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1
Simonelli, George, Caetano Moraes, de Augusto, and dos Lobato. "Multivariate study and optimization of biodiesel production using commercial surfactants." Chemical Industry and Chemical Engineering Quarterly 25, no. 2 (2019): 183–92. http://dx.doi.org/10.2298/ciceq180318031s.
Повний текст джерелаАнотація:
Alkaline transesterification of vegetable oils or animal fats (apolar substances) with a short-chain alcohol (polar substance) is the best-known chemical route for biodiesel production. However, because they are substances of different polarities, there is a need to promote contact between the phases. Biodiesel was produced from soybean oil, methanol, potassium hydroxide, and surfactants DBB 7104 and DBB 7107. In this paper we verify whether it is better to use surfactant DBB 7104 or DBB 7107, and if there is an optimum experimental condition for the surfactant. The yield in biodiesel was verified for different production conditions on a bench scale. From a fractional experimental plan (26-2), with a variation of temperature, time, methanol-to-oil mole ratio, weight of surfactant, type of surfactant and weight of catalyst, it was possible to perform a multivariate analysis of the process. The most influential variables in the response were the temperature and the weight of the catalyst. Surfactant DBB 7107 was considered better than the surfactant DBB 7104. The optimal conditions were 0.7% w/w of the surfactant DBB 7107, 1 g of KOH, 30 min, methanol to oil mole ratio of 6:1 and temperature equal to 33.5?C.
2
Gritskova, I. А., D. I. Shragin, S. М. Levachev, А. А. Ezhova, Е. V. Milushkova, V. М. Kopylov, S. А. Gusev, N. I. Prokopov, and N. A. Lobanova. "FUNCTIONAL ORGANOSILICON SUBSTANCES AS STABILIZERS OF POLYMERIC SUSPENSIONS." Fine Chemical Technologies 11, no. 2 (April 28, 2016): 5–16. http://dx.doi.org/10.32362/2410-6593-2016-11-2-5-16.
Повний текст джерелаАнотація:
The review presents schemes for obtaining homologous series of the linear α,ω-carbofunctional oligodimethylsiloxanes with the silicone chain length from 6 to 60 siloxane units containing carboxydecyl, aminopropyl and glycidoxypropyl groups at the chain ends allowing to obtain organosilicon surfactants with reproducible structure and properties. Data on the surfactant colloidchemical properties and kinetic regularities of styrene polymerization in their presence are provided. Systematic research of heterophase styrene polymerization kinetic regularities in the presence of water-insoluble α,ω-carbofunctional oligodimethylsiloxane allowed to formulate the fundamental differences of polymerization kinetic regularities from those observed in the presence of water-soluble surfactants. The mechanism of interfacial adsorption layers formation with water-insoluble α,ω-carbofunctional oligodimethylsiloxanes on the surface of monomer drops and polymer-monomeric particles was considered. This mechanism consists in the forced surfactant replacement by the formed polymer (because of their incompatibility) to the interfacial adsorption layer and in the formation of the surfactant supermolecular structures. The latter in total with the polymer provide its high durability.
3
Jiang, Ting Ting, Jia Lu, Hai Yu Wang, Bao Hui Wang, Hong Jing Han, and Hong Jun Wu. "Analysis on Toxic and Hazardous Substances of Polymer Surfactants Used in Oilfields." Advanced Materials Research 805-806 (September 2013): 1344–47. http://dx.doi.org/10.4028/www.scientific.net/amr.805-806.1344.
Повний текст джерелаАнотація:
Polymer surfactant, which combines the advantages of polymer and surfactant, is a new type of oil displacement agents in oilfield.Meanwhile, the hazardous composition of the polymer surfactant is unknown.In order to clarify its potential impacts on the operator health during production,the hazardous composition and toxicity in the two solutions ,which polymer surfactants prepared by using fresh water and waste water were investigated.And the existence of inorganic and organic pollutants in the solution were also studied.The results were shown that determination of inorganic phosphorus and arsenic exceeded the standard limits.The polymer surfactant powder and solution extraction products were analyzed, it can be concluded basicly that there is no organic pollutants, or it can be ignorable.
4
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.
Повний текст джерелаАнотація:
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
5
Svietkina, Olena, Iryna Kovalevska, Kateryna Sai, and Kostiantyn Prokopenko. "Intensifying the process of methane gas hydrates crystallization in the presence of surface-activated substances." E3S Web of Conferences 230 (2021): 01004. http://dx.doi.org/10.1051/e3sconf/202123001004.
Повний текст джерелаАнотація:
The crystallization process of gas hydrates during their formation in the presence of surface-active substances (SAS) is studied. The research is conducted in two directions – theoretical and experimental. Experimental data on the crystallization rate of methane gas hydrates formation in the presence of surfactants have been obtained: high-molecular compounds are used on the basis of polymeric quaternary ammonium salts containing side aliphatic radicals of various lengths in the acyl fragment, as well as a number of specific surfactants. The process of methane gas hydrates formation is performed using a laboratory setup of the NPO modification for the gas hydrates creation. To analyse the experimental data, technical and metrological instruments are used: stalagmometric method with automatic photoelectric drop counting, conductometric method, Wheatstone bridge, spectrophotometric titration of amino end-groups, viscometer VPZh-1. It has been substantiated that the crystal formation rate depends on the surfactant concentration. New experimental dependences of the gas hydrates formation on surfactants under thermobaric conditions in the presence of surfactants have been found. It has been revealed that the crystallization process during the methane gas hydrates formation is accelerated in the presence of a surfactant. As a result of their application, the effect of solubilization and catalysis arises with the formation of the so-called “diffusion zone”, the size of which decreases in the presence of surfactants, thereby accelerating the substance transfer to the surface on which crystallization occurs. An increase in the surfactant concentration leads to an increase in the rate of molecular diffusion, and also creates a more intense turbulent diffusion.
6
Li, H. Q., and H. F. Schröder. "Surfactants – standard determination methods in comparison with substance specific mass spectrometric methods and toxicity testing by Daphnia magna and Vibrio fischeri." Water Science and Technology 42, no. 7-8 (October 1, 2000): 391–98. http://dx.doi.org/10.2166/wst.2000.0593.
Повний текст джерелаАнотація:
The recovery of different types of surfactants formerly applied and up-coming new ones from spiked wastewater and ultra-pure water was examined by sum parameter determinations (substance-group-specific Methylene Blue (MBAS), Bismuth Active (BiAS) and Disulfine Blue Active Substances (DSBAS)) and by substance-specific mass spectrometric detection (MS). For MS determination atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) was applied in the flow injection (FIA) and liquid chromatographic separation (LC) mode. Quantitation was performed in the multiple ion detection mode using mass and tandem (MS/MS) mass spectrometric detection. In parallel the ecotoxicological potential of these surfactants was determined by Daphnia magna and Vibrio fischeri toxicity testing. MS was found to provide more reliable data in surfactant analysis than the substance-group-specific methods. The toxicity of the up-coming new surfactants against water organisms should not be neglected.
7
Trismawati and D. Wikanaji. "Morinda citrifoliia L. as a renewable raw material for surface active agent." MATEC Web of Conferences 204 (2018): 05011. http://dx.doi.org/10.1051/matecconf/201820405011.
Повний текст джерелаАнотація:
Surface active agent (surfactant) is a substance or a blend of substances that lower the surface tension or interfacial tension between two liquids. It contains both hydrophobic groups (its tail) and hydrophilic groups (its head). Surfactants lower the surface tension of a liquid by spreading spontaneously over its surface. To understand its suitability for raw material of surfactant, the seed of Morinda citrifolia L is extracted for its fatty acid contents and evaluated for its spreading ability into other liquid. Its fatty acid contents are analyzed by FTIR and GCMS method and its spreading ability is evaluated by its diffusion characteristic using Helle Shaw Cell. From FTIR it is known that the oil seed of Morinda citrifolia has functional groups suitable for the hydrophobic part of surfactant. From GCMS it is known that the seed of Morinda citrifolia L contains huge amount of poly unsaturated fatty acid (PUFA) of C19:2 suitable for the hydrophobic part of surfactant. From diffusion experiment using Hele Shaw Cell it is known that the spreading ability of its PUFA in oil phase is approaching its commercial synthetic surfactant has but it is not in water phase.
8
Nguyen, Thuy N., Stephanie M. Cunsolo, Peter Gal, and J. Laurence Ransom. "Infasurf and Curosurf: Theoretical and Practical Considerations with New Surfactants." Journal of Pediatric Pharmacology and Therapeutics 8, no. 2 (April 1, 2003): 97–114. http://dx.doi.org/10.5863/1551-6776-8.2.97.
Повний текст джерелаАнотація:
Type II pneumocytes, normally responsible for surfactant production and release, are insufficiently formed and differentiated in the premature infant born before 34 weeks' gestation. Without an adequate amount of pulmonary surfactant, alveolar surface tension increases, leading to collapse and decreased lung compliance. Pulmonary surfactants are naturally occurring substances made of lipids and proteins. They lower surface tension at the interface between the air in the lungs, specifically at the alveoli, and the blood in the capillaries. This review examines the relative benefits of the two most recently marketed surfactants, calfactan (Infasurf) and poractant alfa (Curosurf).
9
Lee, Jiyun, and Seung-Jun Choi. "Influence of Blending of Nonionic Emulsifiers Having Various Hydrophilic Head Sizes on Lipid Oxidation: Investigation of Antioxidant Polarity—Interfacial Characteristics Relationship." Antioxidants 10, no. 6 (May 31, 2021): 886. http://dx.doi.org/10.3390/antiox10060886.
Повний текст джерелаАнотація:
The purpose of this study was to deliver insights into the effect of interfacial composition and antioxidant polarity on the lipid oxidation of emulsions. Emulsions were created using blends of nonionic ethoxylated fatty acid alcohol surfactants with different hydrophilic head sizes, and lipophilic (TBHQ) and amphiphilic (lauryl gallate) antioxidants were incorporated into the emulsions. At the same surfactant concentration, emulsion stabilized with surfactant with a smaller hydrophilic head was more susceptible to lipid oxidation than that stabilized with surfactant with a larger hydrophilic head. When surfactants with a similar hydrophilic head size were used, lipid oxidation in emulsion containing more surfactant was slightly faster than that containing less surfactant. When emulsions were created with a 1:1 molar ratio mixture of surfactants with small and large hydrophilic heads, surfactant concentration (1.00 and 2.932 mM) had little effect on lipid peroxide generation rate. However, the concentration of thiobarbituric acid-reactive substances (TBARSs) in the emulsion prepared at 1.00 mM increased faster than that prepared at 2.93 mM. Alteration of interfacial composition and surfactant concentration did not affect antioxidant ability, regardless of antioxidant polarity, to inhibit lipid peroxide generation. However, the ability of lauryl gallate and TBHQ to prevent TBARS generation was elevated by mixing surfactants with small and large hydrophilic heads and by decreasing surfactant concentration. In most emulsions, lauryl gallate showed a more effective antioxidant ability than TBHQ.
10
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.
Повний текст джерелаАнотація:
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).
11
Kosolapov, Viktor. "Formation of a surfactant adsorption layer on microroughnesses of friction surfaces." Bulletin of Kharkov National Automobile and Highway University, no. 95 (December 16, 2021): 38. http://dx.doi.org/10.30977/bul.2219-5548.2021.95.0.38.
Повний текст джерелаАнотація:
Formation of an adsorption surface layer on microneralities of friction surfaces. The model of interaction of the molecule of surface-active substance with the microasperity of friction surface has been given. It has been found that the distance of interaction and the thickness of an adsorbed layer of surface-active substances depend on value of a field of an adsorbing surface and energy of thermal oscillations of molecules of surface-active. It has been shown that the distance of interaction and the thickness of an adsorbed layer of surface-active substances decrease at magnification of temperature of working liquid.
12
Sedyakina, Natalya, Nataliya Feldman, and Sergey Lutsenko. "Microemulsions based on polyglycerol polyricinoleate as drug delivery systems." Farmacevticheskoe delo i tehnologija lekarstv (Pharmacy and Pharmaceutical Technology), no. 2 (April 1, 2020): 24–33. http://dx.doi.org/10.33920/med-13-2002-02.
Повний текст джерелаАнотація:
The aim of the work is to develop composition of reverse microemulsion stabilized by the surfactant from a number of polyglycerol polyricinoleates for encapsulating water-soluble biologically active substance (BAS) and studying the kinetics of its release into the medium simulating the medium of the small intestine. Materials and methods. Possible stable (equilibrium) phases of the reverse microemulsion in the pseudoternary system water–PG-3-PR/Tween 80–paraffin oil were determined by titration of surfactant/co-surfactant mixtures–oil in water with hydrophilic-lipophilic balance (HLB) values of the surfactant mixture ranging from 4.0 to 7.0. Stability of a number of compositions during storage at 20 °C for 6 months was studied. Based on the obtained data, a composition was selected for encapsulating methylene blue (MS) dye as a model of a water-soluble biologically active substance. Microemulsion was obtained by mixing paraffin oil and surfactants with selected mass ratio followed by the addition of an aqueous phase. Reverse microemulsion morphology was evaluated with transmission electron microscopy (TEM). To evaluate the in vitro drug release rate, aliquots of an aqueous dye solution (control sample) and MB-containing microemulsions were placed in dialysis bags and immersed in 0.01 M phosphate-buffered saline (PBS) (pH 7.4) in a thermostatic shaking incubator at 180 rpm and 37 °C. Aliquots of the release medium were selected at predetermined time intervals and the concentration of MB dye was determined using a UV spectrophotometer at 660 nm. Results. Composition containing 13.5 wt% paraffin oil, 76.5 wt% mixture of PG3-PR/Tween 80 (HLB 5.5) and 10 wt% water was chosen to encapsulate the biologically active agents. Number average droplet diameter in the dispersed phase of the obtained microemulsion was 55 nm. Dye-loaded microemulsion sample showed a prolonged release of biologically active substances within 48 hours of the experiment (15.2%) and low initial release rate. Conclusion. Possible stable phases of reverse microemulsion in the pseudoternary system water–PG-3-PR/Twin 80–paraffin oil were determined in the course of the work and optimal microemulsion composition for encapsulating medicinal substances was found. It was shown that the resulting microemulsion system provides a sustained release of methylene blue as a model of a water-soluble biologically active substance in a medium simulating medium of the small intestine. The obtained data allow to consider this composition as a potential nanoscale system for the sustained delivery of water-soluble drugs.
13
Burlachenko, Anastasia S., Olesya V. Salishcheva, Lyubov S. Dyshlyuk, and Alexander Y. Prosekov. "Investigation of the Kinetic Regularities of the Process of Biodegradation of Betaine Surfactant by Bacteria of the Genus Pseudomonas." Applied Sciences 11, no. 19 (September 25, 2021): 8939. http://dx.doi.org/10.3390/app11198939.
Повний текст джерелаАнотація:
Surfactants are extremely common organic compounds that enter the environment in large quantities in the form of household and industrial wastewater. The toxicity of surfactants for biological systems, the high concentration of substances and the duration of the bioremediation process of polluted ecosystems requires improving the biotechnology of microbial wastewater treatment for surfactants. The purpose of this work is to study the kinetic laws of the reaction of the biological decomposition of betaine surfactants. Pseudomonas bacteria were used as bio-destructors of the surfactants. Kinetic data were obtained to create the possibility of further optimization of research on the biodegradation of toxic organic substances. The strains that were promising destructors of cocamidopropylbetaine were selected. The toxicity of high concentrations of surfactants in relation to microorganisms of the genus Pseudomonas was proven. Safe values of the surfactant concentration for conducting biodegradation tests were found. A kinetic model of the biodestructive process was constructed. It proves that the processes of biodegradation are described by a kinetic equation of the first order. With the derived equation, it is possible to determine the time interval of biodegradation of cocamidopropylbetaine to the specified values by means of mathematical calculations.
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Klovak, V., L. Nechpai, S. Lelyushok, and S. Kulichenko. "FLUORESCENCE CHARACTERISTICS OF FLUORESCEIN AND EOSIN Y SOLUTIONS IN WATER-MICELLAR SURFACTANT MEDIA." Bulletin of Taras Shevchenko National University of Kyiv. Chemistry, no. 1 (57) (2020): 23–26. http://dx.doi.org/10.17721/1728-2209.2020.1(57).6.
Повний текст джерелаАнотація:
The effect of cationic, anionic and nonionic surfactants on the fluorescence properties of fluorescein and eosin Y aqueous solutions has been investigated. It has been found that sodium dodecyl sulfate does not affect the position of the maximum wavelengths of solutions of fluorescein and eosin Y in the study of the effect of an anionic surfactant on the fluorescence emission intensity of dyes. The intensity of the signal of the dye solutions when changing the concentration of anionic surfactant changes little. As the concentration of non-ionic surfactant increases, the fluorescence emission intensity of the fluorescein solutions decreases. In contrast, with increasing concentration of Triton X-100, there is an increase in the signal intensity of solutions of more hydrophobic eosin Y with subsequent access to the "plateau" at СТХ-100≥5.1·10–2 mol/L. The position of the maxima fluorescence emission wavelengths for the fluorescein solutions in the 0-1.0·10–5 mol/L range of concentrations of cationic surfactant cetylpyridinium chloride remain unchanged. The position of the maxima shifts to the long-wavelength region of the spectrum at higher concentrations of CPC. The nature of the position dependence of the fluorescence emission maxima of eosin Y solutions in the presence of cationic surfactants is similar. The effect of fluorescence quenching has also been shown in the study of the influence of organic substances of cationic nature on the signal intensity of fluorescein solutions. It has been shown that the concentration dependence is linear in the (0.1–4.0)·10–1 mol/L range of isoniazid molecule concentrations. The data obtained can be implemented in the development of conditions and methods for the determination of pharmacologically active substances of cationic nature by reaction with fluorescein in medicines.
15
Jaya, Adam, M. A. Elita Hafizah, A. Manaf, and Andreas Andreas. "THE INFLUENCE OF SURFACTANT AND PROTECTIVE COLLOID ON POLYVINYL ACETATE EMULSION SYNTHESIZED BY EMULSION POLYMERIZATION TECHNIQUE." Spektra: Jurnal Fisika dan Aplikasinya 5, no. 3 (December 31, 2020): 169–76. http://dx.doi.org/10.21009/spektra.053.01.
Повний текст джерелаАнотація:
A series of experiments have been carried out and reported. This report describes the stages of the polymerization reaction during emulsion Polyvinyl Acetate (PVAc) synthesis. PVAc was synthesized from the Vinyl Acetate Monomer (VAM) with Ammonium Peroxydisulphate (APS) as an inorganic thermal initiator in the aqueous media under reaction temperature was keep at 65 until 75oCs by agitation speed was 300 rpm respectively during 4 hours of reaction time. The protective colloid agents and several types of surfactants were added to improve the obtained emulsion PVAc performance. The polymerization reaction was carried out without the addition of a protective colloid agent. The surfactants were produced the emulsion PVAc with the properties of solid content 0.89%, density 1.02 g/ml, viscosity 0.0033 Poise, pH 2.8, conductivity 12 ms, respectively. While the polymerization reaction involved protective colloid agents by using Polyvinyl Alcohol (PVOH) was obtained properties of emulsion PVAc with Solid Content 4.36%, density 1.17 g/ml, viscosity 0.0216 Poise, pH 2.8, and conductivity 10 ms respectively. The same thing was shown when the surfactant was present in the polymerization reaction. The emulsion PVAc was synthesized with nonionic surfactant has solid content 8.20%, density 1.17 g/ml, viscosity 0.0099 Poise, pH 2.8, and conductivity 7 ms, the result is better rather than synthesized with anionic surfactant has solid content 2.65%, density 1.13 g/ml, viscosity 0.0068 Poise, pH 2.8, and conductivity 11 ms. According to the preliminary observations obtained, emulsion PVAc’s appearance is better when the protective colloid agents and the surfactant is present rather than without additional those substances. The physical properties of emulsion were depended on the addition of protective colloid agents and surfactants. In addition, the complete reaction indicated by solid content value was obtained from emulsion when the additional substances were present. All the testing parameters were observed using Viscometer Ostwald, Pycnometer, pH Meter, FTIR Spectrophotometer, Conductometer, and another supporting testing to explain the polymerization reaction stage of synthesis emulsion PVAc.
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Mao, Cui Ping, and Shu Bin Wu. "Adsorption of Polyvinyl Acetate (PVAc) Adhesive Emulsion from Aqueous Solution by Lignin-Phenol Based Cationic Surfactant Modified Organic Kieselguhr." Applied Mechanics and Materials 472 (January 2014): 861–66. http://dx.doi.org/10.4028/www.scientific.net/amm.472.861.
Повний текст джерелаАнотація:
The kieselguhr was modified by the lignin-based cationic surfactant which obtained from the Mannich reaction. Modified organic kieselguhr exhibited favorable adsorption to adhesive and fine colloidal substance. Dissolved and colloidal substances (DCS) appeared in the secondary fibre reuse process interfered the pulping and papermaking seriously. The organic clay could remove the stickies substances through adsorption approach technically. In this paper, PVAc was chosen as the simulacrum of stickies because of its wide application as the adhesives in wood, textile, paint, paper processing and other industries. The organic kieselguhr was characterized by scanning electron microscope (SEM) and infrared spectrum (IR), etc. Then the adsorption experiment of PVAc emulsion from aqueous solution was carried out. 78.61% of the adhesive was absorbed by the organic kieselguhr, while the untreated clay only removed 53.41%. Common cationic surfactant, such as dodecyl trimethyl ammonium bromide (DTAB) and cetyl trimethyl ammonium bromide (CTAB), the modified clays were taken as the reference substance. The results indicated that the modified organic kieselguhr had well absorption efficacy to the stickies simulacrum, which provided a novel approach for the stickies controlling.
17
Matiyev, K. I., A. M. Samedov, and F. M. Akhmedov. "Reduction of acidity and corrosive activity of an oilstock." SOCAR Proceedings, no. 3 (September 30, 2021): 87–91. http://dx.doi.org/10.5510/ogp20210300533.
Повний текст джерелаАнотація:
A new composition has been developed to reduce the acid number and corrosive activity of oilstock, which includes hydroxides of group 1A elements, substances with demulsifying properties, as well as surfactants that create additional auxiliary properties. The activity of the developed compositions to reduce acidity and corrosion activity was studied on various types of oils taken from the Dubendi site. Keywords: naphthenic acids; acid number; corrosive activity; surfactant; oilstock.
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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.
Повний текст джерелаАнотація:
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
19
Grace, Andrew, Peter Kwok, and Michael Kawke. "Surfactant in Middle Ear Effusions." Otolaryngology–Head and Neck Surgery 96, no. 4 (April 1987): 336–40. http://dx.doi.org/10.1177/019459988709600406.
Повний текст джерелаАнотація:
Evidence from animal studies suggests that substances that lower surface tension are present in the middle ear cleft, where they may facilitate opening of the eustachian tube. The purpose of this study was to investigate whether or not surface-tension-lowering substances are present in middle ear effusions. Aspirates from children and adults with secretory otitis media—both serous otitis media and mucoid otitis media—were analyzed by means of two-dimensional thin-layer chromatography. Phospholipids, the major components of pulmonary surfactant, were present in appreciable quantities in all aspirates. Differences in total phosphate content and phospholipid composition were found when effusions from adults and children were compared.
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Alves, Anthony V., Marina Tsianou, and Paschalis Alexandridis. "Fluorinated Surfactant Adsorption on Mineral Surfaces: Implications for PFAS Fate and Transport in the Environment." Surfaces 3, no. 4 (September 28, 2020): 516–66. http://dx.doi.org/10.3390/surfaces3040037.
Повний текст джерелаАнотація:
Fluorinated surfactants, which fall under the class of per- and polyfluoroalkyl substances (PFAS), are amphiphilic molecules that comprise hydrophobic fluorocarbon chains and hydrophilic head-groups. Fluorinated surfactants have been utilized in many applications, e.g., fire-fighting foams, paints, household/kitchenware items, product packaging, and fabrics. These compounds then made their way into the environment, and have been detected in soil, fresh water, and seawater. From there, they can enter human bodies. Fluorinated surfactants are persistent in water and soil environments, and their adsorption onto mineral surfaces contributes to this persistence. This review examines how fluorinated surfactants adsorb onto mineral surfaces, by analyzing the thermodynamics and kinetics of adsorption, and the underlying mechanisms. Adsorption of fluorinated surfactants onto mineral surfaces can be explained by electrostatic interactions, hydrophobic interactions, hydrogen bonding, and ligand and ion exchange. The aqueous pH, varying salt or humic acid concentrations, and the surfactant chemistry can influence the adsorption of fluorinated surfactants onto mineral surfaces. Further research is needed on fluorinated surfactant adsorbent materials to treat drinking water, and on strategies that can modulate the fate of these compounds in specific environmental locations.
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Alexandrova, Lidia A., Ljudmil S. Grigorov, Nikolay A. Grozev, and Stoyan I. Karakashev. "Investigation of Interfacial Free Energy of Three-Phase Contact on a Glass Sphere in Case of Cationic-Anionic Surfactant Aqueous Mixtures." Coatings 10, no. 6 (June 18, 2020): 573. http://dx.doi.org/10.3390/coatings10060573.
Повний текст джерелаАнотація:
The wetting of adsorbed surfactants solids is important for various technological applications in particular for the process of foam flotation. The present work aims at calculating the surface tensions of the three phase interfaces at different surfactant concentrations using the Girifalco and Good method. For this purpose, the surface tension and contact angle vs. surfactant concentration of the test substances amines and sulfonates and their mixture were measured for liquid–air interface. Calculated surface tension of solid–air interface vs. concentration for C10 amine and mixed systems are close to those for the liquid–air surface, but are slightly lower. In the case of mixed systems, the graph has a specific structure similar to that of liquid–air surface dependence. In contrast to the solid–air interface results, the solid–liquid surface tension values are significantly lower. In case of the mixed surfactant systems, C10amine/C10 sulfonate, a synergetic effect on the surface tension is observed. The specific behavior of the mixed systems is interpreted with the emergence of aggregates consisting of the anionic and cationic surfactants. It is shown that in the whole area of concentrations complete wetting does not occur.
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Klovak, V., S. Lelyushok, S. Kulichenko, and O. Zaporozhets. "INFLUENCE OF SURFACTANTS ON THE FLUORESCEIN FLUORESCENCE PROPERTIES." Bulletin of Taras Shevchenko National University of Kyiv. Chemistry, no. 1(55) (2018): 42–45. http://dx.doi.org/10.17721/1728-2209.2018.1(55).10.
Повний текст джерелаАнотація:
The use of fluorescence as an analytical signal makes it possible to reduce the limits of detection of analytes. The study of spectral properties of luminophores is important for the development of new methods for analyzing various objects. The use of micellar systems enables to increase quantum yields by 2–10 times and fluorescence intensity by 3–80 times and reduce the limits of detecting analytes by 1–2 orders of magnitude. Organized media based on surfactants influence on the fluorescence of luminescent indicators and their complex compounds due to changes in their microspheric solution of their photophysical characteristics, aggregate state and microprobe nature. Cationic surfactants occupy a special place among cytotoxicants. Low levels of maximum permissible concentrations of cationic surfactants require the use of sensitive analytical methods that combine simplicity and availability with reliability and expressiveness. Known chemical and microbiological methods for the determination of cationic surface-active antiseptics, disinfectants and preservatives characterize by complexity and labor intensity and are not suitable for the operational control of their concentration in places of local use. Therefore, the purpose of the work was to study the influence of various types of surfactants on the fluorescence properties of fluorescein to develop a method for determining the content of ethonium. The influence of surface-active substances of different types on the fluorescence properties of fluorescein was investigate. The anionic surfactant almost does not effect on the intensity of the dye signal. Nonionic surfactant leads to a gradual decrease in the fluorescence intensity of fluorescein. The most visible influence was observe with adding into the solution cationic surface-active substances. There is harsh intensity decrease of the dye fluorescence with subsequent exit to the «plateau» in the system of fluorescein-cetylpyridinium chloride. The cationic surfactant ethonium works the same. Received results will laid in the basis of the method development of ethonium determination in the medical drugs.
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Klekotka, Urszula, Dariusz Satuła, Anna Basa, and Beata Kalska-Szostko. "Importance of Surfactant Quantity and Quality on Growth Regime of Iron Oxide Nanoparticles." Materials 13, no. 7 (April 9, 2020): 1747. http://dx.doi.org/10.3390/ma13071747.
Повний текст джерелаАнотація:
This study shows the influence of selected nonstandard surfactants on the growth and properties of magnetite nanoparticles. Particles were obtained using thermally decomposed iron (III) acetylacetonate in an organic environment. For synthesis, three different concentrations (4, 8, and 16 mmol) of tested surfactants were used. Five types of each long-chain carboxylic acid and amines were selected for stabilization of nanoparticles. Nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and infrared spectroscopy. Magnetic properties of the nanoparticles were tested by conventional room temperature Mössbauer spectroscopy with and without external magnetic field. TEM images clearly showed that application of tertiary amines causes the nanoparticles to form nanoflowers, in contrast to other compounds, which do not show such growth. Influence of surfactant amount on growth regime depends on the nature of the substances. Mössbauer spectroscopy confirms differences in magnetic core composition as a result of the surfactant amount present in synthetic procedure.
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Byakov, V. M., and Sergey V. Stepanov. "Positronium Formation in Aqueous Solutions of Surfactant Substances." Materials Science Forum 105-110 (January 1992): 1505–8. http://dx.doi.org/10.4028/www.scientific.net/msf.105-110.1505.
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Byakov, V. M., and S. V. Stepanov. "Positronium formation in aqueous solutions of surfactant substances." Radiation Physics and Chemistry 41, no. 3 (March 1993): 559–65. http://dx.doi.org/10.1016/0969-806x(93)90020-u.
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Erenkov, Oleg, Daniil Yavorskii, and Elena Yavorskaya. "The polymeric materials turning after workpiece processing with surface-active substances." MATEC Web of Conferences 298 (2019): 00073. http://dx.doi.org/10.1051/matecconf/201929800073.
Повний текст джерелаАнотація:
The results of experimental investigations of surface quality after the lathe machining of polymeric materials subjected to preliminary treatment with surface-active substances are presented. The new combined method for polymer parts was developed. This method is based on directed change in the polymer properties by preliminary chemical treatment of the surface layer so as to reduce its resistance in the cutting zone. It has been demonstrated in experiments that the preliminary treatment of workpiece with surfactants ensures an improvement in quality of the surface machined by turning. This is indicated by a reduction in the roughness parameters by a factor of 2–4.5, and the minimum roughness is achieved at a cut depth equal to 1.0–1.15 the surfactant penetration depth into the material
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Ribeiro, Marcelo Pinheiro, and Alexandre Botari. "Evaluation of effluent post-treatment by slow filtration and adsorption with activated carbon produced from spent coffee grounds in surfactant removal in sewage treatment." Ambiente e Agua - An Interdisciplinary Journal of Applied Science 17, no. 1 (February 8, 2022): 1–10. http://dx.doi.org/10.4136/ambi-agua.2756.
Повний текст джерелаАнотація:
Environmental pollution is a worldwide concern, especially when caused by sewage dumping into water bodies. Many substances are present in industrial or domestic wastewater, causing contamination in superficial water collection. Surfactants stand out for being widely used both industrially and domestically. The use of detergents and many types of surfactants was increased during the Covid-19 pandemic period, a fact observed in the levels in the effluent sample analysis from a Sewage Treatment Plant (STP) - Vila City around 21 and 39 mg L-1 in this period. This work evaluated the surfactant concentrations in the primary and secondary treatment units of the Vila City STP, in the city of Paranavaí-PR.-Brazil. In addition, the use of a post-treatment by slow sand filtration and adsorption by activated carbon produced from spent coffee grounds in the complementary removal of surfactants was proposed. A mixed bed with sand and activated carbon columns was made on a pilot scale, and filtration/adsorption runs were performed simulating slow filtration with rates of approximately 15 m3 m-2 day-1. The parameters used for the efficiency removal evaluation in a pilot plant run were: turbidity (NTU) and surfactant concentrations. The removal of surfactant concentrations was about 9% and 7% in the Upflow Anaerobic Sludge Bed reactors (UASB-RALF) and in the secondary treatment, respectively, at the STP – Vila City units. In the post-treatment proposed by filtration/adsorption, bed columns on a pilot scale plant obtained a reduction of approximately 94% in terms of turbidity (NTU) and 95% in terms of surfactant removal.
Keywords: activated carbono, coffee poder, effluent, surfactants.
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Burakaeva, A. D., G. V. Petrova, A. I. Khlytchiev, N. A. Akhalaia, S. V. Sorokun, and Z. A. Bashirova. "Increasing Efficiency of Waste Water Treatment of Wine-Making Enterprises with Simultaneous Production of Bio Surface for Oil Industry." Ecology and Industry of Russia 24, no. 2 (February 26, 2020): 41–45. http://dx.doi.org/10.18412/1816-0395-2020-2-41-45.
Повний текст джерелаАнотація:
A method for pre-treatment of wastewater with the simultaneous production of biological surface-active substances (bio-surfactants) by deep cultivation of the microscopic fungus Hypomyces odoratus in the wastewater of a winery has been developed. In wastewater after cultivation of the fungus under aerobic conditions for 12 hours, a steady decrease in BOD was observed by 2.5 times, COD by 3 times, the content of suspended solids, sulfates, phosphates, ammonium ions, nitrates, nitrites, anionic surfactants decreased significantly substances (ACAS), cationic surfactants (CAS), wastewater in chemical composition began to approach the indicators of municipal sewage. The complexity of the composition obtained during the cultivation of the biomass fungus and the isolated exopolysaccharide contributed to a decrease in the surface tension of the oil and indicated that the fungus synthesizes the bio-surfactant complex. After contact with a 12-hour mass of fungus or exopolysaccharide obtained from biomass in highly viscous, water-flooded bituminized oil, an improvement in rheological indices was noted, and the water cut and content of paraffin deposits decreased.
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Djuraevna, Teshaboeva Nodira. "Strength Indicators Of Cement Systems With Additives Of Surface - Active Substances." American Journal of Applied sciences 03, no. 05 (May 31, 2021): 203–9. http://dx.doi.org/10.37547/tajas/volume03issue05-32.
Повний текст джерелаАнотація:
In the article, the study was to establish the effect of surfactant additives on the strength characteristics of cement systems. The determinations were carried out on cements of various mineralogical composition, freshly ground and stale, on cement-sand mortars and concretes. For control samples and with additives, the same plasticity was chosen, and the water-cement ratio than for various additives fluctuated within certain limits.
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Ibragimova, D. A., O. M. Kamil, T. V. Yankova, N. A. Yashtulov, and N. K. Zaitsev. "THE EFFECT OF SURFACTANTS ON THE CHEMILUMINESCENT REACTION OF LUMINOL WITH HYDROGEN PEROXIDE." Fine Chemical Technologies 12, no. 6 (December 28, 2017): 71–76. http://dx.doi.org/10.32362/2410-6593-2017-12-6-71-76.
Повний текст джерелаАнотація:
The luminol-hydrogen peroxide chemiluminescent system is widely used for the creation of diagnostic systems, for chemical analysis, for studying the kinetics and mechanisms of chemical reactions, for the creation of special and emergency light sources, and for monitoring living systems. However, the use of the luminol-hydrogen peroxide chemiluminescent system is limited by the fact that there are almost no ways of managing the reaction. The introduction of organized molecular systems into the luminol-hydrogen peroxide chemiluminescent system can create an additional channel for controlling chemiluminescent reactions. The luminol-hydrogen peroxide system was not previously studied in various classes of hydrocarbon and perfluorinated micellar solutions. This work was the first to study the effect of cationic, anionic and nonionic hydrocarbon surface-active substances (cetyltrimethylammonium bromide, sodium decyl sulfate, sodium dodecyl sulfate, triton X 100) and perfluorinated surface-active substances (FT-135 and FT-248) on the chemiluminescent systems luminol-hydrogen peroxide-potassium hexacyanoferrate(III) and luminol-hydrogen peroxide-copper(II) sulphate. The systems retain the ability to chemiluminescence in the presence of a surfactant. Cationic surfactants lower the intensity of chemiluminescence, and anionic surfactants increase the intensity of chemiluminescence. The introduction of a surfactant into the system allows increasing the range of dependence of the chemiluminescence intensity on the catalyst concentration. Kinetic curves of the growth and decay of chemiluminescence were measured in the systems. The rate constants of the chemiluminescence decay were measured in the framework of the first-order kinetics model.
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Erenkov, O. Yu. "The Effect of Treating Semiproducts of Polymeric Materials with Surfactants on the Quality of their Machining." International Polymer Science and Technology 45, no. 2 (February 2018): 75–77. http://dx.doi.org/10.1177/0307174x1804500210.
Повний текст джерелаАнотація:
The results of experimental investigations of surface quality after the lathe machining of polymeric materials subjected to preliminary treatment with surface-active substances are presented. It has been demonstrated in experiments that the preliminary treatment of semiproducts with surfactants ensures an improvement in quality of the surface machined by turning. This is indicated by a reduction in the roughness parameters by a factor of 2–4.5, and here the minimum roughness is achieved at a depth of cut equal to 1.0–1.15 of the depth of penetration of the surfactant into the material.
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Nakov, Natalija, Jelena Acevska, Katerina Brezovska, and Aneta Dimitrovska. "Overview on chromatographic and potentiometric based approaches for pKa determination of sparingly soluble substances." Macedonian Pharmaceutical Bulletin 63, no. 02 (2018): 21–27. http://dx.doi.org/10.33320/maced.pharm.bull.2017.63.02.003.
Повний текст джерелаАнотація:
The dissociation constant (pKa) is one of the most important physicochemical property of the compounds and it is of great importance for the pharmaceutical industry. Many of the active pharmaceutical ingredients are sparingly soluble in water or have no chromophore, thus the conventional UV/Vis spectrometry and potentiometry methods are not applicable. This article presents an overview of several approaches based on RP-HPLC and cosolvent/surfactant potentiometry that have been recently published for the pKa determination of sparingly soluble active pharmaceutical ingredients. Additionally, different calculation methods that have been used for the estimation of the aqueous dissociation constant are summarized. Keywords: dissociation constant, pKa, sparingly soluble substances, determination, reverse-phase liquid chromatography, potentiometry, surfactants
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Shibaev, Andrey V., Anna L. Aleshina, Natalya A. Arkharova, Anton S. Orekhov, Alexander I. Kuklin, and Olga E. Philippova. "Disruption of Cationic/Anionic Viscoelastic Surfactant Micellar Networks by Hydrocarbon as a Basis of Enhanced Fracturing Fluids Clean-Up." Nanomaterials 10, no. 12 (November 27, 2020): 2353. http://dx.doi.org/10.3390/nano10122353.
Повний текст джерелаАнотація:
Studies of the effects produced by the solubilization of hydrophobic substances by micellar aggregates in water medium are quite important for applications of viscoelastic surfactant solutions for enhanced oil recovery (EOR), especially in hydraulic fracturing technology. The present paper aims at the investigation of the structural transformations produced by the absorption of an aliphatic hydrocarbon (n-decane) by mixed wormlike micelles of cationic (n-octyltrimethylammonium bromide, C8TAB) and anionic (potassium oleate) surfactants enriched by C8TAB. As a result of contact with a small amount (0.5 wt%) of oil, a highly viscoelastic fluid is transformed to a water-like liquid. By small-angle neutron scattering (SANS) combined with cryo-TEM, it was shown that this is due to the transition of long wormlike micelles with elliptical cross-sections to ellipsoidal microemulsion droplets. The non-spherical shape was attributed to partial segregation of longer- and shorter-tail surfactant molecules inside the surfactant monolayer, providing an optimum curvature for both of them. As a result, the long-chain surfactant could preferably be located in the flatter part of the aggregates and the short-chain surfactant—at the ellipsoid edges with higher curvature. It is proven that the transition proceeds via a co-existence of microemulsion droplets and wormlike micelles, and upon the increase of hydrocarbon content, the size and volume fraction of ellipsoidal microemulsion droplets increase. The internal structure of the droplets was revealed by contrast variation SANS, and it was shown that, despite the excess of the cationic surfactant, the radius of surfactant shell is controlled by the anionic surfactant with longer tail. These findings open a way for optimizing the performance of viscoelastic surfactant fluids by regulating both the mechanical properties of the fluids and their clean-up from the fracture induced by contact with hydrocarbons.
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Ishiguro, Munehide, and Luuk K. Koopal. "Predictive model of cationic surfactant binding to humic substances." Colloids and Surfaces A: Physicochemical and Engineering Aspects 379, no. 1-3 (April 2011): 70–78. http://dx.doi.org/10.1016/j.colsurfa.2010.11.075.
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Toraman, Muhammed Cemal, and Ali Bayat. "Effect of Surfactant Compound Sprays on The Rate of Adsorption on Different Target Surfaces." JOURNAL OF ADVANCES IN AGRICULTURE 10 (September 27, 2019): 1834–45. http://dx.doi.org/10.24297/jaa.v10i0.8442.
Повний текст джерелаАнотація:
The first operation of adsorption on leaf surfaces in pulverization is drop sticking. In the water wettability of the surfaces, the sticking of the drops has a great importance. Drop contact angle, contact height, and contact diameter values in the third and tenth seconds were measured with Drop Shape Analysis 10 device to determine adsorption, spreading, and sticking levels by applying mixtures of ten surface active substances including different contents with pure water to different leaf surfaces. The adsorption and sticking rates of the drops they formed on different leaf surfaces were determined for the time they are obtained from the data obtained in both time periods. Furthermore, the spreading rates of the mixtures prepared by taking into account the change rates during the last seven seconds between these two periods were determined as the sticking rate. Coating shares related to covering rates of different surface active substances with different surface properties on the surface of leaves were evaluated as possible work success according to the adsorption, spreading and sticking levels anticipated in spraying. According to their results on the application surfaces, surface active substances and leaves were evaluated statistically by the SPSS 15 program in terms of their similar properties. It has been found that surface active substance mixtures with sodium carboxymethylcellulose and carboxymethylcellulose contents had the largest drop contact angles and contact heights with the smallest drop contact diameters on the leaf surfaces, and a negative impact on the adsorption performance as they spread very little over seven seconds. It has been determined that drops with surface active substance including trisiloxane + allyloxypolyethyleneglycol and alcoholethoxylate, alkylphenolethoxylate have formed the smallest contact angles, minimum drop heights and largest contact diameters on the surface of the leaves, as well as increased adsorption and sticking by spreading rapidly for seven seconds.
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Borrego, Encarnación, Dolores Sicilia, Soledad Rubio, and Dolores Pérez-Bendito. "Evaluation of the Mixed Aggregate Method as an Alternative to the Bismuth Active Substances and Cobalt Thiocyanate Active Substances Procedures for the Determination of Nonionic Surfactants in Raw and Treated Sewage." Journal of AOAC INTERNATIONAL 85, no. 1 (January 1, 2002): 173–81. http://dx.doi.org/10.1093/jaoac/85.1.173.
Повний текст джерелаАнотація:
Abstract The mixed aggregate (MA) method was evaluated for the routine determination of total ethoxylated nonionic surfactants in municipal raw and treated sewage. Nonionics in wastewater samples were enriched with a C8 solid-phase extraction cartridge, eluted with ethyl acetate–methanol, and separated from interferences with stacked strong anionic (quaternary ammonium form) and cationic (benzenesulfonic acid form) exchange columns. Sample extracts were evaporated to dryness and redissolved in distilled water. The total amount of ethoxylates, on a weight basis, was determined by measuring the critical micelle concentration of a mixed micelle made up of ethoxylates and the anionic surfactant sodium dodecyl sulfate, used as the reagent. The dye Coomassie Brilliant Blue G was used as a photometric probe. The minimum amount of ethoxylate required for a single determination was 1 μg. For raw sewage samples, mean recoveries and standard deviations were 98 ± 6 and 98 ± 4% at fortification levels of 0.3 and 0.6 μg/mL, respectively. For treated sewage samples, mean recoveries and standard deviations were 95 ± 2 and 100 ± 2% at fortification levels of 0.03 and 0.06 μg/mL, respectively. The MA method and the classical bismuth active substances and cobalt thiocyanate active substances procedures were compared. The former offers some significant advantages over the classical procedures in terms of sensitivity, selectivity, precision, simplicity, and rapidity; the type of response is independent of both the molecular weight and the chain length of the surfactant.
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Abhishek S., Patil, Shaikh Bilal J., Bhosale Ankush S., Raut Indrayani D., and Nitalikar Manojkumar M. "NIOSOMES: A PROMISING DRUG DELIVERY CARRIER." International Journal of Pharmaceutical Sciences and Medicine 6, no. 6 (June 30, 2021): 15–27. http://dx.doi.org/10.47760/ijpsm.2021.v06i06.002.
Повний текст джерелаАнотація:
Niosomes are non-ionic surfactant-based multilamellar or unilamellar vesicles in which an aqueous solute solution is completely encapsulated by a membrane formed by surfactant macromolecules organised as a bilayer. Because vesicles are made up of a bilayer of non-ionic surface-active substances, the term "Niosomes" was coined (non-ionic surfactants). Niosomes are an unique drug delivery technology that encapsulates the medication in a vesicle. Ionic drug carriers are hazardous and inappropriate, whereas niosomal drug carriers are less dangerous. Niosomes do not require any specific handling or storage conditions.Niosomes have shown to be a promising drug carrier, with the potential to minimise medication side effects and improve therapeutic efficacy in a variety of disorders. Drug insolubility, instability, limited bioavailability, and fast degradation are all issues that niosomes address. The benefits, preparations, assessment, and medicinal uses of niosomes are discussed in this review article.
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Fernianti, Dewi, and Wisnu . "Anionic surfactant adsorption in detergent sewage with cation ion exchange method." International Journal of Advanced Chemistry 9, no. 2 (December 16, 2021): 196. http://dx.doi.org/10.14419/ijac.v9i2.31848.
Повний текст джерелаАнотація:
Surfactant is one of chemical substances added in detergent. The surfactant type added in detergent is anionic surfactant, namely Alkyl Benzene Sulfonate (ABS). Alkyl Benzene Sulfonate is a slow-degradable chemical substance due to branched chain in its structure, which causes low oxygen supply from the air due to foam covering the water surface. This condition can cause a dangerous impact for the organisms in the water.This study aimed to adsorb the anionic surfactant contained in detergent sewage using cation exchange resin. Before the adsorption process, cation resin regeneration process was performed following the standard operational procedures of PT. Pertamina RU III, Plaju using 4% H2SO4solution at regeneration time of 45 minutes. Surfactant adsorption process occurred at room temperature with resin mass variables of 50, 100, and 150 g and contact time of 5, 10, 15, 20, and 25 minutes. Furthermore, the surfactant content was analyzed using a spectrophotometer at 652 nm wavelength. The study analysis results showed that the adsorption process of anionic surfactant in the detergent sewage with cation ion exchange method at 50 g resin in 5 – 25 minutes obtained a resin adsorption capacity of 0.72 g, while 150 g resin at 5 – 25 minutes only obtained a resin adsorption capacity of 0.18 g.The best adsorption percentage was achieved from 150 g resin at a contact time of 25 minutes due to adsorbing the anionic surfactant up to 100%. Meanwhile, the closest equation assessment approach was presented fromthe Langmuir adsorption isotherm model by gaining a linear graphic at R2 = 0.9946.
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Khoerunisa, Ilhanni, Aji Najihudin, and Siti Hindun. "REVIEW ARTIKEL: SOLID LIPID NANOPARTICLES (SLN) METODE DAN KARAKTERISTIK." Jurnal Insan Farmasi Indonesia 3, no. 2 (December 28, 2020): 307–16. http://dx.doi.org/10.36387/jifi.v3i2.548.
Повний текст джерелаАнотація:
Solid Lipid Nanoparticles are composed of active substances, solid fats, water and surfactants. SLN has advantages by having a small particle size of 50-1000 nm and a large absorption efficiency value of 40-100%. SLN has a homogeneous particle size with a IP value that is closed to zero. One of the methods used to produce SLN is HSH/ High pressure homogeneity where the process uses pressure to produce small particle size. The HSH/ High-speed homogeneity method uses stirring speed as a parameter in the manufacture of nanoparticles. Solvent emulsification method does not use high temperatures in the homogeneity process. The most important SLN characteristics are particle size and entrapment efficiency values. These characteristics are strongly influenced by large concentration of solid fat and surfactants. The greater amount of the surfactant used, the smaller the particle size and the increasing value of the trap efficiency. If the solid fat concentration used is greater, the particle size will be as larger, but the absorption efficiency value will be greater because the fat will provide more space for the active substance to be entrapped.
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Zhang, Ya Xin, and Hong Tao Wang. "Study of PCP Photodegradation by TiO2 Catalyst Based on Different Properties of Soil Washing Effluents." Advanced Materials Research 878 (January 2014): 791–96. http://dx.doi.org/10.4028/www.scientific.net/amr.878.791.
Повний текст джерелаАнотація:
Remediation of hydrophobic organic contaminants (HOCs) in soils and groundwater has becoming an issue of extensive concern around the world. Surfactant enhanced remediation has been suggested as a promising technology for abating such contaminants, and the nonionic surfactants have often been employed based on their high solubilization capabilities and comparatively low critical micelle concentrations (CMCs). A major problem arises after soil washing because the collected surfactant-containing wastes must be properly disposed or treated. In this study, 13 different soil with different basic properties were artificially contaminated with pentachlorophenol (PCP) and washed with TX100, a widely used nonionic surfactant. The properites of the as-required 13 washing effluents were test, and photocatalystic degradation of PCP using commercial P25 TiO2 was carried out. The degradation curves were fitted to the pseudo-first-order kinetic law, and simple correlation coefficients were obtained between the first-order rate constants k and washing effluents properties. The results obtained indicated that the degradation rate of PCP mainly depended on the concentration of PCP and TX100 in the wasted effluents, while othe substances washed out from soil showed very limited impact on the photocatalysis procedure.
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Kuzina, Olga A., and Aleksandr B. Shabarov. "Calculation and experimental method for determining the filtration parameters of the mixture “oil — aqueous solution of surfactants”." Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 6, no. 1 (2020): 41–64. http://dx.doi.org/10.21684/2411-7978-2020-6-1-41-64.
Повний текст джерелаАнотація:
The article describes a physical and mathematical cluster precise model and a method for calculating the flow of a two-phase mixture “oil — aqueous solution of surface-active substances” in the pore space of rocks. This method allows us to predict the effect of the type of aqueous solution of surface-active substances and the temperature of the solution on the type of relative permeabilities (RPP). The results of an experimental study of stationary two-phase fluid filtration in a reservoir model through a composite column of core samples are presented. A method is given for determining the relative permeability functions using additional reagents based on the obtained generalized experimental data and calculating pressure losses due to friction, local resistances, and interfacial interaction during the flow of oil-water mixture in the pore channels. Formulas are proposed for calculating losses from interphase interaction taking into account the influence of the type of surfactant and formation temperature. The dependences of the relative amplitude of pressure loss on interfacial interaction and the position of the maximum loss of the bell-shaped curve on the type of surfactant, formation temperature and adhesion work are obtained, which allow approximating the magnitude of pressure loss on interfacial interactions taking into account surfactants and temperature. The effect of temperature on the type of relative permeabilities is shown. It was established that the use of the studied aqueous surfactant solutions instead of water for oil displacement leads to a decrease in the residual oil saturation in the core due to a decrease in interfacial tension at the oil-water interface, which as a result leads to an increase in oil recovery.
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Cvrković-Karloci, Željka, Damir Krznarić, Marijan Šeruga, and Božena Ćosović. "Simple Electrochemical Determination of Surface-Active Substances in Natural Waters." International Journal of Electrochemistry 2011 (2011): 1–7. http://dx.doi.org/10.4061/2011/416834.
Повний текст джерелаАнотація:
A simple electrochemical determination of surface-active substances by using time-dependent variation of the capacitive current in a.c. voltammetry at the HMDE is described. Surface-active substances were accumulated by stirring solution at the deposition potential of −0.6 V versus Ag/AgCl (sat. NaCl). The capacitive current was recorded for different deposition times in the range 0–120 s, wherefrom the linear calibration plot is constructed. The proposed method was verified for model surfactant TritonX-100 in the concentration range 0.02–0.25 mg/L and for humic acid in the concentration range 1.65–20 mg/L. The application of the method was demonstrated for freshwater samples of the Drava river, Danube river, and the wetland Kopački Rit, Croatia. The shape of theiac-Ecurves as well as the obtained concentrations of surface-active substances by using humic acid as the calibration substance are quite well describing the type and the nature of organic matter in the freshwater samples.
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Soll, Roger F., and Jerold F. Lucey. "Surfactant Replacement Therapy." Pediatrics In Review 12, no. 9 (March 1, 1991): 261–67. http://dx.doi.org/10.1542/pir.12.9.261.
Повний текст джерелаАнотація:
Despite medical and technological advances, respiratory distress syndrome (RDS) remains a major cause of morbidity and mortality in premature infants. Thirty years have passed since Avery and Mead demonstrated that infants dying of RDS were deficient in pulmonary surfactant. In those three decades, advances in our understanding of the composition, function, and metabolism of pulmonary surfactant have finally led to clinical trials of surfactant replacement therapy in thousands of premature infants. This article reviews the current status of surfactant replacement therapy. BACKGROUND Pulmonary surfactant is essential for normal lung function. Surfactant forms a film at the alveolar surface, which prevents the lung from collapsing at the end of expiration. Surfactant may have other functions as well, including the prevention of pulmonary edema, the prevention of infection, and the prevention of lung injury from toxic substances, such as oxygen (Table 1) CHEMICAL MAKEUP The chemical makeup of pulmonary surfactant has been well defined (Table 2). Lipids are the major component, comprising up to 80% to 90% of surfactant by weight. The majority of the lipids in pulmonary surfactant are highly polar phospholipids, predominantly phosphatidylcholine. Three proteins associated with surfactant have been these surfactant proteins may play a critical role in surfactant function by improving the adsorption of surfactant at the alveolar surface and by aiding in surfactant re-uptake and metabolism.
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Yakubova, Ol'ga Sergeyevna, Elena Yur'yevna Demyantseva, and Regina Smith Smith. "PHYSICOCHEMICAL PROPERTIES OF SULPHATE WASTE LIQUOR AFTER SOAP EXTRACTION IN THE PRESENCE OF SURFACTANTS." chemistry of plant raw material, no. 4 (December 14, 2021): 337–43. http://dx.doi.org/10.14258/jcprm.2021049521.
Повний текст джерелаАнотація:
During the wood delignification a multicomponent spent liquor (black liquor) is formed. Depending on the type of wood, black liquor is enriched with valuable extractives. The isolation of extractives from processing liquors and their conversion into biologically active substances, tall products is according to development trend of pulp and paper industry. It includes the introduction of scientific based technologies in manufacturing processes with reference to modern environmental protection requirements. Now the extraction efficiency of sulphate soap does not exceed 75–80% whereby the quality of obtained soap is low. Sulphate soap, especially extracted after hardwood cooking, contains a large amount of impurities. This complicates the process of soap treatment into valuable biologically active substances (beta-sitosterol, etc.).
In the present work the addition of demulsifying and coagulating substances into the black liquor is proposed to intensify the hardwood sulphate soap extraction. The chemical colloidal characteristics of the obtained sulphate soap were investigated. Two critical micelle concentration (CMC) were found on the surface tension isotherms. The second critical micelle concentration (CMC2) in the concentration range of 0.9–1.0% CMC2 indicates the restructuring of micelles into a spherocylindrical shape. A comparative qualitative and quantitative analysis of the composition of sulfate soap obtained in industrial conditions and in the presence of selected additives in laboratory was carried out. Surfactants promote the extraction of phytosterol from black liquor obtained from hardwood species cooking. The influence of surfactant addition on the main physical and colloidal chemical characteristics of black liquor before and after isolation of sulphate soap is investigated. A decrease in viscosity and a de foaming of a black liquor solution is observed as a result of the addition of surfactant additives.
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Klyosova, K. G., I. V. Bushueva, and S. A. Gladisheva. "Study of the influence of concentration of surface-active substances on trifuzol release from veterinary intrauterine suppositories." Farmatsevtychnyi zhurnal, no. 4 (July 30, 2020): 88–93. http://dx.doi.org/10.32352/0367-3057.4.20.09.
Повний текст джерелаАнотація:
The main direction in increasing meat and milk production for the coming years is the intensification of all livestock industries. Disease animals with lesions of the genitals are fairly common, causing considerable economic damage due to loss of productivity of animals and even infertility. At the present time the search continues for veterinary medicines, which would ensure the effectiveness of treatment of diseases of the sexual sphere, in particular, cattle, and the extension of the range of veterinary medicines and their dosage forms. So, the goal is to improve the existing veterinary intrauterine suppositories by the use of more effective active substances and foaming agent in its composition that improves the efficiency of the funds and consequently the effectiveness of treatment of inflammatory diseases of the reproductive organs in cattle.
Use piperidine 2-(5-(2-furyl)-4-phenyl-1,2,4-triazole-3-ylthio)acetate (trifuzol) as active substances in veterinary intrauterine suppository provides increased therapeutic effectiveness in the treatment, particularly of catarrhal endometritis in cows compared with the known means. Its use allows to improve the course of the pathological process.
Introduction sodium lauryl sulfate in the composition of the suppository can improve the clinical effect of the proposed use of the funds due to the fact that the melting means it begins to foam, grow in volume and take in this view of the entire uterine cavity of the animal and thus distribute the active substance evenly over the entire inner surface of the uterus as a result of biopharmaceutical research determined that the optimal release trifuzol of intrauterine suppositories is provided by a combination of auxiliary substances – the fundamentals-media (a mixture of polyethylene oxides with a molecular weight of 1 500 and 400 in the ratio 9:1) and surfactant (sodium lauryl sulfate).
The aim of this study was scientific substantiation of surfactant concentration (sodium lauryl sulfate) in-utero drug trifuzol in the form of suppositories.
Suppositories were prepared by the method of pouring with the use of forms from semi-automatic Franco-Crespi. The concentration of the surfactant (sodium lauryl sulfate) were 0,5%, 1%, 2%, 3% and 5% by weight of the drug, the content trifuzol – 0.1 g each suppositories.
Research on the scientific basis of the concentration of surfactant in the suppository was carried out according to plan one-way with repeated observations.
It is proved that the concentration of the surfactant (sodium lauryl sulfate) significantly affects its release from the dosage form. Found that 0.5% concentration of sodium lauryl sulfate for optimal release trifuzol of veterinary intrauterine suppositories.
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De Moraes, Dayane Cristina, and Daniel De Paula. "PROCESSAMENTO DO ÓLEO DE GIRASSOL COMO ESTRATÉGIA PARA A PRODUÇÃO DE COSMÉTICOS ORGÂNICOS." Eclética Química Journal 38, no. 1 (October 25, 2017): 187. http://dx.doi.org/10.26850/1678-4618eqj.v38.1.2013.p187-201.
Повний текст джерелаАнотація:
Organic cosmetic formulations must not contain synthetic or semisynthetic substances. Otherwise, they must have materials of organic origin in their composition, which may be manufactured according to strict rules of extraction, purification and processing. The modifications allowed for the production of organic raw materials include hydrolysis, esterification, transesterification, hydrogenation, and saponification reactions. The saponification process consists of oils and fats transformation into surfactant by a reaction of triglycerides, present in oils, with an alkali. The surfactants are applied in several products and can act as emulsifiers, detergents, foaming agents, conditioners, bactericides and solubilizers. One of the biggest challenges to the development of organic cosmetics is to replace synthetic surfactants by natural excipients that have the same functional properties as the first ones. Thus, the aim of this work was to obtain organic surfactants by the saponification of sunflower oil using an up-scalable method. Four different alkalis were used to carry out the saponification reaction (NaOH, KOH, TEA and AMP-95). The final products were evaluated according to organoleptic properties, free alkalinity index and foaming, emulsifying and detergent capacity, based on official methods previously described in the literature. It was observed that the characteristics, as well as the applicability of surfactants on the formulation of organic cosmetics may vary according to the alkali used in the saponification process. The surfactant obtained from KOH presented the higher number of applications in organic cosmetics, which may be used in the formulation of liquid and bar soaps and emulsifying systems.
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Ansone-Bertina, Linda, Karina Upska, Linda Dobkevica, Jorens Kviesis, Raimonds Meija, and Maris Klavins. "Immobilised Humic Substances as Low-Cost Sorbents for Emerging Contaminants." Applied Sciences 11, no. 7 (March 28, 2021): 3021. http://dx.doi.org/10.3390/app11073021.
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Environmental pollution with contaminants of emerging concern (CECs) is a worldwide problem that is receiving increasing attention. Although these substances have been released in the aquatic environment for a long time, wastewater treatment plants are still incapable of removing emerging contaminants completely. Consequently, trace metals, metalloids and pharmaceuticals, as well as surfactant leftovers, are often found in environmental samples. Environmentally friendly and cost-effective sorbents such as humic substances can be used for purification if their sorption properties are increased by immobilization. To our knowledge, immobilized humic substances have not been widely studied as sorbents up to now. In this study, humic substances were immobilized to obtain low-cost sorbents. The chosen methods for characterization of the obtained sorbents showed successful immobilization. Traditional pollutants, such as Cr(III) (a metal), As(V) (a metalloid) and chlorpromazine (a pharmaceutical), were used as representative contaminants. Sorption experiments were conducted using the batch system, and sorption was also studied based on the sorbent dosage, initial concentration of the studied element or substance, solution pH and sorption time. The results show that all the obtained immobilized humic substances in this study can be used as sorbents to remove contaminants from water. At the same time, from these humic substances, only those immobilized using iron compounds are suitable for the removal of arsenic.
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Wang, Chong, and Min Wang. "Formation of Core–Shell Structures in Emulsion Electrospun Fibres: A Comparative Study." Australian Journal of Chemistry 67, no. 10 (2014): 1403. http://dx.doi.org/10.1071/ch14214.
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Electrospinning has attracted great attention in recent years from different industries including biomedical engineering. Owing to the relative ease of fabricating ultrafine fibres with core–shell structures, emulsion electrospinning has been investigated intensively for making nanofibrous delivery vehicles for local and sustained release of bioactive or therapeutic substances, especially biomolecules such as growth factors. In preparing emulsions for electrospinning, different surfactants, ionic or non-ionic, can be used, which may subsequently influence the evolution of the core–shell structure in the electrospun emulsion jet or fibre. In this investigation, emulsions consisting of deionized water or phosphate buffer saline as the water phase, a poly(lactic-co-glycolic acid) solution as the oil phase and Span 80 (a non-ionic surfactant) or sodium dodecyl sulfate (an ionic surfactant) were electrospun into fibres for studying the core–shell structure and its evolution in emulsion electrospun fibres. Different microscopies were employed to study the morphological changes of the water phase in fibre samples collected at different locations along the jet (or fibre) trajectory during emulsion electrospinning. It was found that the evolution of the fibre core–shell structure was significantly different when different surfactants were used. If Span 80 was the surfactant, the water phase within the thick emulsion jet (or fibre) close to the Taylor cone existed in a discrete state whereas in ultrafine fibres collected beyond a certain distance from the Taylor cone, a mostly continuous water-phase core was observed. If sodium dodecyl sulfate was the surfactant, the core–shell structure in the thick jet (or fibre) was irregular but relatively continuous. A single core core–shell structure was eventually developed in ultrafine fibres. The core–shell structure in electrospun fibres and its evolution were also affected by the emulsion composition (e.g. polymer solution concentration, water-phase volume, and ion addition in the water phase).
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Filippov, A. P., A. S. Kovalenko, and V. G. Il'in. "Composition and Nano-Periodic Structure of Compounds Formed by the Reaction of Molybdenum and Tungsten Heteropolyanions with Cationic Surfactants1." Adsorption Science & Technology 16, no. 9 (October 1998): 685–95. http://dx.doi.org/10.1177/026361749801600902.
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Keggin heteropolyanions (HPAns) of structure [PMo12O40]3– and [PW12O40]3– have been allowed to react in acidic media at room temperature with some cationic surfactants of the quaternary ammonium or primary amine type to yield meso-structured insoluble salts with the general formulae Am3[PM12O40], Etn3[PM12O40]2, Etn3[PM12O40]2•nEtnCl2 or AmnH7-n[PM11O39]•xH2O, where Am and Etn are, respectively, mono- and di-cationic surfactant species, M is Mo or W and n can vary in the range 0 to ∼3. All of the materials obtained possessed nano-periodic structures whose maximum d100 parameters ranged from 26 Å to 36 Å, exhibiting lamellar, tetragonal, hexagonal or cubic meso structures depending on the synthesis conditions employed and the nature of the surfactant and HPAns used. The values of the highest d100 parameter obtained for the substances prepared were generally in line with the length of the hydrophobic tail in the surfactant molecule but less dependent on the nature of the metal (Mo or W) when the latter was incorporated in a Keggin anion. However, the structure of the materials was considerably influenced by the pH value of the reaction medium and the P/M ratio when transformation of the Keggin anions into lacunary or other anions was possible.
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Hakim, Azizul, and Motoyoshi Kobayashi. "Charging, aggregation, and aggregate strength of humic substances in the presence of cationic surfactants: Effects of humic substances hydrophobicity and surfactant tail length." Colloids and Surfaces A: Physicochemical and Engineering Aspects 577 (September 2019): 175–84. http://dx.doi.org/10.1016/j.colsurfa.2019.05.071.
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