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Deresh Ramjugernath - One of the best experts on this subject based on the ideXlab platform.
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isothermal vapor liquid equilibrium data for the 1 1 2 2 tetrafluoroethene 1 1 2 2 3 3 4 4 Octafluorocyclobutane binary system measurement and modeling from 248 to 283 k
Journal of Chemical & Engineering Data, 2012Co-Authors: Francois Jacobus Conradie, Philippus L. Crouse, Xavier Courtial, Izak J. Van Der Walt, Deresh RamjugernathAbstract:High pressure vapor–liquid equilibrium data are presented for the 1,1,2,2-tetrafluoroethene + 1,1,2,2,3,3,4,4-Octafluorocyclobutane binary system. The isothermal measurements were undertaken at (248.3, 263.0, and 282.9) K, with pressures ranging from (0.040 to 2.340) MPa. A static–analytical apparatus was used to carry out the measurements. The liquid and vapor phases were sampled at equilibrium using a movable rapid on-line sampler–injector (ROLSI). The uncertainties in the measurements are less than 0.1 K, 1.5 kPa, and 0.007 for the temperature, pressure, and equilibrium phase mole fractions, respectively. The experimental data were correlated with the Peng–Robinson equation of state incorporating the Mathias–Copeman alpha function, with the Wong–Sandler mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. The model accurately describes the experimental data.
Alenka Vesel - One of the best experts on this subject based on the ideXlab platform.
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Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and surfaces. A, Physicochemical and Engineering Aspects, 2017Co-Authors: Alenka Vesel, Michal Sedlacik, Ondrej Grulich, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Petra SvrcinovaAbstract:The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil. © 2011 Elsevier B.V.
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The effect of plasma treatment on structure and properties of poly(1-butene) surface
European Polymer Journal, 2017Co-Authors: Alenka Vesel, Ondrej Grulich, Lenka Chvátalová, Lubomír Beníček, Antonín Minařík, Uros Cvelbar, Petr Ponížil, Aleš Mráček, Roman Cermak, Petr SajdlAbstract:This paper is focused on the chemical and morphology changes in the surface of poly(1-butene) (PB-1) generated by plasma treatment. The radio frequency capacitively coupled plasma (air, argon, argon then allylamine, argon containing ammonia and argon with Octafluorocyclobutane) was used. Modified surface of PB-1 was characterized by contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy. The surface hydrophilization by air and argon with ammonia plasmas was evaluated as most sufficient. Oppositely, a high level of hydrophobicity of PB-1 surface was reached by combination of argon with Octafluorocyclobutane plasma. Upon plasma modification, hydrophilicity/hydrophobicity of treated surfaces remained stable within three days under air atmosphere and then values of contact angle slowly recovered to those of unmodified PB-1. However, morphology and surface chemical composition of plasma-modified samples remained generally unchanged during observed time. Changes in surface hydrophilicity/hydrophobicity of plasma-treated PB-1 were attributed to variance of conformation of the surface molecules. © 2012 Elsevier Ltd. All rights reserved.
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plasma treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011Co-Authors: Michal Sedlacik, Ondrej Grulich, Petra Svrcinova, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Alenka VeselAbstract:Abstract The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil.
Francois Jacobus Conradie - One of the best experts on this subject based on the ideXlab platform.
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Isothermal vapor-liquid equilibrium data for the 1,1,2,3,3,3-hexafluoroprop-1-ene + 1,1,2,2,3,3,4,4- Octafluorocyclobutane binary system: measurement and modeling from (292 to 352) K and pressures up to 2.6 MPa
American Chemical Society, 2015Co-Authors: Francois Jacobus Conradie, Pl Crouse, Nelson W, Courtail X, Ij ,van Der Walt, Ramjugernath DAbstract:Isothermal vapor–liquid equilibrium data are presented for the 1,1,2,3,3,3-hexafluoroprop-1-ene and 1,1,2,2,3,3,4,4-Octafluorocyclobutane binary system at (292.89, 323.02 and 352.71) K, with pressures ranging from (0.3 to 2.6) MPa. The data were measured using an apparatus based on the “static-analytic” method, equipped with a single movable rapid online sampler-injector (ROLSI). The expanded uncertainties are estimated at 0.11 K, 4 kPa, 0.010 and 0.007 for the temperature, pressure, and the equilibrium liquid and vapor mole fractions, respectively. The experimental vapor–liquid equilibrium data were correlated using the Peng–Robinson equation of state with the Mathias–Copeman alpha function. The model provides a satisfactory description of the experimental data.National Research Foundation (South Africa
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isothermal vapor liquid equilibrium data for the 1 1 2 2 tetrafluoroethene 1 1 2 2 3 3 4 4 Octafluorocyclobutane binary system measurement and modeling from 248 to 283 k
Journal of Chemical & Engineering Data, 2012Co-Authors: Francois Jacobus Conradie, Philippus L. Crouse, Xavier Courtial, Izak J. Van Der Walt, Deresh RamjugernathAbstract:High pressure vapor–liquid equilibrium data are presented for the 1,1,2,2-tetrafluoroethene + 1,1,2,2,3,3,4,4-Octafluorocyclobutane binary system. The isothermal measurements were undertaken at (248.3, 263.0, and 282.9) K, with pressures ranging from (0.040 to 2.340) MPa. A static–analytical apparatus was used to carry out the measurements. The liquid and vapor phases were sampled at equilibrium using a movable rapid on-line sampler–injector (ROLSI). The uncertainties in the measurements are less than 0.1 K, 1.5 kPa, and 0.007 for the temperature, pressure, and equilibrium phase mole fractions, respectively. The experimental data were correlated with the Peng–Robinson equation of state incorporating the Mathias–Copeman alpha function, with the Wong–Sandler mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. The model accurately describes the experimental data.
Aleš Mráček - One of the best experts on this subject based on the ideXlab platform.
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Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and surfaces. A, Physicochemical and Engineering Aspects, 2017Co-Authors: Alenka Vesel, Michal Sedlacik, Ondrej Grulich, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Petra SvrcinovaAbstract:The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil. © 2011 Elsevier B.V.
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The effect of plasma treatment on structure and properties of poly(1-butene) surface
European Polymer Journal, 2017Co-Authors: Alenka Vesel, Ondrej Grulich, Lenka Chvátalová, Lubomír Beníček, Antonín Minařík, Uros Cvelbar, Petr Ponížil, Aleš Mráček, Roman Cermak, Petr SajdlAbstract:This paper is focused on the chemical and morphology changes in the surface of poly(1-butene) (PB-1) generated by plasma treatment. The radio frequency capacitively coupled plasma (air, argon, argon then allylamine, argon containing ammonia and argon with Octafluorocyclobutane) was used. Modified surface of PB-1 was characterized by contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy. The surface hydrophilization by air and argon with ammonia plasmas was evaluated as most sufficient. Oppositely, a high level of hydrophobicity of PB-1 surface was reached by combination of argon with Octafluorocyclobutane plasma. Upon plasma modification, hydrophilicity/hydrophobicity of treated surfaces remained stable within three days under air atmosphere and then values of contact angle slowly recovered to those of unmodified PB-1. However, morphology and surface chemical composition of plasma-modified samples remained generally unchanged during observed time. Changes in surface hydrophilicity/hydrophobicity of plasma-treated PB-1 were attributed to variance of conformation of the surface molecules. © 2012 Elsevier Ltd. All rights reserved.
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plasma treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011Co-Authors: Michal Sedlacik, Ondrej Grulich, Petra Svrcinova, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Alenka VeselAbstract:Abstract The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil.
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Surface properties of plasma-modified poly(1-butene)
2010Co-Authors: Lenka Chvátalová, Roman Cermak, Aleš MráčekAbstract:Surface properties of poly(1-butene) films has been modified by a radio frequency plasma treatment. To minimize degradation and ageing effects it is necessary adjusted the gas composition and the plasma conditions on the polymer type. For this purpose plasma containing five various gasses or their mixtures: air, argon, argon then allylamine, argon wearing ammonia and argon with Octafluorocyclobutane, were used. Changes in the surface hydrophilicity, roughness and the chemical composition of modified poly(1-butene) films were investigated by contact angle measurements, atomic force microscopy and X-ray photoelectron spectroscopy. All types of plasma treatment expect fluorocarbon plasma cause increase of polar functional groups on the surfaces and their hydrophilicity. On the other hand, fluorocarbon plasmas cause increase of contact angle and hydrophobicity.
Ondrej Grulich - One of the best experts on this subject based on the ideXlab platform.
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Plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and surfaces. A, Physicochemical and Engineering Aspects, 2017Co-Authors: Alenka Vesel, Michal Sedlacik, Ondrej Grulich, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Petra SvrcinovaAbstract:The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil. © 2011 Elsevier B.V.
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The effect of plasma treatment on structure and properties of poly(1-butene) surface
European Polymer Journal, 2017Co-Authors: Alenka Vesel, Ondrej Grulich, Lenka Chvátalová, Lubomír Beníček, Antonín Minařík, Uros Cvelbar, Petr Ponížil, Aleš Mráček, Roman Cermak, Petr SajdlAbstract:This paper is focused on the chemical and morphology changes in the surface of poly(1-butene) (PB-1) generated by plasma treatment. The radio frequency capacitively coupled plasma (air, argon, argon then allylamine, argon containing ammonia and argon with Octafluorocyclobutane) was used. Modified surface of PB-1 was characterized by contact angle measurements, X-ray photoelectron spectroscopy, and atomic force microscopy. The surface hydrophilization by air and argon with ammonia plasmas was evaluated as most sufficient. Oppositely, a high level of hydrophobicity of PB-1 surface was reached by combination of argon with Octafluorocyclobutane plasma. Upon plasma modification, hydrophilicity/hydrophobicity of treated surfaces remained stable within three days under air atmosphere and then values of contact angle slowly recovered to those of unmodified PB-1. However, morphology and surface chemical composition of plasma-modified samples remained generally unchanged during observed time. Changes in surface hydrophilicity/hydrophobicity of plasma-treated PB-1 were attributed to variance of conformation of the surface molecules. © 2012 Elsevier Ltd. All rights reserved.
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plasma treated carbonyl iron particles as a dispersed phase in magnetorheological fluids
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011Co-Authors: Michal Sedlacik, Ondrej Grulich, Petra Svrcinova, Petr Filip, Aleš Mráček, Vladimir Pavlinek, Marián Lehocký, Alenka VeselAbstract:Abstract The aim of this paper is to document suitability of plasma-treated carbonyl iron particles as a dispersed phase in magnetorheological fluids. Surface-modified carbonyl iron particles were prepared via their exposure to 50% argon and 50% Octafluorocyclobutane plasma. The X-ray photoelectron spectroscopy was used for analysis of chemical bonding states in the surface layer. Plasma-treated particles were adopted for a dispersed phase in magnetorheological (MR) fluids, and the MR behaviour was investigated using rotational rheometer equipped with magnetic field generator. Viscoelasticity changes of MR fluids were measured in the small-strain oscillatory shear flow as a function of the strain amplitude, frequency and the magnetic flux density. The MR fluids based on plasma-treated particles exhibit promoted suspension stability, which is attributed to the interactions between fluorine bonded on particle surface and methyl groups of silicone oil.
