactant–polymer interactions were dominant in deionized water. However, in seawater, the surfactant addition had no effect on the rheological properties. Similarly, changing the headgroup of polyoxyethylene zwitterionic surfactants had no major effect on the foamability and foam stability. The findings of the present study reveal that the betaine-based polyoxyethylene zwitterionic surfactant can be a good choice for enhanced oil recovery application and the nature of the headgroup has no major impact on the thermal, rheological, and foaming properties of the surfactant in typical harsh reservoir conditions (high salinity, high temperature).
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Tian, Maozhang, Fan Zhang, Lu Wang, Xing Dong, Lifei Zhang, and Xia Guo. "Activity of Polyphenoloxidase in red Fuji Apples Promoted with Cationic Surfactant – Role of Surfactant Structure." Tenside Surfactants Detergents 58, no. 5 (September 1, 2021): 383–93. http://dx.doi.org/10.1515/tsd-2020-2322.
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Abstract In this study, we observed the activity of polyphenoloxidase (PPO) in red Fuji apples in the presence of single-chained surfactants (including cetyl trimethyl ammonium bromide (CTAB), and dodecyl trimethyl ammonium bromide (DTAB)) and gemini surfactants (pentamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide), octamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide, dodecamethylene-α,ω-bis(dodecyl dimethyl ammonium bromide), pentamethylene-α,ω-bis(cetyl dimethyl ammonium bromide), and octamethylene-α,ω-bis(cetyl dimethyl ammonium bromide)). It was found that all these surfactants enhanced the activity of PPO in a wide range of temperature at low content. When PPO was denatured by incubating at high temperature, the surfactants caused reactivation of PPO. Compared to the single-chained surfactants, the gemini surfactants increased PPO activity at a much lower concentration. Moreover, the single-chained surfactant and the gemini surfactant acted together to further increase PPO activity, and the synergistic effect reduced the amount of surfactant used. In addition, the Michaelis-Menten constant for PPO did not change in the presence of the surfactants, suggesting the active site should remain well with the surfactants.
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Du, Bin, Shi Sheng Zhou, and Nan Wang. "Modification of Printing Aluminum Powders by Wet Covering Method with Composite Surfactants." Advanced Materials Research 179-180 (January 2011): 596–601. http://dx.doi.org/10.4028/www.scientific.net/amr.179-180.596.
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Considering the fact of low gloss and masking power of aluminum powder, the aluminum powder is chemically modified by wet covering with eight kinds of single surfactants such as Oleic acid, Stearic acid, Sodium dodecyl sulfonate, Sodium stearate, Polyvinyl alcohol, Polyethylene glycol, Tween-80 and Emulsifier-OP in different proportions on the surface of aluminum powder and the gloss of aluminum paste printing ink concocted with the covered aluminum powder is tested. The results show that the gloss of the aluminum powder covered by one percent Polyvinyl alcohol increases most significant. In order to upgrade the gloss of the aluminum paste printing ink, an orthogonal experiment is carried out by choosing four surfactants such as Polyvinyl alcohol as influencing factors and their addition amounts as researched levels. The optimal surface modification formula is obtained based on the experiment. The dosage of surfactant is one percent of the aluminum powder, Sodium dodecyl sulfonate accounts for 25.00% of the total surfactant’s weight, Sodium stearate accounts for 37.50% of the total surfactant’s weight, Tween-80 accounts for 12.50% of the total surfactant and Polyvinyl alcohol accounts for 25.00% of the total surfactant’s weight. The prescription can concoct the commodity aluminum powder and passed 1200 mesh to the aluminum paste printing ink with commodity ink to satisfy the request of relief printing and intaglio printing. The gloss of the printed aluminum paste printing ink reaches 81.3.
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Pino, Marcela Sofia, Michele Michelin, Rosa M. Rodríguez-Jasso, Alfredo Oliva-Taravilla, José A. Teixeira, and Héctor A. Ruiz. "Hot Compressed Water Pretreatment and Surfactant Effect on Enzymatic Hydrolysis Using Agave Bagasse." Energies 14, no. 16 (August 4, 2021): 4746. http://dx.doi.org/10.3390/en14164746.
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Agave bagasse is a residual biomass in the production of the alcoholic beverage tequila, and therefore, it is a promising raw material in the development of biorefineries using hot compressed water pretreatment (hydrothermal processing). Surfactants application has been frequently reported as an alternative to enhance monomeric sugars production efficiency and as a possibility to reduce the enzyme loading required. Nevertheless, the surfactant’s action mechanisms in the enzymatic hydrolysis is still not elucidated. In this work, hot compressed water pretreatment was applied on agave bagasse for biomass fractionation at 194 °C in isothermal regime for 30 min, and the effect of non-ionic surfactants (Tween 20, Tween 80, Span 80, and Polyethylene glycol (PEG 400)) was studied as a potential enhancer of enzymatic saccharification of hydrothermally pretreated solids of agave bagasse (AGB). It was found that non-ionic surfactants show an improvement in the conversion yield of cellulose to glucose (100%) and production of glucose (79.76 g/L) at 15 FPU/g glucan, the highest enhancement obtained being 7% regarding the control (no surfactant addition), using PEG 400 as an additive. The use of surfactants allows improving the production of fermentable sugars for the development of second-generation biorefineries.
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Green, Jerry M. "Varying Surfactant Type Changes Quizalofop-P Herbicidal Activity." Weed Technology 11, no. 2 (June 1997): 298–302. http://dx.doi.org/10.1017/s0890037x00042986.
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Varying the type of nonionic surfactant greatly changed the biological activity of the ethyl ester of quizalofop-P on giant foxtail, barnyardgrass, and corn. These studies statistically evaluated 22 surfactants with widely different chemical, physical, and surface properties. Of the 14 surfactant properties analyzed, dynamic surface tension was the most important to enhance quizalofop-P activity. Alcohol ethoxylate surfactants like Genapol® 24-L-92 and Tergitol® 15-S-7 were among the most effective adjuvants. These surfactants performed significantly better than the commercial nonionic surfactant, Induce®, and equal to a high-quality petroleum crop oil concentrate, Agri-dex®. These surfactants offer a lower dose option to crop oil concentrates and a more effective surfactant alternative for mixtures that prohibit crop oil concentrates.
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Nagy, Roland, Réka Kothencz, Máté Hartyányi, and László Bartha. "Relationship between Some Colloidal Properties of Non-Ionic-Anionic Surfactant Mixtures." Processes 10, no. 6 (June 6, 2022): 1136. http://dx.doi.org/10.3390/pr10061136.
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Non-ionic surfactants are compatible with different types of materials, therefore they can be applied in various packages. Fatty-acid derivates as non-ionic surfactants and their mixtures were investigated to study their colloidal behavior. The HLB value, the particle size, the emulsification capacity and the interfacial tension of various commercial, non-ionic surfactants, and their mixtures with sodium lauryl-ether-sulfate (SLES), were determined. The surfactant mixtures were prepared in different non-ionic: anionic surfactant ratios to examine their effect on several surfactant characteristics. The interfacial tension between the oil phase and aqueous phase was measured using the spinning drop method and the average hydrodynamic diameter of surfactants in the aqueous solution was determined using the dynamic light scattering method. The relationship between various colloidal properties of surfactants was investigated. It was found that there is a significant relationship between the colloidal characteristics and the structure of surfactants that can contribute to their efficient selection method.
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Zhang, Wannian, Feng Luo, Zhigang Gao, Haizhu Chi, Jinlong Wang, Fang Yu, and Yu-Peng He. "Study of Interfacial Properties of Anionic–Nonionic Surfactants Based on Succinic Acid Derivatives via Molecular Dynamics Simulations and the IGMH Method." Colloids and Interfaces 8, no. 4 (July 1, 2024): 41. http://dx.doi.org/10.3390/colloids8040041.
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Surfactants are widely used in fields such as oil recovery and flotation. The properties and mechanisms of surfactants can be effectively studied using molecular dynamics (MD) simulations. Herein, the aggregation behavior of surfactants was studied at the oil–water interface by MD simulation, and the micro-morphology of surfactants was analyzed under a low concentration and saturated state at the oil–water interface, respectively. The visualization results of the MD simulation showed that DTOA was saturated at the oil–water interface at 120 surfactant molecules, whereas 160 surfactant molecules were required for BEMA. In addition, the effect of surfactant concentration on the interfacial thickness and hydrogen bond distribution was studied, with the inflection point of hydrogen bond distribution identified as a characteristic parameter for surfactant saturation at the oil–water interface. The aggregation behavior of their hydrophobic and hydrophilic chains at the oil–water interface was qualitatively assessed using order parameters. Finally, the aggregation state of surfactants in salt-containing systems was studied, and it was found that the surfactants could effectively adsorb magnesium ions and calcium ions at the oil–water interface. However, the curve of the number of hydrogen bonds varies greatly, with a possible reason being that BEMA has a different coordination manner with diverse metal ions. This study provides some original insights into both the theoretical study and practical application of anionic and nonionic surfactants.
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Kamal, Muhammad. "A Novel Approach to Stabilize Foam Using Fluorinated Surfactants." Energies 12, no. 6 (March 26, 2019): 1163. http://dx.doi.org/10.3390/en12061163.
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Selection of surfactants for enhanced oil recovery and other upstream applications is a challenging task. For enhanced oil recovery applications, a surfactant should be thermally stable, compatible with reservoir brine, and have lower adsorption on reservoir rock, have high foamability and foam stability, and should be economically viable. Foam improves the oil recovery by increasing the viscosity of the displacing fluid and by reducing the capillary forces due to a reduction in interfacial tension. In this work, foamability and foam stability of two different surfactants were evaluated using a dynamic foam analyzer. These surfactants were fluorinated zwitterionic, and hydrocarbon zwitterionic surfactants. The effect of various parameters such as surfactant type and structure, temperature, salinity, and type of injected gas was investigated on foamability and foam stability. The foamability was assessed using the volume of foam produced by injecting a constant volume of gas and foam stability was determined by half-life time. The maximum foam generation was obtained using hydrocarbon zwitterionic surfactant. However, the foam generated using fluorinated zwitterionic surfactant was more stable. A mixture of zwitterionic fluorinated and hydrocarbon fluorinated surfactant showed better foam generation and foam stability. The foam generated using CO2 has less stability compared to the foam generated using air injection. Presence of salts increases the foam stability and foam generation. At high temperature, the foamability of the surfactants increased. However, the foam stability was reduced at high temperature for all type of surfactants. This study helps in optimizing the surfactant formulations consisting of a fluorinated and hydrocarbon zwitterionic surfactant for foam injections.
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White, Graham F. "Multiple interactions in riverine biofilms - surfactant adsorption, bacterial attachment and biodegradation." Water Science and Technology 31, no. 1 (January 1, 1995): 61–70. http://dx.doi.org/10.2166/wst.1995.0015.
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Many organic pollutants, especially synthetic surfactants, adsorb onto solid surfaces in natural and engineered aquatic environments. Biofilm bacteria on such surfaces make major contributions to microbial heterotrophic activity and biodegradation of organic pollutants. This paper reviews evidence for multiple interactions between surfactants, biodegradative bacteria, and sediment-liquid interfaces. Biodegradable surfactants e.g. SDS, added to a river-water microcosm were rapidly adsorb to sediment surface and stimulated the indigenous bacteria to attach to the sediment particles. Recalcitrant surfactants and non-surfactant organic nutrients did not stimulate attachment Attachment of bacteria was maximal when biodegradation was fastest, and was reversed when biodegradation was complete. Dodecanol, the primary product of SDS-biodegradation, markedly stimulated attachment. When SDS was added to suspensions containing sediment and either known degraders or known non-degraders, only the degraders became attached, and attachment accelerated surfactant biodegradation to dodecanol. These cyclical cooperative interactions have implications for the design of biodegradability-tests, the impact of surfactant adjuvants on biodegradability of herbicides/pesticides formulated with surfactants, and the role of surfactants used to accelerate bioremediation of hydrocarbon-polluted soils.
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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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Petrovic, Lidija, Verica Sovilj, Jadranka Milanovic, and Jaroslav Katona. "A conductometric investigation of hydroxypropylmethyl cellulose/sodium dodecyl sulfate/nonionic surfactant systems." Journal of the Serbian Chemical Society 79, no. 11 (2014): 1421–32. http://dx.doi.org/10.2298/jsc140321059p.
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Surfactant mixtures are very often used in various cosmetic and pharmaceutical products because they commonly act in synergism and provide more favorable properties than the single surfactants. At the same time, the 9 presence of polymers in mixtures of surfactants may lead to molecular interactions thereby affecting product stability and activity. For these reasons it is very important to determine the surfactant interactions influence on 1micellization and mixed micellization, as well as polymer-surfactants mixed micelles interactions. In this work we examined self-aggregation of nonionic surfactants, polysorbate 20 (Tween 20), polyoxyethylene octylphenyl ether (Triton X100) and polyoxyethylene-polyoxypropylene block copolymer (Pluronic F68) with ionic surfactant, sodium dodecylsulfate, in aqueous solution at 40?C using conductometric titration method. It was found that concentration region for mixed micelle formation depends on nonionic surfactant characteristics and its concentration. Formation of surfactants mixed micelles in the presence of nonionic polymer, hydroxypropylmethyl cellulose, and their binding to polymer hydrophobic sites, were investigated too. Analysis of obtained results points to different kinds of interactions in investigated systems, which are crucial for their application.
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Hassan, Mohammed, Sadeq M. Al-Hazmi, Ibrahim A. Alhagri, Ahmed N. Alhakimi, Adnan Dahadha, Mohammad Al-Dhoun, and Yazan Batineh. "Micellar Catalysis of Chemical Reactions by Mixed Surfactant Systems and Gemini Surfactants." Asian Journal of Chemistry 33, no. 7 (2021): 1471–80. http://dx.doi.org/10.14233/ajchem.2021.23187.
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Micellar catalysis exhibited by mixed surfactant systems and gemini surfactants was reviewed. The review focused on mixed surfactant systems and tried to correlate the changes in the physico-chemical properties of these systems to the variations of their catalytic activities. Mixed surfactant systems are promising as the catalytic efficiency of some single surfactants was significantly enhanced in the presence of other critically selected surfactants. The selection should consider the charge, size, and structures of the head group as well as an appropriate length of hydrocarbon tail. The overall conclusion has arrived the mixed surfactant systems could be a tool by which the reaction rate can be tuned by changing the composition and/or the components’ structures. The higher catalytic activity of gemini surfactants compared to conventional ones, their facile synthesis and liability for structure control made them of superior choice for micellar catalysis.
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Perron, Gérald, Josée Francoeur, Jacques E. Desnoyers, and Jan C. T. Kwak. "Heat capacities and volumes in aqueous polymer and polymer–surfactant solutions." Canadian Journal of Chemistry 65, no. 5 (May 1, 1987): 990–95. http://dx.doi.org/10.1139/v87-169.
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The apparent molar volumes and heat capacities of aqueous mixtures of neutral polymers and ionic surfactants were measured at 25 °C. The polymers chosen were poly(vinylpyrrolidone) (PVP) and poly(ethyleneoxide) (PEO) and the surfactants were the C8, C10, and C12 homologs of sodium alkylsulfates and the C10, C12, and C16 homologs of alkyltrimethylammonium bromides. The polymer–surfactant interactions depend on the nature of both components and on the chain length of the surfactant. The thermodynamic properties of the cationic surfactants are essentially the same in the absence and presence of polymer indicating little surfactant–polymer interaction. On the other hand, the thermodynamic properties of anionic surfactants are shifted, upon the addition of polymers, in the direction of enhanced hydrophobic association. The effect increases with the surfactant chain length and with the polymer concentration. The effect is larger with PVP than with PEO.
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García-Cervilla, Raúl, Arturo Romero, Aurora Santos, and David Lorenzo. "Surfactant-Enhanced Solubilization of Chlorinated Organic Compounds Contained in DNAPL from Lindane Waste: Effect of Surfactant Type and pH." International Journal of Environmental Research and Public Health 17, no. 12 (June 23, 2020): 4494. http://dx.doi.org/10.3390/ijerph17124494.
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Application of surfactants in the remediation of polluted sites with dense nonaqueous phase liquid (DNAPL) still requires knowledge of partitioning between surfactants and pollutants in the organic and aqueous phases and the time necessary to reach this balance. Two real DNAPLs, generated as wastes in the lindane production and taken from the polluted sites from Sabiñanigo (Spain), were used for investigating the solubilization of 28 chlorinated organic compounds (COCs) applying aqueous surfactant solutions of three nonionic surfactants (E-Mulse® 3 (E3), Tween®80 (T80), and a mixture of Tween®80-Span®80 (TS80)) and an anionic surfactant (sodium dodecyl sulfate (SDS)). The initial concentrations of surfactants were tested within the range of 3–17 g·L−1. The pH was also modified from 7 to >12. The uptake of nonionic surfactants into the organic phase was higher than the anionic surfactants. Solubilization of COCs with the nonionic surfactants showed similar molar solubilization ratios (MSR = 4.33 mmolCOCs·g−1surf), higher than SDS (MSR = 0.70 mmolCOCs·g−1SDS). Furthermore, under strong alkaline conditions, the MSR value of the nonionic surfactants was unchanged, and the MSR of SDS value increased (MSR = 1.32 mmolCOCs·g−1SDS). The nonionic surfactants did not produce preferential solubilization of COCs; meanwhile, SDS preferentially dissolved the more polar compounds in DNAPL. The time required to reach phase equilibrium was between 24 and 48 h, and this contact time should be assured to optimize the effect of the surfactant injected on COC solubilization.
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Toscano, Stefania, Giovanni La Fornara, and Daniela Romano. "Salt Spray and Surfactants Induced Morphological, Physiological, and Biochemical Responses in Callistemon citrinus (Curtis) Plants." Horticulturae 8, no. 3 (March 17, 2022): 261. http://dx.doi.org/10.3390/horticulturae8030261.
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The growth and aesthetic value of ornamental plant species used near coastlines are negatively influenced by salt spray. The presence of surfactants could enhance salt damage. To analyze the influences of salt spray and surfactants alone and in combination with each other, individual Callistemon plants were subjected to different treatments for 8 weeks: a solution simulating the composition of seawater (salt spray), a solution containing an anionic surfactant (surfactant), a solution with salt spray and anionic surfactant (salt plus surfactants), and deionized water (control). To study the influence of different climatic conditions, two growing periods, from January to March (I CP) and from May to July (II CP), were established. Salt spray, alone or with surfactant action, influences plants’ growth and aesthetic features in different cycle periods. The percentage of leaf damage significantly increased with salt spray and salt plus surfactants during II CP (~27%). Additionally, the Na+ and Cl− contents were enhanced in the leaves in both CPs, but the contents in the roots were only enhanced in the II CP. The gas exchanges were significantly influenced by the treatments, especially during the II CP, when a reduction in net photosynthesis due to salt spray was observed starting from the second week of stress. At the end of the experiment, in both cycle periods, the leaf proline content increased in the salt spray and salt plus surfactants treatments. In both CPs, PCA revealed that the morphological and physiological parameters were directly associated with the control and surfactants treatments, whereas the mineral contents and biochemical parameters were directly correlated with the salt and salt plus surfactants treatments. The additive effect of surfactant stress, compared to salt stress, did not appear to be significant, with the exception of CP II, and for some parameters, the solubilization action of surfactants was favored by higher temperatures.
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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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Shalabi, Kamal, Hany M. Abd Abd El-Lateef, Mohamed M. Hammouda, Amany M. A. Osman, Ahmed H. Tantawy, and Mohamed A. Abo-Riya. "Perspectives on Corrosion Inhibition Features of Novel Synthesized Gemini-Fluorinated Cationic Surfactants Bearing Varied Spacers for Acid Pickling of X60-Steel: Practical, and In Silico Calculations." Materials 16, no. 14 (July 24, 2023): 5192. http://dx.doi.org/10.3390/ma16145192.
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Through our present study, three novel Gemini-fluorinated cationic surfactants bearing different spacers (FSG6-2, FSG6-4, and FSG6-6) were synthesized, and their structures were explained via different spectroscopic instruments such as 1H, 13C, and 19F NMR spectra. The surface activity of the as-prepared surfactants was examined. The inhibiting influence of FSG6 molecules on the X60 steel corrosion in the pickling solution (HCl) was examined by diverse methods comprising electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and X-ray photoelectron spectroscopy (XPS) experimentations, and computational calculations. The inhibition effectiveness of FSG6 surfactants followed the order of 93.37% (FSG6-2) < 96.74% (FSG6-4) < 98.37% (FSG6-6) at 2.0 × 10−4 M. The FSG6 surfactants function as mixed-type inhibitors, according to PDP investigations. The H2O molecules that adsorbed on the steel interface were substituted with surfactant molecules, and the surfactant’s inhibitory activity is likely caused by the improvement in an adsorptive layer on the steel substrate, as specified by the EIS results. The Langmuir isotherm describes the absorption of FSG6 molecules on the metal surface. The XPS investigations validate the steel interface’s extremely protective nature. The mechanism of interaction between FSG6 molecules with an X60-steel employing the DFT calculations and MC simulations methods was also examined and discussed.
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Riechers, Dean E., Loyd M. Wax, Rex A. Liebl, and Don G. Bullock. "Surfactant Effects on Glyphosate Efficacy." Weed Technology 9, no. 2 (June 1995): 281–85. http://dx.doi.org/10.1017/s0890037x00023356.
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Field and greenhouse studies were performed to examine the influence of various surfactants with glyphosate on whole plant efficacy. Relationships were examined between glyphosate phytotoxicity and surfactant properties, including ionic form, degree of ethoxylation, and hydrophobe composition. Cationic tertiary amine surfactants enhanced glyphosate performance in both field and greenhouse studies. Nonionic allinol and octoxynol surfactants were not effective in combination with glyphosate. In field studies, glyphosate efficacy increased with increasing surfactant ethylene oxide (EO) content. Soybean and velvetleaf responded similarly to glyphosate-surfactant spray applications, as both demonstrated significant linear and quadratic relationships between increasing surfactant ethoxylation and phytotoxicity, while common lambsquarters showed a significant linear relationship only. Cationic surfactants were evaluated in the greenhouse and a significant quadratic regression of glyphosate phytotoxicity to common lambsquarters on increasing surfactant ethoxylation indicated an optimum surfactant EO content of about 10 moles. Both tertiary and quaternary ethoxylated fatty amines were effective with glyphosate in decreasing common lambsquarters' fresh weight. Fatty amine hydrophobe composition did not correlate with glyphosate phytotoxicity to common lambsquarters.
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Pilipović, Ana, Ivana Vapa, Vesna Tepavčević, Gorana Puača, and Mihalj Poša. "Ternary Mixed Micelle Hexadecyltrimethylammonium Bromide—Dodecyltrimethylammonium Bromide—Sodium Deoxycholate: Gibbs Free Energy of Mixing and Excess Gibbs Energy of Mixing." Molecules 28, no. 18 (September 20, 2023): 6722. http://dx.doi.org/10.3390/molecules28186722.
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Pharmaceutical, food, and cosmetic formulations often contain binary or ternary surfactant mixtures with synergistic interactions amongst micellar building blocks. Here, a ternary mixture of the surfactants hexadecyltrimethylammonium bromide, dodecyltrimethylammonium bromide, and sodium deoxycholate is examined to see if the molar fractions of the surfactants in the ternary mixed micellar pseudophase are determined by the interaction coefficients between various pairs of the surfactants or by their propensity to self-associate. Critical micelle concentrations (CMC) of the analyzed ternary mixtures are determined experimentally (spectrofluorimetrically using pyrene as the probe molecule). Thermodynamic parameters of ternary mixtures are calculated from CMC values using the Regular Solution protocol. The tendency for monocomponent surfactants to self-associate (lower value of CMC) determines the molar fractions of surfactant in the mixed micelle if there is no issue with the packing of the micelle building units of the ternary mixed micelle. If a more hydrophobic surfactant is incorporated into the mixed micelle, the system (an aqueous solution of surfactants) is then the most thermodynamically stabilized.
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Wang, Biao, Xue Wang, Futang Hu, Xiangyu Wang, Zhongji Yang, Xiuyu Zhu, Gen Li, and Keliang Wang. "Study on the Properties of Compound Surfactants with PO Groups." Energies 17, no. 2 (January 20, 2024): 513. http://dx.doi.org/10.3390/en17020513.
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The compound surfactant system has considerable development prospects for improving oil recovery. A synergistic effect can be achieved through the orderly arrangement of the two surfactants on the interface, which can make up for the performance defects of a single surfactant. In this paper, the effects of the number of propylene oxides (PO) in composite surfactants on interfacial tension and emulsion stability were systematically studied. The results showed that the solubility of composite surfactants was significantly improved under high-salinity conditions by adding anionic–nonionic surfactants to a single anionic surfactant. The interfacial tension of composite surfactants shows a V-shaped change of first decreasing and then increasing with the increase in PO groups. As the number of PO groups increases, the emulsion first increases and then decreases. Among the series of composite surfactants, LBAS/C12PO10S has the lowest interfacial tension, reaching the order of 10−3 mN/m, and the emulsion formed by it exhibits superior stability. This indicates that the synergistic effect of the two surfactants can be improved by adjusting the number of PO groups. Furthermore, the LBAS/C12PO10S composite system can be mixed with crude oil to form Winsor III microemulsion, which has great potential for application in enhanced oil recovery via chemical flooding.
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Gull, Nuzhat, Mohd Ishtikhar, Md Sayem Alam, Syedah Noorul Sabah Andrabi, and Rizwan Hasan Khan. "Spectroscopic studies on the comparative refolding of guanidinium hydrochloride denatured hen egg-white lysozyme and Rhizopus niveus lipase assisted by cationic single-chain/gemini surfactants via artificial chaperone protocol." RSC Advances 7, no. 45 (2017): 28452–60. http://dx.doi.org/10.1039/c6ra21528a.
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Haq, Bashirul, Jishan Liu, Keyu Liu, and Dhafer Al Shehri. "Study of phase behaviour and ionic effect of green surfactants in MEOR." APPEA Journal 58, no. 1 (2018): 84. http://dx.doi.org/10.1071/aj17202.
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The phase behaviour of surfactant systems is an important characteristic for microbial enhanced oil recovery (MEOR) and is a key method for understanding and predicting the performance of surfactant systems. In addition, ions play a vital role in surfactant chemistry and the ionic effects of green surfactants are not yet well characterised. Green surfactants are biodegradable and environmental friendly and perceived to have great potential for MEOR. This study characterises some green anionic and non-ionic surfactants through phase behaviour study, interfacial tension (IFT) and core flooding experiments. At the same time, the combined effect of the surfactants with alcohols on IFT through laboratory experiments are looked into. Our laboratory experiments have confirmed that the non-ionic surfactant is more active in the reduction of IFT than anionic surfactant. Bio-surfactant is unable to form stable middle phase. Temperature and pressure appear to have little effect on the IFT of non-ionic surfactant. There is no significant reduction in IFT values when the non-ionic surfactant is combined with pentanol in varying concentrations. The role of alkyl group carbon number in non-ionic surfactant was also investigated in this study. It was found that the IFT value decreased by increasing the lower limit alkyl group carbon number.
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Lv, Sheng Hua, Gong Rui, and Guo Yun Zhang. "Preparation and Properties of Modified Starch with Methoxy Polyethylene Glycol Methacrylate." Advanced Materials Research 455-456 (January 2012): 589–93. http://dx.doi.org/10.4028/www.scientific.net/amr.455-456.589.
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The modified starch surfactant was synthesized by grafting copolymerization of methoxy polyethylene glycol methacrylate (MPGM) with starch. The effects of monomers composition and side chain length on surface activity of starch surfactants were investigated. The modified starch surfactant was synthesized when the molar ratio of AGU (starch) and MPEGMA was 1: 0.3 at 85 °C for 2h. The FTIR result shows that starch had successfully reacted with MPGM. Modified starch surfactants are poor foam surfactant with excellent surface activity. The modified starch surfactants are biodegradable and environmentally friendly and may be extensively used in various fields in future.
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Sun, Yuhai, Yujun Feng, Hongwei Dong, Zhi Chen, and Likun Han. "Synthesis and aqueous solution properties of homologous gemini surfactants with different head groups." Open Chemistry 5, no. 2 (June 1, 2007): 620–34. http://dx.doi.org/10.2478/s11532-006-0072-7.
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AbstractA series of homologous gemini surfactants possessing identical hydrophobic chains but different ionic head groups (cationic, anionic, zwitterionic) were synthesized, and their aqueous solution properties were examined. The results showed that the surface activities of gemini surfactants are superior to those of corresponding conventional monomeric surfactants, and molecular arrangements of gemini surfactants at the air-water interface are tighter than those of corresponding conventional surfactants. It was also found that zwitterionic gemini surfactant possesses the highest surface activity among the three surfactants. The behavior at the air-water interface is closely related to the molecular structural features of surfactants, which provide an indication for synthesizing highly-efficient surfactants.
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Mitru, Daniel, Gheorghe Nechifor, Stefania Gheorghe, Alina Roxana Banciu, Lucian Ionescu, Catalina Stoica, Daniela Liliana Ionica, and Irina Eugenia Lucaciu. "Removal and Effects of Surfactants in Activated Sludge System." Revista de Chimie 71, no. 1 (February 7, 2020): 100–106. http://dx.doi.org/10.37358/rc.20.1.7819.
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The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active substances, which are biorefractory, toxic or persistent. Even though anionic and non-ionic surfactants often used in commercial detergents composition are reasonably degradable under aerobic conditions and not particularly toxic at low concentrations, high concentration of surfactants influenced the activated sludge activity and are harmful for the aquatic environment. In the literature, data on the biodegradability and/or ecotoxicity of a certain type of surfactant (anionic, nonionic, cationic) are usually presented. Our study aimed to assess the biodegradability of a mixture of two types of surfactants (anionic mixed with non-ionic) and also, effects caused by their presence of elevated concentrations to the activated sludge micro-organisms, within a batch experiment. We performed a biodegradability test (according Zahn-Wellens method) on 2 synthetic solutions with high concentrations of anionic surfactant �methyl dodecylbenzene sulfonate (15-25 mg/L) and non-ionic surfactant -4-nonylphenyl-polyethylene glycol (10 mg/L). The study established different percent of biodegradability (measured by COD decrease and surfactants removal) depending on initial concentrations of anionic and nonionic surfactants in the tested solutions. High surfactants concentrations modulated the activity and morphology of activated sludge, so its degradation efficiency of the organic substrate has decreased. Surfactant solutions resulting from biodegradability experiment have been tested for toxicity to planktonic crustaceans (Daphnia magna).
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Kitatsuji, Katsura, Hiroshi Miyata, and Tetsuro Fukase. "Lysis of filamentous bacteria by surfactants." Water Science and Technology 34, no. 5-6 (September 1, 1996): 145–53. http://dx.doi.org/10.2166/wst.1996.0546.
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A microbial substance that lyses filamentous bacteria was obtained. The substance also exhibited some properties of a bio-surfactant. Lysing of filamentous bacteria with synthetic surfactants was also examined. Several synthetic surfactants were found to be capable of lysing filamentous bacteria. Nonionic synthetic surfactants with an HLB of 11-15 were found to lyse type 1701 and type 021N in an activated sludge sampled from a sewage treatment plant. Use of the synthetic surfactant to lyse filamentous bacteria was also demonstrated in a continuous-feed aeration tank, and settleability of sludge was improved. The surfactants did not adversely effect floc-forming microorganisms as evidenced by the high rate of TOC removal. The results indicate that synthetic surfactants can be used to prevent filamentous bulking in the activated sludge process.
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Blus, Kazimierz, and Jadwiga Bemska. "EFFECT OF NONIONIC SURFACTANTS ON THE DYEING PROCESS OF CELLULOSE FIBRES WITH C.I. REACTIVE BLUE 217." AUTEX Research Journal 10, no. 3 (September 1, 2010): 64–68. http://dx.doi.org/10.1515/aut-2010-100302.
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Abstract This investigation addressed the role of nonionic surfactants on the sorption of C.I. Reactive Blue 217 by cellulose fibres, focusing on the influence of the surfactant concentration and type on the spectroscopic properties of this dye. It was found that surfactants in dyeing baths change the spectroscopic properties of dye solutions, resulting in the decomposition of aggregates and agglomerates to form a surfactant-dye complex. The surfactants in baths counteract the aggregating action of sodium chloride. The performed studies concerned the sorption kinetics of dye from dyeing baths containing various surfactants and their influence on the exhaustion coefficients of the dye. Changes in the electrokinetic potential of the dyeing bath were also examined. It was found that nonionic surfactants retard the sorption processes of dye from the dyeing bath, improving dyeing quality.
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Saifullin, Emil R., Polina O. Putintseva, Rustam N. Sagirov, Mikhail A. Varfolomeev, Chengdong Yuan, Roman S. Pavelyev, Sergey A. Nazarychev, et al. "Novel Nonylphenol Polyethoxylated Based Surfactants for Enhanced Oil Recovery for High-Mineralization Carbonate Reservoir." Energies 15, no. 3 (January 28, 2022): 961. http://dx.doi.org/10.3390/en15030961.
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Surfactant flooding can mobilize trapped oil and change the wettability of the rock to be more hydrophilic, which increases the oil recovery factor. However, the selection of surfactants is difficult in the case of high salinity conditions. In this work, we synthesized three novel anionic-nonionic surfactants based on widely used nonionic surfactant nonylphenol polyethoxylated (NPEO) and evaluated their efficiencies for enhanced oil recovery (EOR) in high salinity water (20% NaCl). The modified surfactants showed a decrease in interfacial tension (IFT) up to 10 times compared with the nonionic precursor. All surfactants had changed the wettability of rock to be more hydrophilic according to contact angle measurements. The effectiveness of surfactants was proved by spontaneous imbibition experiments, in which the synthesized surfactants showed a better displacement efficiency and increased oil production by 1.5–2 times. Filtration experiments showed an increase in oil recovery factor by 2–2.5 times in comparison with the nonionic NPEO. These promising results prove that the synthesis of new surfactants by modifying NPEO is successful and indicate that these novel surfactants have a great potential for EOR in high salinity reservoirs.
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De Ruiter, Hans, Andre J. M. Uffing, and Esther Meinen. "Influence of Surfactants and Ammonium Sulfate on Glyphosate Phytotoxicity to Quackgrass (Elytrigia repens)." Weed Technology 10, no. 4 (December 1996): 803–8. http://dx.doi.org/10.1017/s0890037x00040835.
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Field and greenhouse experiments were conducted to investigate the influence of two cationic alkylamine surfactants, three nonionic surfactants, and ammonium sulfate on the performance of glyphosate (isopropylamine salt) against quackgrass. In the field experiments, the reinfestation of quackgrass in the year after treatment was zero or negligible in all plots that received the recommended rate of glyphosate (1.44 kg ae/ha). At one-fourth of the recommended rate (0.36 kg ae/ha) the glyphosate-adjuvant combinations also severely inhibited the reinfestation of quackgrass. At the low herbicide rate and without ammonium sulfate, lipophilic surfactants were less effective than more hydrophilic surfactants. In the greenhouse experiments, the glyphosate doses giving 50% response (ED50) were determined. Ranking of the surfactants according to the ED50for glyphosate demonstrated a similar result to that observed in the field experiment. Ammonium sulfate added to the glyphosate-surfactant combinations reduced the ED50for glyphosate 5-fold. The field and greenhouse experiments demonstrated that two hydrophilic nonionic surfactants enhance glyphosate efficacy against quackgrass to the same extent as the hydrophilic cationic tallowamine surfactant. These two nonionic surfactants have a relatively low toxicity to non-target organisms and may substitute the more toxic alkylamine surfactants.
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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.
Full textAbstract:
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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Fardous, Jannatul, Faria Farzana Perveen, Md Ohidullah, AHM Saifuddin, and Sakina Sultana. "Effects of concentration and synergism on drug solubilising behaviour of PVP K 30 and PEG 6000." Jahangirnagar University Journal of Biological Sciences 3, no. 2 (June 19, 2016): 49–55. http://dx.doi.org/10.3329/jujbs.v3i2.28285.
Full textAbstract:
The effect of concentration and synergism on drug solubilising behaviour of PVP K 30 and PEG 6000 were investigated. Our results showed that amount of drug solubilised by the surfactants decreased as surfactant concentration was increased. Regarding the effect of synergism of the two surfactants on drug solubilisation our results failed to show synergism. The amount of drug solubilised by a single surfactant did not differ much when combination of surfactants were used.Jahangirnagar University J. Biol. Sci. 3(2): 49-55, 2014 (December)
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Davey, Tim W., and Alan R. Hayman. "Synthesis of ω-Hydroxy Quaternary Ammonium Bolaform Surfactants." Australian Journal of Chemistry 51, no. 7 (1998): 581. http://dx.doi.org/10.1071/c98001.
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Several members of a novel class of w-substituted asymmetric bolaform surfactants have been synthesized in order to investigate their surfactant and biological properties. The ω-hydroxy trialkylammonium and pyridinium surfactants have significant antimicrobial and antifungal activity relative to their conventional analogues. For conventional quaternary ammonium alkyl surfactants, increasing the hydrocarbon chain length causes a decrease in the surfactant monomer solubility and a corresponding decrease in the biological activity. No such trend is observed for the ω-hydroxy quaternary ammonium bromide series.
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Liu, Jianfei, and Weihong Chen. "Remediation of phenanthrene contaminated soils by nonionic–anionic surfactant washing coupled with activated carbon adsorption." Water Science and Technology 72, no. 9 (July 16, 2015): 1552–60. http://dx.doi.org/10.2166/wst.2015.357.
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Batch experiments were conducted to investigate the performance of nonionic–anionic mixed surfactants and their recovery through activated carbon. The solubilization capabilities of mixed surfactants toward phenanthrene (PHE) were reduced by addition of anionic surfactant to the mixed systems. Results showed that sorption of Triton X-100 (TX100) onto soil decreased with increasing mass fraction of sodium dodecyl sulfate (SDS) in the mixed surfactant solutions. Soil contaminated with PHE at 200 mg/kg was washed with different surfactant concentrations at various mass ratios of nonionic–anionic mixed surfactant. Experiments with low-concentrations of mixed surfactants revealed that removal efficiencies for PHE-contaminated soil close to the individual higher nonionic surfactant concentration can be achieved. Overall performance considering both soil washing and surfactant recovery steps is apposite when an TX100:SDS mass ratio of 8:2 at 3 g/L is used.
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Murtaza, Mobeen, Hafiz Mudaser Ahmad, Muhammad Shahzad Kamal, Syed Muhammad Shakil Hussain, Mohamed Mahmoud, and Shirish Patil. "Evaluation of Clay Hydration and Swelling Inhibition Using Quaternary Ammonium Dicationic Surfactant with Phenyl Linker." Molecules 25, no. 18 (September 22, 2020): 4333. http://dx.doi.org/10.3390/molecules25184333.
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Water-based drilling fluids are extensively used for drilling oil and gas wells. However, water-based muds cause clay swelling, which severely affects the stability of wellbore. Due to two adsorption positions, it is expected that cationic gemini surfactants can reduce the clay swelling. In this work, quaternary ammonium dicationic gemini surfactants containing phenyl linkers and different counterions (Cl− and Br−) were synthesized, and the effect of variation in counterions on swelling and hydration properties of shales was studied. Numerous water-based drilling fluid formulations were prepared with different concentrations of surfactants to study the swelling inhibition capacity of surfactants. The performance of surfactant-containing drilling muds was evaluated by comparing them with base drilling mud, and sodium silicate drilling mud. Various experimental techniques were employed to study drilling mud characteristics such as rheology and filtration. The inhibition properties of drilling mud formulations were determined by linear swelling experiment, capillary suction time test, particle size distribution measurement, wettability measurements, and X-ray Diffraction (XRD). Experimental results showed that surfactant-based formulation containing bromide counterion exhibited superior rheological properties as compared to other investigated formulations. The filtration test showed that the gemini surfactant with chloride counterion had higher filtrate loss compared to all other formulations. The bentonite swelling was significantly reduced with increasing the concentration of dicationic surfactants as inhibitors, and maximum reduction in the linear swelling rate was observed by using a formulation containing surfactant with chloride counterion. The lowest capillary suction timer (CST) was obtained in the formulation containing surfactant with chloride counterion as less CST indicated the enhanced inhibition capacity. The particle size measurement showed that average bentonite particle size increased upon the addition of surfactants depicting the inhibition capacity. The increase in basal spacing obtained from XRD analysis showed the intercalation of gemini surfactants in interlayers of bentonite. The contact angle measurements were performed to study the wettability of the bentonite film surface, and the results showed that hydrophobicity increased by incorporating the surfactants to the drilling fluid.
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Miao, Zong Cheng, Yi Wei Wang, Xing Zhang, Lei Zhang, Zhi Xue Wang, and Yuan Yuan Li. "Antimicrobial Study of Symmetrical Gemini Cationic Surfactant Based on N-Hexadecyldimethylamine." Key Engineering Materials 575-576 (September 2013): 245–48. http://dx.doi.org/10.4028/www.scientific.net/kem.575-576.245.
Full textAbstract:
Gemini surfactants generally exhibit superior properties to those of their single-chain analogues with a similar chain length and head group, especially for gemini cationic surfactants. Gemini cationic surfactants have recently attracted considerable attention due to the increasing microbial resistance to common quaternary ammonium compounds. A novel symmetrical gemini cationic surfactant based onn-hexadecyldimethylamine was synthesized through epichlorohydrin andn-hexadecyldimethylamine as rude materials. The chemical structure of the product was confirmed using1H-NMR and FT-IR. The minimum inhibitory concentration of the surfactant toescherichia colirises to 100 ppm, and a higher concentration surely contributes to increase its effect, butstaphylococcus aureusis immune to this surfactant.