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Frederick R. Phelan Jr., Nicos Martys, Charles C. Han
Lattice Boltzmann simulations have been carried out for two-phase systems in homogeneous shear flow at supercritical Capillary numbers and a viscosity ratio of unity. The simulations predict a three-stage mechanism for drop breakup. In the first stage, the
Characterization techniques for polymers have been discussed in literature. Normally these techniques are categorized in terms of mechanical testing methods, thermal analysis, electron and optical microscopy, nmr techniques, chromatographic methods
Kinetics of polymer phase separation has been briefly reviewed. This is a section on this subject for Encyclopedia of Materials: Science and Technology. This section includes summary of sinodal decomposition, critical temperature shift under shear flow
G Kim, C L. Jackson, M Libera, R Stadler, Charles C. Han, F V. Gyldenfeldt, V Balsamo
Distinctive behaviors of PCL(polycaprolactone) in block copolymers are significant for various polymer applications such as low temperature adhesives, biocompatibilizer and pigments. Thus, there has been increasing interest in the morphologies of block
Erik K. Hobbie, Haonan Wang, H Jeon, H W. Kim, D Stout, Charles C. Han
Optical studies of viscoelastic emulsions under simple shear flow reveal long-range spatial correlation in the orientation of the deformed domains. As the volume fraction of droplets increases, the tilt angle between the direction of orientation and the
Sheng Lin-Gibson, H W. Kim, G Schmidt, Charles C. Han, Erik K. Hobbie
Abstract: The equilibrium structure and shear response of model polymer-clay nanocomposite gels are measured using X-ray scattering, light scattering, optical microscopy, and rheometry. The suspensions form physical gels via the bridging of neighboring
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
Li Piin Sung, Jack F. Douglas, Charles C. Han, Alamgir Karim
We show that the addition of a small concentration of a block copolymer surfactant to a thin phase separating blend film can suppress the pattern formation that occurs in the blend films without block copolymer. This effect is observed even at very low
Li Piin Sung, Jack F. Douglas, Charles C. Han, Alamgir Karim
We show that the addition of a small concentration of a block copolymer surfactant to a thin phase separating blend film can supppress the pattern formation that occurs in the blend films without block copolymer. This effect is obseved even at very low
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
Erik K. Hobbie, Haonan Wang, H W. Kim, Charles C. Han, E A. Grulke, Jan Obrzut
We describe an optical metrology for measuring shear-induced structure and orientation in dilute dispersions of multiwalled carbon nanotubes. Small-angle polarized light scattering and optical microscopy are combined in situ to quantify the structural
Erik K. Hobbie, H Jeon, Haonan Wang, H W. Kim, D J. Stout, Charles C. Han
Light scattering and optical microscopy have been used to measure the morphology as a function of shear rate and composition in polymer blends with viscoelastic asymmetry in the melt components. The blends studied are immiscible mixtures of low-vinyl
Haonan Wang, K Shimizu, H W. Kim, Erik K. Hobbie, G Z. Wang, Charles C. Han
The kinetic interplay between crystallization and phase separation in a polymer blend has been examined. By controlling the relative quench depths for liquid-liquid phase separation and crystallization, the growth kinetics of the characteristic length
Z G. Wang, Haonan Wang, B S. Hsiao, D Gersappe, Charles C. Han
Results from in-situ time-resolved SAXS measurement on PEH melt crystallization, subjected to a step shear, indicate that an oriented lamellar structure is formed at the initial crystallization stage upon cessation of the step shear. Randomly distributed
Results from DSC, SAXS and WAXD show some new insights into the evolution of structural variables during Curie transition in PVDF/TrFE copolymer. The differences of long period evolution between the melt-crystallized samples in the paraelectric phase (> 80
Haonan Wang, Charles C. Han, K Shimizu, Erik K. Hobbie, Z G. Wang, J C. Meredith, Alamgir Karim, Eric J. Amis, B S. Hsiao, E T. Hsieh
The phase diagram of coexisting liquid-liquid phase separation (LLPS) and crystallization in nearly isorefractive blends of statistical ethylene/hexane and ethylene/butene copolymers has been investigated. A variety of techniques that exploit
The shear orientation of viscoelastic clay-polymer solutions was investigated by means of rheology and flow birefringence (δn). The polymer chains are in dynamic adsorption/desorption equilibrium with the clay particles to form a network. The elastic
G Schmidt, A Nakatani, Paul Butler, Charles C. Han
The influence of shear on viscoelastic polymer-clay solutions was investigated by means of small-angle neutron scattering (SANS) under shear. SANS measured the shear-induced orientation of polymer and platelets. With increasing shear rate an anisotropic