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SPECIAL SEMINARS

POLYMER NANOFIBERS AND NANOTUBES: ENCAPSULATION, INTERCALATION AND RELEASE AT THE NANO- AND MICRO-SCALE

Professor Alex L. Yarin
Department of Mechanical and Industrial Engineering
University of Illinois at Chicago

Time: Tuesday, April 29th, 3:00 p.m.
Location: Aggarwal Lecture Hall, Room 130
Polymer Engineering Academic Center
250 South Forge Street, Akron, OH 44325-0301

Lectures Are Free And Open To The Public

Click here to print the flyer

Abstract

Two novel methods of encapsulation and intercalation in cylindrical confinements of nanoscale diameters are studied experimentally and theoretically. In the first method, coelectrospinning and emulsion co-electrospinning are introduced to encapsulate polymer materials in nano- and microfibers. In the second method, polymer macromolecules, surfactant molecules or polymer nanoparticles are driven into carbon nanotubes and microcapillaries by self-sustained diffusion from an evaporating dilute solution droplet. Nanoparticles driven into microcapillaries formed long photonic crystals. Two release methods are realized experimentally and studied theoretically. In the first one, pressure-driven flows through bundles of long parallel carbon nanotubes produced via co electrospinning with carbonization are realized. A theoretical method is given to recover flow-active nanotube diameter-distribution via the dependence of the fluid throughput on the pressure. In the second method, release of a water-soluble compound embedded in polymer nanofibers submerged in water or buffer solution is studied. It is shown that the limiting stage of the process is desorption from the nanopore surface, which is accompanied by fast diffusion of released molecules in water. Such applications as drug or growth factor release for stem cell differentiation on oriented polymer nanofiber scaffolds are also discussed.

Resume

Professor Alex Yarin received his M.Sc. in Engineering Physics in 1977 from Polytechnic University of Sankt-Petersburg, Russia, and Ph. D. in Physics and Mathematics in 1980 from the Institute for Problems in Mechanics USSR Academy of Sciences, Moscow, Russia. Prior to joining the University of Illinois at Chicago, he was a faculty member of Mechanical Engineering Department, Technion University and served in various capacities as Associate Professor (1990-1997), Professor (1997-1999), and Eduard Pastel Chair (1999-2005) at the Mechanical Engineering Department at Technion. He is the author of 2 books, 6 book chapters, 176 research articles in professional journals and 4 patents.

Contact Person: Professor Thein Kyu, Department of Polymer Engineering, (330) 972-6672.

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Nanoconfined Molecules:
Part 1: Structure of Surfactant and Polymers under One-dimensional Confinement
Part II: A New Selective Adsorption Mechanism of Rubber Molecules onto Nanoparticle Aggregates

Hatsuo Ishida
Department of Macromolecular Science and Engineering
Case Western Reserve University, Cleveland, Ohio 44106

Time: Thursday, April 24th, 2:30 p.m.
Location: Aggarwal Lecture Hall, Room 130
Polymer Engineering Academic Center
250 South Forge Street, Akron, OH 44325-0301

Lectures Are Free And Open To The Public

Click here to print the flyer

Abstract

Part I: Silicate gallery is used to study the structure of surfactant molecules and polymers under one-dimensional confinement. Three characterization techniques were used to examine exactly the same sample to minimize interpretation inconsistency. Confinement of molecules led to exhibit unusual properties such as discrete change of molecular stacking, unexpected increase in Tm, and total disappearance of Tg phenomenon. Molecular structural interpretation of these phenomena will be given.
Part II: A novel mechanism of nano-particle network formation in a binary immiscible rubber blend has been proposed. A remarkable reduction of percolation threshold concentration of the nano-particle dispersed rubber blend prepared by the solution mixing was explained by the selective adsorption of a rubber via nano-confinement mechanism.
This new mechanism is based on the size matching of a molecule and nanoparticle voids rather than traditionally used enthalpic mechanism, although the new mechanism does not conflict with the traditional mechanism. Applicability to other nano-particles and polymers will also be shown. This new mechanism is proposed to be universally applicable to all nanofillers and polymers.

Resume

Professor Hatsuo Ishida received his B.S. degree in Chemical Engineering and M.S. degree in Industrial Chemistry from Doshisha University, Kyoto, Japan. His Ph.D. degree in Macromolecular Science was awarded from Case Western Reserve University, Cleveland, Ohio. He is currently Professor of Macromolecular Science at Case Western Reserve University. Professor Ishida has pioneered in the molecular characterization of composite interfaces. His activity extends to synthesis, surface vibrational spectroscopy, and rheology and processing of composite materials. He has also pioneered in the development of new, very versatile polymers called polybenzoxazines, the first commercial polymer in the new millennium. Professor Ishida’s research has culminated in some 350 papers and to his credits, he received numerous awards.

Contact Person: Professor Thein Kyu, Department of Polymer Engineering, (330) 972-6672.

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