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1
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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Olkowska, Ewa, Marek Ruman, and Żaneta Polkowska. "Occurrence of Surface Active Agents in the Environment." Journal of Analytical Methods in Chemistry 2014 (2014): 1–15. http://dx.doi.org/10.1155/2014/769708.
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Due to the specific structure of surfactants molecules they are applied in different areas of human activity (industry, household). After using and discharging from wastewater treatment plants as effluent stream, surface active agents (SAAs) are emitted to various elements of the environment (atmosphere, waters, and solid phases), where they can undergo numerous physic-chemical processes (e.g., sorption, degradation) and freely migrate. Additionally, SAAs present in the environment can be accumulated in living organisms (bioaccumulation), what can have a negative effect on biotic elements of ecosystems (e.g., toxicity, disturbance of endocrine equilibrium). They also cause increaseing solubility of organic pollutants in aqueous phase, their migration, and accumulation in different environmental compartments. Moreover, surfactants found in aerosols can affect formation and development of clouds, which is associated with cooling effect in the atmosphere and climate changes. The environmental fate of SAAs is still unknown and recognition of this problem will contribute to protection of living organisms as well as preservation of quality and balance of various ecosystems. This work contains basic information about surfactants and overview of pollution of different ecosystems caused by them (their classification and properties, areas of use, their presence, and behavior in the environment).
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Anestopoulos, Ioannis, Despina-Evgenia Kiousi, Ariel Klavaris, Monica Maijo, Annabel Serpico, Alba Suarez, Guiomar Sanchez, et al. "Marine-Derived Surface Active Agents: Health-Promoting Properties and Blue Biotechnology-Based Applications." Biomolecules 10, no. 6 (June 9, 2020): 885. http://dx.doi.org/10.3390/biom10060885.
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Surface active agents are characterized for their capacity to adsorb to fluid and solid-water interfaces. They can be classified as surfactants and emulsifiers based on their molecular weight (MW) and properties. Over the years, the chemical surfactant industry has been rapidly increasing to meet consumer demands. Consequently, such a boost has led to the search for more sustainable and biodegradable alternatives, as chemical surfactants are non-biodegradable, thus causing an adverse effect on the environment. To these ends, many microbial and/or marine-derived molecules have been shown to possess various biological properties that could allow manufacturers to make additional health-promoting claims for their products. Our aim, in this review article, is to provide up to date information of critical health-promoting properties of these molecules and their use in blue-based biotechnology (i.e., biotechnology using aquatic organisms) with a focus on food, cosmetic and pharmaceutical/biomedical applications.
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Abouzeid, Fatma M. "Study of Steel Electro-dissolution Behavior in Presence of Some Surfactants. Electrochemical Investigation and Surface Active Properties Determination." Revista de Chimie 72, no. 3 (July 29, 2021): 179–97. http://dx.doi.org/10.37358/rc.21.3.8447.
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Steel electro-dissolution performance was investigated in orthophosphoric acid in the presence of N-oleyl 1.3 diaminopropane, Benzalkounuim chloride, Soduim lauryl sulphate and Di-Isononyl phthalate as a surfactant using potentiodynamic polarization measurements. The retardation performance of these surfactants was examined. The surfactant surface active parameters were estimated based on surface tension measurements. The parameters calculated comprise the critical micelle concentration (CMC), maximum surface excess (Гmax), minimum surface area (Amin) and effectiveness (πCMC). The micellization thermodynamic parameters (ΔGmic, ΔSmic) for the estimated surfactants were also computed. Results obtained from surface active properties are comparable with those gained from galvanostatic polarization measurements. Temperature influence on the steel dissolution performance was examined at 25 to 40oC range. Steel kinetic study in orthophosphoric acid- free solution and orthophosphoric acid containing surfactant was also examined. The dissolution kinetic and activated parameters were computed. Results based on microscopy measurement indicate that, addition of new four surfactants, resulting in the solution shows potential, a discrete progress in the metal texture was monitored. Improvement produced in electro-polishing bath by the investigated SAS that owing to the adsorption of such surface active agents on the anode surface.
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Cui, Wei Lin, Wu Ju Xu, and Ling Jian Song. "The Influence of Different Kinds of Surfactants on Rheology in Polymer/Surfactant Complex Flooding." Applied Mechanics and Materials 437 (October 2013): 1089–92. http://dx.doi.org/10.4028/www.scientific.net/amm.437.1089.
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Because of alkaline declining the sweep efficiency, causing scale formation problem in the reservoir and the well bottom and the tubular pipes, so polymer/surfactant compound flooding technology is the emphasis in the research of enhanced recovery. So the articles study the regulation of different kinds of surface active agents at different temperature by MARS Rheometer. The testing result showed that the variation of viscocity under the interaction between the surface active agent and association polymer according to “three stage” model .The linear viscoelastic region of stress decrease when different surface active agents are put into polymer liquor, and the higher frequency, the better elasticity of polymer liquor. The hydrophobic association between the surface active agents and polymer decrease with a higher temperature, but the ionic surfactant is aggravate. The systematic study of binary system rheology can contribute to correctly understand and apply binary system.
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Olkowska, Ewa, Marek Ruman, Magdalena Drąg-Śmigalska, and Żaneta Polkowska. "Selected anionic and cationic surface active agents: case study on the Kłodnica sediments." Limnological Review 17, no. 1 (March 1, 2017): 11–21. http://dx.doi.org/10.1515/limre-2017-0002.
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AbstractSurface active agents (surfactants) are a group of chemical compounds, which are used as ingredients of detergents, cleaning products, cosmetics and functional products. After use, wastes containing surfactants or their degradation products are discharged to wastewater treatment plants or directly into surface waters. Due to their specific properties of SAAs, compounds are able to migrate between different environmental compartments such as soil, sediment, water or even living organisms and accumulate there. Surfactants can have a harmful effect on living organisms. They can connect with bioactive molecules and modify their function. Additionally, they have the ability to migrate into cells and cause their damage or death. For these reasons investigation of individual surfactants should be conducted. The presented research has been undertaken to obtain information about SAA contamination of sediment from the River Kłodnica catchment caused by selected anionic (linear alkylbenzene sulfonates (LAS C10-C13)) and cationic (alkylbenzyldimethylammonium (BDMA-C12-16), alkyl trimethyl ammonium (DTMA), hexadecyl piridinium chloride (HP) chlorides) surfactants. This river flows through an area of the Upper Silesia Industrial Region where various companies and other institutions (e.g. coal mining, power plants, metallurgy, hospitals) are located. To determine their concentration the following analytical tools have been applied: accelerated solvent extraction– solid phase extraction – high performance liquid chromatography – UV-Vis (anionic SAAs) and conductivity (cationic SAAs) detectors. In all sediments anionic SAAs have been detected. The concentrations of HTMA and BDMA-C16in tested samples were higher than other cationic analytes. Generally, levels of surfactants with longer alkyl chains were higher and this observation can confirm their higher susceptibility to sorption on solid surfaces.
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Kawasaki, Hideya. "Surfactant-free solution-based synthesis of metallic nanoparticles toward efficient use of the nanoparticles’ surfaces and their application in catalysis and chemo-/biosensing." Nanotechnology Reviews 2, no. 1 (February 1, 2013): 5–25. http://dx.doi.org/10.1515/ntrev-2012-0079.
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AbstractThe choice of stabilizer and the stabilizer-to-precursor ions molar ratio during metal nanoparticle synthesis are important for controlling the shape, size, and dispersion stability of the nanoparticles. However, the active sites on the nanoparticles surfaces may be blocked by the stabilizing agents used, resulting in a less-than-effective utilization of the surfaces. In this review, various surfactant-free solution-based methods of synthesizing metal nanoparticles are described, along with the applications of such nanoparticles in catalysis and sensing. “Surfactant-free” synthesis does not imply truly bare metal nanoparticles synthesis but implies one where the metal nanoparticles are prepared in the absence of additional stabilizing agents such as thiolate and phosphine compounds, surfactants, and polymers. These metal nanoparticles are stabilized by the solvents or the simple ions of the reducing agents or low-molecular-weight salts used. Surfactant-free synthesis of metal nanoparticles via photochemical-, ultrasonochemical-, and laser ablation-mediated synthesis methods is also described. Because of the effective utilization of their surfaces, metal nanoparticles prepared without surfactants, polymers, templates, or seeds are expected to exhibit high performance when used in catalysis (synthetic catalysis and electrocatalysis) and sensing (surface-enhanced Raman scattering (SERS)), surface-assisted laser desorption/ionization-mass spectrometry (SALDI-MS)).
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Chatterjee, M., M. K. Naskar, B. Siladitya, and D. Ganguli. "Role of organic solvents and surface-active agents in the sol-emulsion-gel synthesis of spherical alumina powders." Journal of Materials Research 15, no. 1 (January 2000): 176–85. http://dx.doi.org/10.1557/jmr.2000.0029.
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Spherical alumina particles were prepared following the sol-emulsion-gel method by systematic variation of (i) the concentration of the surfactant Span 80 above or below the critical micelle concentration (CMC) in different organic solvents and (ii) hydrophilic–lipophilic balance (HLB) of different surfactants in cyclohexane. The experimentally determined CMC of Span 80 was found to increase with increasing dielectric constant of the organic solvent, influencing the sol droplet and alumina particle size. With an increase in the HLB value of the surfactants, the tendency of monodispersed sphere formation among the particles increased with a decrease in the size distribution and average particle size (d50).
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Kurrey, Ramsingh, Anushree Saha, and Manas Kanti Deb. "Distribution of Some Selected Surface Active Agents (SAAs) in the Aquatic and Global Environment with Their Toxic Impact: A Comprehensive Review." Journal of Ravishankar University (PART-B) 33, no. 1 (July 4, 2020): 31–46. http://dx.doi.org/10.52228/jrub.2020-33-1-6.
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Surface active agents (SAAs) are a class of compounds, which find various applications in different fields of human activities. Surfactants are generally amphiphilic molecules, which are strongly adsorbed at interfaces between the phases. Surfactants windily used as detergency, emulsion, stabilizing and dispersing agents have led to the discharge of highly contaminated wastewaters in aquatic environment. Once reached in the various compartments of the environment such as rivers, lakes, soils, and sediments, surfactants can undergo aerobic or anaerobic degradation. Concentrations of surfactants in wastewaters, river waters, and sewage waters can range milligrams in maximum cases, while it reaches several grams in sludge, soil and sediments in environments. The environmental facts of SAAs and concentration in surface waters, soils or sediments are reviewed in details. This review provides information on levels of surface-active agents in various environmental samples including soil, sediments, sewage wastewater, river wastewater and aerosols.
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Cichoń, Ewelina, Bartosz Mielan, Elżbieta Pamuła, Anna Ślósarczyk, and Aneta Zima. "Development of highly porous calcium phosphate bone cements applying nonionic surface active agents." RSC Advances 11, no. 39 (2021): 23908–21. http://dx.doi.org/10.1039/d1ra04266a.
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Abaturov, А. Е. "Bacterial surfactants as agents with antibiofilm activity." CHILD`S HEALTH 16, no. 1 (April 6, 2021): 94–104. http://dx.doi.org/10.22141/2224-0551.16.1.2021.226463.
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Biosuragents are a heterogeneous group of biological surface-active amphiphilic compounds. The producers of biosurfactants are various microorganisms: bacteria and fungi. The class of biosurfactants consists of two groups: low molecular weight and high molecular weight compounds. Representatives of low molecular weight compounds are lipopeptides, glycolipids, fatty acids, phospholipids that reduce surface and interfacial tension, and high molecular weight compounds are polymer and dispersed biosurfactants, which are emulsion stabilizers. The most studied biosurfactants with the potential of drugs are lipopeptides and glycolipids. A subgroup of lipopeptides are polymyxins, pseudo-factins, putisolvins, surfactin, fengycin and others; and glycolipids — rhamnolipids, trehalose, sophorose, cellobiose, mannosileritritol lipids, and others. Biosurfactants play a key role in the life of biofilms: they regulate the adhesion of bacteria and biofilm matrix, support the functioning of the matrix channels, providing the nutrient needs of bacteria. It has also been shown that biosurfactants are involved in the formation and dispersion of formed biofilms. These substances, directly reacting with the components of the matrix, induce degradation of the biofilm. Biosurfing agents, possessing antimicrobial, antifungal and antiviral, and antitumor properties, are a promising class of compounds that, possessing a combination of antibacterial and antibiofilm action, open up new perspectives in the treatment of recurrent chronic infectious diseases. It is believed that surface-active compounds, both representatives of lipopeptides and glycolipids, can be the molecular basis for the development of drugs that will enhance the effectiveness of antibiotic therapy for problem infections, especially those caused by antibiotic-resistant strains.
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Parsi, Kurosh. "Interaction of detergent sclerosants with cell membranes." Phlebology: The Journal of Venous Disease 30, no. 5 (May 14, 2014): 306–15. http://dx.doi.org/10.1177/0268355514534648.
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Commonly used detergent sclerosants including sodium tetradecyl sulphate (STS) and polidocanol (POL) are clinically used to induce endovascular fibrosis and vessel occlusion. They achieve this by lysing the endothelial lining of target vessels. These agents are surface active (surfactant) molecules that interfere with cell membranes. Surfactants have a striking similarity to the phospholipid molecules of the membrane lipid bilayer. By adsorbing at the cell membrane, surfactants disrupt the normal architecture of the lipid bilayer and reduce the surface tension. The outcome of this interaction is concentration dependent. At high enough concentrations, surfactants solubilise cell membranes resulting in cell lysis. At lower concentrations, these agents can induce a procoagulant negatively charged surface on the external aspect of the cell membrane. The interaction is also influenced by the ionic charge, molecular structure, pH and the chemical nature of the diluent (e.g. saline vs. water). The ionic charge of the surfactant molecule can influence the effect on plasma proteins and the protein contents of cell membranes. STS, an anionic detergent, denatures the tertiary complex of most proteins and in particular the clinically relevant clotting factors. By contrast, POL has no effect on proteins due to its non-ionic structure. These agents therefore exhibit remarkable differences in their interaction with lipid membranes, target cells and circulating proteins with potential implications in a range of clinical applications.
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Kaczorowski, Marcin, and Gabriel Rokicki. "Reactive surfactants – chemistry and applications. Part II. Surface - active initiators (inisurfs) and surface - active transfer agents (transurfs)." Polimery 62 (February 2017): 79–85. http://dx.doi.org/10.14314/polimery.2017.079.
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Shapovalov, A. N., R. R. Dema, and S. P. Nefedyev. "Efficiency Improvement of Sintering as a Result of Surface-Active Substance Use in Pelletizing at the JSC "Ural Steel"." Materials Science Forum 870 (September 2016): 507–15. http://dx.doi.org/10.4028/www.scientific.net/msf.870.507.
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A set of pilot experiments to improve pelletizing through the use of the sinter charge humidification of water-soluble organic surface-active agents (surfactants) has been performed in the sintering plant JSC "Ural Steel". It has been found that the surfactant use provides an improved granularity of the sinter charge and increases its gas permeability during sintering that ensures a better technology and quality. The maximum efficiency from the surfactant use is manifested in the area of the optimum moisture content of the sinter charge (7 – 8 %) at a flow rate of the experimental binder 1.2-1.6 l/h (surfactant concentration in an aqueous solution is 0.3 – 0.4 ml/l).
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Taba, Paulina, Russell F. Howe, and Graine Moran. "FTIR AND NMR STUDIES OF ADSORBED CETHYLTRIMETHYLAMMONIUM CHLORIDE IN MCM-41 MATERIALS." Indonesian Journal of Chemistry 8, no. 1 (June 17, 2010): 1–6. http://dx.doi.org/10.22146/ijc.21639.
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The high use of surface-active agents (surfactants) by industry and households today leads to environmental pollution, therefore treatments are required to remove such substances from the environment. One of the important and widely used methods for removal of substances from solution is adsorption. In this research, MCM-41 and its modified product of MCM41-TMCS were used to adsorb cationic surfactants, cethyltrimethylammonium chloride, CTAC. FTIR and NMR methods were used to study the interaction between the surfactants and the adsorbents. MCM-41 was synthesized hydrothermally at 100 oC and its modification was conducted by silylation of MCM-41 with trimethylchloro silane (MCM41-TMCS). Both unmodified and modified MCM-41 can adsorb the surfactant. The interaction of CTAC with MCM-41 was mostly the electrostatic interaction between the electropositive end of the surfactant and MCM-41, whereas in modified MCM-41 hydrophobic interactions become more dominant. These hydrophobic interactions appear however to involve the methyl groups on the head group of the surfactant interacting with the modified surface. Keywords: FTIR, NMR, adsorbed CTAC, MCM-41 materials
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Wybieralska, Katarzyna, and Anna Wajda. "Removal of Organic Dyes from Aqueous Solutions with Surfactant-Modified Magnetic Nanoparticles." Polish Journal of Chemical Technology 16, no. 2 (June 26, 2014): 27–30. http://dx.doi.org/10.2478/pjct-2014-0025.
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Abstract The paper presents the results of studies on the possibility of using magnetic nanoparticles modified with selected hydrophobic surfactants for model post-production water purification. Colloidal solutions of iron hydroxide (III) and iron oxide (II and III) were obtained and their particles were subjected to surface modification using surfactants. Thus obtained magnetic fluids were used as active agents in the process of removing selected organic dyes from their aqueous solutions. The effectiveness of the modified compounds was analysed using spectrophotometric methods. It has been shown that the effectiveness of the process depends on the type of surfactant used to modify selected magnetic nanoparticles.
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Lepo, Joe Eugene, M. Patricia Hancock, Candy L. Zuleger, Katharine Roupp-Edwards, Tim Reilly, and David E. Fritz. "EFFECTIVENESS AND SAFETY OF BIOSURFACTANTS AS AGENTS OF OIL SPILL RESPONSE." International Oil Spill Conference Proceedings 1997, no. 1 (April 1, 1997): 687–96. http://dx.doi.org/10.7901/2169-3358-1997-1-687.
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ABSTRACT Biosurfactants play an important role in facilitating the natural biodegradation of petroleum hydrocarbons. In order to characterize the biosurfactant-producing potential of environments at risk of anthropogenic oil contamination, we collected a number of distinct marine bacteria that emulsified crude oil from relatively pristine and from polluted areas. The bacteria belonged to diverse taxonomic groups and varied widely in oil-emulsifying capability, surface tension reduction of culture media, and hydrophobicity. We used laboratory assays that directly evaluated biosurfactant preparations from these and other strains for use as cleaning agents for oiled surfaces. The subjects of the study were the oil emulsification capabilities and the surface-active characteristics of the biosurfactants, which were compared to those of selected synthetic surfactants. We also examined the ability of different biosurfactants and synthetic surfactants to wash oil from porcelain tiles. To assess the efficacy of biosurfactants as enhancers of oil biodegradation, we applied preparations of biosurfactants along with our standard mix of hydrocarbon-degrading bacteria in either shake-flask experiments or in sandy-beach microcosms. In general, surfactants of either class (biosurfactants or synthetic surfactants) performed similarly in all of these experiments. Although some biosurfactants show merit as cleaning agents, the current production technology may not make their use cost-effective. Safety issues relating to biosurfactants were addressed by examining their toxicity and their biodegradability (and thus persistence in the environment) relative to selected synthetic surfactants. Standard toxicology bioassays were used: (1) the mysid, 7-day chronic estimator, and (2) the inland silverside 7-day chronic estimator. The biodegradability of biosurfactants and synthetic surfactants was compared by measuring the increased biochemical oxygen demand generated by the surfactants in raw seawater. Some biosurfactants were indeed highly biodegradable; however, we found no tight association of biodegradability to either class of surfactants. These results suggest that the environmental safety of surfactants is best evaluated on the basis of toxicity and degradability data for specific cases.
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Abdellattif, Magda H., A. M. F. Eissa, and H. M. Mohamed. "Synthesis of Anionic Surface Active Agents Containing Heterocyclic Moiety From Long Chain Fatty Alcohols." JOURNAL OF ADVANCES IN CHEMISTRY 13, no. 10 (March 4, 2017): 5935–43. http://dx.doi.org/10.24297/jac.v13i10.5819.
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A series of novel groups of anionic surface active agent were synthesized. Synthesis of these surfactants via the reaction of long chain fatty alcohols (octyl, decyl and dodecyl) with maleic anhydride to give monoester. The monoester chloride reacted with amino derivatives of heterocyclic rings followed by addition of NaHSO3 .The surface tension, interfacial tension; Kraft point, emulsifying and wetting power were evaluated. Stability to hydrolysis, biodegradability and biological activities were measured. A comparison studies between the chemical structures and the results were done.
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Adilina, Indri Badria, Egi Agustian, Yenny Meliana, and Anny Sulaswatty. "SYNTHESIS AND PROPERTIES OF ETHOXYLATED GLYCEROL MONOOLEATE AS PALM OIL BASED NONIONIC SURFACTANTS." Jurnal Kimia Terapan Indonesia 17, no. 1 (June 10, 2015): 49–55. http://dx.doi.org/10.14203/jkti.v17i1.22.
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Palm oil based nonionic surfactants were synthesized by reacting glycerol monooleate with ethylene oxide at 80 ºC in the prescence of an alkaline catalyst. Purification of the products was conducted by use of acetic acid and black carbon which gave ethoxylated products (EGMO) with a higher level of viscocity and greater solubility in water. Physical and chemical properties of the product such as surface activity, cloud point, acid value, ester value, hydroxyl value, and hydrophilic-lipophilic balance was also determined and results varied depending on the reagent molar ratio. The synthesized EGMO were soluble in water and therefore show potential use as surface active agents in personal care and cosmetic products.Keywords: nonionic surfactant, ethoxylation, glycerol monooleate, palm oil
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Juwarkar, Asha, P. Sudhakar Babu, Kirti Mishra, and Megha Deshpande. "APPLICATION OF BIOSURFACTANT IN OIL SPILL MANAGEMENT." International Oil Spill Conference Proceedings 1993, no. 1 (March 1, 1993): 503–4. http://dx.doi.org/10.7901/2169-3358-1993-1-503.
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ABSTRACT Surfactants are surface active agents which reduce surface tension and interfacial tension between two immiscible phases and help in emulsification. Toxicity, nonbiodegradability, and limited structural types of chemical surfactants have initiated the need for effective substitutes. Biosurfactants, which are synthesized by specific microbial cultures, have surface active properties comparable to chemical surfactants. They are compounds that can help in oil spill cleanup operations without presenting the problems posed by chemical surfactants. Two bacterial cultures were isolated from oil-contaminated soil and were used for biosurfactant production. The biosurfactants produced by the Bacillus licheniformis, BS1, and Pseudomonas aeruginosa, BS2, in mineral media containing glucose as the carbon source belong to the class of lipoprotein and glycolipid, respectively. They were found to reduce the surface and interfacial tension of water and water-hexadecane systems from 72 dynes/cm and 40 dynes/cm to 28 to 30 dynes/cm and 1 to 3 dynes/cm, respectively. These results were comparable with chemical surfactants with respect to surface tension reduction (Slic Gone 34 dynes/cm and Castrol 30 dynes/cm). The low interfacial tension allows the formation of stable emulsion. The two cultures were grown on different substrates, namely, glucose, mannitol, glycerol, hexadecane, oily sludge, and crude oil. Emulsion formation of hexadecane in water was tested with the cell-free broth containing biosurfactant from the respective substrate broths. Emulsions of 56 percent stability to 100 percent stability were obtained from these biosurfactant-containing broths. Both biosurfactants were able to emulsify crude oil. A surfactant's ability to form a stable emulsion is the first step in oil spill cleanup. The emulsified oil can then be acted upon very easily by the microorganisms under study. Therefore, the biosurfactants produced by the microorganisms under study offer a good potential for use in oil spill cleanup.
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Fletcher, P. D. I. "Book ReviewA directory of surface active agents available in Europe, 3rd edition, Surfactants Europa." Journal of Chemical Technology & Biotechnology 67, no. 2 (October 1996): 214. http://dx.doi.org/10.1002/(sici)1097-4660(199610)67:2<214::aid-jctb4555>3.0.co;2-0.
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Lugovaya, I. S., S. V. Pozyabin, and T. O. Azarnova. "Case of acute esophagogastroectasia in a cat." Veterinariya, Zootekhniya i Biotekhnologiya 1, no. 7 (2021): 13–20. http://dx.doi.org/10.36871/vet.zoo.bio.202107002.
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Cases of poisoning of domestic animals with household chemicals, in particular, chlorine-containing and surface-active substances (surfactants) are not uncommon, however, the changes occurring in the body under the action of this group of substances are insufficiently described. This article describes a case of acute gastric dilatation and megaesophagus in a cat, presumably against the background of poisoning with surfactants and chlorine-containing agents, including pathogenetic X-ray diagnostics and blood tests.
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Titta, A., M. Le Merrer, F. Detcheverry, P. D. M. Spelt, and A. L. Biance. "Level-set simulations of a 2D topological rearrangement in a bubble assembly: effects of surfactant properties." Journal of Fluid Mechanics 838 (January 12, 2018): 222–47. http://dx.doi.org/10.1017/jfm.2017.887.
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A liquid foam is a dispersion of gas bubbles in a liquid matrix containing surface-active agents. Its flow involves the relative motion of bubbles, which switch neighbours during a so-called topological rearrangement of type 1 (T1). The dynamics of T1 events, as well as foam rheology, have been extensively studied, and experimental results point to the key role played by surfactants in these processes. However, the complex and multiscale nature of the system has so far impeded a complete understanding of the mechanisms involved. In this work, we investigate numerically the effect of surfactants on the rheological response of a 2D sheared bubble cluster. To do so, a level-set method previously employed for simulation of two-phase flow has been extended to include the effects of surfactants. The dynamical processes of the surfactants – diffusion in the liquid and along the interface, adsorption/desorption at the interface – and their coupling with the flow – surfactant advection and Laplace and Marangoni stresses at the interface – are all taken into account explicitly. Through a systematic study of the Biot, capillary and Péclet numbers that characterise the surfactant properties in the simulation, we find that the presence of surfactants can affect the liquid/gas hydrodynamic boundary condition (from a rigid-like situation to a mobile one), which modifies the nature of the flow in the volume from a purely extensional situation to a shear. Furthermore, the work done by surface tension (the 2D analogue of the work by pressure forces), resulting from surfactant and interface dynamics, can be interpreted as an effective dissipation, which reaches a maximum for a Péclet number of order unity. Our results, obtained at high liquid fraction, should provide a reference point, with which experiments and models of T1 dynamics and foam rheology can be compared.
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Faísca, Francisco, Luis Filipe, Zeljko Petrovski, Miguel M. Santos, Sandra Gago, and Luís C. Branco. "Ionic Systems and Nanomaterials as Antiseptic and Disinfectant Agents for Surface Applications: A Review." Surfaces 4, no. 2 (June 7, 2021): 169–90. http://dx.doi.org/10.3390/surfaces4020016.
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Antiseptics and disinfectants are extensively used for a variety of topical and hard-surface applications. A wide variety of biocides as active chemical agents is found in these products, including alcohols, phenols, iodine, and chlorine. Many of these active agents demonstrate broad-spectrum antimicrobial activity; however, the mode of action of these agents is not well-documented. This review is focused on several examples of ionic systems based on ionic surfactants and ionic liquids as well as nanomaterials and nanoparticles acting as antiseptics and disinfectants for surfaces. It is important to note that many of these biocides may be used singly or in combination in a variety of products, which vary considerably in activity against microorganisms. Antimicrobial activity can be influenced by several factors such as formulation effects, presence of an organic load, synergy, temperature, dilution, and test method. The most promissory compounds based on ionic systems and nanomaterials published in mainly the last decade is chronologically reported in this review.
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Canevari, Gerard P. "BASIC STUDY REVEALS HOW DIFFERENT CRUDE OILS INFLUENCE DISPERSANT PERFORMANCE." International Oil Spill Conference Proceedings 1987, no. 1 (April 1, 1987): 293–96. http://dx.doi.org/10.7901/2169-3358-1987-1-293.
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ABSTRACT Previous research has shown that crude oils contain various amounts of indigenous surface active agents that stabilize water-in-oil emulsions. It is also known that crude oils stabilize such emulsions to different extents. One aspect of the study was to investigate the relationship between the emulsion forming tendency of the various crude oils and the level of performance of a chemical dispersant on the particular crude oil. The results of the extensive laboratory test program indicated that dispersant effectiveness is a function of both dispersant type and the specific crude oil. However, there is no apparent correlation between the degree of emulsion-forming tendency of the crude oil, which is a function of the indigenous surfactant content, and effectiveness. A “clean” hydrocarbon, tetradecane (C14), was also tested in order to evaluate the absence of any indigenous surfactants on performance. It was found that tetradecane exhibited a higher level of effectiveness compared to the crude oils for each of the dispersants tested. In essence, the indigenous surfactants in the crude oil, in every instance, reduce dispersant effectiveness but to an unpredictable level. This is probably due to the fact that these agents present in crude oil promote a water-in-oil emulsion. Since the chemical dispersant is formulated to produce an oil-in-water dispersion, the interference of these crude oil surfactants is apparent. Hence, tetradecane would be an ideal test oil since the degree of dispersion of tetradecane by a particular dispersant represents the maximum dispersion effectiveness for that product. In order to establish more definitively the role of the indigenous surfactants, this surfactant phase was successfully separated from nine crude oils representative of different emulsion forming tendencies. It was found that the amount of surfactant residue extracted from the crude oil did correlate with the emulsion forming tendency of the crude oil. Finally, the above separated surfactant residue was added to tetradecane at the same concentrations as in the respective crude oil. As expected, in every instance, the surfactant residue decreased dispersant performance compared to “pure” tetradecane.
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Makarewicz, Edwin, and Krzysztof Jan´czak. "The influence of organic diluents and solvents on the stability of PVC plastisol water dispersions." Polish Journal of Chemical Technology 9, no. 1 (January 1, 2007): 43–50. http://dx.doi.org/10.2478/v10026-007-0011-1.
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The influence of organic diluents and solvents on the stability of PVC plastisol water dispersions The work presents the research, the aim of which is to specify the influence of organic diluents and solvents such as xylene, toluene, n-butyl acetate and butanol as well as cyclohexanone on the stability of water dispersions of the PVC plastisol containing various surface-active agents (SAA). The applied surfactants were characterised by a specific ethoxylation number, molecular mass, the Hildebrand parameter, hydrophilic-hydrophobic balance, surface activity, the limiting viscosity number, the Haller interaction constant, the limiting equivalent conductivity and the Kohlrausch-Onsager equation "b" constant. Basing on the molar refraction and the Hildebrand parameter, the interactions between the plastisol constituents and the constituents of water dispersions of the PVC plastisol were established. The sedimentation tests on the PVC plastisol water dispersions stabilized by various surface-active agents with an organic diluent or solvent added indicated that the addition resulted in the dispergation yield, a reduction in the PVC plastisol molecular size in water dispersion and the increased Huggins interaction constant, showing both surface lyophilisation and higher adsorption of surface-active agents.
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Tantawy, Ahmed H., Hany I. Mohamed, Ahmed A. Khalil, Kaouser A. Hebash, and Mahmoud Z. Basyouni. "Novel bioactive imidazole-containing polymeric surfactants as petroleum-collecting and dispersing agents: Synthesis and surface-active properties." Journal of Molecular Liquids 236 (June 2017): 376–84. http://dx.doi.org/10.1016/j.molliq.2017.04.040.
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Pirog, T. P., L. V. Kliuchka, T. A. Shevchuk, and G. O. Iutynska. "Destruction of Biofilms on Silicone Tubes under the Action of a Mixture of Nocardia vaccinii IMV B-7405 Surfactants with other Biocides." Mikrobiolohichnyi Zhurnal 83, no. 4 (August 17, 2021): 43–53. http://dx.doi.org/10.15407/microbiolj83.04.043.
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The formation of pathogenic microorganisms biofilms on the central venous catheter is the cause of catheter-associated infections. An alternative method of combating biofilms is the use of “antibacterial” and “antifungal” locks, which are solutions of antibiotics or antifungal drugs in a mixture with other natural compounds, which can be microbial surface-active substances (surfactants) or essential oils. Aim. To investigate the role of Nocardia vaccinii IMV B-7405 surfactants mixture with other antimicrobial compounds in the destruction of biofilm on silicone tubes. Methods. N. vaccinii IMV B-7405 was grown in medium containing as carbon source purified glycerol and waste from biodiesel production, refined sunflower oil, oil after frying French-fried potatoes, Potato wedges and meat. The surfactants were extracted from supernatant of cultural liquid by modified Folch mixture. 2 mL of surfactant solutions, antifungal drugs (nystatin, fluconazole) or tea tree essential oil of the same concentration (5–640 μg/mL) were added to test tubes with silicone tubes (with pre-formed biofilm from test culture). To study the synergistic effect of the biofilms destruction, a mixture of surfactant solutions and antifungal substances (or essential oil) of the same concentration in a ratio of 1:1 (1 mL of each solution) was added to the test tubes. Sterile tap water (2 mL) was added to control test tubes instead of surfactants preparations, antifungal substances or essential oil. The degree of biofilm destruction (%) was determined as the difference between the adhesion of cells on the inner side of silicone tubes, untreated and treated with surfactants, antifungal drugs, essential oil, or their mixture. Results. It was found that surfactants synthesized by N. vaccinii IMV B-7405 on all substrates showed synergism of yeast and bacterial biofilms destruction on silicone tubes in a mixture with nystatin, fluconazole and tea essential oil in the whole range of investigated concentrations (5–640 μg/mL), but the highest effect was achieved at a concentration of 20–40 μg/mL. Thus, the degree of Candida albicans D-6, Candida utilis BVS-65 and Candida tropicalis PE-2 biofilms destruction under the action of a mixture of surfactants synthesized on waste from the biodiesel production and waste oil, with antifungal drugs was 45.8–71.8% and was higher than with only surfactants (21.2–41.6%), nystatin (22.4–24.1%) or fluconazole (28.1–31.3%). The destruction of Candida genus yeast biofilms under the action of surfactants synthesized on oil-containing substrates in a mixture with both nystatin and fluconazole reached 50.1–71.2%, which is 10–30% higher compared to the use of surfactants alone or only antifungal agents. The degree of Pseudomonas sp. MI-2, Escherichia coli IEM-1, Staphylococcus aureus BMS-1, Bacillus subtilis BT-2 (spores) biofilms destruction on silicone tubes treated with a mixture of tea tree essential oil and surfactants synthesized on all oil-containing substrates was 10–29% higher than in the case of using only solutions of surfactants (11.5–45.4%) or essential oil (21.4–34.5%) for the tubes treatment. Conclusions. The data obtained make it possible to consider surfactants synthesized by N. vaccinii IMV B-7405 on a wide range of cheap and accessible substrates as promising components of “antibacterial” and “antifungal” locks in combination with essential oils and antifungal agents.
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Olkowska, Ewa, Marek Ruman, Anna Kowalska, and Żaneta Polkowska. "Determination of Surfactants in Environmental Samples. Part II. Anionic Compounds." Ecological Chemistry and Engineering S 20, no. 2 (June 1, 2013): 331–42. http://dx.doi.org/10.2478/eces-2013-0024.
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Abstract Surface active agents (SAA) with negative charge of polar group are named as anionic compounds. They are the main constituent of most products containing synthetic surfactants. The linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES) and alkyl sulfates (AS) are typically applied from this class of compounds. Those surfactants are ingredients of household detergents and cleaners, laundry detergents, cosmetic etc. Moreover they can be applied in the paper, textile and tanning industry as optical brighteners, dispersant, wetting and suspending agents. They can be substrates in the formulation of different products like dyes, pigments, pesticides, exchange resins, plasticizers and pharmaceuticals. Anionic surfactants after use are passed into sewage-treatment plants, where they are partially degraded and adsorbed to sewage sludge (applied in agriculture fields). Finally, the anionic SAA or their degradation products are discharged into surface waters and onto bottom sediments, soils or living organisms. Therefore, it is important (widely application, bioaccumulation, toxicity for living organisms) to investigate the environmental fate of those class of compounds in more details. This research involves determination the concentration of anionic surfactants with use appropriated analytical techniques in environmental samples The official methodology for determination of anionic SAA in liquid samples is based on the ion-pair reaction of these analytes compounds with methylene blue (MB) and an extraction with toxic solvent chloroform. During isolation step of anionic compounds from solid samples are employed Soxhlet and ultrasonic-assisted extraction techniques with use of methanol or mixture of other organic solvents as extraction medium. To overcome disadvantages of those traditional techniques were applied following techniques at sample preparation step from liquid and solid matrices: solid-phase extraction (SPE) and solid-phases microextraction (SPME); accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), respectively. For estimate total concentration of anionic analytes in extracts the spectrophotometric technique is used (as official regulation). For determination concentration of individual analytes were applied gas (derivatization step requires) and liquid chromatography mainly with mass spectrometry technique. The presence of anionic surface active agents was confirmed in various ecosystems (liquid and solid environmental samples).
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Boyer, Ivan, Christina L. Burnett, Wilma F. Bergfeld, Donald V. Belsito, Ronald A. Hill, Curtis D. Klaassen, Daniel C. Liebler, et al. "Safety Assessment of PEGs Cocamine and Related Ingredients as Used in Cosmetics." International Journal of Toxicology 37, no. 2_suppl (September 2018): 10S—60S. http://dx.doi.org/10.1177/1091581818794417.
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The Cosmetic Ingredient Review Expert Panel assessed the safety of 47 polyethylene glycols (PEGs) cocamine and related ingredients, which are reported to function mostly as surfactants and antistatic agents. The Panel reviewed the relevant data and developed a framework to satisfy previously identified data deficiencies for this group of materials as well as extend the scope of related materials covered by the analysis. The irritation potential of these ingredients is consistent with the surface active properties that are characteristic of surfactants. The Panel concluded that the PEGs cocamine and related ingredients were safe as ingredients in cosmetic formulations in the current practices of use and concentration when formulated to be nonirritating.
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Taba, Paulina. "FTIR AND NMR STUDIES OF ADSORBED TRITON X-114 IN MCM-41 MATERIALS." Indonesian Journal of Chemistry 9, no. 2 (June 22, 2010): 184–88. http://dx.doi.org/10.22146/ijc.21527.
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One source of water pollutions is caused by the high use of surface-active agents (surfactants) by industries and households. As a consequence, it is required to remove such substances from the environment One of the important and widely used methods for removal of substances from solution is adsorption. In this research, MCM-41 and its modification MCM41-TMCS were used to adsorb nonionic surfactant, Triton X-114. FTIR and NMR methods were used to study the interaction between the surfactants and the adsorbents. MCM-41 was synthesized hydrothermally at 100 oC and its modification was conducted by silylation of MCM-41 with trimethylchloro silane (MCM41-TMCS). Both unmodified and modified MCM-41 can adsorb the surfactant. The amount adsorbed in the unmodified material is higher than that in the modified one. The interaction of Triton X-114 with MCM-41 was hydrogen bonding between the silanol groups in MCM-41 and hydroxyl groups of Triton X-114. For modified samples, Triton X-114 interacted with alkylsilyl groups mostly through hydrophobic interaction. It is more likely that the interaction was through C12, C13, C26 and C27 of Triton X-114. Keywords: FTIR, NMR, adsorbed Triton X-114, MCM-41 materials
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Shamsuri, Ahmad Adlie, and Siti Nurul Ain Md. Jamil. "Functional Properties of Biopolymer-Based Films Modified with Surfactants: A Brief Review." Processes 8, no. 9 (August 26, 2020): 1039. http://dx.doi.org/10.3390/pr8091039.
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An increase of environmental awareness recently has increased the interest of researchers in using of biopolymer-based films. The films have been prepared extensively by utilizing starch, carboxymethyl cellulose, chitosan, protein, gelatin, carrageenan, alginate, pectin, guar gum and pullulan. They are typically modified with surface-active agents (surfactants) such as glycerol monostearate, sucrose ester, sodium stearoyl lactate, sodium dodecyl sulfate, ethyl lauroyl arginate HCl, Span 20 to 80, Tween-20 to 80 and soy lecithin for improving the functional properties of the films. In this brief review, two types of biopolymer-based films that prepared through casting method were categorized, specifically solution- and emulsion-based films. The four types of surfactants, namely non-ionic, anionic, cationic and amphoteric surfactants that are regularly used to modify biopolymer-based films are also described. The functional properties of the films modified with different types of surfactants are briefly reviewed. This study enhances the attraction of researchers in biopolymer-based films and the improvement of new concepts in this niche area.
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Stone, H. A., and L. G. Leal. "The effects of surfactants on drop deformation and breakup." Journal of Fluid Mechanics 220 (November 1990): 161–86. http://dx.doi.org/10.1017/s0022112090003226.
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The effects of surface-active agents on drop deformation and breakup in extensional flows at low Reynolds numbers are described. In this free-boundary problem, determination of the interfacial velocity requires knowledge of the distribution of surfactant, which, in turn, requires knowledge of the interfacial velocity field. We account for this explicit coupling of the unknown drop shape and the evolving surfactant distribution. An analytical result valid for nearly spherical distortions is presented first. Finite drop deformation is studied numerically using the boundary-integral method in conjunction with the time-dependent convective–diffusion equation for surfactant transport. This procedure accurately follows interfacial tension variations, produced by non-uniform surfactant distribution, on the evolving interface. The numerical method allows for an arbitrary equation of state relating interfacial tension to the local concentration of surfactant, although calculations are presented only for the common linear equation of state. Also, only the case of insoluble surfactant is studied.The analytical and numerical results indicate that at low capillary numbers the presence of surfactant causes larger deformation than would occur for a drop with a constant interfacial tension equal to the initial equilibrium value. The increased deformation occurs owing to surfactant being swept to the end of the drop where it acts to locally lower the interfacial tension, which therefore requires increased deformation to satisfy the normal stress balance. However, at larger capillary numbers and finite deformations, this convective effect competes with ‘dilution’ of the surfactant due to interfacial area increases. These two different effects of surface-active material are illustrated and discussed and their influence on the critical capillary number for breakup is presented.
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Olkowska, Ewa, Marek Ruman, Anna Kowalska, and Żaneta Polkowska. "Determination of Surfactants in Environmental Samples. Part III. Non-Ionic Compounds." Ecological Chemistry and Engineering S 20, no. 3 (September 1, 2013): 449–61. http://dx.doi.org/10.2478/eces-2013-0033.
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Abstract Non-ionic surface active agents are a diverse group of chemicals which have an uncharged polar head and a non-polar tail. They have different properties due to amphiphilic structure of their molecules. Commercial available non-ionic surfactants consist of the broadest spectrum of compounds in comparison with other types of such agents. Typically, non-ionic compounds found applications in households and industry during formulation of cleaning products, cosmetics, paints, preservative coatings, resins, textiles, pulp and paper, petroleum products or pesticides. Their are one of the most common use class of surfactants which can be potential pollution sources of the different compartment of environment (because of they widely application or discharging treated wastewaters to surface water and sludge in agricultural). It is important to investigate the behavior, environmental fate of non-ionic surfactants and their impact on living organisms (they are toxic and/or can disrupt endocrine functions). To solve such problems should be applied appropriated analytical tools. Sample preparation step is one of the most critical part of analytical procedures in determination of different compounds in environmental matrices. Traditional extraction techniques (LLE - for liquid samples; SLE - for solid samples) are time and solvent-consuming. Developments in this field result in improving isolation efficiency and decreasing solvent consumption (eg SPE and SPME - liquid samples or PLE, SFE and MAE - solid samples). At final determination step can be applied spectrophotometric technique, potentiometric titrametration or tensammetry (determination total concentration of non-ionic surfactants) or chromatographic techniques coupled with appropriated detection techniques (individual analytes). The literature data concerning the concentrations of non-ionic surfactants in the different compartments of the environment can give general view that various ecosystems are polluted by those compounds.
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Gutierrez, Tony, Gordon Morris, Dave Ellis, Barbara Mulloy, and Michael D. Aitken. "Production and characterisation of a marine Halomonas surface-active exopolymer." Applied Microbiology and Biotechnology 104, no. 3 (December 7, 2019): 1063–76. http://dx.doi.org/10.1007/s00253-019-10270-x.
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AbstractDuring screening for novel emulsifiers and surfactants, a marine gammaproteobacterium, Halomonas sp. MCTG39a, was isolated and selected for its production of an extracellular emulsifying agent, P39a. This polymer was produced by the new isolate during growth in a modified Zobell’s 2216 medium amended with 1% glucose, and was extractable by cold ethanol precipitation. Chemical, chromatographic and nuclear magnetic resonance spectroscopic analysis confirmed P39a to be a high-molecular-weight (~ 261,000 g/mol) glycoprotein composed of carbohydrate (17.2%) and protein (36.4%). The polymer exhibited high emulsifying activities against a range of oil substrates that included straight-chain aliphatics, mono- and alkyl- aromatics and cycloparaffins. In general, higher emulsification values were measured under low (0.1 M PBS) compared to high (synthetic seawater) ionic strength conditions, indicating that low ionic strength is more favourable for emulsification by the P39a polymer. However, as observed with other bacterial emulsifying agents, the polymer emulsified some aromatic hydrocarbon species, as well as refined and crude oils, more effectively under high ionic strength conditions, which we posit could be due to steric adsorption to these substrates as may be conferred by the protein fraction of the polymer. Furthermore, the polymer effected a positive influence on the degradation of phenanthrene by other marine bacteria, such as the specialist PAH-degrader Polycyclovorans algicola. Collectively, based on the ability of this Halomonas high-molecular-weight glycoprotein to emulsify a range of pure hydrocarbon species, as well as refined and crude oils, it shows promise for the bioremediation of contaminated sites.
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Mercurio, M. R., J. M. Fiascone, D. M. Lima, and H. C. Jacobs. "Surface tension and pulmonary compliance in premature rabbits." Journal of Applied Physiology 66, no. 5 (May 1, 1989): 2039–44. http://dx.doi.org/10.1152/jappl.1989.66.5.2039.
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In vitro surface properties of pulmonary surfactant thought to be essential to its ability to increase pulmonary compliance include minimum surface tension less than 10 dyn/cm and large surface tension variability and hysteresis. We tested four surface-active agents (Tween 20, a detergent; and FC-100, FC-430, and FC-431, industrial fluorocarbons), all lacking these properties, for their ability to increase pulmonary compliance in surfactant-deficient premature rabbits. Fetal rabbits were delivered by cesarean section at 27 days (full term = 31 days) and injected via tracheostomy with 50% lactated Ringer solution, adult rabbit surfactant, or one of the four experimental agents. Dynamic compliance was measured using 1 h of mechanical ventilation followed by alveolar lavage. Each experimental agent produced a dynamic compliance significantly higher than 50% lactated Ringer solution and statistically equal to or greater than natural surfactant. Equilibrium surface tension of the agents and minimum and equilibrium surface tension of the alveolar washes each correlated with compliance (P less than 0.05). This suggests that some surface properties of pulmonary surfactant believed to be essential are not, although surface tension does seem to play a role in pulmonary compliance.
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Mohareb, Rafat M., Abdelfatah M. Badawi, Mahmoud R. Noor El-Din, Nesreen A. Fatthalah, and Marian R. Mahrous. "Synthesis and Characterization of Cationic Surfactants Based on N-Hexamethylenetetramine as Active Microfouling Agents." Journal of Surfactants and Detergents 18, no. 3 (January 3, 2015): 529–35. http://dx.doi.org/10.1007/s11743-014-1662-6.
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Pantyo, V. V., M. M. Fizer, O. I. Fizer, G. M. Koval, and E. M. Danko. "Anti-microbial activity of heterocyclic cationic surface-active substances." Reports of Vinnytsia National Medical University 24, no. 1 (May 18, 2020): 36–40. http://dx.doi.org/10.31393/reports-vnmedical-2020-24(1)-07.
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Annotation. The development and rapid pace of the spread of resistance to antimicrobial agents predetermines the search for new methods of counteracting pathogenic and conditionally pathogenic microorganisms. In this context, studies of the antimicrobial activity of newly synthesized chemicals, which in the future can be considered as candidates for antiseptic and disinfectants, are relevant. The aim of the work was to determine the antimicrobial activity of new ionic associates based on the surface-active cetylpyridinium cation with respect to certain opportunistic microorganisms. The antimicrobial activity of four ionic associates based on the cetylpyridinium cation with respect to clinical isolates of E. coli, P. vulgaris, K. pneumonia, P. aeruginosa, S. aureus, as well as the collection test strains of S. aureus ATCC 25923, E. coli ATCC 29522 and P. aeruginosa ATCC 27853 was studied. Screening studies were performed by the disk diffusion method. With substances that showed an antimicrobial effect, quantitative studies were carried out by the method of serial macro-dilutions in a liquid nutrient media. Screening studies revealed the antibacterial activity of the substances against E. coli ATCC 25923, E. coli (clinical isolate), P. vulgaris and K. pneumonia. With these microorganisms quantitative studies were carried out with the determination of the minimum inhibitory and minimum bactericidal concentrations. The most pronounced antimicrobial activity for the investigated microflora was shown by tetraphenylborate and cetylpyridinium perchlorate. The MIC and MBC values of these substances ranged between 1.625–3.125 mmol / L and 3.125–12.5 mmol / L, respectively. The studied associates showed high antimicrobial activity against representatives of the Enterobacteriaceae family in in vitro studies. Promising is the further study of the effect of the counter-anion associates of cationic surfactants on the biofilm formation of conditionally pathogenic microorganisms.
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Shi, Hui Bei, and Yong Zhu Cui. "The Preparation and Application of Non/Anionic Pre-Treatment Agent for Spandex Fabric." Advanced Materials Research 781-784 (September 2013): 2672–75. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.2672.
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Spandex fabric is widely used with excellent elasticity. The oil (especially a silicone oil), which is used for easement of processing is difficult to be removed in the former processing, furthermore only rely on a treatment agent is very difficult to achieve the cleaning effect. This article we attempted to take advantage of a complex of anionic surfactants and a nonionic surface active agent to built Anionic / non-ionic agents, which has better foaming stability and the fabric processed has better whiteness, the capillary effect, the elastic elongation and elastic recovery compared to the fabric of the normal treatment.
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Nathoo, S. A., and A. Gaffar. "Studies on Dental Stains Induced by Antibacterial Agents and Rational Approaches for Bleaching Dental Stains." Advances in Dental Research 9, no. 4 (December 1995): 462–70. http://dx.doi.org/10.1177/08959374950090041801.
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Extrinsic stain resides in the dental pellicle and can be caused by introduction of chromogenic materials or therapeutic agents into the oral cavity. In contrast, intrinsic tooth stain is found within the tooth structure and can be caused by a variety of agents, including hematological and developmental abnormalities and drugs such as tetracycline. The mechanisms of extrinsic stain formation differ with respect to the causative agent. For example, stain induced by chlorhexidine (CH) can be explained by an increased rate in the non-enzymatic browning reactions occurring at the pellicle surface, while food stains are retained on the surface via ion exchange mechanisms. Although most extrinsic dental stain can be removed by abrasive and/or surface-active materials, removal of certain types of surface stain, e.g., staining due to cationic antimicrobial agents, requires specific agents such as aminoguanidine to reduce the stain. A broad-spectrum approach to reduce both intrinsic and extrinsic dental stains clinically requires oxygenating agents. To evaluate this approach and understand the mechanisms of stain removal, we developed a spectroscopic method for measuring stain in vivo. A series of clinical studies was performed to evaluate stain removal by the agents. The results showed that carbamide peroxide in combination with surfactants and anti-redeposition agents, e.g., sodium pyrophosphate, was more effective in bleaching dental stain compared with carbamide peroxide alone. A detailed examination of the tooth structure by microhardness measurements, x-ray photoelectron spectroscopy, and scanning electron microscopy showed that stain decolorization with this system did not have any adverse effects.
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Panteleeva, Lyudmila Grigoryevna. "Sensitivity of coronaviruses to disinfectants according to the results of foreign and domestic studies." Disinfection affairs, no. 3 (September 2021): 28–35. http://dx.doi.org/10.35411/2076-457x-2021-3-28-35.
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More than 40 different species of the family Coronaviridae are known. The greatest epidemiological significance was acquired by SARS-CoV-2, the causative agent of a new coronavirus infection-COVID-19. It can persist on the surfaces of various objects from several hours to several days. It is sensitive to disinfectants from different chemical groups: chlorine-, oxygen-active, cationic surfactants, alcohols, aldehydes, and iodine-containing agents. Keywords: coronaviruses, survival rate, disinfectants, virucidal activity, virus sensitivity.
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Olkowska, Ewa, Marek Ruman, Anna Kowalska, and Żaneta Polkowska. "Determination of Surfactants in Environmental Samples. Part I. Cationic Compounds / Oznaczanie Surfaktantów W Próbkach Środowiskowych. Część I. Związki Kationowe." Ecological Chemistry and Engineering S 20, no. 1 (March 1, 2013): 69–77. http://dx.doi.org/10.2478/eces-2013-0005.
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Abstract Compounds from the group of cationic surfactants are widely applied in household, industrial, cleaning, disinfectant, cosmetic and pharmaceutical products as their specific properties (antimicrobial, emulsifying, anticorrosion, softening). After use, cationic surfactants are disposed to wastewater-treatment plants and finally with effluent water to surface waters due to their incomplete degradation. Moreover, they can freely circulate in different environmental compartments including living organisms. It becomes indispensable to recognize in more detail behavior, fate and biological effects of cationic surfactants. This analytical problem can be solved with use sensitive and reliable analytical techniques at sample preparation step and final determination step. In recent years, during isolation analytes from environmental samples mainly were used liquid-liquid extraction (LLE) - liquid matrices or solid-liquid extraction (SLE) - solid matrices. This technique involves application of toxic solvents (chloroform), is time-consuming and interferences are co-extracted. Nowadays, in scientific centers are carried out research to replace this traditional technique. So far, the following techniques were applied: solid-phase extraction (SPE) or it modification (HF-LPME) - liquid samples; accelerated solvent extraction (ASE) and supercritical fluid extraction (SFE) - solid samples. During the determination of total content of cationic surface active agents in environmental samples were used a traditional spectrophotometry technique and potentiometric titration technique. But those techniques are susceptible of interferences on analysis results (anionic and non-ionic compounds). The chromatographic technique (liquid chromatography) applied at the final determination step gives possibility to determine individual cationic surfactants in solvent extracts of environmental samples. The LC systems coupled with mass spectrometers are most powerful tools during such analysis.
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Xi, Wei, Yuanye Ping, and Masoome Agha Alikhani. "A Review on Biosurfactant Applications in the Petroleum Industry." International Journal of Chemical Engineering 2021 (August 30, 2021): 1–10. http://dx.doi.org/10.1155/2021/5477185.
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The inadequacy of worldwide fossil fuel resources, combined with increasing energy demands, encourages global attention to either using alternative energy resources or improving the recovery factor and produce larger quantities from present reservoirs. Among all enhanced oil recovery (EOR) methods, surfactant injection is a well-known technique that reduces the interfacial tension (IFT) between oil and water and increases oil production. Despite numerous advantages of using surfactants, there are also a few obstacles like environmental impacts, high cost, effect on humans and other organisms due to toxicological potential, and availability from nonrenewable resources. Biosurfactants are microbial surface-active agents that decrease the surface tension (ST) of a liquid phase and the IFT of two diverse phases. They are biotechnological products of high value owing to their widespread applications, low toxicity, relatively easy preparation, and specific performance, applied in different industries like organic chemicals and fertilizers, agrochemicals, metallurgy and mining, cosmetics, foods, medical and pharmaceuticals, beverages, environmental management, and petroleum and petrochemical applications in emulsifying and demulsifying wetting agents, detergent spreading and foaming agents, and functional food ingredients. Biosurfactants are synthesized by microbes; therefore, various genetic diversities of microorganisms provide the considerable capability to produce new types of biosurfactants, which can develop EOR technology. Biosurfactants are classified into ex situ and in situ MEOR processes. The genera Pseudomonas, Bacillus, Sphingomonas, and Actinobacteria are the foremost biosurfactant-producing bacteria. This paper reviews relevant reports and results from various presented papers by researchers and companies on applications of microorganisms and biosurfactant technology with specific emphasis on EOR and MEOR processes, based on recently published articles since 2010 until now.
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Eswari, Jujjavarapu S. "Production of Rhamnolipid Biosurfactant from Fed Batch Culture by Pseudomonas aeruginosa using Multiple Substrates." Current Nutrition & Food Science 16, no. 6 (July 15, 2020): 928–33. http://dx.doi.org/10.2174/1573401314666181107100127.
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Objective: Biosurfactants are the surface active agents which are used for the reduction of surface and interfacial tensions of liquids. Rhamnolipids are the surfactants produced by Pseudomonas aeruginosa. It requires minimum nutrition for its growth as it can also grow in distilled water. The rhamnolipids produced by Pseudomonas aeruginosa are extra-cellular glycolipids consisting of L-rhamnose and 3-hydroxyalkanoic acid. Methods: The fed-batch method for the rhamnolipid production is considered in this study to know the influence of the carbon, nitrogen, phosphorous substrates as growth-limiting nutrients. Pulse feeding is employed for limiting nutrient addition at particular time interval to obtain maximum rhamnolipid formation from Pseudomonas aeruginosa compared with the batch process. Results: Out of 3 fed batch strategies constant glucose fed batch strategy shows best and gave maximum rhamnolipid concentration of 0.134 g/l.
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Markowski, Maciej, Włodzimierz Golus, Żaneta Polkowska, and Monika Kwidzińska. "Surfactants: a real threat to the aquatic geoecosystems of lobelia lakes." Limnological Review 17, no. 4 (December 1, 2017): 183–93. http://dx.doi.org/10.1515/limre-2017-0017.
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Abstract Lobelia lakes are valuable elements of the natural environment. They are characterised by low trophy, mainly in-forest location and a high transparency of water. However, similarly to other surface waters, they are subjected to increasing anthropogenic pressures, a good indicator of which is the level of surfactants, also called surface-active agents (SAAs). The aim of the study was to evaluate the intensity of anthropogenic pressures in 13 selected lobelia lakes and 14 streams in the catchments of these lakes in Northern Poland, based on SAA concentrations in the waters of these water bodies. We collected one water sample from each of these water bodies and determined the concentrations of cationic, anionic and non-ionic SAAs. We then compared the results with data concerning the ways in which these catchments and water bodies are used. While ionic (cationic and anionic) SAAs were found to be present in all the 27 samples (with concentrations ranging from 0.05 to 0.51 mg dm−3), non-ionic SAAs were identified in 17 of 27 samples (from 0.00 to 2.43 mg dm−3) with three samples largely exceeding the maximum concentration values reported by other authors. We concluded that SAAs are a real threat to the aquatic geoecosystems of lobelia lakes and that the pressures of tourism and leisure have the greatest impact.
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Pena-Pereira, Francisco, Regina M. B. O. Duarte, Tito Trindade, and Armando C. Duarte. "Determination of anionic surface active agents using silica coated magnetite nanoparticles modified with cationic surfactant aggregates." Journal of Chromatography A 1299 (July 2013): 25–32. http://dx.doi.org/10.1016/j.chroma.2013.05.040.
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Zhang, Yu, Mobing Zhuang, Pablo Campo, Ruta Suresh Deshpande, Devi Sundaravadivelu, Robyn N. Conmy, and Jorge W. Santo Domingo. "Comparative Study to Determine the Biodegradability of Dispersants at Environmentally Relevant Concentrations." International Oil Spill Conference Proceedings 2017, no. 1 (May 1, 2017): 331–46. http://dx.doi.org/10.7901/2169-3358-2017.1.331.
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ABSTRACT Chemical dispersant agents reduce the interfacial tension between oil and water, and increase the surface area to volume ratio of oil droplets thus facilitating the biodegradation of spilled oil. Dispersants are composed of surface active molecules known as surfactants and various commercial products contain Dioctyl Sulfosuccinate (DOSS) as the active surfactant ingredient. Since previous laboratory studies were conducted at oil and dispersant concentrations significantly higher (~0.7 g/L oil with Dispersant to Oil Ratio (DOR) of 1:25) than those typically found in field conditions, experiments were conducted at low levels of oil and dispersant (28 μg/L oil with DOR of 1:25) in order to determine the degradation trends at environmentally relevant concentrations. Experiments were conducted using two crude oils (Alaskan North Slope (ANS) and Endicott) and two dispersant products (Corexit 9500 and Finasol OSR 52) to study the biodegradation of dispersants and dispersed oil and oil alone samples were used as controls. Two oil degrading cultures, isolated from the surface (meso) and deep sea (cryo) of the Gulf of Mexico, were enriched on crude oil at 25 and 5 °C and were used as the inocula. The biodegradation experiments were performed at 5 °C for 56 days and at 25 °C for 48 days using sterile GP2 artificial seawater as the media. The time series concentration of DOSS, the primary surfactant in the dispersants was monitored using LC-MS/MS in addition to the oil concentration which was measured using GC-MS/MS. Although the initial concentration of DOSS in Finasol OSR 52 was 20% higher than in Corexit 9500, over 95% of the anionic surfactant fraction was metabolized for both types of dispersant products by the end of the experiment at 25 °C while it persisted at 5 °C. The effect of dispersant and oil type on microbial community structure was also analyzed using PCR analysis. Results indicated that the abundance of Thalassospira correlated well with hydrocarbon degradation trends. The results from this study significantly expands on our understanding of biodegradation of DOSS, dispersed, and non-dispersed oil and also provides information regarding bacterial community composition.
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Tangparitkul, Suparit, Thibaut Charpentier, Diego Pradilla, and David Harbottle. "Interfacial and Colloidal Forces Governing Oil Droplet Displacement: Implications for Enhanced Oil Recovery." Colloids and Interfaces 2, no. 3 (July 18, 2018): 30. http://dx.doi.org/10.3390/colloids2030030.
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Growing oil demand and the gradual depletion of conventional oil reserves by primary extraction has highlighted the need for enhanced oil recovery techniques to increase the potential of existing reservoirs and facilitate the recovery of more complex unconventional oils. This paper describes the interfacial and colloidal forces governing oil film displacement from solid surfaces. Direct contact of oil with the reservoir rock transforms the solid surface from a water-wet to neutrally-wet and oil-wet as a result of the deposition of polar components of the crude oil, with lower oil recovery from oil-wet reservoirs. To enhance oil recovery, chemicals can be added to the injection water to modify the oil-water interfacial tension and solid-oil-water three-phase contact angle. In the presence of certain surfactants and nanoparticles, a ruptured oil film will dewet to a new equilibrium contact angle, reducing the work of adhesion to detach an oil droplet from the solid surface. Dynamics of contact-line displacement are considered and the effect of surface active agents on enhancing oil displacement discussed. The paper is intended to provide an overview of the interfacial and colloidal forces controlling the process of oil film displacement and droplet detachment for enhanced oil recovery. A comprehensive summary of chemicals tested is provided.
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Matmin, Juan, Irwan Affendi, Salizatul Ibrahim, and Salasiah Endud. "Additive-Free Rice Starch-Assisted Synthesis of Spherical Nanostructured Hematite for Degradation of Dye Contaminant." Nanomaterials 8, no. 9 (September 8, 2018): 702. http://dx.doi.org/10.3390/nano8090702.
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Nanostructured hematite materials for advanced applications are conventionally prepared with the presence of additives, tainting its purity with remnants of copolymer surfactants, active chelating molecules, stabilizing agents, or co-precipitating salts. Thus, preparing nanostructured hematite via additive-free and green synthesis methods remains a huge hurdle. This study presents an environmentally friendly and facile synthesis of spherical nanostructured hematite (Sp-HNP) using rice starch-assisted synthesis. The physicochemical properties of the Sp-HNP were investigated by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DR UV-Vis), and nitrogen adsorption–desorption analysis. The Sp-HNP showed a well-crystallized structure of pure rhombohedral phase, having a spherical-shaped morphology from 24 to 48 nm, and a surface area of 20.04 m2/g. Moreover, the Sp-HNP exhibited enhanced photocatalytic degradation of methylene blue dye, owing to the large surface-to-volume ratio. The current work has provided a sustainable synthesis route to produce spherical nanostructured hematite without the use of any hazardous agents or toxic additives, in agreement with the principles of green chemistry for the degradation of dye contaminant.
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Thakur, Shubham, Amrinder Singh, Ritika Sharma, Rohan Aurora, and Subheet Kumar Jain. "Biosurfactants as a Novel Additive in Pharmaceutical Formulations: Current Trends and Future Implications." Current Drug Metabolism 21, no. 11 (December 29, 2020): 885–901. http://dx.doi.org/10.2174/1389200221666201008143238.
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Background: Surfactants are an important category of additives that are used widely in most of the formulations as solubilizers, stabilizers, and emulsifiers. Current drug delivery systems comprise of numerous synthetic surfactants (such as Cremophor EL, polysorbate 80, Transcutol-P), which are associated with several side effects though used in many formulations. Therefore, to attenuate the problems associated with conventional surfactants, a new generation of surface-active agents is obtained from the metabolites of fungi, yeast, and bacteria, which are termed as biosurfactants. Objectives: In this article, we critically analyze the different types of biosurfactants, their origin along with their chemical and physical properties, advantages, drawbacks, regulatory status, and detailed pharmaceutical applications. Methods: 243 papers were reviewed and included in this review. Results: Briefly, Biosurfactants are classified as glycolipids, rhamnolipids, sophorolipids, trehalolipids, surfactin, lipopeptides & lipoproteins, lichenysin, fatty acids, phospholipids, and polymeric biosurfactants. These are amphiphilic biomolecules with lipophilic and hydrophilic ends and are used as drug delivery vehicles (foaming, solubilizer, detergent, and emulsifier) in the pharmaceutical industry. Despite additives, they have some biological activity as well (anti-cancer, anti-viral, anti-microbial, P-gp inhibition, etc.). These biomolecules possess better safety profiles and are biocompatible, biodegradable, and specific at different temperatures. Conclusion: Biosurfactants exhibit good biomedicine and additive properties that can be used in developing novel drug delivery systems. However, more research should be driven due to the lack of comprehensive toxicity testing and high production cost which limits their use.