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Szymczyk K, Zdziennicka A, Jańczuk B. Properties of some nonionic fluorocarbon surfactants and their mixtures with hydrocarbon ones. Adv Colloid Interface Sci 2021; 292:102421. [PMID: 33957391 DOI: 10.1016/j.cis.2021.102421] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/13/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023]
Abstract
The adsorption of Zonyl FSN-100 (FSN100, having an average 14 oxyethylene units and 6 -CF2 groups) and Zonyl FSO-100 (FSO100, having an average 10 oxyethylene units and 5 -CF2 groups) as well as of their mixtures with p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols) having 10, 16 and 8 oxyethylene groups in molecule (TX100, TX165, TX114) and cetyltrimethylammonium bromide (CTAB) at the solution-air and polytetrafluoroethylene (PTFE)-solution and polymethyl methacrylate (PMMA)-solution interfaces as well as the composition of the surface mixed layer was discussed based on the literature data. The adsorption properties of nonionic fluorocarbon surfactants were compared to those of the classical ones on the basis of the Gibbs standard free energy of adsorption determined by different ways and the intermolecular interactions of the surfactant molecules through the water phase. The synergetic effect in the reduction of the water surface tension by the mixture of fluorocarbon and classical nonionic surfactant was shown and explained by the comparison of the composition of the mixed surface layer to those in the bulk phase. The composition of the mixed fluorocarbon and classical surfactant layer at the solution-air interface was compared to that formed at the PTFE-solution and PMMA-solution interfaces. The changes of the surface tension of the aqueous solution of the fluorocarbon surfactants and their mixtures with classical hydrocarbon ones and their adsorption were analyzed taking into account the PTFE and PMMA surface wettability. This analysis was also based on the components and parameters of the head and tail of the surfactants surface tension as well as those of PTFE and PMMA. Apart from adsorption and wetting properties the aggregation of the fluorocarbon surfactants and their mixtures was discussed. A specific attention was paid to the possibility of two CMC values in the case of nonionic fluorocarbon surfactants as well as the synergism in CMC of mixtures of nonionic fluorocarbon and hydrocarbon surfactants.
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Affiliation(s)
- Katarzyna Szymczyk
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Maria Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland.
| | - Anna Zdziennicka
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Maria Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland
| | - Bronisław Jańczuk
- Department of Interfacial Phenomena, Institute of Chemical Sciences, Faculty of Chemistry, Maria Curie-Skłodowska University in Lublin, Maria Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland
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Effect of Triton X-100 surfactant on the interfacial activity of ionic surfactants SDS, CTAB and SDBS at the air/water interface: A study using molecular dynamic simulations. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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3
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Koopal L, Tan W, Avena M. Mixed ad/desorption kinetics unraveled with the equilibrium adsorption isotherm. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.06.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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4
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Papapostolou A, Karasavvas E, Chatzidoukas C. Oxygen mass transfer limitations set the performance boundaries of microbial PHA production processes – A model-based problem investigation supporting scale-up studies. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.04.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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5
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Moore JE, McCoy TM, Sokolova AV, de Campo L, Pearson GR, Wilkinson BL, Tabor RF. Worm-like micelles and vesicles formed by alkyl-oligo(ethylene glycol)-glycoside carbohydrate surfactants: The effect of precisely tuned amphiphilicity on aggregate packing. J Colloid Interface Sci 2019; 547:275-290. [DOI: 10.1016/j.jcis.2019.03.068] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 10/27/2022]
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Moore JE, McCoy TM, de Campo L, Sokolova AV, Garvey CJ, Pearson G, Wilkinson BL, Tabor RF. Wormlike micelle formation of novel alkyl-tri(ethylene glycol)-glucoside carbohydrate surfactants: Structure–function relationships and rheology. J Colloid Interface Sci 2018; 529:464-475. [DOI: 10.1016/j.jcis.2018.05.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/17/2018] [Accepted: 05/20/2018] [Indexed: 10/16/2022]
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7
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Patra A, Taner HA, Bordes R, Holmberg K, Larsson AC. Selective flotation of calcium minerals using double-headed collectors. J DISPER SCI TECHNOL 2018. [DOI: 10.1080/01932691.2018.1503547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Anuttam Patra
- Chemistry of Interfaces Group, Luleå University of Technology, Luleå, Sweden
| | - Hasan Ali Taner
- Chemistry of Interfaces Group, Luleå University of Technology, Luleå, Sweden
- Department of Mining Engineering, Selcuk University, Konya, Turkey
| | - Romain Bordes
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Krister Holmberg
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Anna-Carin Larsson
- Chemistry of Interfaces Group, Luleå University of Technology, Luleå, Sweden
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Miller R, Aksenenko EV, Kovalchuk VI, Fainerman VB. Adsorption of C 14EO 8 at the interface between its aqueous solution drop and air saturated by different alkanes vapor. Phys Chem Chem Phys 2018; 19:2193-2200. [PMID: 28045155 DOI: 10.1039/c6cp07705f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The dynamic and equilibrium surface tension for drops of aqueous C14EO8 solutions at the interface to pure air or pentane, hexane, heptane and toluene saturated air, and the dynamic surface tension of pure water at these interfaces are presented. Two theoretical models were employed: both assuming a diffusion controlled adsorption of the surfactant, and either a diffusion or kinetic barrier governed adsorption of the alkanes. The experimental results are best described by the model which implies a diffusion control for the C14EO8 molecules and the existence of a kinetic barrier for the alkane molecules. The desorption of alkanes from the surface layer after equilibration and their subsequent removal from the measuring cell was studied as well. The desorption process was shown to be slow for heptane and hexane. However, for the pentane vapor the desorption is quite rapid, and after the desorption commences the surface tension becomes equal to that at the interface with pure air.
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Affiliation(s)
- R Miller
- MPI Colloids and Interfaces, Potsdam, Germany.
| | - E V Aksenenko
- Institute of Colloid Chemistry and Chemistry of Water, Kyiv (Kiev), Ukraine
| | - V I Kovalchuk
- Institute of Biocolloid Chemistry, Kyiv (Kiev), Ukraine
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Miller R, Aksenenko EV, Fainerman VB. Dynamic interfacial tension of surfactant solutions. Adv Colloid Interface Sci 2017; 247:115-129. [PMID: 28063521 DOI: 10.1016/j.cis.2016.12.007] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/14/2016] [Accepted: 12/21/2016] [Indexed: 11/19/2022]
Abstract
The dynamics of surfactant interfacial layers was first discussed more than a century ago. In 1946 the most important work by Ward and Tordai was published which is still the theoretical basis of all new models to describe the time dependence of interfacial properties. In addition to the diffusion controlled adsorption mechanism, many other models have been postulated in literature, however, well performed experiments with well defined surfactant systems have shown that the diffusional transport is the main process governing the entire formation of surfactant adsorption layers. The main prerequisite, in addition to the diffusional transport, is the consideration of the right boundary condition at the interface, given by a respective equation of state. In addition to the classical models of Langmuir and Frumkin, also the so-called reorientation or interfacial aggregation models are to be assumed to reach a quantitative description of respective experimental data. Moreover, the adsorption of surfactants at the interface between water and a gas phase different from air can be strongly influenced by the type of molecules within the gas phase, such as alkane vapours. These oil molecules co-adsorb from the gas phase and change the adsorption kinetics strongly. Besides the discussion of how to apply theoretical adsorption kinetics models correctly, a large number of experimental data are presented and the way of a quantitative analysis of the adsorption mechanism and the main characteristic parameters is presented. This includes micellar solutions as well as mixtures of surfactants of ionic and non-ionic nature.
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Affiliation(s)
- R Miller
- Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Am Mühlenberg 1, 14424 Potsdam, Germany.
| | - E V Aksenenko
- Institute of Colloid Chemistry and Chemistry of Water, 42 Vernadsky Avenue, 03680 Kyiv (Kiev), Ukraine
| | - V B Fainerman
- Donetsk Medical University, 16 Ilych Avenue, 83003 Donetsk, Ukraine
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11
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Tuning Interfacial Activity of Polymeric Resin–Surfactant/n-Alcohol Solution Interactions. J SURFACTANTS DETERG 2016. [DOI: 10.1007/s11743-016-1849-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Ishiguro M, Koopal LK. Surfactant adsorption to soil components and soils. Adv Colloid Interface Sci 2016; 231:59-102. [PMID: 26969282 DOI: 10.1016/j.cis.2016.01.006] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 09/18/2015] [Accepted: 01/27/2016] [Indexed: 10/22/2022]
Abstract
Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on water/air interfaces, the latter gives an impression of surfactant adsorption to a hydrophobic surface and illustrates the importance of the CMC for the adsorption process. Then attention is paid to the most important types of soil particles: humic and fulvic acids, silica, metal oxides and layered aluminosilicates. Information is provided on their structure, surface properties and primary (proton) charge characteristics, which are all important for surfactant binding. Subsequently, the adsorption of different types of surfactants on these individual soil components is discussed in detail, based on mainly experimental results and considering the specific (chemical) and electrostatic interactions, with hydrophobic attraction as an important component of the specific interactions. Adsorption models that can describe the features semi-quantitatively are briefly discussed. In the last part of the paper some trends of surfactant adsorption on soils are briefly discussed together with some complications that may occur and finally the consequences of surfactant adsorption for soil colloidal stability and permeability are considered. When we seek to understand the fate of surfactants in soil and aqueous environments, the hydrophobicity and charge density of the soil or soil particles, must be considered together with the structure, hydrophobicity and charge of the surfactants, because these factors affect the adsorption. The pH and ionic strength are important parameters with respect to the charge density of the particles. As surfactant adsorption influences soil structure and permeability, insight in surfactant adsorption to soil particles is useful for good soil management.
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Zhang J, Meng Y, Tian Y, Zhang X. Effect of concentration and addition of ions on the adsorption of sodium dodecyl sulfate on stainless steel surface in aqueous solutions. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2015.06.057] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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He Y, Yazhgur P, Salonen A, Langevin D. Adsorption-desorption kinetics of surfactants at liquid surfaces. Adv Colloid Interface Sci 2015; 222:377-84. [PMID: 25307125 DOI: 10.1016/j.cis.2014.09.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 10/24/2022]
Abstract
The paper discusses adsorption and desorption energy barriers for macroscopic interfaces of surfactant solutions. Literature data suggest that adsorption and desorption are not always fully diffusion controlled. Apart from electrostatic barriers that lead to strong deviations, other types of barriers are less easy to identify, because smaller deviations from diffusion controlled mechanisms are evidenced. Complete models involving both diffusion and sorption barriers are very complex and involve many adjustable parameters, making the data analysis frequently unreliable. Empirical equations of state are used in most cases, although they are inaccurate, especially close to the cmc. The variation of sorption energies with surface concentration is not accurately described in the models. Finally, convection can mask the effect of sorption energy barriers. Experiments are presented to illustrate the main difficulties encountered.
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The effect of structural modifications on the solution and interfacial properties of straight and branched aliphatic alcohols: The role of hydrophobic effects. J Colloid Interface Sci 2015; 449:364-72. [DOI: 10.1016/j.jcis.2015.01.045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 01/19/2015] [Accepted: 01/19/2015] [Indexed: 11/23/2022]
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16
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Using neutral impact collision ion scattering spectroscopy and angular resolved X-ray photoelectron spectroscopy to analyze surface structure of surfactant solutions. Colloid Polym Sci 2015. [DOI: 10.1007/s00396-015-3541-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Kwaśniewska D, Staszak K, Wieczorek D, Zieliński R. Synthesis and Interfacial Activity of Novel Heterogemini Sulfobetaines in Aqueous Solution. J SURFACTANTS DETERG 2014; 18:477-486. [PMID: 25814830 PMCID: PMC4371128 DOI: 10.1007/s11743-014-1663-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 12/16/2014] [Indexed: 11/23/2022]
Abstract
Three new heterogemini sulfobetaines and their chloride salts were synthesised. The interfacial activities of the obtained chlorides in aqueous solution were studied by equilibrium and dynamic surface tension measurements. The critical micelle concentration, surface excess concentration, minimum area per surfactant molecule and standard Gibbs energy of adsorption as well as micelle lifetime and diffusion coefficient were determined. The adsorption properties and micelle lifetime of these compounds significantly depend on the length of alkyl chain. The critical micelle concentration decreases with increasing chain length of the compounds considered. The values of the diffusion coefficient of N-alkyl-N-methyl-N-(3-sulfopropyl)-6-(N-alkyl-N-methylamino)hexylammonium chloride tend to decrease as the concentration is increased.
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Affiliation(s)
- Dobrawa Kwaśniewska
- Department of Technology and Instrumental Analysis, Faculty of Commodity Science, Poznań University of Economics, al. Niepodległości 10, 61-875 Poznan, Poland
| | - Katarzyna Staszak
- Institute of Technology and Chemical Engineering, Poznan University of Technology, pl. Skłodowskiej-Curie 2, 60-965 Poznan, Poland
| | - Daria Wieczorek
- Department of Technology and Instrumental Analysis, Faculty of Commodity Science, Poznań University of Economics, al. Niepodległości 10, 61-875 Poznan, Poland
| | - Ryszard Zieliński
- Department of Technology and Instrumental Analysis, Faculty of Commodity Science, Poznań University of Economics, al. Niepodległości 10, 61-875 Poznan, Poland
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Deleu M, Crowet JM, Nasir MN, Lins L. Complementary biophysical tools to investigate lipid specificity in the interaction between bioactive molecules and the plasma membrane: A review. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:3171-3190. [DOI: 10.1016/j.bbamem.2014.08.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/05/2014] [Accepted: 08/21/2014] [Indexed: 02/08/2023]
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19
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Szymczyk K. Behaviour of the fluorocarbon surfactants in the monolayer at the water–air interface and in the bulk phase. J Fluor Chem 2013. [DOI: 10.1016/j.jfluchem.2013.02.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Kamerzell TJ, Esfandiary R, Joshi SB, Middaugh CR, Volkin DB. Protein-excipient interactions: mechanisms and biophysical characterization applied to protein formulation development. Adv Drug Deliv Rev 2011; 63:1118-59. [PMID: 21855584 DOI: 10.1016/j.addr.2011.07.006] [Citation(s) in RCA: 350] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/19/2011] [Accepted: 07/26/2011] [Indexed: 12/18/2022]
Abstract
The purpose of this review is to demonstrate the critical importance of understanding protein-excipient interactions as a key step in the rational design of formulations to stabilize and deliver protein-based therapeutic drugs and vaccines. Biophysical methods used to examine various molecular interactions between solutes and protein molecules are discussed with an emphasis on applications to pharmaceutical excipients in terms of their effects on protein stability. Key mechanisms of protein-excipient interactions such as electrostatic and cation-pi interactions, preferential hydration, dispersive forces, and hydrogen bonding are presented in the context of different physical states of the formulation such as frozen liquids, solutions, gels, freeze-dried solids and interfacial phenomenon. An overview of the different classes of pharmaceutical excipients used to formulate and stabilize protein therapeutic drugs is also presented along with the rationale for use in different dosage forms including practical pharmaceutical considerations. The utility of high throughput analytical methodologies to examine protein-excipient interactions is presented in terms of expanding formulation design space and accelerating experimental timelines.
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Affiliation(s)
- Tim J Kamerzell
- Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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Yeo WH, Chung JH, Liu Y, Lee KH. Size-Specific Concentration of DNA to a Nanostructured Tip Using Dielectrophoresis and Capillary Action. J Phys Chem B 2009; 113:10849-58. [DOI: 10.1021/jp900618t] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Woon-Hong Yeo
- Department of Mechanical Engineering, University of Washington, Box 352600, Seattle, Washington 98195, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Box 19018, Arlington, Texas 76019, and NanoFacture, Inc., P.O. Box 52651, Bellevue, Washington 98015
| | - Jae-Hyun Chung
- Department of Mechanical Engineering, University of Washington, Box 352600, Seattle, Washington 98195, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Box 19018, Arlington, Texas 76019, and NanoFacture, Inc., P.O. Box 52651, Bellevue, Washington 98015
| | - Yaling Liu
- Department of Mechanical Engineering, University of Washington, Box 352600, Seattle, Washington 98195, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Box 19018, Arlington, Texas 76019, and NanoFacture, Inc., P.O. Box 52651, Bellevue, Washington 98015
| | - Kyong-Hoon Lee
- Department of Mechanical Engineering, University of Washington, Box 352600, Seattle, Washington 98195, Department of Mechanical and Aerospace Engineering, University of Texas at Arlington, Box 19018, Arlington, Texas 76019, and NanoFacture, Inc., P.O. Box 52651, Bellevue, Washington 98015
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Honciuc A, Baptiste DJ, Campbell IP, Schwartz DK. Solvent dependence of the activation energy of attachment determined by single molecule observations of surfactant adsorption. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:7389-7392. [PMID: 19563226 DOI: 10.1021/la900307f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Single-molecule total internal reflection fluorescence microscopy was used to obtain real-time images of fluorescently labeled hexadecanoic (palmitic) acid molecules as they adsorbed at the interface between fused silica and three different solvents: hexadecane (HD), tetrahydrofuran (THF), and water. These solvents were chosen to explore the effect of solvent polarity on the activation energy associated with the attachment rate, i.e., the rate at which molecules were transferred to the surface from the near-surface layer. Direct counting of single-molecule events, made under steady-state conditions at extremely low coverage, provided direct, model-independent measurements of this attachment rate, in contrast with conventional ensemble-averaged methods, which are influenced by bulk transport and competing detachment processes. We found that the attachment rate increased with increasing temperature for all solvents. Arrhenius analyses gave activation energies of 5+/-2 kJ/mol for adsorption from HD, 10+/-2 kJ/mol for adsorption from THF, and 19+/-2 kJ/mol for adsorption from water. These energies increased systematically with the solvent polarity and, therefore, with the expected strength of the solvent-substrate interaction. We hypothesize that the adsorption of amphiphilic solute molecules from solution can be regarded as a competitive exchange between solute molecules and surface-bound solvent. In this scenario, adsorption is an activated process, and the activation energy for attachment is associated with the solvent-substrate interaction energy.
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Affiliation(s)
- Andrei Honciuc
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, USA
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Adsorption and onset of lubrication by a double-chained cationic surfactant on silica surfaces. J Colloid Interface Sci 2009; 332:382-8. [DOI: 10.1016/j.jcis.2008.12.065] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Revised: 12/19/2008] [Accepted: 12/20/2008] [Indexed: 11/18/2022]
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25
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Mora MF, Felhofer J, Ayon A, Garcia CD. Surfactants as a Preferred Option to Improve Separation and Electrochemical Detection in Capillary Electrophoresis. ANAL LETT 2008. [DOI: 10.1080/00032710701792927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
Fengycin is a biologically active lipopeptide produced by several Bacillus subtilis strains. The lipopeptide is known to develop antifungal activity against filamentous fungi and to have hemolytic activity 40-fold lower than that of surfactin, another lipopeptide produced by B. subtilis. The aim of this work is to use complementary biophysical techniques to reveal the mechanism of membrane perturbation by fengycin. These include: 1), the Langmuir trough technique in combination with Brewster angle microscopy to study the lipopeptide penetration into monolayers; 2), ellipsometry to investigate the adsorption of fengycin onto supported lipid bilayers; 3), differential scanning calorimetry to determine the thermotropic properties of lipid bilayers in the presence of fengycin; and 4), cryogenic transmission electron microscopy, which provides information on the structural organization of the lipid/lipopeptide system. From these experiments, the mechanism of fengycin action appears to be based on a two-state transition controlled by the lipopeptide concentration. One state is the monomeric, not deeply anchored and nonperturbing lipopeptide, and the other state is a buried, aggregated form, which is responsible for membrane leakage and bioactivity. The mechanism, thus, appears to be driven mainly by the physicochemical properties of the lipopeptide, i.e., its amphiphilic character and affinity for lipid bilayers.
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Mora MF, Giacomelli CE, Garcia CD. Electrophoretic Effects of the Adsorption of Anionic Surfactants to Poly(dimethylsiloxane)-Coated Capillaries. Anal Chem 2007; 79:6675-81. [PMID: 17676757 DOI: 10.1021/ac070953g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Poly(dimethylsiloxane) (PDMS) is one of the most convenient materials to construct capillary electrophoresis microchips. Even though PDMS has many advantages, its use is often limited by its hydrophobicity. Although it is well-known that the surface properties of PDMS can be modified by anionic surfactants, very little is known regarding the driving forces or the electrophoretic consequences of the adsorption of anionic surfactants. In this work, the adsorption of alkyl surfactants on PDMS was studied by performing electroosmotic flow (microEOF) measurements. In order to mimic the behavior of PDMS microchannels, fused-silica capillaries were coated with PDMS and used for the microEOF measurements. This approach allowed using standard CE instrumentation and provided significant advantages over similar experiments performed on microchips. The change in the microEOF in the presence of surfactants was correlated to the surfactant adsorbed amount which, plotted versus surfactant concentration, gives an adsorption isotherm. The adsorption isotherms were obtained using alkyl surfactants with different chain lengths and head groups. According to our results, the interaction of alkyl surfactants with the PDMS surface is determined by a combination of hydrophobic and electrostatic interactions, where the former is more significant than the latter. The affinity of each surfactant for the PDMS surface was calculated by fitting the adsorption profiles with a Langmuir equation and, in the case of single-charged surfactants, correlated to the corresponding cmc value.
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Affiliation(s)
- Maria F Mora
- Department of Chemistry, The University of Texas at San Antonio, San Antonio, TX 78249, USA
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Nordstierna L, Furó I, Stilbs P. Mixed adsorption of fluorinated and hydrogenated surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:7969-74. [PMID: 16952229 DOI: 10.1021/la060757p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The adsorption isotherms of sodium perfluorooctanoate and sodium decyl sulfate and their 1:1 mixture on gamma-alumina are recorded by depletion-type experiments with (1)H and (19)F NMR spectroscopy as the detection tool. The isotherms of the different surfactant species, obtained with and without added salt, closely resemble each other. Salt addition changes the isotherms from stepwise to the familiar S-shaped. After having reached saturation, a further increase of surfactant concentration in the mixed system leads to decyl sulfate desorption and increased perfluorooctanoate adsorption. The (19)F chemical shift of adsorbed perfluorooctanoate suggests that, for saturated surfaces, the two sorts of adsorbed surfactants form molecularly mixed surface aggregates.
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Affiliation(s)
- Lars Nordstierna
- Division of Physical Chemistry and Industrial NMR Center, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden
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Staszak K, Prochaska K. Adsorption at the liquid/liquid interface in mixed systems with hydrophobic extractants and modifiers. J Colloid Interface Sci 2006; 294:411-7. [PMID: 16112679 DOI: 10.1016/j.jcis.2005.07.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2005] [Revised: 07/12/2005] [Accepted: 07/16/2005] [Indexed: 11/24/2022]
Abstract
The dynamic interfacial tension for binary mixtures of hydrophobic metal ion extractants and a modifier were measured by using the drop volume technique. Four types of equimolar mixtures were considered: two chelating extractants: 2-hydroxy-5-nonylacetophenone oxime (HNAF) and beta-diketone (1-phenyldecan-1,3-dion), two solvating extractants: trioctylphosphine oxide (TOPO) and tributyl phosphate (TBP), chelating and solvating extractants TOPO and beta-diketone, and the chelating extractant HNAF and the modifier (decanol). With the aid of the Ward and Torday equation the values of the diffusion coefficients of individual compounds and their equimolar mixtures were estimated. It was found that in the case of two types of investigated mixtures, i.e., HNAF + beta-diketone and HNAF + decanol the compound HNAF that was dominant in the mixed adsorbed monolayer and the more interfacially active also determined the kinetics of adsorption in mixed systems. In contrary to the mixture of two chelating reagents, in the case of a mixture of two solvating extractants the mixed system behaves like the less active, though dominant at the interface, reagent TBP. The same effect was observed in both of the considered diluents (toluene and octane).
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Affiliation(s)
- Katarzyna Staszak
- Institute of Chemical Engineering and Technology, Poznań University of Technology, Pl. M. Skłodowskiej-Curie 2, 60-965 Poznań, Poland
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Kalogianni EP, Varka EM, Karapantsios TD, Pegiadou S. Dynamic surface activity of phenylalanine glycerol-ether surfactant solutions measured by a differential maximum bubble pressure tensiometer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:46-51. [PMID: 16378398 DOI: 10.1021/la050982r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A refined differential maximum bubble pressure tensiometer was used for measuring the dynamic surface tension at various concentrations of a nonconventional surfactant, a member of a new homologous series of phenylalanine glycerol-ether amphiphiles, with 10 carbon atoms to the hydrophobic alkyl chain (C(10)-PhGE). The effective bubble formation frequency for the examined surfactant concentrations was varied from 2 bubbles per second to 1 bubble per 20 s. The variation of equilibrium surface tension with concentration as well as the critical micelle concentration were determined by a Wilhelmy plate technique. Comparisons between dynamic and equilibrium surface tension values demonstrate that, under the employed surface deformation rates, the equilibrium surface tension is a misleading indicator of surface activity. This is also supported by simple surface rheology considerations. Results based on a diffusion-controlled kinetic analysis provide further evidence on the strong dependence of surface activity on the particular time scale of deformation.
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Affiliation(s)
- Eleni P Kalogianni
- Department of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
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