Thursday, April 23, 2009
Presented by the Soft Materials Discussion Group
Recent advances in the understanding of material properties allow for better material design and manipulation. This meeting will highlight two prominent researchers in the field, followed by a student poster session.
The Soft Materials Discussion Group regularly convenes investigators in the New York region with an interest in soft materials research and development, and provides a forum for scientists, engineers, and other key stakeholders working in academia, industry, and not-for-profit entities to exchange ideas and discuss advances. To ensure impact globally, the meeting proceedings will be disseminated electronically through the Academy's eBriefings program. The interdisciplinary topics include a range of technologically important materials in colloids, polymers, emulsions, liquid and organic crystals, membranes, proteins, cells, and tissue.
Suresh Rajaraman, Air Products and Chemicals
Electrostatic Forces Are Not Always Pair-wise Additive
Eric Dufresne, Yale University
We exploit optical forces and thermal fluctuations to measure femtoNewton scale forces between micron-sized plastic particles floating in oil. Particle surfaces spontaneously charge and we observe long-range electrostatic repulsions between pairs. Interestingly, the repulsion between any pair of particles can be strongly reduced when other particles are nearby. This effect is not accounted for by the usual suspects: nonlinearity in the Poisson-Boltzmann equation or counter-ion correlations. However, we can quantitatively predict interparticle forces in a variety of geometries by simply assuming that the surface charge densities adjust to keep the surface electrostatic potentials at a fixed value.
ieDesign, Development and Application of Thermally Responsive "Smart" Intelimer® Polymers
Steven P. Bitler, Landec Corp.
Landec has designed and developed a series of "smart" stimuli-responsive (thermal) polymers based on side chain crystalline polymers that exhibit sharp melt or switch temperatures. This sensitive and specific thermal switch has been used to control physical and mechanical properties including permeability, adhesion and viscous flow in response to small temperature changes. These "smart" temperature switch materials have shown particular utility in biological applications, not only because of their ability to exhibit a tailored temperature switch within the range of 0-50°C, but also because of their safety properties. For industrial applications, higher temperature switch materials have been produced. These thermally responsive materials have been applied to food packaging, seed coating, adhesives, personal care and drug delivery.