Plasticization and antiplasticization of polymer melts diluted by low molar mass species (2010)
Stukalin, Evgeny B., Douglas, Jack F., Freed, Karl F.
An analysis of glass formation for polymer melts that are diluted by structured molecular additives is derived by using the generalized entropy theory, which involves a combination of the Adam-Gibbs...
Starr, Francis W., Douglas, Jack F.
We investigate the impact of the addition of nanoparticles (NP) on the fragility of a model glass-forming polymer melt by molecular dynamics simulations. We find significant changes in fragility for...
Anisotropic self-assembly of spherical polymer-grafted nanoparticles (2009)
Pinar Akcora, Hongjun Liu, Sanat K. Kumar, Joseph Moll, Yu Li, Brian C. Benicewicz, ...
Particle motion during the compaction of granular matter (2008)
Slotterback, Steven, Toiya, Masahiro, Goff, Leonard, Douglas, Jack F., Losert, Wolfgang
We track particle motions in a granular material subjected to compaction using a laser scattering based imaging method where compaction is achieved through thermal cycling. Particle displacements in...
Obrzut, J., Douglas, Jack F., Kharchenko, S. B., Migler, K. B.
The blending of carbon nanotubes (CNTs) into polymer matrices leads to intrinsically nonequilibrium materials whose properties can depend strongly on flow history. We have constructed a...
Relaxation Behavior of polymer structures fabricated by nanoimprint lithography (2007)
Ding, Yifu, Ro, Hyun Wook, Germer, Thomas A., Douglas, Jack F., Okerberg, Brian C., Karim, Alamgir, ...
We study the decay of imprinted polystyrene (PS) patterns under thermal annealing using light diffraction. The first-order diffraction intensity from the imprinted gratings was measured as a function...
Relationship Between Dispersion Metric and Properties of PMMA/SWNT Nanocomposites (2007)
Kashiwagi, Takashi, Fagan, Jeffrey, Douglas, Jack F, Yamamoto, Kazuya, Heckert, Alan N, Leigh, Stefan D, ...
Particle spatial dispersion is a crucial characteristic of polymer composite materials and this property is recognized as especially important in nanocomposite materials due to the general tendency...
The Effect of Nanoparticle Shape on Polymer-Nanocomposite Rheology and Tensile Strength (2007)
Knauert, Scott T., Douglas, Jack F., Starr, Francis W.
Nanoparticles can influence the properties of polymer materials by a variety of mechanisms. With fullerene, carbon nanotube, and clay or graphene sheet nanocomposites in mind, we investigate how...
Nanoparticle Networks Reduce the Flammability of Polymer Nanocomposites (2005)
Kashiwagi, Takashi, Du, Fangming, Douglas, Jack F., Winey, Karen I, Harris, Richard H., Shields, John R.
Synthetic polymer materials are rapidly replacing more traditional inorganic materials such as metals and natural polymeric materials such as wood. Since these novel materials are flammable, they...
Nature of the Breakdown in the Stokes-Einstein Relationship in a Hard Sphere Fluid (2005)
Kumar, Sanat K., Szamel, Grzegorz, Douglas, Jack F.
Molecular Dynamics simulations of high density hard sphere fluids clearly show a breakdown of the Stokes-Einstein equation (SE). This result has been conjectured to be due to the presence of mobile...
Exact Solution of a Field Theory Model of Frontal Photopolymerization (2005)
Warren, James A., Cabral, Joao T., Douglas, Jack F.
Frontal photopolymerization (FPP) provides a versatile method for the rapid fabrication of solid polymer network materials by exposing photosensitive molecules to light. Dimensional control of...
On the growth and form of spherulites (2004)
Gránásy, László, Pusztai, Tamás, Tegze, György, Warren, James A., Douglas, Jack F.
Many structural materials (metal alloys, polymers, minerals, etc.) are formed by quenching liquids into crystalline solids. This highly non-equilibrium process often leads to polycrystalline growth...
Structural Signatures of Vitrification in Hard Core Fluids (2003)
Kumar, Sanat K., Garde, Shekhar, Douglas, Jack F., Starr, Francis W.
Computer simulations of hard spheres and disks are used to estimate the most probable cavity size, $\xi_{\rm cavity}$, and a ``rattle'' size, $\xi_{\rm rattle}$, over which a particle can translate...
Early-stage compositional segregation in polymer-blend films (2003)
Wang, H., Douglas, Jack F, Satija, S. K., Composto, Russell J, Han, C. C.
The existence of a transient period during the surface enrichment of a binary polymer blend by one of its components has been suggested by previous theoretical and experimental studies as well as...
Growth of 'dizzy dendrites' in a random field of foreign particles (2003)
László Gránásy, Tamás Pusztai, James A. Warren, Jack F. Douglas, Tamás Börzsönyi, Vincent Ferreiro
LETTERS Growth of ‘dizzy dendrites ’ in a random field of foreign particles (2003)
László Gránásy, Tamás Pusztai, James A. Warren, Jack F. Douglas
Microstructure plays an essential role in determining the properties of crystalline materials1. A widely used method to influence microstructure is the addition of nucleating agents1. Observations on...
What do we learn from the local geometry of glass-forming liquids? (2002)
Starr, Francis W., Sastry, Srikanth, Douglas, Jack F., Glotzer, Sharon C.
We examine the local geometry of a simulated glass-forming polymer melt. Using the Voronoi construction, we find that the distributions of Voronoi volume $P(v_V)$ and asphericity $P(a)$ appear to be...
Combinatorial Study of Surface Pattern Formation in Thin Block Copolymer Films (2001)
Amis, Eric J., Douglas, Jack F., Karim, Alamgir, Meredith, J. Carson, Smith, Archie P.
Dynamic Entropy as a Measure of Caging and Persistent Particle Motion in Supercooled Liquids (1999)
Allegrini, Paolo, Douglas, Jack F., Glotzer, Sharon C.
The length-scale dependence of the dynamic entropy is studied in a molecular dynamics simulation of a binary Lennard-Jones liquid above the mode-coupling critical temperature $T_c$. A number of...
Filler-Induced Composition Waves in Phase-Separating Polymer Blends (1999)
Lee, Benjamin P., Douglas, Jack F., Glotzer, Sharon C.
The influence of immobile filler particles (spheres, fibers, platelets) on polymer blend phase separation is investigated computationally using a generalization of the Cahn-Hilliard-Cook (CHC) model....
Gaylord, Richard J., Twardowski, Thomas E., Douglas, Jack F.
The localization model of rubber elasticity is applied to the deformation behavior of a network formed by cross-linking a strained melt. Recently, Kramer et al. made an important study of the effect...
String-like Clusters and Cooperative Motion in a Model Glass-Forming Liquid (1997)
Donati, Claudio, Douglas, Jack F., Kob, Walter, Plimpton, Steven J., Poole, Peter H., Glotzer, Sharon C.
A large-scale molecular dynamics simulation is performed on a glass-forming Lennard-Jones mixture to determine the nature of dynamical heterogeneities which arise in this model fragile liquid. We...
Propagating waves of self-assembly in organosilane monolayers
Douglas, Jack F., Efimenko, Kirill, Fischer, Daniel A., Phelan, Fredrick R., Genzer, Jan
Wavefronts associated with reaction–diffusion and self-assembly processes are ubiquitous in the natural world. For example, propagating fronts arise in crystallization and diverse other...
Molecular simulation of the swelling of polyelectrolyte gels by monovalent and divalent counterions
Yin, De-Wei, Horkay, Ferenc, Douglas, Jack F., De Pablo, Juan J.
Permanently crosslinked polyelectrolyte gels are known to undergo discontinuous first-order volume phase transitions, the onset of which may be caused by a number of factors. In this study we examine...
Grain boundaries exhibit the dynamics of glass-forming liquids
Zhang, Hao, Srolovitz, David J., Douglas, Jack F., Warren, James A.
Polycrystalline materials are composites of crystalline particles or “grains” separated by thin “amorphous” grain boundaries (GBs). Although GBs have been exhaustively investigated at low...