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Статті в журналах з теми "Surfactant substances"
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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.
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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.
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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.
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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.
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
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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.
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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.
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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.
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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).
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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.
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Mitru, Daniel, Gheorghe Nechifor, Stefania Gheorghe, Alina Roxana Banciu, Lucian Ionescu, Catalina Stoica, Daniela Liliana Ionica, and Irina Eugenia Lucaciu. "Removal and Effects of Surfactants in Activated Sludge System." Revista de Chimie 71, no. 1 (February 7, 2020): 100–106. http://dx.doi.org/10.37358/rc.20.1.7819.
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).
Дисертації з теми "Surfactant substances"
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Tuhkala, M. (Marko). "Dielectric characterization of powdery substances using an indirectly coupled open-ended coaxial cavity resonator." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526205595.
Повний текст джерелаАнотація:
Abstract The main objective of this thesis was to research and develop a sensitive characterization method for dielectric powdery substances which could be utilized in various industrial and research fields. With modern electromagnetic simulation tools and the presented experimental measurements, the characterization of dielectric powders using an indirectly coupled open-ended coaxial cavity resonator operating in TEM mode at 4.5 GHz was found to have potential. The modelling and the experimental measurement results of commonly used dielectric powders revealed that, from the nine classical mixing rules, it was possible to derive reliable inclusion permittivity values when using the properties of the perturbed resonator and the Bruggeman symmetric and the Looyenga mixing theories. In addition, the determination accuracy of the inclusion permittivity was found to be greatly improved with the correction factor included into the previously presented permittivity equation of the quarter wave coaxial resonator. Determination of the dielectric losses was found to be reliable when using the differences between the perturbed and unperturbed resonator and the general mixing model equation. The sensitivity of the characterization method was researched with both humidity exposed and surfactant treated modified SiO2, Al2O3 and ZrO2 powders. Experimental results showed that the effect of adsorbed water on the particles was most pronounced when measuring the dielectric losses of the inclusions. Furthermore, a clear correlation with the theory of the general mixing model was found. Thus, in addition to the changed dielectric properties between dry and humidity exposed powders, it was also possible to determine the moisture content with reasonable accuracy. This correlated well with the traditional, mass based, determination. Stearic acid coating of the particles induced only a small change in inclusion permittivity but a notable change in dielectric losses. Unlike the cases with the larger particle sized SiO2 and Al2O3, the dielectric loss of ZrO2 inclusions, with stearic acid coating, was decreased significantly from 6.2 × 10-3 to 3.8 × 10-3. When characterizing magnesium and calcium titanate composite powders, with CaTiO3 molar ratios of 0.0, 0.02, 0.05 and 0.1, the method was found to have good sensitivity and accuracy. Additions of CaTiO3 exhibited a clear increase in net inclusion permittivities from 13.4 up to 14.9 and in dielectric loss tangents from 7.1 × 10-3 up to 8.5 × 10-3. In addition, a good correlation was found in the theoretical determination of the CaTiO3 molar ratios using the resonator measurement results and the general mixing model. The characterization method was proved to be capable of measuring the dielectric properties and detecting even very slight changes in the powders. Thus, the method could be utilized in various types of powdery material characterization, for example, in the analysis and quality control of different composite powdersTiivistelmä Väitöstyön päätavoitteena oli tutkia ja kehittää herkkä jauhemaisten eristemateriaalien karakterisointimenetelmä, jota voitaisiin hyödyntää usealla teollisuuden ja tutkimuksen alueella. Hyödyntäen nykyaikaisia sähkömagnetiikan simulointityökaluja sekä kokeellisia mittauksia, havaittiin TEM -moodissa 4,5 GHz taajuudella toimivan avoimen epäsuorasti kytketyn koaksiaalionteloresonaattorin soveltuvan karakterisoimaan eristejauheita. Sähkömagneettinenmallinnus yhdessä yleisesti käytettyjen eristejauheiden kokeellisten mittausten kanssa osoitti, että partikkelin permittiivisyysarvot voitiin johtaa luotettavasti. Tällöin käytettiin näytemateriaalilla täytetyn resonaattorin ominaisuuksia, sekä yhdeksästä vertaillusta klassisesta sekoitusyhtälöstä Bruggeman symmetristä ja Looyengan sekoitusteorioita. Tämän lisäksi tarkkuutta voitiin parantaa huomattavasti lisäämällä korjauskerroin aikaisemmin julkaistuun neljännesaalto-koaksiaaliresonaattorin permittiivisyyden määrittävään yhtälöön. Eristehäviöiden määrittäminen havaittiin luotettavaksi, kun käytettiin mitattavalla materiaalilla muutetun ja tyhjän resonaattorin ominaisuuksien eroja, sekä general mixing model -yhtälöä. Karakterisointimenetelmän herkkyys tutkittiin ilmankosteudelle altistetuilla, sekä pintakäsittelyllä muutetuilla SiO2, Al2O3 ja ZrO2 -jauheilla. Mittaustulokset osoittivat, että partikkelin pinnalle adsorpoituneen veden vaikutus oli kaikkein korostunein, kun mitattiin partikkelien eristehäviöitä. Tämän lisäksi havaittiin myös selkeä korrelaatio general mixing model -teorian kanssa. Näin ollen muuttuneiden eristeominaisuuksien määritysten lisäksi voitiin määrittää jauheen kosteussisältö riittävällä tarkkuudella. Tulokset korreloivat hyvin perinteisen massaeroihin perustuvan määrittämisen kanssa. Partikkelien pinnoitus steariinihapolla aiheutti ainoastaan pienen muutoksen permittiivisyyteen mutta merkittävän muutoksen eristehäviöihin. Toisin kuin suuremman partikkelikoon SiO2:lla ja Al2O3:lla ZrO2 -partikkelin eristehäviö laski huomattavasti steariinihappopinnoituksen jälkeen, 6,2 × 10-3:sta 3,8 × 10-3:een. Karakterisoitaessa magnesium- ja kalsiumtitanaattikomposiittijauheita käyttämällä CaTiO3 -moolisuhteita 0,0, 0,02, 0,05 ja 0,1 menetelmällä havaittiin olevan hyvä herkkyys ja tarkkuus mitattavan materiaalin muutoksille. CaTiO3 -määrän lisäykset aiheuttivat selkeän nousun partikkelien kokonaispermittiivisyyksissä, joka kasvoi 13,4:sta 14,9:ään, sekä häviötangentissa, joka kasvoi 7,1 × 10-3:sta aina 8,5 × 10-3:een. Tämän lisäksi resonaattorin mitattuihin ominaisuuksiin sekä general mixing model -yhtälöön perustuvan teoreettisen määrityksen havaittin korreloivan hyvin CaTiO3 -moolisuhteisiin. Karakterisointimenetelmän osoitettiin soveltuvan eristeominaisuuksien mittaukseen sekä havaitsemaan jopa erittäin pienet muutokset jauheiden eristeominaisuuksissa. Menetelmää voitaisiin hyödyntää usean tyyppisissä jauhemateriaalien ominaisuuksien määrityksissä, kuten esimerkiksi erilaisten komposiittijauheiden analysoinnissa ja laaduntarkkailussa
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Chaaban, Abdul Amir. "Etude de l'organisation structurale des nanocolloïdes humiques." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30062/document.
Повний текст джерелаАнотація:
L'organisation des substances humiques à l'échelle moléculaire reste une question largement débattue, et à ce jour, il n'a pas été possible de trancher entre une structure polymérique en pelotte plus ou moins flexible et un assemblage supramoléculaire de molecules hétérogènes associées par des liaisons hydrogènes et des interactions hydrophobes. Dans cette thèse, nous étudions la reconformation induite par l'addition de tensio-actifs cationiques (Chlorure de C n-trimethylammonium) sur une série de substances humiques (acides fulvique et humiques) ainsi que sur de la matière organique naturelle contenue dans des eaux noires. Des mesures de turbidité, de diffusion de lumière, mobilité électrophorétique, tension de surface, spectroscopie de fluorescence, diffusion des neutrons aux petits angles, et cryomicroscopie à transmission, permettent de decrire les complexes formés entre le tensio-actif et la matière humique. L'association matière humique/tensio-actif dépend à la fois d'interactions d'origine électrostatique et hydrophobe. Une série de structures moléculaires, vésicules, disques, globules, pseudo-micelles, est observée en cryomicroscopie selon la concentration en surfactant. La séquence obtenue est cohérente avec un système catanionique, en d'autres termes une partie de la matière humique est amphiphile et s'organise en assemblage supramoléculaire. L'addition de tensio-actif modifie également fortement le spectre de fluorescence de la matière humique, les nouvelles bandes bien résolues présentes sur le spectre indiquant une restructuration majeure de l'assemblage supramoléculaireThe structural organization of humic nanocolloids remains a matter of harsh debate, and surprisingly, it is yet not possible to decide between an arrangement of the humic matter in the form of randomly coiled macromolecules more or less connected, and a supramolecular organization of small heterogeneous molecules linked by hydrogen bonds and hydrophobic interactions. In this study, we investigate the reconformation induced by the addition of cationic surfactants (C n-trimethylammonium chloride) of varying alkyl chain length with a series of humic substances (HS) and Dissolved Organic matter (DOM) from two blackwater rivers of the Central Amazon. Turbidity measurements, Dynamic light scattering, electrophoretic mobility, surface tension, fluorescence spectroscopy, small angle neutron scattering and cryo-transmission electron microscopy (cryo-TEM), are combined to describe the Humic Substance/Surfactant complexes obtained. The association between the oppositely charged HS and cationic surfactant is driven by both electrostatic and hydrophobic interactions. A variety of molecular structures, unilamellar vesicles, disks, globules, spheroidal micelles, are visualized by cryo-TEM depending on surfactant concentration. Such sequence, consistent with those displayed by catanionic systems, provides an independent confirmation of both the amphiphilic nature of HS and of its supramolecular organization. In addition, the molecular rearrangement was investigated using single-scan fluorescence emission spectra spectroscopy, thus identifying the chemical groups responsible for the fluorescence properties in HS and DOM. The addition of cationic surfactant to HS/DOM unveils an unexpected fine structure of humic-like fluorescence through new emission peaks that are not evidenced in the references HS/DOM. An enhanced protein-like fluorescence indicating major restructuration and structural stacking/de-stacking is observed. All our results support a supramolecular organization of humic substances and DOM
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Щукіна, Людмила Павлівна, Георгій Вікторович Лісачук, Ярослав Олегович Галушка, Олена Юріївна Федоренко та Лариса Олександрівна Міхеєнко. "Технологічна цінність промислових хімічних добавок при їх використанні у виробництві будівельної кераміки". Thesis, Одеський національний політехнічний університет, 2013. http://repository.kpi.kharkov.ua/handle/KhPI-Press/31485.
Повний текст джерелаАнотація:
Досліджено технологічну ефективність комплексної поверхнево-активної добавки "MasterКерам" при її використанні у виробництві стінової кераміки для покращення властивостей керамічних мас і матеріалів. Встановлено водоредуційний ефект добавки та її позитивний вплив на міцність коагуляційної та конденсаційної структури мас. Визначена оптимальна кількість добавки, рекомендована для використання у виробництві стінової кераміки рядового призначення.The technological efficiency of complex surface-active additive "MasterCeram" using to improve the properties of ceramic masses and materials in the manufacture of wall ceramics is investigated. The water-reducing effect of the additive and its positive influence on the strength of the coagulation and condensation structure of ceramic masses are established. The optimal amount of additive, which recommended for use in the manufacture of terraced wall ceramic, are established.
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Mahi, Abdellah. "Etude de l'influence des tensioactifs sur l'adsorption des substances humiques et de l'atrazine sur charbon actif." Limoges, 1992. http://www.theses.fr/1992LIMO0161.
Повний текст джерелаАнотація:
Ce travail a pour but d'une part de mettre en évidence les interactions suceptibles de se produire entre certains tensioactifs (anionique, cationique ou non ionique) et les substances humiques et d'autres part d'étudier l'influence de la présence de ces tensioactifs sur l'élimination sur charbon actif en poudre (CAP) des acides humiques d'origine commerciale (AHc) et d'un pesticide : l'atrazine. Des expériences de dialyse ainsi que l'étude de l'influence de la présence de tensioactifs sur l'absorbance en UV 0 254 nm ont montré que les acides humiques (AHc) n'interagissent pas avec le tensioactif cationique (BHTA). Ces interactions sont d'autant plus intenses que les valeurs de PH sont élevées. L'étude de l'adsorption sur CAP en reacteur continu montre que le tensioactif anionique inhibe l'adsorption des acides humiques alors que celle-ci augmente en présence du tensioactif cationique. Le tensioactif non ionique (DE6) présente un comportement plus complexe: à faible concentration il a un effet promoteur de l'adsoption et au-delà d'une concentration de 20 mg/-1 il a un effet défavorable sur l'élimination des acides humiques. L'étude de l'influence de l'ordre d'introduction des solutés et de la mise en suspension du CAP a permis de contribuer à mieux cerner le mécanisme de coadsorption AHc-tensioactifs : Le DSS lorsqu'il s'adsorbe à la surface du CAP déjà chargée négativement, fait varier le potentiel zêta vers des valeurs de plus en plus négatives augmentant ainsi les forces de répulsions entre AHc chargés négativement et la surface de ce CAP. Le BHTA agit sur la surface du CAP en neutralisant les charges négatives, ce qui améliore l'approche des macromolécules(AHc). Le DE6 conditionne la surface du CAP tout en gardant constant son potentiel électrocinétique, il en résulte progressivement un encombrement et une approche de plus en plus difficile pour les AHc. Quelle que soit la nature du tensioactif utilisé comme cosoluté l'élimination de l'atrazine sur CAP est toujours diminuée. L'application de modèles mathématiques (modèle compétitif de Langmuir de la non compétition de l'adsorbion) employés pour la prévision des équilibres d'adsorption de plusieurs soluté a permis de montrer que cette inhibition de l'adsorption de l'atrazine sur CAP ne peut être ni de nature compétitive, ni de nature purement non compétitive.
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Péroval, Claudine. "Influence de la composition, de la structure et du greffage de substances hydrophobes sur les propriétés fonctionnelles de films à base d'arabinoxylanes." Dijon, 2002. http://www.theses.fr/2002DIJOS039.
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Errico, Mary J. "The Cyclodextrin-Perfluorinated Surfactant Host-Guest Complex: Fundamental Studies for Potential Environmental Remediation and Therapeutic Applications." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3758.
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Perfluoroalkyl substances (PFASs) are contaminants of emerging concern, and have been detected in drinking water, wildlife, humans, and the environment. Cyclodextrins (CDs), cyclic sugars composed of glucose monomers, are proposed as a potential remediation strategy. CDs can form host-guest complexes with hydrophobic molecules; this complexation could be capitalized on for PFAS removal and sequestration. These dissertation projects aim to study the fundamental host-guest interactions between a variety of PFASs and CDs for eventual applications in environmental and biological remediation. 1D and 2D Nuclear magnetic resonance (NMR) spectroscopic methods were employed to determine the strength, dynamics, and structure of the CD:PFAS host-guest complexes. Legacy and emerging PFASs were studied with the three native CDs (α-, β-, and γ-CDs) as well as β-CD derivatives. β-CD and its derivatives exhibit the strongest complexation with all studied PFASs, with association constants of 102-105 M-1, depending on PFAS chain length, functional groups, and branching. The host-guest complex was not significantly disturbed under different environmental conditions, such as changing pH, ionic strength, and in the presence of humic acid. A competition study between perfluorooctanoic acid (PFOA), β-CD, and human serum albumin (HSA), the most abundant protein in blood serum, was then conducted using NMR, circular dichroism, and fluorescence spectroscopies. Excess β-CD was able to totally reverse all PFOA binding to HSA. Finally, the host-guest complex was studied within a biological organism to test its viability as a remediation strategy. The attenuation of the toxicity of PFOA in zebrafish embryos, a model organism for toxicology studies, was tested with β-CD. Excess β-CD increased the LC50 (lethal concentration for 50 % of the population) of PFOA compared to PFOA in the absence of β-CD (p < 0.0001). These dissertation projects suggest that the encapsulation of PFASs by CDs has potential in PFAS remediation strategies.
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Benkhedja, Houaria. "Extraction au point de trouble de substances organiques et électrolytes à l'aide de mélangeurs-décanteurs." Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/14245/1/BENKHEDJA.pdf.
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Au-dessus d’une certaine température appelée température de trouble (Tc), les solutions aqueuses de la majorité des tensioactifs non ioniques polyéthoxylés se séparent en deux phases liquides en équilibre : la phase diluée et le coacervat. Grâce à la solubilisation micellaire de composés hydrophobes, amphiphiles ou même ioniques et à leur concentration dans le (faible) volume de coacervat, une extraction à deux phases aqueuses (extraction par point de trouble ou par coacervat)peut être réalisée et appliquée à des opérations de dépollution d'effluents industriels ou à la concentration ou encore à la séparation de substances à haute valeur ajoutée. L’extraction par point de trouble (CPE) est une technique relativement simple et écologique pour l'élimination des matières toxiques de l'environnement, qui s’est avérée efficace dans le traitement de divers contaminants (organiques et inorganiques dissous ou dispersés) de l’eau. Une première partie de cette thèse consiste à rappeler quelques notions sur la pollution industrielle des eaux et quelques généralités sur les tensioactifs (TA) et sur l’extraction liquide-liquide. Elle est suivie d’une description des réactifs, du matériel et des méthodes utilisées au cours de ce travail, comme préliminaire à la mise au point d'un procédé d'extraction par coacervat. Quelques propriétés thermodynamiques superficielles (adsorption) et d’association (micellisation) de deux tensioactifs non ioniques industriels (le Simulsol NW342 et le Tergitol 15-S-7) ont été déterminées. Les courbes de démixtion des systèmes binaires (eau/TA) ainsi que l’effet de divers additifs (sel, composés organiques, tensioactifs ioniques) sur le point de trouble sont étudiés. Le diagramme isotherme du système ternaire (eau/TA/ phénol) est tracé. Une application du modèle de Flory-Huggins-Rupert pour la prédiction des courbes de démixtion des tensioactifs non ioniques a été expérimentée. L’extraction à un seul contact, à partir de solutions modèles, utilise des alcools oxo éthoxylés biodégradables (Simulsol NW342 et Tergitol 15-S-7) pour des polluants organiques dissous (phénol, 1-phényléthanol et alcool benzylique) et un mélange de tensioactifs non ionique (Simulsol NW342) et ionique (SDS ou CTAB) pour des polluants métalliques solubles (plomb(II), molybdène(VI)). On cherche le meilleur compromis entre le pourcentage de soluté extrait (E%),la fraction volumique du coacervat (фv), et les pourcentages de soluté et de tensioactif restants dans la phase diluée (Xs,d et XTA, d), en utilisant un plan d'expériences de type Scheffé et un lissage empirique des courbes. Les résultats sont très prometteurs car les pourcentages d’extraction varient de 60 à 95% pour les solutés organiques et de 40 à 85% pour les solutés métalliques, les meilleures performances étant obtenues pour le phénol et le plomb. D’autre part, il est possible, en jouant sur le pH, d’améliorer les séparations et de recycler le tensioactif après désextraction des solutés. Les cinétiques d’extraction, de séparation et de clarification ont été aussi étudiées pour une meilleure compréhension de ces systèmes. Enfin, l’extraction continue du phénol à partir du mélange eau/4%Simulsol NW342/0,2%phénol (mass.) a été testée sur deux appareillages (extracteur centrifuge et mélangeurdécanteur)thermostatés. Dans un procédé multi-étagé à courants croisés sur un mélangeur-décanteur, on arrive à réduire la concentration du phénol à moins de 0,3ppm (concentration limite selon la législation) après six étages.
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Fribertová, Marcela. "Posouzení základních ukazatelů odpadní vody firmy Dermacol." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216589.
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This master thesis is focused on waste waters from cosmetics industry and basic indicators of these waters. The pollution of the environment caused by increase industrial development has a negative effect on ecosystem. Waste waters are part of the pollution. In theoretical part a basic indicators of waters (its definition and way of determination) have been described. Membrane processes for water purification have been mentioned as well – particularly the ultrafiltration. The experimental part of thesis deals with practical determination of indicators mentioned in methods described in the theoretical part. Results are discussed at the close. The discussion is focused on evaluation of efficiency of the device for waste waters adjustment, which is in use in the Dermacol company, which produces cosmetics products.
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Rossi, C?tia Guaraciara Fernandes Teixeira. "Inibi??o ? corros?o do a?o AISI 1020, em meios ?cido e salino, por tensoativos e subst?ncias nitrogenadas microemulsionados." Universidade Federal do Rio Grande do Norte, 2007. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17668.
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Corrosion inhibition efficiency of saponified coconut oil (SCO) and sodium dodecilbenzene sulfonate (DBS) surfactants in AISI 1020 carbon steel was evaluated by electrochemical methods. These surfactants were also evaluated as microemulsion systems (SCO-ME and DBS-ME), of O/W type (water-rich microemulsion), in a Winsor IV region. They were obtained according to the following composition: 15% SCO, 15% butanol (30% Co-surfactant/Surfactant C/T), 10% organic phase (FO, kerosene) and 60% aqueous phase (FA). These systems were also used to solubilize the following nitrogenated substances: Diphenylcarbazide (DC), 2,4-dinitro-phenyl-thiosemicarbazide (TSC) and the mesoionic type compound 1,3,4-triazolium-2-thiolate (MI), that were investigated with the purpose of evaluating their anticorrosive effects. Comparative studies of carbon steel corrosion inhibition efficiencies of free DBS and DBS-ME, in brine and acidic media (0.5%), showed that DBS presents better inhibition results in acidic media (free DBS, 89% and DBS-ME, 93%). However, the values obtained for DBS in salted solution (72% free DBS and 77% DBS-ME) were similar to the ones observed for the SCO surfactant in brine (63% free SCO and 74% SCO-ME). Analysis of corrosion inhibition of the nitrogenated substances that were solubilized in the SCO-ME microemulsion system by the linear polarization method in brine (0.5% NaCl) showed that such compounds are very efficient an corrosion inhibitors [DC-ME-SCO (92%), TSC-ME-SCO (93%) and MI-ME-SCO (94%)]
A efici?ncia de inibi??o ? corros?o em a?o AISI 1020 dos tensoativos ?leo de coco saponificado (OCS) e dodecilbenzeno sulfonato de s?dio (DBS), foi avaliada por m?todos eletroqu?micos. Estes tensoativos foram tamb?m avaliados em sistemas microemulsionados (OCS-ME e DBS-ME), do tipo O/A (microemuls?o rica em ?gua) com regi?o de trabalho Winsor IV, e foram obtidos na seguinte composi??o: 15% de OCS, 15% de butanol (30% de Cotensoativo/tensoativo - C/T), 10% de fase org?nica (FO, querosene) e 60% de fase aquosa (FA), tendo sido utilizados, ainda, para a solubiliza??o das subst?ncias nitrogenadas difenilcarbazida (DC), 2,4-dinitro-fenil-tiossemicarbazida (TSC) e do heterociclo do tipo mesoi?nico 1,3,4-triaz?lio-2-tiolato (MI), que foram disponibilizadas para avalia??o dos seus efeitos anticorrosivos. Os estudos comparativos das efici?ncias dos tensoativos DBS livre e DBS-ME na inibi??o da corros?o de a?o carbono, em meios salino e ?cido (0,5%), mostraram que o DBS apresenta melhores resultados de inibi??o em meio ?cido (DBS livre, 89% e DBS-ME, 93%). No entanto, os valores obtidos para o DBS em meio salino (72% DBS livre e 77% DBS-ME) foram semelhantes aos valores observados para o tensoativo OCS em meio salino (63% OCS livre e 74% OCS-ME). A an?lise de inibi??o ? corros?o das subst?ncias nitrogenadas solubilizadas no sistema microemulsionado OCS-ME, pelo m?todo de curvas de polariza??o linear em meio salino (NaCl 0,5%) mostrou que tais compostos s?o muito eficazes na inibi??o ? corros?o [DC-ME-OCS (92%), TSC-ME-OCS (93%) e MI-ME-OCS (94%)]
Книги з теми "Surfactant substances"
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Transport and remediation of subsurface contaminants: Colloidal, interfacial, and surfactant phenomena. Washington, DC: American Chemical Society, 1992.
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(Editor), David A. Sabatini, and Robert C. Knox (Editor), eds. Transport and Remediation of Subsurface Contaminants: Colloidal, Interfacial, and Surfactant Phenomena (Acs Symposium Series). An American Chemical Society Publication, 1998.
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Thurman, E. M., and Jennifer Field. "Separation of Humic Substances and Anionic Surfactants from Ground Water by Selective Adsorption." In Advances in Chemistry, 107–14. Washington, DC: American Chemical Society, 1988. http://dx.doi.org/10.1021/ba-1988-0219.ch008.
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Guerranti, Cristiana, Serena Anselmi, Francesca Provenza, Andrea Blašković, and Monia Renzi. "Action of Surfactants in Driving Ecotoxicity of Microplastic-Nano Metal Oxides Mixtures: A Case Study on Daphnia magna under Different Nutritional Conditions." In Surfactants [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99487.
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The series of experiments presented in the paper served to clarify the effects of contemporary exposure to surfactant, microplastics (polyethylene and polyvinyl chloride), and nanoparticles (TiO2 and ZnO) on the model organism Daphnia magna. Exposure was evaluated with respect to the age of the organisms (“young”, 24 hours old, and “aged” 10 days old specimens), trophic status (feeding or fasting), and the simultaneous presence of a surfactant. All the above-mentioned substances are present in the wastewater coming from various environmental sources from cosmetic products. The experiments were conducted in compliance with the OECD 202:2004 guideline, which is also a reference for ecotoxicity tests required by REACH. The results showed that surfactants enhance effects of toxicity produced by the exposure to the microplastic + nanoparticle mixtures. The influence due to factors such as nutrition (effect in fasting >> feeding conditions) and the age of individuals (effects in older >> younger animals) is essential. Concerning young individuals, exposure to PE-TiO2 is the most significant in terms of effects produced: it is very significant, especially in the presence of surfactant (both under fasting and feeding conditions). On the contrary, exposure to the PE-Zn mixture shows the minor effects. The comparison with the literature, especially as regards the possibility of interpreting the toxicity trends for the various mixtures with respect to the individual elements that compose them, leads to hypothesize additive effects still to be investigated and confirms the greatest toxicity contribution of TiO2.
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Shyshkina, Alexandra. "THE APPLICATION OF COLLOIDAL SURFACES AS A CATALYST OF CEMENT HYDRATION REACTIONS." In Integration of traditional and innovation processes of development of modern science. Publishing House “Baltija Publishing”, 2020. http://dx.doi.org/10.30525/978-9934-26-021-6-43.
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The purpose of this work is to establish the fundamental possibility of using complex complexes consisting of colloidal and molecular surfactants to catalyze the hydration of cement compositions, the study of mechanical properties. As a result of research, it was found that the introduction of colloidal surfactant into the reaction powder concrete leads to a sharp increase in the strength of concrete at the age of 7 days. It is noted the presence of the optimal content of colloidal surfactant in the amount of 0.0007% by weight of water, which ensures the formation of the maximum strength of the system. In the next step of the experiment, an additional molecular surfactant was introduced into the system. As a result of experiments it was found that the introduction of this substance increases the strength of concrete. Thus, it was found that dimers of colloidal surfactant, which are nanocatalysts for cement hydration reactions, lead to an increase in the strength of concrete and the rate of its formation.
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Pardakhty, Abbas. "Non-Ionic Surfactant Vesicles (Niosomes) as New Drug Delivery Systems." In Pharmaceutical Sciences, 154–84. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-1762-7.ch007.
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Lipid vesicular systems composed of hydrated amphihiles with or without bilayer inducing agents such as cholesterol. On the basis of used amphiphilic molecule different nomenclature are used as liposomes, ufasomes and niosomes. Nonionic surfactants with mono-, di- or trialkyl chains form niosomes which are lipid vesicles with more chemical stability in comparison with phospholipids of liposomes. Both hydrophobic and hydrophilic chemicals can be encapsulated in niosomes as a new drug delivery system. This drug carrier system could have administered via injection, oral, pulmonary, vaginal, rectal, ophthalmic, nasal or transdermal routes with penetration enhancing potential. This chapter presents a detailed explain about niosome forming components, methods of preparation and routes of administration. Many examples for drug delivery potential of niosomes are also available in this review. Vaccine adjuvant and genetic substances vector capabilities are not given here.
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Pardakhty, Abbas. "Non-Ionic Surfactant Vesicles (Niosomes) as New Drug Delivery Systems." In Advances in Medical Technologies and Clinical Practice, 89–119. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0751-2.ch004.
Повний текст джерелаАнотація:
Lipid vesicular systems composed of hydrated amphihiles with or without bilayer inducing agents such as cholesterol. On the basis of used amphiphilic molecule different nomenclature are used as liposomes, ufasomes and niosomes. Nonionic surfactants with mono-, di- or trialkyl chains form niosomes which are lipid vesicles with more chemical stability in comparison with phospholipids of liposomes. Both hydrophobic and hydrophilic chemicals can be encapsulated in niosomes as a new drug delivery system. This drug carrier system could have administered via injection, oral, pulmonary, vaginal, rectal, ophthalmic, nasal or transdermal routes with penetration enhancing potential. This chapter presents a detailed explain about niosome forming components, methods of preparation and routes of administration. Many examples for drug delivery potential of niosomes are also available in this review. Vaccine adjuvant and genetic substances vector capabilities are not given here.
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Djekic, Ljiljana. "Liposomes." In Advances in Medical Technologies and Clinical Practice, 27–51. IGI Global, 2017. http://dx.doi.org/10.4018/978-1-5225-0751-2.ch002.
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This chapter reviews the current progress in liposome based pharmaceuticals with particular emphasis on the carrier design, size, surface properties, drug delivery performances and therapeutic applications for different routes of administration. There were described selected examples of encapsulation of drug substances by liposomes which allowed improvement of therapeutic index of cytotoxic drugs (such as antineoplastics, antibiotics) or sustained drug release and reduction of the frequency of administration of analgesics and local anesthetics, and potentiate the immunogenicity of vaccines against hepatitis A and influenza. Furthermore, the performances of the marketed pharmaceuticals which represent pulmonary surfactant substituents (in the form of liposome vesicles) in premature infants and topical preparations with high molecular weight actives (e.g., heparin sodium) encapsulated in liposomes, were highlighted. The most important factors that affect the development of new drugs with this type of nanomaterials and their safety were commented.
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Obladen, Michael. "Holding breath." In Oxford Textbook of the Newborn, edited by Michael Obladen, 91–94. Oxford University Press, 2021. http://dx.doi.org/10.1093/med/9780198854807.003.0014.
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The physical properties of surfactant were identified in the early 1950s from research on warfare chemicals by Pattle in Britain and by Radford and Clements in the US. The causal relationship between respiratory distress syndrome and surfactant deficiency was established in Boston by Avery and Mead in 1959. The Australian obstetrician Liggins induced lung maturity with glucocorticoids in 1972, but his discovery was not fully accepted for another 20 years. When the major surfactant compound was identified as dipalmitoyl-phosphatidylcholine, this substance was nebulized with little effect and it became clear that there were other components of natural surfactant required besides phospholipids. A century of basic research was rewarded when Fujiwara introduced bovine surfactant substitution in Japan in 1980 to treat and prevent respiratory distress syndrome in preterm infants. Surfactant substitution greatly alleviated respiratory distress syndrome and increased the preterm infant’s chance of survival. In addition, it has set high scientific standards for the introduction of new therapies for neonates and made the randomized multicentre trial the favoured tool for clinical innovations.
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Wlodzimierz Sulek, Marian. "Aqueous Solutions of Oxyethylated Fatty Alcohols as Model Lubricating Substances." In Surfactants in Tribology. CRC Press, 2008. http://dx.doi.org/10.1201/9781420060089.ch17.
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"Aqueous Solutions of Oxyethylated Fatty Alcohols as Model Lubricating Substances." In Surfactants in Tribology, Volume 1, 357–86. CRC Press, 2008. http://dx.doi.org/10.1201/9781420060089-26.
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Kovalenko, Galina, and Larisa Perminova. "Heterogeneous Biocatalysts for the Final Stages of Deep Processing of Renewable Resources into Valuable Products." In Molecular Biotechnology [Working Title]. IntechOpen, 2020. http://dx.doi.org/10.5772/intechopen.89411.
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Heterogeneous biocatalysis is a part of biotechnology and it has commercial potential for industrial implementation, in particular the final stages of deep processing of renewable raw materials. The commercially attractive heterogeneous biocatalysts are prepared by immobilizing practically valuable enzymatic active substances onto solid inorganic supports. Heterogeneous biocatalytic processes of the target conversion of substrate into valuable market product are carried out in periodic or continuous modes using traditional batch and packed-bed reactors, as well as novel types of vortex reactors in accordance with the principles of green chemistry. Heterogeneous biocatalysts for the final stages of deep processing of vegetable raw materials such as starch and oils are described here. One of the biocatalysts is glucoamylase immobilized by adsorption on mesoporous carbon support Sibunit™ type. This glucoamylase-active biocatalyst is used at the stage of starch saccharification, i.e., hydrolysis of dextrin to treacle and glucose syrups used in food and confectionary industries. The second of the biocatalysts is recombinant T. lanuginosus lipase immobilized on mesoporous silica KSK™ type and macroporous carbon aerogel. These lipase-active biocatalysts can effectively compete with traditional organic synthesis catalysts, and they are used in low-temperature processes carried out in unconventional anhydrous media such as interesterification of vegetable oils’ triglycerides with ethyl acetate for producing ethyl esters of fatty acids (biodiesel and vitamin F) and esterification of fatty acids with aliphatic alcohols for synthesis of various esters used as fragrances, flavorings, odors, emollients, and nonionic surfactants in perfume and cosmetics industries. The prepared heterogeneous biocatalysts due to their high enzymatic activity and operational stability are promising for practical implementation.
Тези доповідей конференцій з теми "Surfactant substances"
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Vathanapanich, Y., and F. Srisuriyachai. "Reduction of Surfactant Adsorption by Alkali Substances in Carbonate Reservoir." In 79th EAGE Conference and Exhibition 2017. Netherlands: EAGE Publications BV, 2017. http://dx.doi.org/10.3997/2214-4609.201701291.
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Simion, Demetra, Carmen Gaidau, Jianzhong Ma, and Zhang Wenbo. "New nanostructured composite obtained by innovative technologies." In The 8th International Conference on Advanced Materials and Systems. INCDTP - Leather and Footwear Research Institute (ICPI), Bucharest, Romania, 2020. http://dx.doi.org/10.24264/icams-2020.ii.22.
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The paper is focused on obtaining a new nanostructured composite by innovative technologies based on: fibrillar cellulose/titanium dioxide/surfactants (bolaform- dodecandioyl-diglycine and surfactant classic-collagen hydrolysate)/ethanol/water, for improved surface properties. Innovation consists in technologies for obtaining new nanostructured composites, solubilisation/compatibilisation of their component substances for the conditioning of supports processed with the film created by evaporation of the emulsion nanocomposites. Fibrillar cellulose/titanium dioxide nanocomposites have been stabilized with bolaform surfactants in a 1:1 ratio of ethanol/water solvents in order to increase the uniformity of titanium dioxide shell nanocomposites. Nanostructured “cauliflower”-like composites developed as a result of biopolymer-surfactant interactions for fibrillar cellulose/titanium dioxide/bolaform couple in ethanol/water system are reported by SEM microscopy. The analysis by FTIR-ATR spectroscopy of bolaform, fibrillar cellulose and dynamic light scattering of 2 types of nanocomposites emulsions (with bolaform and classic surfactant emulsions) were reported. The new nanocomposites could provide the hybrid film with increased mechanical resistance to water and heat. Supports processing with the composite film improve wet/dry friction resistance, water resistance and tensile strength. Environmentally-friendly supports with smart multifunctional features are obtained for various applications.
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Gaver, Donald P., Melissa A. Krueger, and Samir N. Ghadiali. "The Influence of Surfactant Physicochemical Properties on Pulmonary Interfacial Flow Analogues." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0218.
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Abstract Many of the lung’s mechanical properties are influenced by pulmonary surfactant physicochemical characteristics. Pulmonary surfactant is a complex lipid-protein mixture formed in the type II alveolar cells and secreted into the alveolar subphase [1]. These substances reduce the surface tension at the air-liquid interface of the lining fluid that coats the interior of the lung. At sufficiently high concentrations, pulmonary surfactant reduces the surface tension to near zero and. in the process, stabilizes the alveoli and small airways [2–4].
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Imamura, Koreyoshi, K. Takeda, K. Yamamoto, H. Imanaka, and N. Ishida. "Thermal stability of amorphous sugar matrix, dried from methanol, as an amorphous solid dispersion carrier." In 21st International Drying Symposium. Valencia: Universitat Politècnica València, 2018. http://dx.doi.org/10.4995/ids2018.2018.7716.
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Developing a technique to disperse hydrophobic ingredients homogeneously in a water-soluble solid matrix (solid dispersion) is one of the topics that have been extensively investigated in the pharmaceutical and food industries. Recently, we have devised a novel solid dispersion technique (surfactant-free solid dispersion), in which a preliminarily amorphized sugar was dissolved in an organic media containing hydrophobic component, without using any surface active substances, and then vacuum dried into the amorphous solid mixture [Food Chem., 197 (2016) 1136; Mol. Pharm., 14 (2017) 791]. In this study, the physicochemical properties, especially thermal stability of the surfactant-free amorphous solid dispersion, were investigated. keywords: solid dispersion; amorphous sugar; surfactant-free; vacuum drying; glass transition temperature
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Aldi, Nicola, Nicola Casari, Devid Dainese, Mirko Morini, Michele Pinelli, Pier Ruggero Spina, and Alessio Suman. "The Effects of Third Substances at the Particle/Surface Interface in Compressor Fouling." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64425.
Повний текст джерелаАнотація:
Since the beginning of the 1950s, manufacturers and operators have struggled to understand, reduce and eliminate compressor fouling and its effects on gas turbine operation. Several devices (inertial separators, barriers, filters, etc.) and strategies (on-line and off-line washing, manual cleaning, etc.) have been adopted in order to limit and/or eliminate the foulants which stick to the compressor blade and vane surfaces. The state of the power plant design and installation and environmental conditions determine the rate of fouling and, in turn, gas turbine performance losses. The types of contaminant (organic or inorganic), their concentration and their ability to stick are variable depending on the weather conditions. Desert, tropical, rural, and off-shore conditions are characterized by different foulants with different characteristics which determine compressor fouling. In this paper, an analysis of the influence of third substances at the particle/surface interface is presented. The analysis is carried out on two different compressor rotors, transonic and subsonic. Firstly, a sensitivity analysis is proposed related to the particle diameter and foulant mixture in order to highlight the influence of air humidity due to environmental conditions or the pressure drop after the filtration stages. The effects of a water electrolytic solution (generated by the presence of inorganic matter) and a water surfactant solution (used in the case of washing) are also considered. In this case, the properties of the mixture substance (solid particles bound by a liquid film) are considered. Secondly, using previous numerical analyses (particle-laden flow with a Eulerian-Lagrangian approach) as a starting point, the variation in particle sticking ability is evaluated against the presence of third substances (water solutions and oily substances) and the particle kinematic characteristics using a sticking model based on an energy balance equation. The results show the influence of the third substance on particle sticking capability using a susceptibility-to-fouling criterion. Particularly in the presence of humid conditions, sticking capability increases with respect to dry conditions, even though the major effects are due to the mixture viscosity and not only to the presence of liquid water. The sticking capability of the mixture varies according to particle diameter as a function of the particle normal velocity. The results are presented in order to easily quantify the effects of the presence of a third substance at the particle/surface interface according to the type of liquid phase involved in the sticking process.
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Afanas'ev, S. O., and M. A. Pal'chikov. "The course of paranoid schizophrenia comorbid with substance abuse surfactant: clinical happening." In Scientific dialogue: Medical issues. ЦНК МОАН, 2019. http://dx.doi.org/10.18411/spc-15-05-2019-04.
Повний текст джерела
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Salazar, V., J. E. Gonza´lez, and L. A. Rivera. "Measurement of Temperatures on In-Flight Water Droplets by Laser Induced Fluorescence Thermometry." In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47100.
Повний текст джерелаАнотація:
This work presents the use of laser induced fluorescence for instantaneous temperature measurements of a 200μm diameter water droplets monodispersed stream traveling downward in a standard stagnant atmosphere. The droplets are doped with small concentrations of a natural fluorescence dye (Pyrene), and with a surfactant substance, cetyldimetylbenzylammoniumchloride (CDBAC) to improve the fluorescence emission. The rate of the two-band pyreme emission (excimer to monomer) is used to determine the temperature. The temperature distribution along the stream of droplets determined for different initial temperatures: (30°C, 40°C and 50°C) at the exit of the nozzle compared very favorably with numerical results.
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Slamet, Muhammad Ibadurrohman, and Pangiastika Putri Wulandari. "Synthesis of methyl ester sulfonate surfactant from crude palm oil as an active substance of laundry liquid detergent." In PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON APPLIED CHEMISTRY 2017. Author(s), 2017. http://dx.doi.org/10.1063/1.5011915.
Повний текст джерела
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Iburi, Yuki, Jie Huang, and Takayuki Saito. "The Effects of Bubble Interface Contamination on Bubble Motion, Bubble-Induced Surrounding Liquid Motion and Mass Transfer." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-30406.
Повний текст джерелаАнотація:
Mass transfer from a bubble to the surrounding liquid plays an important role in chemical engineering processes. To improve the efficiency and safety of the processes, a deep understanding of the mass transfer mechanism from bubbles to the surrounding liquid is essential. In the present study, we examined a CO2 single bubble of 2∼3 mm in equivalent diameter that ascended zigzag in purified water and contaminated water (500ppm 1-pentanol solution). We used a high speed video camera systems with high spatial and temporal resolution, for visualization of the bubble wake and bubble-induced surrounding liquid motion. The dissolution process of CO2 from the bubble to the surrounding liquid was visualized via LIF/HPTS (Laser Induced Fluorescence) method. HPTS, which is a fluorescent substance, was excited by Ar ion laser with a wavelength of 458 nm, then emitted with a wavelength of 513 nm. A pH level of CO2 solution decreased with increase in CO2 concentration; hence the emission intensity of HPTS was reduced. As a result, dark regions observed below the bubble rear accorded with the bubble wakes; from visualization of this bubble wakes through the high speed video cameras, dynamic CO2 dissolution process was obtained. In the purified water, the bubble shape was oblate ellipsoid, and horse-shoe-like vortices were formed in the rear of the bubble. On the other hand, in the contaminated water, the bubble was nearly spherical. Furthermore, behavior of the vortices changed. These different results in two conditions were caused by the decrease in the surface tension owing to the bubble surface contamination. While the bubble was rising, the non-uniform distribution of the surfactant on the bubble surface occurred. Hence, a gradient of the surface tension was formed on the bubble surface, furthermore, it caused the Marangoni convection. Meanwhile, in order to consider the relationship between dissolution process and the surrounding liquid motion, we measured the liquid phase velocities via PIV.