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Use of quantitative structure activity relationships in prediction of CMC of nonionic surfactants
, Article Quantitative Structure-Activity Relationships ; Volume 19, Issue 2 , 2000 , Pages 135-141 ; 09318771 (ISSN) ; Konouz, E ; Sharif University of Technology
2000
Abstract
The CMC of a set of51 alkylpolyoxyethylene glycol ethers, R(EO)(m), and alkylphenol (ethylene oxide) ethers, RΦ(EO)(m), was related to topological, electronic and molecular structure parameters using a stepwise regression method. In development of the models linear and quadratic terms were used without the use of cross terms. Different strategies including Akaike Information Criterion (AIC) were used for choosing the best model. Specification of the best model in agreement with the experiment indicates that volume of the hydrophobic group and surface area of the molecule play a major role in the mechanism of micellization of nonionic surfactants. It was demonstrated that the CMC of these...
Qualitative Study of the Dynamic Adsorption Layer by Bubble Rising Method
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor) ; Lotfi, marzieh (Co-Advisor)
Abstract
Surface phenomena and dynamic interfacial properties plays a significant role in multiphase gas-liquid & liquid-liquid processes applied in different industrial applications. However, current laboratory equipment and represented methods for dynamic and unsteady state condition caused by motivation of interface of two phases (like rising bubble), in purpose of qualitative investigation of interphase properties are not satisfying enough. Also, common modeling methods are represented with lots of modified assumptions which are not validated properly with experimental results. In current thesis, with development of laboratory tools and applying the “rising bubble method” for investigating the...
The impact of surfactants on wettability change and level of water imbibition in relation to EOR in carbonate reservoirs
, Article Petroleum Science and Technology ; Volume 31, Issue 20 , 2013 , Pages 2098-2109 ; 10916466 (ISSN) ; Bastani, D ; Badakhshan, A ; Sharif University of Technology
2013
A simple shape-controlled synthesis of gold nanoparticles using nonionic surfactants
, Article RSC Advances ; Volume 3, Issue 21 , 2013 , Pages 7726-7732 ; 20462069 (ISSN) ; Karami, P ; Robatjazi, H ; Sharif University of Technology
2013
Abstract
Green and simple synthesis strategies have gained tremendous popularity for the production of anisotropically-shaped noble metallic nanoparticles. The long-term stability of the produced particles, the short timescale of the target reaction(s), as well as the use of non-toxic chemicals, are pivotal features of a useful green procedure. Herein we describe a simple and convenient wet-chemical approach to synthesize stable, non-toxic and water-soluble small gold nanotriangles (GNTs) and gold nanospheres (GNSs) in one step at room temperature, using Tween 20 and Tween 80, respectively. A high level of purity and monodispersity was obtained for the GNTs, in addition to an excellent colloidal...
Effects of contaminants on the mass-transfer characteristics of a two-impinging-streams gas-liquid reactor
, Article Chemical Engineering and Technology ; Volume 34, Issue 11 , 2011 , Pages 1797-1806 ; 09307516 (ISSN) ; Savari, C ; Sharif University of Technology
Abstract
The mass-transfer characteristics of a new type of two-impinging-streams reactor (TISR) was studied by means of sodium sulfite solution as the liquid phase and air as the gas phase, in the presence and absence of various types of surface-active agents (SAAs). The influences of anionic, cationic, and nonionic SAAs on the specific interfacial area and overall volumetric mass-transfer coefficient obtained in the TISR were investigated. It was found that the presence of a little amount of the above-mentioned contaminants increases the specific interfacial area and decreases the overall volumetric mass-transfer coefficient. On the basis of the experimental results obtained for various types of...
Combined model of mass-transfer coefficients for clean and contaminated liquid-liquid systems
, Article Industrial and Engineering Chemistry Research ; Volume 50, Issue 8 , 2011 , Pages 4608-4617 ; 08885885 (ISSN) ; Dehkordi, A. M ; Darbandi, M ; Shahalami, M ; Saien, J ; Sharif University of Technology
Abstract
Mass-transfer rates to and from drops in liquid-liquid extraction processes are often reduced by the presence of contaminants. To design an industrial extractor, it is essential to consider this contamination effect in a quantitative manner. To achieve this goal, an experimental investigation was conducted on the mass transfer into single drops for n-butanol-succinic acid-water, as the recommended test system by the European Federation of Chemical Engineering (EFCE). The effects of anionic (sodium dodecyl sulfate, SDS), cationic (dodecyl trimethyl ammonium chloride, DTMAC), and nonionic (octylphenol decaethylene glycol ether, Triton X-100) surfactants on the hydrodynamic and mass-transfer...
Mechanism of surfactant in trichloroethene degradation in aqueous solution by sodium persulfate activated with chelated-Fe(II)
, Article Journal of Hazardous Materials ; Volume 407 , 2021 ; 03043894 (ISSN) ; Li, M ; Gu, X ; Danish, M ; Shan, A ; Ali, M ; Qiu, Z ; Sui, Q ; Lyu, S ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The mechanism of surfactants in surfactant-in situ chemical oxidation (S-ISCO) coupled process for trichloroethene (TCE) degradation was firstly reported. The performance of TCE solubilization and inhibition of TCE degradation in three nonionic surfactants (TW-80, Brij-35, TX-100) in PS/Fe(II)/citric acid (CA) system was compared and TW-80 was evaluated to be the optimal surfactant in S-ISCO coupled process due to the best TCE solubilizing ability and minimal inhibition for TCE degradation (only 31.8% TCE inhibition in the presence of 1 g L−1 TW-80 surfactant). The inhibition mechanism in TCE degradation was also demonstrated by comparing the strength of ROSs and PS utilization. In the...
Influence of β-lactoglobulin and its surfactant mixtures on velocity of the rising bubbles
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Vol. 460 , October , 2014 , pp. 361-368 ; ISSN: 09277757 ; Krzan, M ; Lotfi, M ; Dukhin, S. S ; Kovalchuk, V. I ; Javadi, A ; Gunes, D. Z ; Gehin-Delval, C ; Malysa, K ; Miller, R ; Sharif University of Technology
Abstract
The rising velocity of air bubbles in surfactant solutions is a sensitive measure for the formation of a dynamic adsorption layer (DAL) at the bubble surface. Due to a certain surface coverage by adsorbed species the bubble surface starts to become immobilized and the rising velocity is retarded. There is a large difference in the retardation effect in presence of the protein β-lactoglobulin (BLG) alone and its mixed solutions with surfactants. In presence of added surfactants BLG forms complexes, which adsorb and retard the bubble rising velocity according to their respective surface activity and adsorption kinetics. While the nonionic surfactant C12DMPO does not show significant increase...
Influence of quantum effect on deviation from linear isotherm regularity
, Article Scientia Iranica ; Volume 19, Issue 3 , June , 2012 , Pages 555-560 ; 10263098 (ISSN) ; Parsafar, G. A ; Sharif University of Technology
2012
Abstract
A general regularity was found based on an effective pair potential of Lennard-Jones LJ (12, 6), for both dense, nonmetallic and nonionic fluids and solids according to which (Z-1) v2 linearly varies with respect to ρ2 for each isotherm, and this equation of state (EoS I) is known as LIR. However, despite the fact that Ne is a simple spherical species, unexpectedly, its solid and liquid phases both show a significant deviation from EoS I. In this work, we have investigated the accuracy of the EoS I for other systems, including quantum light molecules, such as D 2, H 2 and He, in both fluid and solid states at different temperatures. Like Ne, we have noticed that these systems do not well...
Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 3. dilational surface rheology
, Article Journal of Physical Chemistry B ; Volume 119, Issue 9 , January , 2015 , Pages 3768-3775 ; 15206106 (ISSN) ; Aksenenko, E. V ; Lylyk, S. V ; Lotfi, M ; Miller, R ; Sharif University of Technology
Abstract
The influence of the addition of the nonionic surfactants C12 DMPO, C14 DMPO, C10 OH, and C10 EO5 at concentrations between 10-5 and 10-1 mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10-5 mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10-4 to 10-3 mmol/L) for mixtures of BCS with C12 DMPO and C14 DMPO and for mixtures of BLG with C10 EO5 , while for mixture of BCS with C10 EO5 the value of |E| only slightly increased. The |E| values...
Wettability alteration of carbonate rock by nonionic surfactants in water-based drilling fluid
, Article International Journal of Environmental Science and Technology ; 2018 ; 17351472 (ISSN) ; Ramazani SaadatAbadi, A ; Jafari Behbahani, T ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2018
Abstract
The influx of solid or liquid particles of drilling mud into the pores of rock or mud loss phenomenon and clay swelling can sometimes lead to severe productive formation damage and cause to wettability alterations of reservoir rock from hydrophilic to oleophilic. Therefore, designing an appropriate fluid that is compatible with formation fluids and could reduce reservoir damage and increase the productivity of wells is very important. The two main mechanisms of surfactants are reduction of the surface tension and wettability alteration of rock reservoir that are effective in taking the oil. Regarding the importance of the wettability in reservoir productivity, this article is aimed to study...
Investigating the effects of pH, surfactant and ionic strength on the stability of alumina/water nanofluids using DLVO theory
, Article Journal of Thermal Analysis and Calorimetry ; 2018 ; 13886150 (ISSN) ; Yoozbashizadeh, H ; Madaah Hosseini, H. R ; Sharif University of Technology
Springer Netherlands
2018
Abstract
Alumina nanofluids are one of the most useful nanofluids. In order to evaluate the colloidal behavior of nanoparticles in alumina/water nanofluid, the influence of effective factors such as pH, ionic strength and surfactants, was studied. Zeta potential, particle size and turbidity change of each nanofluid was investigated. According to the results for 0.05, 0.1 and 0.2 mass% nanofluid, point of zero charge was obtained at pH values of 9.5, 10.2 and 10.5, respectively. The highest nanofluid stability occurred at pH 4 and its lowest was at pH 10. The anionic surfactant had a greater effect on the stability in compared with cationic and nonionic surfactants. By increasing in ionic strength,...
Investigating the effects of pH, surfactant and ionic strength on the stability of alumina/water nanofluids using DLVO theory
, Article Journal of Thermal Analysis and Calorimetry ; Volume 135, Issue 2 , 2019 , Pages 1185-1196 ; 13886150 (ISSN) ; Yoozbashizadeh, H ; Madaah Hosseini, H. R ; Sharif University of Technology
Springer Netherlands
2019
Abstract
Alumina nanofluids are one of the most useful nanofluids. In order to evaluate the colloidal behavior of nanoparticles in alumina/water nanofluid, the influence of effective factors such as pH, ionic strength and surfactants, was studied. Zeta potential, particle size and turbidity change of each nanofluid was investigated. According to the results for 0.05, 0.1 and 0.2 mass% nanofluid, point of zero charge was obtained at pH values of 9.5, 10.2 and 10.5, respectively. The highest nanofluid stability occurred at pH 4 and its lowest was at pH 10. The anionic surfactant had a greater effect on the stability in compared with cationic and nonionic surfactants. By increasing in ionic strength,...
Retarding effect of contaminants on the performance of a two-impinging-jets liquid-liquid extraction contactor
, Article Chemical Engineering and Technology ; Volume 33, Issue 6 , June , 2010 , Pages 1003-1010 ; 09307516 (ISSN) ; Doghahe, S. A. O ; Dehkordi, A. M ; Sharif University of Technology
2010
Abstract
In industrial liquid-liquid extraction processes, the feed is not clean liquid but there are various kinds of contaminants in the feed entering the extractors. In this regard, a two-impinging-jets contacting device (TIJCD) was tested through the standard test system recommended by the European Federation of Chemical Engineering (EFCE), namely toluene-acetone-water, in the presence and absence of various types of surface-active agents (SAAs). The influences of anionic, cationic, and nonionic SAAs such as sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride (DTMAC), and octylphenol decaethylene glycol ether (Triton X-100), respectively, on the extraction efficiency and overall...
Adsorption of proteins at the solution/air interface influenced by added non-ionic surfactants at very low concentrations for both components. 1. Dodecyl dimethyl phospine oxide
, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 475, Issue 1 , June , 2015 , Pages 62-68 ; 09277757 (ISSN) ; Javadi, A ; Lylyk, S. V ; Bastani, D ; Fainerman, V. B ; Miller, R ; Sharif University of Technology
Abstract
The adsorption of proteins at liquid interfaces happens at rather low bulk concentrations due to their rather high surface activity. In contrast typical surfactants start to decrease the surface tension at bulk concentration in the range of mmol/l and reach a minimum value at about two or three orders of magnitude higher concentration. The two proteins studied here, β-lactoglobulin and β-casein, adsorb already remarkably at much lower concentrations, i.e. less than 1. μmol/l. When smallest amounts of a non-ionic surfactant are added to low concentrated protein solutions, changes in the surface tension are observed which cannot be explained by the existing theoretical models. An agreement...
Surfactant-assisted synthesis and characterization of hydroxyapatite nanorods under hydrothermal conditions
, Article Materials Science- Poland ; Volume 27, Issue 4 , 2009 , Pages 961-971 ; 01371339 (ISSN) ; Solati Hashjin, M ; Sara Shafiei, S ; Goudarzi, A ; Salarian, R ; Nemati, A ; Sharif University of Technology
2009
Abstract
Hydroxyapatite (HAp) nanorods with uniform morphology and controllable size were successfully synthesized by precipitating Ca(NO3) 24H2O and (NH4)2HPO4 in the presence of cetyltrimethylammonium bromide (CTAB) and polyethylene glycol 400 (PEG 400) as cationic surfactant and non-ionic cosurfactant, respectively, under hydrothermal conditions. The effect of hydrothermal temperature on the composition, morphology and size of HAp particles was studied using X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM). Results revealed that the morphology and size of HAp particles can be effectively controlled by the presence of CTAB and PEG...
Wettability alteration of carbonate rock by nonionic surfactants in water-based drilling fluid
, Article International Journal of Environmental Science and Technology ; Volume 16, Issue 11 , 2019 , Pages 6547-6556 ; 17351472 (ISSN) ; Ramazani SaadatAbadi, A ; Jafari Behbahani, T ; Sharif University of Technology
Center for Environmental and Energy Research and Studies
2019
Abstract
The influx of solid or liquid particles of drilling mud into the pores of rock or mud loss phenomenon and clay swelling can sometimes lead to severe productive formation damage and cause to wettability alterations of reservoir rock from hydrophilic to oleophilic. Therefore, designing an appropriate fluid that is compatible with formation fluids and could reduce reservoir damage and increase the productivity of wells is very important. The two main mechanisms of surfactants are reduction of the surface tension and wettability alteration of rock reservoir that are effective in taking the oil. Regarding the importance of the wettability in reservoir productivity, this article is aimed to study...
Studies of the rate of water evaporation through adsorption layers using drop shape analysis tensiometry
, Article Journal of Colloid and Interface Science ; Volume 308, Issue 1 , 2007 , Pages 249-253 ; 00219797 (ISSN) ; Makievski, A. V ; Krägel, J ; Javadi, A ; Miller, R ; Sharif University of Technology
2007
Abstract
With modified measuring procedure and measuring cell design in the drop profile tensiometer PAT, it became possible to study the rate of water evaporation through adsorbed or spread surface layers. This method was employed to measure the rate of water evaporation from drops covered by adsorbed layers of some proteins and surfactants, in particular n-dodecanol. It was shown that the formation of dense (double or condensed) adsorbed layers of protein and the formation of 2D-condensed n-dodecanol layer decrease the water evaporation rate by 20-25% as compared with pure water. At the same time, the adsorbed layers of ordinary surfactants (sodium dodecyl sulfate and nonionic ethoxylated...