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Search Publications by: Charles C. Han (Assoc)

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Displaying 1 - 25 of 55

Chapter I. Overview of Polymer Blends Characterization

October 16, 2008
Author(s)
Charles C. Han
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

October 16, 2008
Author(s)
Charles C. Han
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

Morphology Study of Polystyrene-Polybutadiene-Polycaprolactone (PS-b-PB-b-PCL), Polybutadiene-Polycaprolactone (PB-b-PCL), and Polystyrene-Polycaprolactone (PS-b-PCL) Semicrystalline Block Copolymers

October 16, 2008
Author(s)
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

Shear Induced Tilt Order in Polymer Blends

October 16, 2008
Author(s)
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

Shear-Induced Structure in Polymer-Clay Nanocomposite Solutions

June 1, 2004
Author(s)
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

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

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

Optical Measurements of Structure and Orientation in Sheared Carbon-Nanotube Suspensions

March 1, 2003
Author(s)
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

Shear-Induced Structure in Polymer Blends With Viscoelastic Asymmetry

March 1, 2003
Author(s)
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

Phase Diagram of a Nearly Isorefractive Polyolefin Blend

January 1, 2002
Author(s)
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

Rheology and Flow-Birefringence From Viscoelastic Polymer-Clay Solutions

January 1, 2002
Author(s)
G Schmidt, A Nakatani, Charles C. Han
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

Small Angle Neutron Scattering From Viscoelastic Polymer-Clay Solutions

January 1, 2002
Author(s)
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