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Chemical Engineering

Selected Works

1992

Articles 1 - 10 of 10

Full-Text Articles in Engineering

Correlation Of Heat Of Mixing Data By The Nrtl And Uniquac Models. Part 2; Predictions Of Calorimetric Properties, Yasar Demirel, H.O. Paksoy, H. Gecegormez Dec 1991

Correlation Of Heat Of Mixing Data By The Nrtl And Uniquac Models. Part 2; Predictions Of Calorimetric Properties, Yasar Demirel, H.O. Paksoy, H. Gecegormez

YASAR DEMIREL

Here the parameters are employed to predict the calorimetric properties.

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Scanning Electrochemical Mass Sensitivity Mapping Of The Quartz Crystal Microbalance In Liquid Media, Andrew C. Hillier, M. D. Ward Dec 1991

Scanning Electrochemical Mass Sensitivity Mapping Of The Quartz Crystal Microbalance In Liquid Media, Andrew C. Hillier, M. D. Ward

Andrew C. Hillier

The mass sensitivity distribution of the quartz crystal microbalance, denoted S(r,8), was determined in situ for pianopiano and plano-convex Aleut quartz resonators. The method involved measuring the frequency change associated with localized mass deposits created by electrochemical deposition using a scanning microelectrode in close proximity to the QCM eiectroded surface. Complete mathematical descriptions of S(r,8) were obtained from the measured data under conditions commonly encountered in QCM experiments. Our experimental resuits suggest that crystal contouring increases sensitivity toward the resonator center while reducing the extent of field fringing. Increaslng solution viscosity reduces the sensitivity to mass changes in the center …

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Investigation Of A Monotropic Liquid Crystal Polyurethane Based On Biphenol, 2,6-Tolylene Diisocyanate, And A Six Methylene Containing Flexible Spacer. 1. Thermal And Structure Characterization, William Macknight, Fotios Papadimitrakopoulos, Shaw L. Hsu Dec 1991

Investigation Of A Monotropic Liquid Crystal Polyurethane Based On Biphenol, 2,6-Tolylene Diisocyanate, And A Six Methylene Containing Flexible Spacer. 1. Thermal And Structure Characterization, William Macknight, Fotios Papadimitrakopoulos, Shaw L. Hsu

William MacKnight

No abstract provided.

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Investigation Of A Monotropic Liquid Crystal Polyurethane Based On Biphenol, 2,6-Tolylene Diisocyanate, And A Six Methylene Containing Flexible Spacer. 2. Ir Spectroscopic Phase Characterization, William Macknight, Fotios Papadimitrakopoulos, Eiji Sawa Dec 1991

Investigation Of A Monotropic Liquid Crystal Polyurethane Based On Biphenol, 2,6-Tolylene Diisocyanate, And A Six Methylene Containing Flexible Spacer. 2. Ir Spectroscopic Phase Characterization, William Macknight, Fotios Papadimitrakopoulos, Eiji Sawa

William MacKnight

No abstract provided.

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Polymer Miscibility In Capillaries, William Macknight, P. Cifra, F. E. Karasz Dec 1991

Polymer Miscibility In Capillaries, William Macknight, P. Cifra, F. E. Karasz

William MacKnight

A thermodynamic analysis predicts an increase in miscibility, relative to that in the bulk
state, for a polymer mixture confined in a capillary with a diameter of the order of the size
of the polymer coils. This is derived by using both the concepts of growing domains and a
consideration of the thickness of polymer-polymer interfaces. The analysis is combined
with a Monte Carlo lattice simulation that provides results on such confined systems.
Intermixing, described in terms of the number of heterocontacts and the dimensions of
the polymer chains in the capillary parallel and perpendicular to the tubular axis, is …

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Spectroscopic Study Of An Ionic Blend Made From The Acid Form Of Sulfonated Polystyrene And Poly[Ethyl Acrylate-Co-(4-Vinylpyridine)], William Macknight, Kazuo Sakurai, Elliot P. Douglas Dec 1991

Spectroscopic Study Of An Ionic Blend Made From The Acid Form Of Sulfonated Polystyrene And Poly[Ethyl Acrylate-Co-(4-Vinylpyridine)], William Macknight, Kazuo Sakurai, Elliot P. Douglas

William MacKnight

Infrared spectroscopic measurements were performed for a series of stoichiometric blends made from sulfonated polystyrene and poly[ethyl acrylate-co-(4-vinylpyridine)].Comparison of the spectra before and after blending revealed that the sulfonic acid groups formed sulfonate anions and the pyridine groups formed pyridinium cations in the blends. These changes were ascribed to an acid/base interaction occurring upon blending. Quantitative analysis in terms of both the S-0 single-bond stretching and the pyridinium cation ring vibration band indicated that most of the sulfonic acid and pyridine groups took part in the interaction.

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Thermal And Rheological Properties Of Miscible Polyethersulfone/Polyimide Blends, William Macknight, K. Liang, J. Grebowicz, E. Valles, F. E. Karasz Dec 1991

Thermal And Rheological Properties Of Miscible Polyethersulfone/Polyimide Blends, William Macknight, K. Liang, J. Grebowicz, E. Valles, F. E. Karasz

William MacKnight

Blends of an aromatic polyethersulfone (commercial name Victrex) and a polyimide (com- mercial name Matrimid 5218), the condensation product of 3,3’,4,4’-benzophenone tetra- carboxylic dianhydride and 5 (6)-amino-1- (4’-aminophenyl) -1,3,3’-trimethylindane,
were studied by differential scanning calorimetry, dynamic mechanical analysis, and rheological techniques. The blends appeared to be miscible over the whole range of compositions when cast as films or precipitated from solution in a number of solvents. After annealing above the apparent phase boundary, located above Tg,the blends were irreversibly phase separated indicating that the observed phase boundary does not represent a true state of equilibrium. Only a narrow “processing window” …

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Surface Segregation In Polymer Blends: A Monte Carlo Simulation, William Macknight, P. Cifra, F. E. Karasz Dec 1991

Surface Segregation In Polymer Blends: A Monte Carlo Simulation, William Macknight, P. Cifra, F. E. Karasz

William MacKnight

A Monte Carlo (MC) simulation of surface enrichment in polymer blends is presented. The algorithm introduced by Madden is used in this simulation, in which a compressible blend is condensed against a solid wall, with the surface of the blend forming an interface with holes (or solvent) that is parallel to the wall. Three regimes in the mixture are thus recognized: the interface at the wall, the bulk regime, and the interface with the vacuum (or solvent) at the surface of the mixture. Under certain conditions, enrichment of one of the components is observed, both at the surface and close …

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Correlation Of Heats Of Mixing Data By The Nrtl And Uniquac Models. Part 1, Estimation Of The Model Parameters, Yasar Demirel, H. Gecegormez, H.O. Paksoy Dec 1991

Correlation Of Heats Of Mixing Data By The Nrtl And Uniquac Models. Part 1, Estimation Of The Model Parameters, Yasar Demirel, H. Gecegormez, H.O. Paksoy

YASAR DEMIREL

Using the data for heats of mixing, temperature dependent parameters of the NRTL and UNIQUAC models have been estimated for 57 systems of binary mixtures.

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Calculation Of Excess Heat Capacities, Yasar Demirel, H.O. Paksoy Dec 1991

Calculation Of Excess Heat Capacities, Yasar Demirel, H.O. Paksoy

YASAR DEMIREL

Experimental data of excess heat capacities for 29 binary liquid mixtures of various types have been correlated by the NRTL and UNIQUAC models.

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