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Publications

Search Publications by Jack F. Douglas

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Displaying 1 - 25 of 343

Effects of Aspect Ratio of Multi-Walled Carbon Nanotube on Flammability Properties of Polymer Nanocomposites

October 12, 2021
Author(s)
Bani Cipiriano, Takashi Kashiwagi, Srinivasa R. Raghavan, Ying Yang, E A. Grulke, Kazuya Yamammoto, John R. Shields, Jack F. Douglas
The effects of the aspect ratio of multi-walled carbon nanotube (MWNT) on viscoelastic properties and flammability properties of PS/MWNT nanocomposites are studied with two different MWNTs having average aspect ratios of 49 and 150. While no significant

Fluctuation Effects on Surface Pattern Formation in Thin Block Copolymer Films

October 12, 2021
Author(s)
A C. Smith, Jack F. Douglas, Eric J. Amis, Alamgir Karim
Hole formation on the surface of thin block copolymer films is investigated as a function of time (t), temperature (T) and film thickness. The size of the holes, hs, approaches a steady state value at long times hs,∞ = hs(t -> ∞) and we introduce a simple

Laser Based Angle-Resolved Photoemission, the Sudden Approximation and Quasiparticle-Like Spectral Peaks in Bi 2 Sr 2 Cu 2 O 8 +D

October 12, 2021
Author(s)
j D. Koralek, Jack F. Douglas, N C. Plumb, Z Sun, A V. Fedorov, M M. Murnane, H C. Kapteyn, Steven T. Cundiff, Y Aiura, K Oka, H. Eisaki, D S. Dessau
A new low photon energy regime of angle-resolved photoemission spectroscopy is accessed with lasers and used to study the hight Tc superconductor Bid2^CaCu2O8d+^delta. The low energy increases bulk sensitivity, reduces background, and improves resolution

Model for Dispersion Rheology

October 12, 2021
Author(s)
J Bicerano, Jack F. Douglas, D A. Brune
A general model of the viscosity of complex-shaped particle dispersions is developed based on an exact virial expansion about the low concentration limit and a mathematical analogy between the hydrodynamics of concentrated particle suspensions and the

Polycrystalline Growth: Dirt Versus Dynamical Heterogeneity

October 12, 2021
Author(s)
L Granasy, T Pusztai, T Borzsonyi, James A. Warren, Jack F. Douglas
Most research into microstructure formation during solidification has focused on single crystal growth forms, ranging from faceted crystals to dendritic growth patterns. However, these growth forms can be peturbed by heterogeneities yielding a rich variety

Temperature Effects on Surface Pattern Formation in Thin Block Copolymer Films

October 12, 2021
Author(s)
A P. Smith, Jack F. Douglas, Eric J. Amis, Alamgir Karim
Hole formation on the surface of thin films of symmetric diblock copolymers is investigated as a function of time, t, temperature, T, and film thickness, h. The size of the holes approaches a steady state value at long times and their long-time size is

Tuning the Fragility of Polymer Melts With Antiplasticizer Additives

October 12, 2021
Author(s)
Robert A. Riggleman, K Yoshimoto, Jack F. Douglas, J J. de Pablo
Using molecular dynamics simulations, we have developed and analyzed a model that exhibits antiplasticization behavior by decreasing the glass transition temperature, increasing the density of the system below the glass transition temperature of the pure

Dynamic Heterogeneity and Collective Motion in Star Polymer Melts

February 4, 2020
Author(s)
Jack F. Douglas, Jinpeng Fan, Hamed Emamy, Francis W. Starr, Alexandros Chremos
While glass formation of linear chain polymers has been widely explored, comparatively little is known about glass formation in star polymer melts. We study the segmental dynamics of star polymers via molecular dynamics simulations and contrast the

Influence of Polymer Topology on Crystallization in Thin Films

January 22, 2020
Author(s)
Jack F. Douglas, Andrea Giuntoli, Alexandros Chremos
We investigate how varying molecular topology of polymers influences crystallization in thin polymer films. In particular, we simulate linear and star polymers having a progressively increasing number of arms (f ≤ 16) for fixed molecular mass of polymer

Lattice theory for binding of linear polymers to a solid substrate from polymer melts: II. Influence of van der Waals interactions and chain semi?exibility on molecular binding and adsorption

September 30, 2019
Author(s)
Jack F. Douglas, Jacek Dudowicz, Karl Freed
The Polymeric Langmuir Theory (PLT), developed in Paper I, is employed to investigate the influence of van der Waals interactions and chain rigidity on the thermodynamics of the reversible molecular binding to interfaces in one component polymer fluids

The Interfacial Zone in Thin Polymer Films and Around Nanoparticles in Polymer Nanocomposites

September 26, 2019
Author(s)
Jack F. Douglas, Wengang Zhang, Hamed Emamy, Fernando Vargas-Lara, Beatriz Betancourt, Francis W. Starr
We perform coarse-grained simulations of model unentangled polymer materials to quantify the range over which interfaces alter the structure and dynamics in the vicinity of the interface. We study both model polymer-nanoparticle (NP) composites with

The Interfacial Zone Around Nanoparticles in Polymer Nanocomposites

September 2, 2019
Author(s)
Jack F. Douglas, Beatriz Betancourt, Fernando Vargas-Lara, Francis W. Starr, Wengang Zhang
We perform coarse-grained simulations of model nanoparticles having a diameter on the order of 10 nm in an unentangled polymer matrix in the limit of low nanoparticle concentration to understand how the presence of nanoparticles alter the segmental