197 results on '"John F. Scamehorn"'
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2. An Overview of Surfactant-Based Separation Processes
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John F. Scamehorn and Jeffrey H. Harwell
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Materials science ,Adsorption ,Coacervate ,Chemical engineering ,Pulmonary surfactant ,Emulsion ,Absorption (chemistry) ,Froth flotation ,Micelle ,Separation process - Abstract
Surfactant-Based separation processes are a major emerging technological area in both surfactant science and separations science. Surfactant-based separations have a number of potential advantages over traditional methods. From an economic point of view, ore flotation is currently far and away the most important surfactant-based separation process, so much so that froth flotation is frequently used as a synonym for ore flotation. This chapter outlines the separation processes utilize a wide range of phenomena involving surfactants to effect separations. All but two concern removing components from a liquid phase; absorption into emulsion solutions involves removal of organics from a gas phase, and admicellar chromatography may be adapted to gas phase separations. One way to characterize these techniques is by the surfactant aggregate structure effecting the separation: micelles, adsorbed surfactant aggregates, emulsions, foams and coacervate.
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- 2020
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3. Surfactant - Based Separation Processes
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John F. Scamehorn
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Adsorption ,Aqueous solution ,Pulmonary surfactant ,Chemistry ,Metal ions in aqueous solution ,Extraction (chemistry) ,Analytical chemistry ,Ultrafiltration ,Microemulsion ,Froth flotation - Abstract
Preface -- Contributors -- Part I: Separations Using Membranes -- 1 Ose of Micellar-Enhanced Ultrafiltration to Remove Dissolved Organics from Aqueous Streams /Sherril D. Christian and John F. Scamehorn -- 2 Use of Micellar-Enhanced UJtrafiltration to Remove Multivalent Metal Ions from Aqueous Streams /John F. Scamehorn, Sherril D. Christian, and Rex T. Ellington -- Part 11: Separations Based on Extraction -- 3 Reversed Micellar Extraction of Proteins /T. Alan Hatton -- 4 Novel Separations Using Aphrons /Felix Sebba -- 5 Microemulsion-Based Separations /Stig E. Friberg and Parthasakha Neogi -- 6 Liquid-Coacervate Extraction /Nancy D. Gullickson, John F. Scamehorn, and Jeffrey H. Harwell -- Part 111: Separations Based on Adsorption -- 7 Adsorbed Surfactant Bilayers as TwoDimensional Solvents: Admicellar-Enhanced Chromatography /Jeffrey H. Harwell and Edgar A. O'Rear -- 8 Adsorbed Surfactant Bilayers as Two-Dimensional Solvents: Surface Modification by Thin-Film Formation /Jengyue Wu, Chonlin Lee, Edgar A. O'Rear, and Jeffrey H. Harwell -- 9 Surfactant-Enhanced Carbon Regeneration /D. Lowry Blakeburn and John F. Scamehorn -- Part IV: Separations Based on Foams -- 10 Adsorptive Bubble Separation Processes /Thomas E. Carleson -- 11 Mineral Separation by Froth Flotation /Douglas W. Fuerstenau and Ronalda Herrera-Urbina -- Part V: Separations Based on Precipitation -- 12 Recovery of Surfactant from Surfactant- Based Separations Using a Precipitation Process 323 /Lori L. Brant, Kevin L. Stellner, and John F. Scamehorn -- Index.
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- 2020
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4. New Graduate Programs In Petrochemical Technology And In Polymer Science At Chulalongkorn University, Bangkok, Thailand An International Academic Partnership
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Somchai Osuwan, Raymond D. Daniels, and John F. Scamehorn
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- 2020
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5. Overview and History of the Study of Solubilization
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Connie S. Dunaway, Sherril D. Christian, and John F. Scamehorn
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Chromatography ,Chemistry ,Solubilization - Published
- 2020
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6. Solubilization in Surfactant Aggregates
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Sherril D. Christian and John F. Scamehorn
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Partition coefficient ,Pulmonary surfactant ,Chemistry ,Critical micelle concentration ,Vesicle ,Kinetics ,Inorganic chemistry ,Micellar solutions ,Ionic bonding ,Micelle - Abstract
Part 1 Overview: overview and history of the study of solubilization. Part 2 Solubilization in micelles: solubilization of gases thermodynamics of solubilization of polar additives in micellar solutions solubilization of uncharged molecules in ionic micellar solutions - toward an understanding at the molecular level solubilization in mixed micelles solubilization in amphiphilic copolymer solutions kinetics of solubilization in surfactant-based systems. Part 3 Solubilization in nonmicellar surfactant aggregates: adsolubilization solubilization in micelles and vesicles studied by fluorescence techniques, interplay between the microproperties of the aggregates and the locus and extent of solubilization solubilization of organic compounds by vesicles. Part 4 Methods of measuring solubilization: solubilization, as studied by nuclear spin relaxation and NMR-based self-diffusion techniques the partitioning of neutral solutes between micelles and water as deduced from critical micelle concentration determinations vapor pressure studies of solubilization comparison of experimental methods for the determination of the partition coefficients of n-alcohols in SDS and DTAB micelles. Part 5 Applications of solubilization: solubilization and detergency solubilization in micellar separations.
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- 2020
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7. Study of nonionic surfactants on HVOCs removal from coacervate solutions using cocurrent vacuum stripping in a packed column
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Pornchai Suriya-Amrit, Boonyarach Kitiyanan, John F. Scamehorn, Somchai Osuwan, Sirinthip Kittisrisawai, Sumaeth Chavadej, and Suratsawadee Kungsanant
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Packed bed ,Cloud point ,Chromatography ,Coacervate ,Aqueous solution ,Stripping (chemistry) ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Filtration and Separation ,02 engineering and technology ,General Chemistry ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Nonionic surfactant ,0210 nano-technology ,0105 earth and related environmental sciences - Abstract
Cloud point extraction has been shown to be an effective technique to remove hydrophobic volatile organic compounds (HVOCs) from aqueous solution using nonionic surfactant. A cocurrent vacuum strip...
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- 2018
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8. Dissolution of Soap Scum by Surfactants. Part III. Effect of Chelant Type on Equilibrium Solubility and Dissolution Rate of Calcium and Magnesium Soap Scums in Various Surfactant Systems
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David A. Sabatini, Sumaeth Chavadej, Sukhwan Soontravanich, John F. Scamehorn, Sawwalak Itsadanont, and Prariyada Theptat
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Magnesium ,General Chemical Engineering ,Inorganic chemistry ,chemistry.chemical_element ,Ethylenediamine ,Calcium stearate ,Soap scum ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Pulmonary surfactant ,Magnesium stearate ,Physical and Theoretical Chemistry ,Solubility ,Dissolution - Abstract
Soap scum can be effectively removed by using an appropriate surfactant with a chelating agent at a high solution pH. The equilibrium solubilities and dissolution rates of two model soap scums [calcium stearate and magnesium stearate: Ca(C18)2 and Mg(C18)2] were investigated in aqueous solutions containing three different types of surfactants [methyl ester sulfonate (MES) as an anionic surfactant; alcohol ethoxylate (EO9) as a nonionic surfactant; and dimethyldodecylamine oxide (DDAO) as an amphoteric surfactant] in the presence of different biodegradable chelants: trisodium ethylenediamine disuccinic acid (Na3EDDS) and tetrasodium glutamate diacetic acid (Na4GLDA) compared with disodium ethylenediamine tetraacetate (Na2EDTA), a chelant with poor biodegradability. The highest equilibrium solubility and dissolution rate of either soap scum were observed at high pH in the DDAO system with Na4GLDA. In addition, the calcium soap scum had a similar to higher equilibrium solubility and a higher dissolution rate constant as compared with the magnesium soap scum.
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- 2015
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9. Surfactant-Based Treatment of Aqueous Process Streams
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John F. Scamehorn, Jeffrey H. Harwell, and Sue Savage-Rumbaugh
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Aqueous solution ,Pulmonary surfactant ,Chemical engineering ,Chemistry ,Scientific method ,STREAMS - Published
- 2017
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10. Detergency of Vegetable Oils and Semi‐Solid Fats Using Microemulsion Mixtures of Anionic Extended Surfactants: The HLD Concept and Cold Water Applications
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Chodchanok Attaphong, John F. Scamehorn, Linh D. Do, and David A. Sabatini
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Vegetable oil ,Pulmonary surfactant ,Chemical engineering ,Chemistry ,Palm kernel ,General Chemical Engineering ,Phase (matter) ,Melting point ,Microemulsion ,Sodium Dioctyl Sulfosuccinate ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films ,Semi solid - Abstract
In spite of the increasing interest in cold temperature detergency of vegetable oils and fats, very limited research has been published on this topic. Extended surfactants have recently been shown to produce very promising detergency with vegetable oils at ambient temperature. However, the excessive salinity requirement (4–14 %) for these surfactants has limited their use in practical applications. In this work, we investigated the mixture of a linear C10–18PO–2EO–NaSO4 extended surfactant and a hydrophobic twin-tailed sodium dioctyl sulfosuccinate surfactant for cold temperature detergency of vegetable oils and semi-solid fats. Four vegetable oils of varying melting points (from −10 to 28 °C) were studied, these were canola, jojoba, coconut and palm kernel oils. Anionic surfactant mixtures showed synergism in detergency performance compared to single surfactant systems. At temperatures above the melting point, greater than 90 % detergency was achieved at 0.5 % NaCl. While detergency performance decreased at temperatures below the melting point, it was still superior to that of a commercial detergent (up to 80 vs. 40 %). Further, results show that the experimental microemulsion phase behaviors correlated very well with predictions from the hydrophilic–lipophilic deviation concept.
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- 2014
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11. Dissolution of Soap Scum by Surfactant. Part II: Effects of NaCl and Added Chelant on Equilibrium Solubility and Dissolution Rate of Calcium Soap Scum in Amphoteric Surfactant Solutions
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Sawwalak Itsadanont, John F. Scamehorn, David A. Sabatini, Sukhwan Soontravanich, Darunrat Ratanalert, and Sumaeth Chavadej
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chemistry.chemical_classification ,Aqueous solution ,General Chemical Engineering ,Inorganic chemistry ,Salt (chemistry) ,Calcium stearate ,Soap scum ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Reaction rate constant ,chemistry ,Pulmonary surfactant ,Physical and Theoretical Chemistry ,Solubility ,Dissolution - Abstract
The effects of solution pH and NaCl on the equilibrium solubility and dissolution rate of a model soap scum (calcium octadecanoate or calcium stearate) in aqueous solutions of dimethyldodecylamine oxide surfactant (DDAO) with and without chelant disodium ethylenediaminetetraacetate are reported. The equilibrium solubility and dissolution rate of soap scum increased with increasing solution pH when the chelant was added in the DDAO system while in the chelant-free systems the opposite trend was observed. The added NaCl has an ambiguous effect on the solubility and dissolution rate of soap scum in the absence of chelant, but a small level of added NaCl reduces both solubility and the dissolution rate constant in the presence of chelant. Both equilibrium and kinetics of dissolution are maximized at high pH with DDAO/chelant and no added salt.
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- 2014
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12. Wetting of polymer surfaces by aqueous surfactant solutions
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Thritima Sritapunya, Brian P. Grady, Boonyarach Kitiyanan, John F. Scamehorn, and Sumaeth Chavadej
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Maximum bubble pressure method ,Materials science ,Capillary number ,Contact angle ,Surface tension ,symbols.namesake ,Colloid and Surface Chemistry ,Gibbs isotherm ,Pulmonary surfactant ,Chemical engineering ,Critical micelle concentration ,symbols ,Organic chemistry ,Wetting - Abstract
An important application of surfactants is to improve the wettability of aqueous solutions on hydrophobic surfaces, as indicated by a decrease in the contact angle of the liquid on the solid. The surfactant adsorbs at the liquid/vapor interface, reducing the surface tension and adsorbs at the solid/liquid interface, reducing the interfacial tension. In this work, the reduction of the surface tension and interfacial tension was measured as well as the advancing contact angle and surfactant adsorption as a function of surfactant concentration for three anionic and three cationic surfactants on eight different polymers with varying hydrophobicity. The Zisman equation (cosine of contact angle is a linear function of surface tension) adequately describes all systems studied as the critical micelle concentration is approached. The dependence of contact angle solely on surface tension does not mean that interfacial tension reduction due to surfactant adsorption is not important; rather, interfacial tension reduction mirrors surface tension reduction with increasing surfactant concentration; the ratio of solid/liquid interfacial tension to the liquid/vapor surface tension was shown to be independent of surfactant concentration for all 48 systems studied here. In general, interfacial tension reduction and surfactant adsorption at the solid/liquid interface are less significant as polymer hydrophobicity decreases. The critical surface tension (surface tension at which contact angle is zero as extrapolated from Zisman plots) differs for the different surfactants on a given polymer, emphasizing the limited generic applicability of the Zisman hypothesis for surfactant solutions. A mathematical analysis was developed to calculate the solid/vapor and the solid/pure water interfacial tensions which depend only on the polymer characteristics. The solid/vapor interfacial tension was found to be 33.3 mN/m and does not depend on polymer structure.
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- 2012
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13. Mechanistic Studies of Particulate Soil Detergency: II: Hydrophilic Soil Removal
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Sumaeth Chavadej, David A. Sabatini, Sureeporn Rojvoranun, and John F. Scamehorn
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Chromatography ,Hydrophobic soil ,Chemistry ,General Chemical Engineering ,technology, industry, and agriculture ,Surfaces, Coatings and Films ,Contact angle ,Polyester ,Pulmonary surfactant ,Chemical engineering ,Dispersion stability ,medicine ,Zeta potential ,Ferric ,Kaolinite ,Physical and Theoretical Chemistry ,medicine.drug - Abstract
In this work, the removal mechanism of kaolinite and ferric oxide (model hydrophilic particulate soils) from hydrophilic (cotton) and hydrophobic (polyester) fabrics was studied using three surfactant types: sodium dodecyl sulfate (SDS), octylphenol ethoxylate (OP(EO)10), and cetyltrimethylammonium bromide (CTAB). This work investigated the relations between zeta potential, surfactant adsorption, contact angle, solid/liquid spreading pressure, and dispersion stability in washing solutions as compared to detergency performance and antiredeposition as a function of surfactant concentration and pH level. The SDS showed the best detergency for both particulate soils, followed by OP(EO)10, with CTAB being the least effective surfactant. For SDS, the electrostatic repulsion between fabric and soil was found to be the dominant force for hydrophilic particulate soil removal. For the nonionic surfactant OP(EO)10, electrostatics are also important and steric effects aid particulate soil detergency. Electrostatic forces and solid/liquid interfacial tension reduction aids CTAB detergency. These same detergency mechanisms have previously been found for the case of hydrophobic soil removal from fabrics. Dispersion stability did not prove to be a dominant mechanism governing particulate soil detergency. From the SEM photos of soiled fabric, ferric oxide attaches to the fabric surface with no entrapment between fabric yarns; moreover, ferric oxide tends to form larger aggregates on cotton compared to polyester fabric. The adhesion of larger particles is hypothesized to be weaker than the smaller ones. Therefore ferric oxide can be more easily removed from cotton fabric than polyester. The SEM photos for kaolinite show little visual difference in particle agglomeration on polyester compared to cotton. Removal of kaolinite from cotton was found to be higher than from polyester, but there is less difference than for ferric oxide.
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- 2012
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14. Arsenic Removal by Precipitation with Calcium Phosphate Hydroxyapatite
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W. Dungkaew, A.E. Flood, Kenneth J. Haller, and John F. Scamehorn
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inorganic chemicals ,integumentary system ,Precipitation (chemistry) ,Inorganic chemistry ,General Engineering ,Arsenate ,chemistry.chemical_element ,Oxyanion ,Calcium ,Phosphate ,Apatite ,Arsenic contamination of groundwater ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Arsenic ,Nuclear chemistry - Abstract
The removal of arsenic from synthetic arsenic contaminated water sample by precipitating arsenic (in the form of arsenate oxyanion) with calcium phosphate hydroxyapatite, HAp, was studied under conditions that induce arsenate incorporated calcium phosphate hydroxyapatite, Ca (P/As)HAp, to form. Arsenate is able to substitute for a fraction of the phosphate in HAp host material as it forms. Consequently, arsenic is successfully removed from the contaminated water achieving up to 99% arsenic removal from 25 ppm initial arsenic concentration. The Ca:(P+As) and P:As mole ratios were found to play an important role in arsenic removal efficiency. Higher Ca:(P+As) and P:As mole ratios give higher arsenic removal efficiency. Surprisingly, the pH of the initial anion solution, a key parameter in arsenic speciation, was found to not have a significant effect on arsenic removal by this process. The advantage of this process is that the precipitation can occur rapidly at relatively low levels of arsenic contamination, implying an easy and inexpensive process for arsenic removal can be developed based on this approach.
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- 2012
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15. Mechanistic Studies of Particulate Soil Detergency: I. Hydrophobic Soil Removal
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Sureeporn Rojvoranun, Chairat Chadavipoo, Wikanda Pengjun, Sumaeth Chavadej, John F. Scamehorn, and David A. Sabatini
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General Chemical Engineering ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films - Published
- 2011
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16. Adsorption of surfactants on carbon black and paper fiber in the presence of calcium ions
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Suvena Somabutr, Boonyarach Kitiyanan, Kunchana Bunyakiat, Kitipat Siemanond, Brian P. Grady, Thritima Sritapunya, Sumaeth Chavadej, Sureerat Jairakdee, John F. Scamehorn, and Thitipong Kornprapakul
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Inorganic chemistry ,chemistry.chemical_element ,Carbon black ,Calcium ,Deinking ,law.invention ,chemistry.chemical_compound ,Colloid and Surface Chemistry ,Adsorption ,chemistry ,Pulmonary surfactant ,law ,Monolayer ,Sodium dodecyl sulfate ,Sulfate - Abstract
Deinking is an important step in recycling of waste paper and flotation is commonly used in this process. By studying the interaction between added surfactant and the solid surfaces of ink pigment and pulp, the fundamental mechanism of flotation deinking can be better understood. In this work, the adsorption of two anionic surfactants (sodium dodecyl sulfate, SDS and sodium octanoate, C8) on both a model ink (hydrophobic carbon black) and a model fiber (hydrophilic office paper) was studied. The effect of pH on the SDS adsorption and the co-adsorption of calcium and surfactant on both surfaces also were investigated. The SDS adsorbs on carbon black as a tail-down monolayer (hemimicelle) while on paper fiber as a head-down, head-out bilayer (admicelle). The C8 forms admicelles on both carbon black and paper fiber indicating the stronger interaction of the carboxylate group with the carbon surface than the surfactant sulfate group, causing the C8 to adsorb at higher levels than SDS on carbon black. This helps explain why soaps are used widely as the surfactant in flotation deinking operations. Calcium causes surfactant adsorption to increase on carbon black as it adsorbs between negatively charge surface sites and the anionic head group of the surfactant (bridging) especially at low surfactant levels while not enhancing surfactant adsorption on paper fiber, explaining its activation effect in deinking processes. At high surfactant loadings, increasing surfactant concentration can cause calcium adsorption to decrease (calcium exclusion effect), probably due to covering up of negative adsorption sites on the surface.
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- 2011
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17. Palm Oil Removal from Fabric Using Microemulsion-Based Formulations
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Pantipa Ratchatawetchakul, Chantra Tongcumpou, Sumaeth Chavadej, Parichat Tanthakit, John F. Scamehorn, and David A. Sabatini
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Chromatography ,Abrasion (mechanical) ,Chemistry ,Laundry ,General Chemical Engineering ,Surfaces, Coatings and Films ,Contact angle ,Polyester ,Surface tension ,Pulmonary surfactant ,Chemical engineering ,Oil droplet ,Microemulsion ,Physical and Theoretical Chemistry - Abstract
Laundry detergency of palm oil on a polyester/cotton blend was measured using an anionic extended surfactant/nonionic secondary alcohol surfactant blend under conditions corresponding to ultralow oil/water interfacial tension microemulsion formation. The oil removal for the surfactant blend could exceed 90%, which was greater than that for either component surfactant alone or for a commercial liquid laundry detergent. Presoaking produced better detergency than increasing the number of wash cycles beyond two due to fabric abrasion (leading to a brightness decrease) with an excessive number of wash cycles. Higher oil contact angles and shorter oil droplet detachment times were found to correspond to higher detergency. High speed photography showed that snap-off occurred rather than roll-up for these systems.
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- 2010
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18. Dissolution Study of Salt of Long Chain Fatty Acids (Soap Scum) in Surfactant Solutions. Part II: Kinetics of Dissolution
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J. Grant Landrum, Chase M. Waite, Sarah A. Shobe, Sukhwan Soontravanich, David A. Sabatini, David R. Scheuing, and John F. Scamehorn
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integumentary system ,General Chemical Engineering ,Inorganic chemistry ,Hard water ,Calcium stearate ,Micelle ,Soap scum ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Pulmonary surfactant ,chemistry ,Stearate ,Physical and Theoretical Chemistry ,Solubility ,Dissolution - Abstract
Dissolution of calcium salt of a long chain fatty acid or soap scum is a major challenge for hard surface cleaners since soap scum forms when soap is exposed to hard water and has very low water solubility. In this paper, the aqueous equilibrium solubility of calcium octadecanoate (or calcium stearate) was measured as a function of pH as well as chelating agent (ethylenediaminetetraacetate disodium salt) and surfactant concentrations. Anionic, nonionic, and amphoteric surfactants were studied. The highest soap scum solubility was observed at high pH with an amphoteric surfactant. Under this condition, the chelant effectively binds calcium, and the stearate anion forms mixed micelles well with the amphoteric surfactant, which is in zwitterionic form at high pH.
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- 2010
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19. Dissolution Study of Salt of Long Chain Fatty Acids (Soap Scum) in Surfactant Solutions. Part I: Equilibrium Dissolution
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Sukhwan Soontravanich, Heyde E. Lopez, John F. Scamehorn, David A. Sabatini, and David R. Scheuing
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General Chemical Engineering ,Physical and Theoretical Chemistry ,Surfaces, Coatings and Films - Published
- 2010
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20. Effect of nonionic surfactant molecular structure on cloud point extraction of phenol from wastewater
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John F. Scamehorn, Somchai Osuwan, Phanphat Taechangam, and Thirasak Rirksomboon
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Partition coefficient ,chemistry.chemical_classification ,Cloud point ,Colloid and Surface Chemistry ,Aqueous solution ,Coacervate ,Chemical engineering ,chemistry ,Pulmonary surfactant ,Organic chemistry ,Micelle ,Alkyl ,Hydrophobe - Abstract
Above a temperature known as the cloud point, aqueous solutions of nonionic ethoxylated surfactants separate into two phases: a coacervate phase concentrated in surfactant and a dilute phase with low surfactant concentration. The coacervate phase contains surfactant aggregates which are micelles or micelle-like and will solubilize any organic solutes originally present in the water, resulting in a liquid–liquid extraction known as a cloud point extraction (CPE). Removal of pollutants from water is an important potential application of CPE and we use phenol as a model organic pollutant in this work. In this study, we investigate the effect of surfactant structure on important equilibrium CPE parameters like cloud point, fractional coacervate volume, and phenol and surfactant partition ratios for alcohol ethoxylates (AEs), a major class of nonionic surfactants. Pure, homogeneous surfactants with linear hydrophobes are studied as well as commercial heterogeneous AEs with both linear and branched hydrophobes. The effects of degree of polymerization in the polyethoxylate group (EO number) as well as hydrophobe size (alkyl carbon number) are systematically investigated as well as the effect of hydrophobe branching. The solubilization equilibrium constant is shown to increase linearly with EO number and is unaffected by alkyl carbon number or hydrophobe branching from which we deduce that the phenol is solubilized with the benzene ring at the surface of the micelle core and the hydroxyl group having attractive interactions with the polyethoxylate chains in the palisade layer of the micelle. The effects of surfactant structural features on net intermicellar attractive forces, micellar excluded volume, and solubilization capacity are discussed. A model is developed which can predict the phenol partition ratio at a given temperature for any AE surfactant dependent on only one simple measured parameter: fractional coacervate volume. This universal model is somewhat unique to phenolics or short chain alcohols because of their solubilization loci in the micelle and mechanism of solubilization. Guidelines for surfactant selection for CPE of phenol or similar solutes are outlined.
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- 2009
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21. Relation of Supersaturation Ratio in Mixed Anionic Surfactant Solutions to Kinetics of Precipitation with Calcium
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John F. Scamehorn and Sukhwan Soontravanich
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Supersaturation ,Precipitation (chemistry) ,General Chemical Engineering ,Sodium ,Inorganic chemistry ,chemistry.chemical_element ,Calorimetry ,Surfaces, Coatings and Films ,law.invention ,chemistry.chemical_compound ,Sulfonate ,chemistry ,Pulmonary surfactant ,law ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate ,Crystallization - Abstract
One synergism of using surfactant mixtures is the reduction in the equilibrium extent of and rate of precipitation. The overall time required for calcium-induced precipitation of mixed sodium dodecyl sulfate (SDS) and sodium octylbenzene sulfonate (SOBS) over a particular range of ratios has been found to increase dramatically when compared to either SDS or SOBS alone. In this study, light transmission and isoperibol calorimetry were used to measure the delay in the precipitation reaction, while scanning electron and optical micrographs of crystals formed give insight into the precipitation mechanism. The smaller the difference in the supersaturation ratio of the two precipitating surfactants, the longer the induction time is. The delay in the extent of precipitation is due to the interruption of crystal formation from dissimilar precipitating surfactants.
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- 2009
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22. Effect of Electrolyte and Temperature on Volatile Organic Compounds Removal from Wastewater Using Aqueous Surfactant Two-Phase System of Cationic and Anionic Surfactant Mixtures
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John F. Scamehorn, Punjaporn Weschayanwiwat, and Duanghathai Krutlert
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Aqueous solution ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Xylene ,Extraction (chemistry) ,Inorganic chemistry ,Filtration and Separation ,General Chemistry ,Ethylbenzene ,Toluene ,chemistry.chemical_compound ,Pulmonary surfactant ,Critical micelle concentration ,Phase (matter) - Abstract
Benzene, toluene, ethylbenzene, and xylene are frequently observed contaminants in industrial wastewaters causing concerns about environmental and health effects. An aqueous surfactant two-phase (ASTP) extraction system using mixtures of cationic and anionic surfactants have been shown to be a promising surfactant-based separation technique to concentrate solutes such as proteins and dyes from aqueous solution. A phase separation of a surfactant solution occurs at certain surfactant compositions and concentrations, forming two isotropic phases. One is rich in surfactant aggregates (surfactant-rich phase) and the other is lean in surfactant aggregates (surfactant-dilute phase). Most of the organic contaminants tend to solubilize and concentrate in the surfactant-rich phase, leaving the surfactant-dilute phase containing only small amounts of contaminants as remediated water. The effect of NaCl addition on the critical micelle concentration (CMC) and the extraction ability of ASTP formed by mixture...
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- 2009
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23. Recovery of nonionic surfactant from VOC-contaminated coacervate phase solutions by co-current vacuum stripping: Effect of surfactant concentration, temperature, and solute type
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Thirasak Rirksomboon, Boonyarach Kitiyanan, Suratsawadee Kungsanant, Somchai Osuwan, and John F. Scamehorn
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Cloud point ,Chromatography ,Coacervate ,Stripping (chemistry) ,Filtration and Separation ,Ethylbenzene ,Toluene ,Micelle ,Analytical Chemistry ,chemistry.chemical_compound ,Raschig ring ,chemistry ,Chemical engineering ,Pulmonary surfactant - Abstract
To make a cloud point extraction (CPE) process economically feasible, the used surfactant in the concentrated or coacervate phase should be recycled and reused. We have demonstrated a co-current vacuum stripping using a 30.5-cm long column packed with glass Raschig rings effectively removes as much as 90% of the toluene from a surfactant coacervate phase solution without flooding or plugging. It was found that the apparent Henry's law constant of the volatile organic compounds (VOCs) was significantly reduced due to solubilization of VOCs in surfactant micelles, but increased substantially with increasing temperature. In addition, it was observed that the increase in hydrophobicity of the VOCs results in higher micellar solubilization in the coacervate solution, leading to lower VOC removal efficiency. However, over 87% of all studied VOCs (benzene, toluene, ethylbenzene, 1,2 dichloroethane, trichloroethylene, and tetrachloroethylene) were removed from a coacervate solution within a single stage operation. The removal of VOCs increases with decreasing surfactant concentration and VOC hydrophobicity, and also increases with increasing system temperature.
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- 2009
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24. Interaction Between an Anionic and an Amphoteric Surfactant. Part II: Precipitation
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Sarah Walsh, Jeffrey H. Harwell, Sukhwan Soontravanich, David A. Sabatini, and John F. Scamehorn
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Chemistry ,Precipitation (chemistry) ,General Chemical Engineering ,Inorganic chemistry ,Protonation ,Solubility equilibrium ,Acid dissociation constant ,Surfaces, Coatings and Films ,Dissociation constant ,chemistry.chemical_compound ,Pulmonary surfactant ,Phase (matter) ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate - Abstract
Use of amphoteric and anionic surfactants is very common in practical formulations such as shampoos and hand dishwashing products. Precipitation of mixtures of dimethyldodecylamine oxide (DDAO) as an amphoteric surfactant and sodium dodecyl sulfate (SDS) as an anionic surfactant were studied at different pH levels. The DDAO is a pH-sensitive surfactant and its protonation can be expressed in terms of a pKa similar to an acid dissociation constant. The protonated form of DDAO carries a positive charge and precipitates with the oppositely charged SDS. Therefore, precipitation phase boundaries are pH dependent due to the varying degree of DDAO protonation. By combining the use of regular solution theory and the pseudophase separation model to describe micellar mixing nonidealities with the precipitate solubility product constant and the protonation dissociation constant, a model to predict the precipitation phase boundary is presented here. The model agrees well with experimental phase boundaries at different pH levels.
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- 2009
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25. Separation of Carbon Black from Silica by Froth Flotation Part 1: Effect of Operational Parameters
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Pisan Chungchamroenkit, Boonyarach Kitiyanan, Sumaeth Chavadej, John F. Scamehorn, and Ummarawadee Yanatatsaneejit
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Aqueous solution ,Chemistry ,Silica gel ,Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,Filtration and Separation ,General Chemistry ,Carbon black ,Electrolyte ,chemistry.chemical_compound ,Pulmonary surfactant ,Critical micelle concentration ,Point of zero charge ,Froth flotation - Abstract
Froth flotation can be applied to separate hydrophobic particles from hydrophilic ones in aqueous solution with the use of an appropriate surfactant. In this work, carbon black was separated from silica gel by means of froth flotation. Since the point of zero charge, or PZC, of the carbon black (3.5) is close to that of the silica gel (4.1), a nonionic surfactant (ethoxylated alcohol) was selected as the separating agent. Based on experimental results using a surfactant concentration of 62 µM or 75% of its critical micelle concentration (CMC), up to 70% of carbon black recovery was achieved with a carbon black enrichment ratio around 3.5. Added electrolyte (NaCl) showed a negligible effect on the separation efficiency. The presence of the surfactant was found to provide both a higher mass transfer surface area and to reduce the coalescence of air bubbles in the froth flotation column.
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- 2009
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26. Continuous Cloud Point Extraction of Volatile Organic Contaminants from Wastewater in a Multi-Stage Rotating Disc Contactor: Effect of Structure and Concentration of Solutes
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Thirasak Rirksomboon, John F. Scamehorn, Somchai Osuwan, and Phanphat Taechangam
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Cloud point ,Chromatography ,Process Chemistry and Technology ,General Chemical Engineering ,Extraction (chemistry) ,Filtration and Separation ,General Chemistry ,Toluene ,Ethylbenzene ,Partition coefficient ,Dichloroethane ,chemistry.chemical_compound ,chemistry ,Phenol ,Benzene - Abstract
Cloud point extraction (CPE) has been successfully scaled up to continuously remove aromatic contaminants from wastewater in a multi-stage rotating disc contactor (RDC) using t-octylphenolpolyethoxylate. The extraction performances for the removal of organic solutes with different structures and degrees of hydrophobicity were compared here for both batch and continuous CPE. Included are the volatile aromatics benzene, toluene, and ethylbenzene; volatile chlorinated compounds dichloroethane, trichloroethylene, and tetrachloroethylene; and non-volatile phenolics phenol, o-cresol, and catechol. The higher the Kow (octanol-water partition coefficient) or hydrophobicity of the solutes, the better the extraction due to the greater affinity of solutes to solubilize into micelles. The empirical linear correlations between log Kow, log (solute partition ratio), and log (height of transfer unit or HTU) were developed. Toluene is used as a model solute for the study of effect of initial solute concentration...
- Published
- 2008
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27. Toluene removal from nonionic surfactant coacervate phase solutions by vacuum stripping
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Boonyarach Kitiyanan, Suratsawadee Kungsanant, Thirasak Rirksomboon, Somchai Osuwan, and John F. Scamehorn
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Mass transfer coefficient ,Packed bed ,Coacervate ,Chromatography ,Stripping (chemistry) ,Chemistry ,Filtration and Separation ,Micelle ,Toluene ,Analytical Chemistry ,Raschig ring ,chemistry.chemical_compound ,Pulmonary surfactant ,Chemical engineering - Abstract
Cloud point extraction (CPE) has been demonstrated to remove volatile aromatic pollutants from wastewater by using a nonionic surfactant as a separating agent. To make this process economically feasible, the surfactant in the concentrated or coacervate phase containing most of the original pollutant must be recycled and reused. This work proposes a vacuum stripping process to strip the volatile pollutant from the coacervate, leaving the concentrated surfactant solution to be recycled to the CPE process. An acrylic column was packed with glass Raschig rings and operated under rough vacuum in co-current mode to remove toluene from the coacervate phase containing the t -octylphenolpolyethoxylate (OP(EO 7 )) nonionic surfactant. Co-current operation is necessary to avoid excessive foaming. In this study, although the apparent Henry's law constant of toluene was drastically reduced due to toluene solubilization in surfactant micelles, up to 90% of toluene was removed from 300 mM OP(EO) 7 surfactant solution using a 30.5-cm long column. The packed column can be operated without flooding and plugging, despite the viscous nature of the coacervate. The toluene removal increases with decreasing liquid loading rate, and column pressure, but with increasing number of distributor holes. The overall liquid phase volumetric mass transfer coefficient is reported for this system.
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- 2008
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28. Interaction Between an Anionic and an Amphoteric Surfactant. Part I: Monomer–Micelle Equilibrium
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Joline A. Munoz, Jeffrey H. Harwell, Sukhwan Soontravanich, David A. Sabatini, and John F. Scamehorn
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General Chemical Engineering ,Inorganic chemistry ,Cationic polymerization ,Oxide ,Protonation ,Micelle ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Monomer ,chemistry ,Pulmonary surfactant ,Titration ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate - Abstract
A mixture of anionic and amphoteric surfactants is composed of three components at intermediate pH levels: anionic, cationic (protonated amphoteric), and zwitterionic (unprotonated amphoteric). Knowledge of the composition of each surfactant in both monomer and micellar forms (monomer–micelle equilibrium) is important in applications using this mixture. Hydrogen ion titration of the mixed surfactant solution as a function of surfactant composition is combined with the pseudophase separation model and regular solution theory for the three-surfactant mixture to calculate the concentration of each surfactant in monomer and in micelle forms at different pH levels. The specific systems studied here contain sodium dodecyl sulfate (SDS) and dimethyldodecylamine oxide (DDAO), which are used in a wide range of consumer products. The degree of protonation of monomeric DDAO is not affected by the presence of SDS, indicating an insignificant formation of ion pairs between these monomers. However, the presence of SDS in micelles shifts the micellar pK a of DDAO protonation significantly and the method used here allows the quantification of partial fugacities of each individual surfactant in micelle form. The composition in the monomer phase at each pH will aid in understanding and predicting solution compositions corresponding to anionic/amphoteric surfactant precipitation boundaries, which is the focus of the subsequent paper in this series.
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- 2008
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29. Oily Soil Detergency under Microemulsion Conditions: Effects of Oil Loading and Surfactant Adsorption
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R. Kaewpukpa, Sumaeth Chavadej, and John F. Scamehorn
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chemistry.chemical_classification ,business.product_category ,Chromatography ,Chemistry ,General Engineering ,Salt (chemistry) ,Alcohol ,Polyester ,Surface tension ,chemistry.chemical_compound ,Adsorption ,Pulmonary surfactant ,Chemical engineering ,Microemulsion ,business ,Motor oil - Abstract
Detergency process of oily soil removal from fabrics is of interest and the mechanisms of oily soil removal are very complicated involving several factors: interfacial tension, oil loading and surfactant adsorption. In this study, the effects of oil loading and the surfactant adsorption on the detergency performance of oily soil removal were investigated. Mixed surfactant systems of branched alcohol propoxylate sulfate sodium salt (Alfoterra 145-3PO), an extended anionic surfactant, and secondary alcohol ethoxylate (Tergitol 15-S-5), a nonionic surfactant, were used to form microemulsions with motor oil. The CMC and CµC values of the mixed surfactants were 0.015 and 0.04 % total active mixed surfactants concentration, respectively. A polyester/cotton blend [65/35] was selected to use as a testing fabric in detergency experiments. The results showed that the oil loading and fabric weight did not affect the efficiency of oil removal. Furthermore, with the selected formulation (0.1 wt.% Alfoterra 145-3PO and 5 wt.% Tergitol 15-S-5), the oil detachment time was investigated at different temperatures (30-50°C) and different total surfactant concentrations (0.04-0.5 %). The results showed that increasing temperature and surfactant concentration were found to decrease the oil detachment time, leading to increasing oil removal.
- Published
- 2008
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30. Benzene removal from waste water using aqueous surfactant two-phase extraction with cationic and anionic surfactant mixtures
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Punjaporn Weschayanwiwat, Onanong Kunanupap, and John F. Scamehorn
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Alkanesulfonates ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Complex Mixtures ,Waste Disposal, Fluid ,Water Purification ,Surface-Active Agents ,Pulmonary surfactant ,Phase (matter) ,Environmental Chemistry ,Chromatography ,Aqueous solution ,Sewage ,Chemistry ,Extraction (chemistry) ,Public Health, Environmental and Occupational Health ,Cationic polymerization ,Benzene ,General Medicine ,General Chemistry ,Pollution ,Separation process ,Quaternary Ammonium Compounds ,Partition coefficient ,Chemical engineering ,Critical micelle concentration - Abstract
A novel separation technique known as an aqueous surfactant two-phase (ASTP) extraction is a promising method to remove organic contaminants from wastewater. When cationic and anionic surfactants are mixed at certain surfactant concentrations and compositions, the solution separates into two immiscible aqueous phases. One is the surfactant-rich and the other is the surfactant-dilute phase. The organic contaminants will solubilize into the surfactant aggregates and concentrate in the small volume surfactant-rich phase. The other phase contains only small amount of surfactants and contaminants as the treated water. Most ASTP studies have used nonionic surfactants above the cloud point. Mixtures of anionic and cationic surfactants can also exhibit aqueous–aqueous phase separation and can be used in the ASTP extraction process. The phase behavior and performance of ASTP extraction using cationic surfactant dodecyltrimethylammonium bromide (DTAB) and anionic surfactant alkyldiphenyloxide di-sulfonate (DPDS) to extract benzene from wastewater was investigated in batch experiments. It was found that phase separation only occurs over a narrow range of molar ratios of DTAB:DPDS from 1.6:1 to 2.4:1. In this study, a 2:1 molar ratio of DTAB:DPDS at which there is no net charge in the surfactant aggregates show the highest extraction efficiency and lowest critical micelle concentration value with greatest synergism (highest negative values of the micellar interaction parameter). At a total surfactant concentration of 50 mM, the benzene partition ratio is 48 and 72% of the benzene is extracted into the surfactant-rich phase solution in a single stage extraction, which is superior performance compared to ASTP extraction using nonionic surfactants.
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- 2008
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31. Diesel Oil Removal by Froth Flotation Under Low Interfacial Tension Conditions II: Continuous Mode of Operation
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John F. Scamehorn, Sunisa Watcharasing, and Sumaeth Chavadej
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Chromatography ,Hydraulic retention time ,Process Chemistry and Technology ,General Chemical Engineering ,Filtration and Separation ,General Chemistry ,Surface tension ,Diesel fuel ,chemistry.chemical_compound ,chemistry ,Pulmonary surfactant ,Batch processing ,lipids (amino acids, peptides, and proteins) ,Microemulsion ,Sodium dodecyl sulfate ,Froth flotation - Abstract
The objective of this study was to investigate the relationship between interfacial tension (IFT) and foam characteristics and the efficiency of diesel oil removal from water in a continuous froth flotation column. The effects of operational parameters, including surfactant concentration, salinity, oil-to-water ratio, foam height, air flow rate, and hydraulic retention time (HRT) on the oil removal were investigated in the continuous mode of a froth flotation operation and compared to batch operation results. Unlike the batch system, for the continuous system used in the present study, having only branched alcohol propoxylate sulfate sodium salt surfactant (C14–15(PO)5SO4Na) and NaCl present in the solution yielded such poor foam characteristics that a stable froth which overflowed the flotation column could not be produced, so the addition of sodium dodecyl sulfate (SDS) as a froth promoter was used to improve the foam stability. Unlike the batch froth flotation system with only C14–15(PO)5SO4Na...
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- 2008
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32. Diesel Oil Removal by Froth Flotation Under Low Interfacial Tension Conditions I: Foam Characteristics, and Equilibration Time
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Sumaeth Chavadej, Ummarawadee Yanatatsaneejit, and John F. Scamehorn
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chemistry.chemical_classification ,Chromatography ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Salt (chemistry) ,Filtration and Separation ,General Chemistry ,Separation process ,Surface tension ,Diesel fuel ,Chemical engineering ,Pulmonary surfactant ,Microemulsion ,Froth flotation ,Carbon number - Abstract
Froth flotation is a surfactant‐based separation process which is suitable for treating dilute wastewaters. To achieve high performance for the froth flotation operation, the combination of an ultra‐low interfacial tension (IFT) between excess oil and excess water phases, high foam production rates, and high stability of the foam produced, must be attained. To obtain the ultra‐low interfacial tensions, a Winsor Type III or middle phase microemulsion has to be formed. In this study, branched alcohol propoxylate sulfate sodium salt with 14–15 carbon number and 4 PO groups (Alfoterra 145–4PO) was used to form microemulsions with diesel oil. From the results of this work, an increase in surfactant concentration decreased the IFT, and increased foam stability. To obtain the minimum IFT in the region of a Winsor Type III microemulsion, the addition of 5 wt.% NaCl was needed. However, this optimum salinity does not result in effective froth flotation due to poor foam characteristics. The results indicat...
- Published
- 2008
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33. Microemulsion Formation and Detergency with Oily Soil: IV. Effect of Rinse Cycle Design
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David A. Sabatini, Chantra Tongcumpou, Parichat Tanthakit, Sumaeth Chavadej, and John F. Scamehorn
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chemistry.chemical_classification ,business.product_category ,Chromatography ,General Chemical Engineering ,Fraction (chemistry) ,Surfaces, Coatings and Films ,Polyester ,Surface tension ,chemistry ,Chemical engineering ,Pulmonary surfactant ,Phase (matter) ,Microemulsion ,Physical and Theoretical Chemistry ,business ,Motor oil ,Alkyl - Abstract
The objective of this work was to apply a microemulsion-based formulation for the removal of motor oil in laundry detergency at low salinity. To produce the desired phase behavior, three surfactants were used: alkyl diphenyl oxide disulfonate (ADPODS), sodium dioctyl sulfosuccinate (AOT) and sorbitan monooleate (Span 80). The mixed surfactant system of 1.5% ADPODS, 5% AOT and 5% Span 80 (13 parts ADPODS, 43.5 parts AOT, and 43.5 parts Span 80 of the total actives) was found to form a middle phase microemulsion (Type III) at a relatively low salinity of 2.83% NaCl. When this formulation was diluted, detergency performance increased with increasing total surfactant concentration and leveled off above about 0.1% total actives on the three types of fabrics studied (pure cotton, 65/35 polyester/cotton blend, and pure polyester). Detergency was found to improve with increasing hydrophilicity of the fabric with cotton being cleanest after washing and polyester the most difficult to clean. To achieve a specified oil removal, less rinse water can be used if a higher number of lower-volume rinses are employed. An interesting characteristic of microemulsion-based formulations is that a substantial fraction of oil removal occurs during the rinse cycle. In this work, this removal is shown to be due to the low oil/water interfacial tension during initial rinsing and is therefore strongly correlated to residual surfactant concentration in the rinse steps. As a result, the number of rinses and the volume of water per rinse can profoundly affect detergency in these systems.
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- 2008
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34. Industrial Home Laundry Closed Loop Cleaning Process
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Stephen Capps, Napaporn Komesvarakul, Lorena K. Serventi, Edwin E. Tucker, Hatice Gecol, John F. Scamehorn, and Kirk Herbert Raney
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Chromatography ,Chemistry ,Laundry ,General Chemical Engineering ,Microfiltration ,chemistry.chemical_element ,Reuse ,Pulp and paper industry ,Surfaces, Coatings and Films ,law.invention ,Pulmonary surfactant ,law ,Scientific method ,Soil water ,Chlorine ,Physical and Theoretical Chemistry ,Filtration - Abstract
This study presents a method to develop an efficient and economical system for cleaning home laundry on a commercial scale with both water and chemical (detergent) reuse. The experiments were done using an industrial-type horizontal-axis machine, two leading consumer heavy-duty liquid laundry detergents, one II wash and rinse waters were filtered after each cycle and reused in the next wash cycle. The surfactant recovery is over 40%. Soiled test strips were used to measure the percentage of soil removal after the wash/filtration sequence for stains and various liquid or particulate soils. The soil removal remained practically constant under simulated steady-state conditions even with water recoveries of nearly 90%. Softness of towels remained unchanged when recycled water was used in this process. Chlorine carry-over from white laundry to the wash process was shown to be minimal. This is important to avoid color fading in mixed loads upon reuse since water is not segregated for colored laundry versus white laundry. Hardness ions can precipitate fatty acids which reduce flux during filtration and decrease surfactant recovery. Preliminary analysis of the different formulations used indicates that an all-nonionic formulation may be best suited to this recycling process.
- Published
- 2007
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35. Surfactant‐Enhanced Carbon Regeneration in a Vapor‐Phase Application
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Pomthong Malakul, Pramoch Rangsunvigit, Pipop Thamtharai, and John F. Scamehorn
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Aqueous solution ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,chemistry.chemical_element ,Filtration and Separation ,General Chemistry ,chemistry.chemical_compound ,Adsorption ,Pulmonary surfactant ,Critical micelle concentration ,Desorption ,medicine ,Sodium dodecyl sulfate ,Carbon ,Activated carbon ,medicine.drug - Abstract
Coal‐based granular activated carbon (GAC) is saturated with trichloroethylene (TCE) by passing air through a fix bed adsorber. In surfactant‐enhanced carbon regeneration, an aqueous solution of anionic surfactant, sodium dodecyl sulfate (SDS), is passed through the bed to induce desorption of TCE. More than 95% of the sorbed TCE was removed in the desorption operation with a 0.1 M SDS solution at a superficial flow rate of 1 cm/min. The desorption rate of TCE from pores of GAC is limited by pore diffusion and not significantly affected by either the concentration of SDS in the regenerant (when well above the critical micelle concentration) or its flow rate. From the breakthrough curve of a subsequent adsorption cycle without a flushing step following the desorption, only 7% of the virgin carbon effective adsorption capacity is observed for the regenerated carbon. With a water flushing step following the regeneration step, the effective adsorption capacity is significantly improved to about 15% o...
- Published
- 2007
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36. Adsorption of Anionic–Cationic Surfactant Mixtures on Metal oxide Surfaces
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David A. Sabatini, A. Upadhyaya, Edgar Acosta, and John F. Scamehorn
- Subjects
Benzethonium chloride ,General Chemical Engineering ,Inorganic chemistry ,Cationic polymerization ,Mole fraction ,Micelle ,Chloride ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Adsorption ,chemistry ,Pulmonary surfactant ,medicine ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate ,medicine.drug - Abstract
This research evaluates the adsorption of anionic and cationic surfactant mixtures on charged metal oxide surfaces (i.e., alumina and silica). For an anionic-rich surfactant mixture below the CMC, the adsorption of anionic surfactant was found to substantially increase with the addition of low mole fractions of cationic surfactant. Two anionic surfactants (sodium dodecyl sulfate and sodium dihexyl sulfosuccinate) and two cationic surfactants (dodecyl pyridinium chloride and benzethonium chloride) were studied to evaluate the effect of surfactant tail branching. While cationic surfactants were observed to co-adsorb with anionic surfactants onto positively charged surfaces, the plateau level of anionic surfactant adsorption (i.e., at or above the CMC) did not change significantly for anionic–cationic surfactant mixtures. At the same time, the adsorption of anionic surfactants onto alumina was dramatically reduced when present in cationic-rich micelles and the adsorption of cationic surfactants on silica was substantially reduced in the presence of anionic-rich micelles. This demonstrates that mixed micelle formation can effectively reduce the activity of the highly adsorbing surfactant and thus inhibit the adsorption of the surfactant, especially when the highly adsorbing surfactant is present at a low mole fraction in the mixed surfactant system. Thus surfactant adsorption can be either enhanced or inhibited using mixed anionic–cationic surfactant systems by varying the concentration and composition.
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- 2007
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37. Surfactant‐Enhanced Regeneration of Polymeric Resin in a Vapor‐Phase Application
- Author
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Pramoch Rangsunvigit, Pomthong Malakul, Pipop Thamtharai, and John F. Scamehorn
- Subjects
Thermogravimetric analysis ,Aqueous solution ,Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,technology, industry, and agriculture ,chemistry.chemical_element ,Filtration and Separation ,General Chemistry ,Volumetric flow rate ,chemistry.chemical_compound ,Adsorption ,chemistry ,Pulmonary surfactant ,Chemical engineering ,Desorption ,Sodium dodecyl sulfate ,Carbon - Abstract
Surfactant enhanced carbon regeneration (SECR) was employed to regenerate a polymeric resin saturated with trichloroethylene (TCE), using an aqueous solution of the anionic surfactant sodium dodecyl sulfate (SDS). More than 95% of the sorbed TCE was removed in the desorption operation with a 0.1 M SDS solution at a superficial flow rate of 1 cm/min. The desorption rate of TCE from pores of the resin is limited by the concentration of SDS in the regenerant and its flow rate. From the breakthrough curve of the subsequent adsorption cycle without a flushing step following the desorption, only 40% of the effective adsorption capacity of the virgin resin is observed for the regenerated resin. With a water flushing step following the surfactant regeneration step, the effective adsorption capacity is significantly improved to about 60% of that of the virgin resin. Thermal gravimetric analysis indicates that the reduction in the effective adsorption capacity of regenerated resin resulted from the residua...
- Published
- 2007
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38. Removal of solvent-based ink from printed surface of high-density polyethylene bottles by alkyltrimethylammonium bromides: Effects of pH, temperature, and salinity
- Author
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Pitt Supaphol, Arubol Chotipong, Sumaeth Chavadej, John F. Scamehorn, and Thirasak Rirksomboon
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chemistry.chemical_classification ,Chemistry ,Inorganic chemistry ,Deinking ,Micelle ,law.invention ,body regions ,Solvent ,Colloid and Surface Chemistry ,Adsorption ,Pulmonary surfactant ,law ,Zeta potential ,High-density polyethylene ,Alkyl ,circulatory and respiratory physiology - Abstract
The effects of pH, temperature, and salinity on the removal of solvent-based ink from high-density polyethylene (HDPE) surfaces were investigated using three alkyltrimethylammonium bromides (i.e., dodecyl-, tetradecyl-, and hexadecyl-trimethylammonium bromide or DTAB, TTAB, and CTAB, respectively). Ink removal increases with increasing concentration, increasing pH, decreasing temperature, and increasing salinity of the CnTAB solutions. The zeta potential of ink becomes more positively charged with increasing pH as well as concentration and alkyl chain length of CnTAB, indicating that adsorption of CnTAB on ink pigment occurred more readily with an increase in any of those parameters. The solubilization of epoxy ink binder was found to increase with increasing surfactant concentration, decreasing temperature, and increasing salinity of the CnTAB solutions. Adsorption of cationic surfactant onto the ink pigment particles and solubilization of ink binder molecules into surfactant micelles are important mechanisms causing ink removal from the plastic surface.
- Published
- 2007
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39. Enhanced triolein removal using microemulsions formulated with mixed surfactants
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Chantra Tongcumpou, Sumaeth Chavadej, John F. Scamehorn, David A. Sabatini, Edgar Acosta, and Nantaya Yanumet
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chemistry.chemical_classification ,General Chemical Engineering ,Hexadecane ,Surfaces, Coatings and Films ,Surface tension ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Pulmonary surfactant ,Phase (matter) ,Microemulsion ,Triolein ,Wetting ,Physical and Theoretical Chemistry ,Alkyl - Abstract
In previous work, a microemulsion-based formulation approach yielded excellent laundry detergency with hydrophobic oily soils hexadecane and motor oil. In this work, the same approach is used in detergency of triolein, which is a model triglyceride, some of the most difficult oils to be removed from fabric. The linker concept was applied in formulation of the microemulsion system. Three different surfactants were used: (i) dihexyl sulfosuccinate, an ionic surfactant with a moderate hydrophile-lipophile balance (HLB); (ii) secondary alcohol ethoxylate, a lipophilic nonionic surfactant with a very low HLB; and (iii) alkyl diphenyl oxide disulfonate (ADPODS), a hydrophilic anionic surfactant with a very high HLB. The phase behavior and interfacial tension (IFT) of the surfactant systems were determined with different concentrations of ADPODS. The results indicate that as the HLB of the system increases, a higher salinity is required to shift the phase transition from Winsor Type I to Type III to Type II. The three formulations at different salinities were used in detergency experiments to remove triolein from polyester/cotton sample fabric. The results showed that there were two peaks of maximum detergency in the range of salinity from 0.1% to 10% NaCl. The higher the hydrophilicity of the system, the higher the salinity required for maximum detergency. The results of the dynamic IFT and the detergency performance from two rinsing methods lead to the hypothesis that one of these maxima in detergency results from a spreading or wetting effect. The other maximum in detergency is believed to be related to ultralow IFT associated with oil/water middle-phase microemulsion formation. Triolein removal exceeding 80% was attained, validating the microemulsion approach to detergency.
- Published
- 2006
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40. Microemulsion phase behavior of anionic-cationic surfactant mixtures: Effect of tail branching
- Author
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A. Upadhyaya, John F. Scamehorn, David A. Sabatini, and Edgar Acosta
- Subjects
Limonene ,Benzethonium chloride ,General Chemical Engineering ,Sodium ,Inorganic chemistry ,Cationic polymerization ,chemistry.chemical_element ,Alcohol ,Branching (polymer chemistry) ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Pulmonary surfactant ,Microemulsion ,Physical and Theoretical Chemistry ,Nuclear chemistry - Abstract
This research evaluated middle-phase microemulsion formation by varying the mole ratio of anionic and cationic surfactants in mixtures with four different oils (trichloroethylene, n-hexane, limonene, and n-hexadecane). Mixtures of a double-tailed anionic surfactant (sodium dihexyl sulfosuccinate, SDHS) and an unbalanced-tail (i.e., doubletailed with tails of different length) cationic surfactant (benzethonium chloride, BCl) were able to form microemulsions without alcohol addition. The amount of NaCl required to form the middle-phase microemulsion decreased dramatically as an equimolar anionic-cationic surfactant mixture was approached. Although the mixture of anionic and cationic surfactants demonstrated a higher critical microemulsion concentration (cμc) compared to the anionic surfactant alone, the Winsor Type IV single-phase microemulsion started at lower surfactant concentrations for the anionic-cationic mixture than for the anionic surfactant alone. Under optimum middlephase microemulsion conditions, mixed anionic-cationic surfactant systems solubilized more oil than the anionic surfactant alone. Pretreatment detergency studies were conducted to test the capacity of these mixed surfactant systems to remove oil form fabrics. It was found that anionic-rich mixed surfactant formulations yielded the largest oil removal, followed by cationic-rich systems.
- Published
- 2006
- Full Text
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41. Contact angle of surfactant solutions on precipitated surfactant surfaces. III. Effects of subsaturated anionic and nonionic surfactants and NaCl
- Author
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Chintana Saiwan, Bungon Luepakdeesakoon, and John F. Scamehorn
- Subjects
Surface tension ,Contact angle ,Adsorption ,Pulmonary surfactant ,Chemistry ,General Chemical Engineering ,Critical micelle concentration ,Monolayer ,Inorganic chemistry ,Wetting ,Physical and Theoretical Chemistry ,Soap scum ,Surfaces, Coatings and Films - Abstract
The contact angles of saturated calcium dodecanoate (CaC12) solutions containing a second subsaturated surfactant on a precipitated CaC12 surface were measured by using the drop shape analysis technique. The subsaturated surfactants used were anionic sodium dodecylsulfate (NaDS), anionic sodium octanoate (NaC8), and nonionic nonylphenol polyethoxylate (NPE). Comparing at the critical micelle concentration (CMC) for each surfactant, NaC8 was the best wetting agent, followed by NaDS, with NPE as the poorest wetter (contact angles of 320, 420, and 620, respectively). Surface tension at the CMC increased in the order NaC8
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- 2006
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42. Removal of solvent-based ink from printed surface of HDPE bottles by alkyltrimethylammonium bromides: effects of surfactant concentration and alkyl chain length
- Author
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Arubol Chotipong, Thirasak Rirksomboon, Pitt Supaphol, John F. Scamehorn, and Sumaeth Chavadej
- Subjects
chemistry.chemical_classification ,Polymers and Plastics ,Chemistry ,Deinking ,Micelle ,law.invention ,body regions ,Colloid and Surface Chemistry ,Adsorption ,Chemical engineering ,Pulmonary surfactant ,law ,Critical micelle concentration ,Polymer chemistry ,Dispersion stability ,Materials Chemistry ,Zeta potential ,Physical and Theoretical Chemistry ,Alkyl - Abstract
Three alkyltrimethylammonium bromides (i.e., dodecyl-, tetradecyl-, and hexadecyltrimethylammonium bromide or DTAB, TTAB, and CTAB, respectively) were used to remove a blue solvent-based ink from a printed surface of high-density polyethylene bottles. Either an increase in the alkyl chain length or the surfactant concentration was found to increase the deinking efficiency. Complete deinking was achieved at concentrations about 3, 8, and 24 times of the critical micelle concentration (CMC) of CTAB, TTAB, and DTAB, respectively. For CTAB, ink removal started at a concentration close to or less than its CMC and increased appreciably at concentrations greater than its CMC, while for TTAB and DTAB, significant deinking was only achieved at concentrations much greater than their CMCs. Corresponding to the deinking efficiency of CTAB in the CMC region, the zeta potential of ink particles was found to increase with increasing alkyl chain length and concentration of the surfactants, which later leveled off at some higher concentrations. Wettability of the surfactants on an ink surface increased with increasing alkyl chain length and concentration of the surfactants. Lastly, solubilization of ink binder in the surfactant micelles was found to increase with increasing alkyl chain length and surfactant concentration. We conclude that adsorption of surfactant on the ink pigment is crucial to deinking due to modification of wettability, zeta potential, pigment/water interfacial tension, and dispersion stability. Solubilization of binder (epoxy) into micelles is necessary for good deinking because the dissolution of the binder is required before the pigment particles can be released from the polymer surface.
- Published
- 2006
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43. Mixtures of anionic and cationic surfactants with single and twin head groups: Adsorption and precipitation studies
- Author
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Ampira Charoensaeng, Edgar Acosta, A. Fuangswasdi, David A. Sabatini, John F. Scamehorn, Sutha Khaodhiar, and Khemarath Osathaphan
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Precipitation (chemistry) ,General Chemical Engineering ,Sodium ,Inorganic chemistry ,Cationic polymerization ,chemistry.chemical_element ,Dodecylpyridinium chloride ,Surfactant system ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Adsorption ,Pulmonary surfactant ,chemistry ,Physical and Theoretical Chemistry ,Sodium dodecyl sulfate - Abstract
This research reports on the adsorption and precipitation of mixtures of anionic and cationic surfactants having single and twin head groups. The surfactant mixtures investigated were: (i) a single-head anionic surfactant, sodium dodecyl sulfate (SDS), in a mixture with the twin-head cationic surfactant pentamethyl-octadecyl-1,3-propane diammonium dichloride (PODD)—adsorption was studied on negatively charged silica; and (ii) a twin-head anionic surfactant, sodium hexadecyl-diphenyloxide disulfonate (SHDPDS), and the single-head cationic surfactant dodecylpyridinium chloride (DPCI)—adsorption was studied on positively charged alumina. Whereas the mixed surfactant system of SHDPDS/DPCI showed adsorption on alumina that was comparable to the of SHDPDS alone, the mixed surfactant system of SDS/PODD showed increased adsorption on silica as compared with PODD alone. The adsorption of the SDS/PODD mixture increased as the anionic and cationic system approached an equimolar ratio. Precipitation diagrams for mixtures of single- and twin-head surfactant systems showed smaller precipitation areas than for single-head-only surfactant mixtures. Thus, the combination of single- and double-head surfactants helps reduce the precipitation region and can increase the adsorption levels, although the magnitude of the effect is a function of the specific surfactants used.
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- 2006
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44. Pilot-scale study of Polyelectrolyte-Enhanced UF for arsenic removal
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Edgar Acosta, Daniel Gallo, John F. Scamehorn, and David A. Sabatini
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Chromatography ,Aqueous solution ,Ultrafiltration ,Arsenate ,chemistry.chemical_element ,General Chemistry ,Polyelectrolyte ,Membrane technology ,chemistry.chemical_compound ,Adsorption ,chemistry ,Maximum Contaminant Level ,Arsenic ,Water Science and Technology ,Nuclear chemistry - Abstract
The removal of arsenic (As) from dilute aqueous solutions has become of greater interest as lower drinking standards are implemented. In polyelectrolyte-enhanced ultrafiltration (PEUF), a cationic water-soluble polyelectrolyte (poly-diallyldimethylammonium chloride [QUAT]) binds the anionic arsenate species and is rejected by the membrane, which has a 10 kDa molecular weight cutoff (MWCO). In the research presented in this article, PEUF was used to treat water with As concentrations of 50-100 μg/L The results demonstrated that PEUF was able to produce treated water that meets the proposed US Environmental Protection Agency maximum contaminant level of 10 μg/L. In this study, the PEUF process was scaled up with a spiral-wound ultrafiltration module operated under steady-state continuous flow conditions (i.e., permeate flux of 80 L/m 2 -h, and a pressure drop of 60 psi, which is typical for large-volume applications). The main process parameters considered in this study were the QUAT-to-As ratio, pH, and the presence of background electrolytes (i.e., sulfate). The As removal efficiency improved with increasing pH, which is an advantage when the As-tainted water is at an elevated pH since most adsorption-based As removal methods perform better at lower pH levels.
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- 2006
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45. Colloid‐Enhanced Ultrafiltration of Chlorophenols in Wastewater: Part V. Simultaneous Removal of a Chlorophenol and a Metal Ion
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Linh D. Do, Thu T. Nguyen, John F. Scamehorn, and Napaporn Komesvarakul
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Chlorophenol ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,Ultrafiltration ,Filtration and Separation ,General Chemistry ,Cetylpyridinium chloride ,Polyelectrolyte ,Colloid ,chemistry.chemical_compound ,Membrane ,Dichlorophenol ,Magnesium ion - Abstract
Polyelectrolyte micellar‐enhanced ultrafiltration (PE‐MEUF) is a separation process to remove target solutes from water using a mixture of a surfactant and an oppositely charged polyelectrolyte as a colloid. An organic solute and a metal cation can simultaneously associate with the colloid, which is subsequently ultrafiltered from solution. An organic solute solubilizes in the surfactant micelle‐like aggregates whereas an inorganic cation binds onto the oppositely charged polyion chains. The solution is then passed through the membrane having pore sizes small enough to block the passage of the surfactant‐polymer aggregates. In this work, PE‐MEUF has been applied to mixtures containing dichlorophenol (DCP) and magnesium ion (Mg2+), using cetylpyridinium chloride (CPC) and sodium poly(styrenesulfonate) (PSS) mixtures. It was observed that the presence of Mg2+ does not affect DCP rejection. The [CPC] to [PSS] ratio and colloid concentration have a significant effect on both DCP and Mg2+ rejections. ...
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- 2005
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46. Colloid‐Enhanced Ultrafiltration of Chlorophenols in Wastewater: Part IV. Effect of Added Salt on the Surfactant Leakage in Surfactant Solutions and Surfactant–Polymer Mixtures
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Thu T. Nguyen, John F. Scamehorn, Linh D. Do, and Napaporn Komesvarakul
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Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,Filtration and Separation ,General Chemistry ,Permeation ,Cetylpyridinium chloride ,Chloride ,Polyelectrolyte ,Surface tension ,chemistry.chemical_compound ,Colloid ,Pulmonary surfactant ,chemistry ,Critical micelle concentration ,medicine ,medicine.drug - Abstract
The critical aggregation concentration (cac) in surfactant–polymer mixtures approximates a lower limit to the surfactant concentration in the permeate (surfactant leakage) in polyelectrolyte micellar‐enhanced ultrafiltration. Here, the cac was measured at different salinities by using surface tension measurements. It was found that the cac increases slightly with the addition of simple salt, then the cac value decreases at higher salt concentration. The critical micelle concentration (CMC), which approximates surfactant leakage in micellar systems (no polymer), decreases monotonically with increasing salinity for ionic surfactants. The surfactant leakage in colloid‐enhanced ultrafiltration (CEUF) processes is investigated by using a dialysis method in the presence of three phenolic solutes with various degrees of chlorination: 2‐monochlorophenol (MCP), 2,4‐dichlorophenol (DCP), and 2,4,6‐trichlorophenol (TCP). Cetylpyridinium chloride (CPC) or n‐hexadecylpyridinium chloride is used as a cationic ...
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- 2005
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47. Surfactant Recovery from Water Using a Multistage Foam Fractionator: Part I Effects of Air Flow Rate, Foam Height, Feed Flow Rate and Number of Stages
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John F. Scamehorn, Savanit Boonyasuwat, Pomthong Malakul, and Sumaeth Chavadej
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Chromatography ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Papermaking ,Cationic polymerization ,Filtration and Separation ,General Chemistry ,Pulp and paper industry ,Cetylpyridinium chloride ,Volumetric flow rate ,chemistry.chemical_compound ,Wastewater ,Pulmonary surfactant ,Critical micelle concentration ,Foam fractionation - Abstract
Surfactants can be present at low concentrations in wastewater from many industries, such as papermaking or detergent manufacture. The surfactant must sometimes be reduced in concentration in order to meet environmental standards before discharging these wastewaters to the environment. Also, recovery of the surfactant for reuse is sometimes economical and desirable. Foam fractionation has been shown to be an effective method of removing anionic and cationic surfactants from water in a single stage in our previous work. In this study, the recovery of a cationic surfactant (cetylpyridinium chloride or CPC) from water by multistage foam fractionation in a bubble‐cap trayed column was investigated with one to four stages operated in steady‐state mode for surfactant concentrations less than or equal to the critical micelle concentration. In comparison with a single‐stage foam fractionator, CPC was found to be removed from water by the multistage foam fractionator much more effectively. Both enrichment...
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- 2005
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48. Ethylbenzene Removal by Froth Flotation Under Conditions of Middle‐Phase Microemulsion Formation II: Effects of Air Flow Rate, Oil‐to‐Water Ratio, and Equilibration Time
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Sumaeth Chavadej, Pramoch Rangsunvigit, Ummarawadee Yanatatsaneejit, and John F. Scamehorn
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Chromatography ,Chemistry ,Turbulence ,Process Chemistry and Technology ,General Chemical Engineering ,Mixing (process engineering) ,Filtration and Separation ,General Chemistry ,Ethylbenzene ,Aerosol ,chemistry.chemical_compound ,Chemical engineering ,Pulmonary surfactant ,Yield (chemistry) ,Microemulsion ,Froth flotation - Abstract
Dihexyl sulfosuccinate (aerosol MA or AMA) was used to prepare microemulsion solutions in a study of the froth flotation process in batch mode to remove emulsified ethylbenzene from water. Oil removal, surfactant removal, and enrichment ratio were used to evaluate the performance of froth flotation. In this study, the effects of air flow rate, oil‐to‐water ratio, and equilibration time were investigated. A very high air flow rate was found to create more turbulence in the froth flotation column, resulting in low oil removal. As the oil‐to‐water ratio decreases, the enrichment ratio increases, whereas the oil removal slightly decreases. The froth flotation column with a feed solution in which the oil and water had been allowed to equilibrate was found to yield much higher ethylbenzene removal than that with a nonequilibrium feed solution. When the feed solution was agitated for 40 minutes to induce a state closer to equilibrium than with no mixing, the ethylbenzene removal was nearly as high as th...
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- 2005
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49. Ethylbenzene Removal by Froth Flotation Under Conditions of Middle‐Phase Microemulsion Formation I: Interfacial Tension, Foamability, and Foam Stability
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Sumaeth Chavadej, Edgar Acosta, Pramoch Rangsunvigit, Anuradee Witthayapanyanon, David A. Sabatini, Ummarawadee Yanatatsaneejit, and John F. Scamehorn
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Chromatography ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Filtration and Separation ,General Chemistry ,Ethylbenzene ,Aerosol ,Surface tension ,Dihexyl sulfosuccinate ,chemistry.chemical_compound ,Chemical engineering ,Pulmonary surfactant ,Middle phase ,Microemulsion ,Froth flotation - Abstract
The objective of this study was to investigate the relationship of the froth flotation performance in removal of emulsified ethylbenzene in water with microemulsion formation and with foam formation characteristics. The surfactant used was dihexyl sulfosuccinate (Aerosol MA or AMA) which can form microemulsions with ethylbenzene. The systems studied were designed to form Winsor Type III microemulsions with ethylbenzene, which generally correspond to ultra‐low interfacial tensions between oil and water phases. By varying the surfactant concentration, NaCl concentration, and oil‐to‐water ratio, it was found that the lowest interfacial tension was obtained at 1 wt% AMA and 3 wt% NaCl, while the interfacial tension was not substantially influenced by the oil‐to‐water ratio. The highest oil removal was achieved in froth flotation with 0.3 wt% AMA and 3 wt% NaCl. No separation was experienced when the NaCl concentration exceeded 4 wt% due to the poor foamability of the froth formed under these conditio...
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- 2005
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50. Removal of Arsenic Anions from Water Using Polyelectrolyte‐Enhanced Ultrafiltration
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John F. Scamehorn, Kenneth J. Haller, and Preeyaporn Pookrod
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Aqueous solution ,Chemistry ,Process Chemistry and Technology ,General Chemical Engineering ,Inorganic chemistry ,Cationic polymerization ,Ultrafiltration ,chemistry.chemical_element ,Filtration and Separation ,General Chemistry ,Polyelectrolyte ,chemistry.chemical_compound ,Ammonium chloride ,Arsenic - Abstract
Polyelectrolyte‐enhanced ultrafiltration (PEUF), using cationic poly(diallyldimethyl ammonium chloride) polyelectrolyte, was used to investigate the removal of arsenic(V) from dilute aqueous soluti...
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- 2005
- Full Text
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