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Search Publications by: Alamgir Karim (Assoc)

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Displaying 26 - 50 of 200

Crystallization of Poly(ethylene oxide) on Topographically Patterned Substrates

October 16, 2008
Author(s)
Brian C. Okerberg, Christopher Soles, Jack F. Douglas, Alamgir Karim
Crystallization of poly(ethylene oxide) (PEO) on topographically patterned substrates is investigated. Primary nucleation was dramatically enhanced during solvent drying on patterned substrates compared to flat films. The nucleation density also increased

Entanglement Effects on the Dewetting of Polymer Thin Films

October 16, 2008
Author(s)
K A. Barnes, Alamgir Karim, Jack F. Douglas, Da-Wei Liu, Eric J. Amis
We investigate the dewetting of entangled and unentangled polymer films from model viscous polymer and inorganic substrates. Linear and hypergraft polyethyloxazoline (PEOX) polymers are chosen as the unentangled and entangled dewetting fluid, respectively

Image Analysis for High-Throughput Materials Science

October 16, 2008
Author(s)
Alamgir Karim, A Sehgal, J C. Meredith, A J. Crosby, Eric J. Amis
Imaging plays a key role in modern day materials science by providing a high-density format of data representation that can be visually interpreted or processed by the human brain in a fraction of a second. We have illustrated a few select examples-

Morphological Changes in Thin Polypropylene Films Induced by 4-Biphenyl Carboxylic Acid

October 16, 2008
Author(s)
Marlon L. Walker, Chad R. Snyder, Naomi Eidelman, E S. Etz, A P. Smith, Alamgir Karim, Eric J. Amis
The crystallization behavior of thin polypropylene films both neat and containing a nucleating agent, 4-biphenyl carboxylic acid, was investigated by optical microscopy, atomic force microscopy, infrared spectroscopy and Raman spectroscopy. High-throughput

NIST Combinatorial Methods Center, July 10, 2001: Meeting Proceedings

October 16, 2008
Author(s)
A Sehgal, Alamgir Karim, Eric J. Amis
The meeting showcased combinatorial research and methods development at NIST as applied to materials science problems. The Combinatorial Methodology is a set of tools and techniques the chemicals and materials science communities will use to accelerate the

Polymer-Surface Interactions in Nanfilled Polymers

October 16, 2008
Author(s)
Alamgir Karim, Jack F. Douglas, A Nakatani, Eric J. Amis, D B. Majumdar
We review recent investigations of conventional and nanoparticle filled polymers using atomic force and optical microscopy, scattering (x-ray, neutron and visible light) to characterize the influence of filler particles on the phase separation morphology

Spinodal Dewetting on Chemically Patterned Substrates

October 16, 2008
Author(s)
A Sehgal, V Ferreiro, Jack F. Douglas, Eric J. Amis, Alamgir Karim
We utilize chemically patterned substrates with arrays of progressively narrower stripes (1-15 mm) to investigate the influence of pattern size on the morphology of dewetting polystyrene films. The early-stage dewetting patterns align with the substrate

Swelling of Grafted Polymer Brushes

October 16, 2008
Author(s)
Jack Douglas, M S. Kent, Sushil K. Satija, Alamgir Karim
The end-grafting of polymer chains to surfaces provides a robust method for modifying surface properties. Such layers are increasingly being employed in applications-modifying the biocompatibility of implants, the wetting, adhesive and frictional

Wetting-Dewetting Transition Line in Thin Polystyrene Films

October 16, 2008
Author(s)
K M. Ashley, D T. Raghavan, Jack F. Douglas, Alamgir Karim
Thin polymeric films are increasingly being utilized in diverse technological applications and it is crucial to have a reliable method to characterize the stability of these films against dewetting. The parameter space that influences the dewetting of thin