The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
B.j. Carroll - One of the best experts on this subject based on the ideXlab platform.
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The formation and retention of liquid pellets in open capillary tubes
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1999Co-Authors: B.j. CarrollAbstract:Abstract Aspects of the behaviour and release of liquid pellets inside narrow capillaries are discussed. Such systems are models for emulsion formation by extrusion from orifices, and are also of relevance to Oily Soil detergency from hollow fibres such as cotton. This communication discusses how the system's contact angle, interfacial tension (static and dynamic) and dimensions can influence the uptake, mobility and release of these small drops from thin capillaries. In particular, the important effect of the geometry of the capillary end is discussed and new equations predict optimum contact angle for droplet extrusion taking the end geometry into account. Some practical implications are outlined.
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Physical aspects of detergency
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 1993Co-Authors: B.j. CarrollAbstract:Abstract This review considers the detergency process from the standpoints of surface and colloid chemistry. The principles concerned in the deposition and adhesion of particulate and Oily Soil to fabrics are set out and the possibilities of movement of these Soils within the fabric are considered in some detail, the emphasis being on Oily Soil movement and location. The experimental approach to detergency is then discussed, attention being focused mainly on those approaches which provide physical/surface chemical insights into the fundamental processes involved. Discussions on the theoretical aspects of the deposition and removal of Oily and particulate Soils are presented, and consideration is given to the different Oily Soil removal mechanisms of roll-up and emulsification. Finally, a brief account of the detergency of oil in situ, i.e. by mechanisms independent of adhesion considerations, is given.
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The influence of capillarity on the location of liquid Soils on textile fabrics
Progress in Colloid & Polymer Science, 1Co-Authors: B.j. CarrollAbstract:A survey is made of published work on the location of Oily Soil on textile fabrics. There is evidence that such Soil tends to build up at certain preferred sites in the fabric, such as between parallel fibres in the yarn. A theoretical explanation is developed which correlates these observations. Because the shape of a droplet of oil of given volume depends upon the local geometry and contact angle at the site where it is located, different sites are associated with different Laplace internal pressures in the drop. It is shown that differences in these internal pressures between sites can bring about a thermodynamically favored movement of the droplet towards sites where the Laplace excess pressure is least. On this basis, a heirarchy of sites can be constructed and this is found to parallel the observed favor of sites for Oily Soil in fabrics.
Viplaw Kumar - One of the best experts on this subject based on the ideXlab platform.
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RELATIONSHIP BETWEEN OIL/WATER INTERFACIAL TENSION AND Oily Soil REMOVAL IN MIXED SURFACTANT SYSTEMS
Journal of colloid and interface science, 1998Co-Authors: Sandeep Verma, Viplaw KumarAbstract:Abstract Detergency of Oily Soil is a complex kinetic process that includes contributions from the wash system physical properties, time and temperature of wash, and the hydrodynamic forces exerted during the wash process. Generally, surfactant mixtures that exhibit a low oil–water interfacial tension are considered to provide superior Oily Soil detergency. In our investigations, we measured the oil–water interfacial tension for C12EO3/NaLAS and C12EO7/NaLAS blends as a function of temperature (18–80°C) and time (0–60 min). The oil–water interfacial tension was found to decrease as a function of time for all blends containing nonionic surfactants, and this decline was most rapid for blends containing a higher fraction of ethoxylated alcohol with less than 3 mol of ethylene oxide. It is proposed that the diffusion of this hydrophobic fraction into the oil phase leads to the measured decline in the oil–water interfacial tension. Also, due to this limitation, no general correlation of oil–water interfacial tension with Oily Soil removal was observed. In view of these observations, it appears that the measurement of the oil–water interfacial tension (using a spinning drop tensiometer) for solutions containing hydrophobic surfactants may give misleading results.
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relationship between oil water interfacial tension and Oily Soil removal in mixed surfactant systems
Joint International Conference on Information Sciences, 1998Co-Authors: Sandeep Verma, Viplaw KumarAbstract:Abstract Detergency of Oily Soil is a complex kinetic process that includes contributions from the wash system physical properties, time and temperature of wash, and the hydrodynamic forces exerted during the wash process. Generally, surfactant mixtures that exhibit a low oil–water interfacial tension are considered to provide superior Oily Soil detergency. In our investigations, we measured the oil–water interfacial tension for C12EO3/NaLAS and C12EO7/NaLAS blends as a function of temperature (18–80°C) and time (0–60 min). The oil–water interfacial tension was found to decrease as a function of time for all blends containing nonionic surfactants, and this decline was most rapid for blends containing a higher fraction of ethoxylated alcohol with less than 3 mol of ethylene oxide. It is proposed that the diffusion of this hydrophobic fraction into the oil phase leads to the measured decline in the oil–water interfacial tension. Also, due to this limitation, no general correlation of oil–water interfacial tension with Oily Soil removal was observed. In view of these observations, it appears that the measurement of the oil–water interfacial tension (using a spinning drop tensiometer) for solutions containing hydrophobic surfactants may give misleading results.
Sandeep Verma - One of the best experts on this subject based on the ideXlab platform.
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RELATIONSHIP BETWEEN OIL/WATER INTERFACIAL TENSION AND Oily Soil REMOVAL IN MIXED SURFACTANT SYSTEMS
Journal of colloid and interface science, 1998Co-Authors: Sandeep Verma, Viplaw KumarAbstract:Abstract Detergency of Oily Soil is a complex kinetic process that includes contributions from the wash system physical properties, time and temperature of wash, and the hydrodynamic forces exerted during the wash process. Generally, surfactant mixtures that exhibit a low oil–water interfacial tension are considered to provide superior Oily Soil detergency. In our investigations, we measured the oil–water interfacial tension for C12EO3/NaLAS and C12EO7/NaLAS blends as a function of temperature (18–80°C) and time (0–60 min). The oil–water interfacial tension was found to decrease as a function of time for all blends containing nonionic surfactants, and this decline was most rapid for blends containing a higher fraction of ethoxylated alcohol with less than 3 mol of ethylene oxide. It is proposed that the diffusion of this hydrophobic fraction into the oil phase leads to the measured decline in the oil–water interfacial tension. Also, due to this limitation, no general correlation of oil–water interfacial tension with Oily Soil removal was observed. In view of these observations, it appears that the measurement of the oil–water interfacial tension (using a spinning drop tensiometer) for solutions containing hydrophobic surfactants may give misleading results.
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relationship between oil water interfacial tension and Oily Soil removal in mixed surfactant systems
Joint International Conference on Information Sciences, 1998Co-Authors: Sandeep Verma, Viplaw KumarAbstract:Abstract Detergency of Oily Soil is a complex kinetic process that includes contributions from the wash system physical properties, time and temperature of wash, and the hydrodynamic forces exerted during the wash process. Generally, surfactant mixtures that exhibit a low oil–water interfacial tension are considered to provide superior Oily Soil detergency. In our investigations, we measured the oil–water interfacial tension for C12EO3/NaLAS and C12EO7/NaLAS blends as a function of temperature (18–80°C) and time (0–60 min). The oil–water interfacial tension was found to decrease as a function of time for all blends containing nonionic surfactants, and this decline was most rapid for blends containing a higher fraction of ethoxylated alcohol with less than 3 mol of ethylene oxide. It is proposed that the diffusion of this hydrophobic fraction into the oil phase leads to the measured decline in the oil–water interfacial tension. Also, due to this limitation, no general correlation of oil–water interfacial tension with Oily Soil removal was observed. In view of these observations, it appears that the measurement of the oil–water interfacial tension (using a spinning drop tensiometer) for solutions containing hydrophobic surfactants may give misleading results.
Kirk Herbert Raney - One of the best experts on this subject based on the ideXlab platform.
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Radiotracer detergency testing in a horizontal‐axis washing machine
Journal of Surfactants and Detergents, 1999Co-Authors: Deborah K. Passwater, Kirk Herbert RaneyAbstract:Proposed regulations by the U.S. Department of Energy have spurred development of energy-efficient washing machines that utilize less water and operate with lower energy requirements than conventional machines. As a result, major changes in washing machine design are required. Among expected changes are increased use of a horizontal-axis wash tub, an increase in fabric-to-wash liquor ratio, greater surfactant concentration in the wash water, and reduced average washing temperatures. As a result, surfactants used in future detergent formulations will be required to clean effectively in this new regime while producing minimal foam. Detergency test methods utilizing radiotracer techniques have been developed to study the detergency process in energy-efficient washing machines. Detergency and redeposition of radiolabeled Oily Soils can be determined in a full-size horizontal-axis washing machine through scintillation counting of wash and rinse water samples. Measurements can be made after each wash process step and combined to determine total cycle detergency. This is a distinct advantage over conventional reflectance detergency methods where only total detergency at the end of the entire washing and rinsing process can be conveniently measured. Also, in contrast to indirect reflectance methods, measurements of absolute Soil removal are obtained with the radiotracer method. In this study, Soil redeposition was determined by measuring residual radioactivity on fabric swatches and then performing a material balance on the Oily Soil.
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Optimization of nonionic/anionic surfactant blends for enhanced Oily Soil removal
Journal of the American Oil Chemists' Society, 1991Co-Authors: Kirk Herbert RaneyAbstract:Previously reported results for alcohol ethoxylate surfactants have shown that optimum removal of both nonpolar and sebum- like liquid Soils from polyester/cotton fabric occurs at the phase inversion temperature (PIT) of the surfactant- water- Soil system. A similar correlation between phase inversion and optimum detergency has been identified for detergent systems containing mixtures of nonionic and anionic surfactants such as alcohol ethoxylates and alcohol ethoxysulfates. Experimental techniques other than direct detergency studies are described which allow determination of the optimum nonionic/ anionic surfactant ratio for removal of a particular Soil at a specified temperature. In addition, implications of these results for development of temperature- insensitive detergent formulations containing alcohol ethoxylates are discussed.
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optimization of nonionic anionic surfactant blends for enhanced Oily Soil removal
Journal of the American Oil Chemists' Society, 1991Co-Authors: Kirk Herbert RaneyAbstract:Previously reported results for alcohol ethoxylate surfactants have shown that optimum removal of both nonpolar and sebum- like liquid Soils from polyester/cotton fabric occurs at the phase inversion temperature (PIT) of the surfactant- water- Soil system. A similar correlation between phase inversion and optimum detergency has been identified for detergent systems containing mixtures of nonionic and anionic surfactants such as alcohol ethoxylates and alcohol ethoxysulfates. Experimental techniques other than direct detergency studies are described which allow determination of the optimum nonionic/ anionic surfactant ratio for removal of a particular Soil at a specified temperature. In addition, implications of these results for development of temperature- insensitive detergent formulations containing alcohol ethoxylates are discussed.
Sumaeth Chavadej - One of the best experts on this subject based on the ideXlab platform.
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Laundry Detergency of Solid Non-particulate Soil or Waxy Solids: Part I. Relation to Oily Soil Removal Above the Melting Point
Journal of Surfactants and Detergents, 2017Co-Authors: Jarussri Chanwattanakit, David A Sabatini, John F. Scamehorn, Sumaeth ChavadejAbstract:In this work, methyl palmitate or palmitic acid methyl ester, a monoglyceride, was used as both a model solid fat below the melting point and as an Oily Soil above the melting point. An anionic extended surfactant [branched alcohol propoxylate sulfate sodium salt (C_123-(PO)_4-SO_4Na)] was used to remove methyl palmitate from cotton and from polyester. Above the melting point (~30 °C) of methyl palmitate, the maximum Oily Soil removal was found to correspond to the lowest dynamic interfacial tension, as is common with liquid Soils. Below the melting point, the lower the contact angle of the wash solution against the Soil (indicating higher wettability), the higher the solid fat Soil detergency. The removed methyl palmitate was found to be mostly in unsolubilized droplets or particles with a small fraction of micellar solubilization for both solid and liquid forms. The presence of surfactant can prevent the agglomeration of detached methyl palmitate particles in both liquid and solid forms, reducing redeposition and enhancing detergency. Below the melting point, the surfactant aids the solution wetting the surfaces, then penetrating the waxy solid, causing detachment as small particles, and dispersion of these particles. Unlike particulate Soil detergency, electrostatic forces are not the dominant factor in fatty Soil detergency.
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Microemulsion Formation and Detergency with Oily Soil: V. Effects of Water Hardness and Builder
Journal of Surfactants and Detergents, 2009Co-Authors: Parichat Tanthakit, David A Sabatini, John F. Scamehorn, Ampika Nakrachata-amorn, Chantra Tongcumpou, Sumaeth ChavadejAbstract:In this study, the impact of water hardness and builder on the phase diagrams of motor oil microemulsions and the detergency of oil removal from a polyester/cotton blend was investigated. Water hardness and builder were found to have insignificant effects on the microemulsion phase diagram with motor oil. A mixed surfactant system of two parts C_14–15(PO)_3SO_4Na, and 98 parts C_12–14H_25–29O(EO)_5H of the total actives at 4% salinity was used to study the effect of water hardness and builders sodium tripolyphosphate (STPP) or ethylenediaminetetraacetic acid (EDTA) on detergency at 30 °C at a total active concentration of 0.3%. This formulation is in the Winsor Type III microemulsion regime. The microemulsion-based formulation resulted in better detergency than a leading commercial liquid laundry detergent at all concentrations up to 0.5% actives. The microemulsion-based formulation showed a plateau in detergency at >80% oil removal above 0.1% actives. The total oil removal decreased with increasing water hardness while the interfacial tension increased. When hard water was used in laundering, the total oil removal improved with increasing concentrations of STPP or EDTA up to stoichiometric levels, with STPP being slightly more effective than EDTA on a molar basis. Even high builder concentration could not improve hard water detergency to that of soft water. A significant fraction of oil removal occurred in the rinse steps vs. the wash step. Increasing water hardness reduced this fractional oil removal in the rinse steps, but it was still over half of total oil removal at 1,000 ppm water hardness.
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Microemulsion Formation and Detergency with Oily Soil: IV. Effect of Rinse Cycle Design
Journal of Surfactants and Detergents, 2008Co-Authors: Parichat Tanthakit, David A Sabatini, John F. Scamehorn, Sumaeth Chavadej, Chantra TongcumpouAbstract: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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Oily Soil Detergency under Microemulsion Conditions: Effects of Oil Loading and Surfactant Adsorption
Advanced Materials Research, 2008Co-Authors: R. Kaewpukpa, Sumaeth Chavadej, John F. ScamehornAbstract: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.
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Microemulsion formation and detergency with Oily Soils: III. Performance and mechanisms
Journal of Surfactants and Detergents, 2005Co-Authors: Chantra Tongcumpou, John F. Scamehorn, E. J. Acosta, L. B. Quencer, A. F. Joseph, D. A. Sabatini, N. Yanumet, Sumaeth ChavadejAbstract:The objective of this study was to investigate the correlation between Oily Soil removal efficiency and low oil-water interfacial tension (IFT) generated by microemulsion formation. A mixture of sodium dioctyl sulfosuccinate, alkyl diphenyl oxide disulfonate, and sorbitan monooleate was selected as a detergent formulation to evaluate detergency performance for two highly hydrophobic oils: hexadecane and motor oil. The maximum detergency corresponds to formation of a Winsor Type III microemulsion as well as to the supersolubilization region, which is a Winsor Type I microemulsion close to the Winsor Type III region. In addition, the oil removal in the rinse step is almost as high as that in the wash step for both regions. We propose the following mechanism to explain these results: During the wash step, the contact angle of the oil on the fabric surface is progressively increased, resulting in the detachment of the oil droplets. However, owing to the very low IFT, the spreading effect is dominant, thereby causing incomplete oil removal. During the subsequent rinse step, the IFT increases, passing through a composition at which the rollup mechanism causes additional oil removal. These results demonstrate that microemulsion formation and the resulting IFT reduction are important mechanisms in Oily Soil detergency.
