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Search Publications by: Jack F. Douglas (Fed)

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Displaying 251 - 275 of 355

Thermal and Flammability Properties of Polypropylene/Carbon Nanotube Nanocomposites

May 1, 2004
Author(s)
Takashi Kashiwagi, E A. Grulke, J N. Hilding, Richard H. Harris Jr., John R. Shields, Kathryn M. Butler, K M. Groth, S B. Kharchenko, Jack F. Douglas
The thermal and flammability properties of polypropylene/multi-walled carbon nanotube, (PP/MWNT) nanocomposites were measured with the MWNT content varied from 0.5 % to 4 % by mass. Dispersion of MWNTs in these nanocomposites was characterized by SEM and

Comparative Specular X-Ray Reflectivity, Positron Annihilation Lifetime Spectroscopy, and Incoherent Neutron Scattering Measurements of the Dynamics in Thin Polycarbonate Films

April 1, 2004
Author(s)
Christopher L. Soles, Jack F. Douglas, Wen-Li Wu, H G. Peng, D W. Gidley
The manner in which the dynamics of a polymer are affected by thin film confinement is one of technological significance, impacting thin film applications such as lubricants, adhesives, and chemically amplified photoresists. In this manuscript we use

Unusual Expansion and Contraction in Ultrathin Glassy Polycarbonate Films

April 1, 2004
Author(s)
Christopher L. Soles, Jack F. Douglas, Ronald L. Jones, Wen-Li Wu
The thermal expansion behavior and glass transitions of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) are extensively studied in the thin film geometry. Both PS and PMMA are similar in that they possess very low entanglement densities. In this

Finite-Size Effects on Surface Segregation in Polymer Blend Films Above and Below the Critical Point of Phase Separation

March 1, 2004
Author(s)
H Grull, Li Piin Sung, Alamgir Karim, Jack F. Douglas, Sushil K. Satija, Makoto Hayashi, H Jinnai, TT Hashimoto, Charles C. Han
We investigate the influence of temperature and confinement on surface segregation in thin films of deuterated polybutadiene and polyisoprene near the critical point for phase separation. Neutron reflectivity measurements show that polyisoprene enriches at

Non-Linear Transport Properties of Carbon Nanotube Filled Polypropylene

February 1, 2004
Author(s)
S B. Kharchenko, Kalman D. Migler, Jack F. Douglas, Jan Obrzut, E A. Grulke
Dispersal of a relatively small concentration [O(1%) volume fraction] of multiwall carbon nanotubes (MWNT) into polypropylene (PP) is found to cause large and complex changes in nanocomposite transport properties. Specifically, both the shear viscosity h(g

Structural Signatures of Varification in Hard Core Fluids

September 1, 2003
Author(s)
S K. Kumar, Jack F. Douglas, Francis W. Starr, S Garde
We investigate the capacities of local measures of free volume in liquids to predict basic aspects of the fluids state- the formation of a liquid from a gas, complex 'caged' fluid dynamics and vitrification. Specifically, we investigate the capacity of the

The Polmerization of Actin: Thermodynamics Near the Polymeriztion Line

August 1, 2003
Author(s)
P S. Niranjan, H Yim, D Forbes, S C. Greer, J Dudowicz, Karl Freed, Jack F. Douglas
We report here new measurements of the extent of polymerization of rabbit muscle actin as a function of T , initial G-actin concentration and initiating salt concentration, in both H2O and D2O buffers. These measurements are unique in being done as a

Modification of Thin Film Phase Separation by a Surfactant

March 25, 2003
Author(s)
Li Piin Sung, Alamgir Karim, Jack F. Douglas, Charles C. Han
Phase separation in thin films leads to the formation of surface patterns (holes, bumps, and bicontinuous surface features) which depend on the film composition. These features are interpreted to arise from surface tension variations within the film that

Incoherent Neutron Scattering and the Dynamics of Thin Film Photoresist Polymers

February 1, 2003
Author(s)
Christopher L. Soles, Jack F. Douglas, Eric K. Lin, Joseph~undefined~undefined~undefined~undefined~undefined Lenhart, Ronald L. Jones, Wen-Li Wu, D M. Goldfarb, M Angelopoulos
Elastic incoherent neutron scattering is employed to parameterize changes in the atomic/molecular mobility in lithographic polymers as a function of film thickness. Changes in the 200 MHz and faster dynamics are estimated in terms of a harmonic oscillator

Combinatorial Mapping of Surface Energy Effects on Diblock Copolymer Thin Film Ordering

January 1, 2003
Author(s)
A P. Smith, A Sehgal, Jack F. Douglas, Alamgir Karim, Eric J. Amis
Combinatorial gradient techniques are used to map the thin film morphology dependence of symmetric diblock copolymers as a function of film thickness and substrate surface energy. An inversion from symmetric to asymmetric lamellar morphology is observed as