Patchy Particles and Surfaces of Engineered Heterogeneity: Synthesis to Dynamic Function
A Symposium on Complex Interfaces and their Technological Importance at the National Meeting of the American Chemical Society
August 17, 18, 2009
Ronald Reagan Center, Washington D.C.
The symposium on Patchy Particles and Surfaces of Engineered Heterogeneity, held at the Fall 2009 National meeting of the American Chemical Society in Washington DC focused on the fundamental understanding of surface heterogeneities and how they can be exploited in different technological areas. The symposium brought together scientists from different disciplines working with heterogeneous interfacial systems to accelerate progress in areas such as self assembly of advanced structures for photonic and optoelecronic applications, biosensors, water purification, and the interface between nanostructures and biomolecules in advanced materials. The program, organized by Maria Santore at the University of Massachusetts and Darrell Velegol of Penn State University featured two full days of oral presentations, including 11 invited speakers and other oral contributions. This website provides a summary of the invited talks to the larger community for scientific transfer to those not able to attend.
Topics Included:
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Production of patchy particles and surfaces. Particle lithography (single particle or crystalline masks), nanosphere lithography, glancing angle deposition, controlled colloidal deposition and templating, and other techniques are being developed to create patchy surfaces and particles of controlled character, giving them “bond regions” and other functionalities.
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Characterization of patchy interfaces. FESEM, TEM, confocal, colloidal force AFM, and other microscopies are required for direct characterization of heterogeneous interfaces. A goal is to relate the information from these new methods to more classical interfacial metrics such as zeta potential and colloidal stability / adhesion. Other techniques will be included, especially those that allow examination of responsive functions like dynamic assembly (i.e., assemblies that change shape or configuration following on a stimulus).
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Assembly and organization. Patchy interfaces possess the unique ability to direct assembly in highly selective ways, leading to new organized colloidal materials, some of which are important to the development of novel energy sources, sensors, and electro-optics.
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Unique dynamic behaviors. From highly specific binding and unusual dynamic signatures (the ability to control rolling and slipping, or the mimic of catch-stick versus catch-slip bonds), to tunable hydrodynamic responsiveness, the adhesive junctions between patchy interfaces and other materials exhibit precisely engineered capability. These fundamental dynamic responses will be the basis for the controlled evolution of assembled structures, and new materials whose dynamic response lies at the heart of their function, for instance biosensors and bioactuators.
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Modeling of patchy particle assembly. Monte Carlo and Brownian dynamics simulations are being used to determine final structures based on the initial patchy particles, plus assembly times.
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Applications. Hunters, scavengers, sensors, motors, assembled materials, bacterial adhesion, and other applications. Interactions of patchy structures with light, or with biomolecules and bacteria.
Highlights from Keynote Talks:
Zbigniew Adamczyk, Polish Academy of Sciences: Deposition of Particles at Heterogeneous and Patterned Surfaces
Terri Camesano, Worcester Polytechnical Institute: Role of LPS Heterogeneity on Adhesion of Gram-Negative Bacteria
Jeffrey Davis, University of Massachusetts: Particle Interactions with Patchy Surfaces in Flow
Jayne Garno, Louisianna State University: Patchy Particles and Surfaces of Engineered Heterogeneity: From Synthesis to Dynamic Function
Naomi Halas, Rice University: New Routes to Reduced Symmetry Plasmonics
Ilona Kretzschmar, City College of New York: “Patchy" Particles
Eric Luijten, Northwestern University: Assembly Behavior of Janus Particles and the Role of Hydrodynamic Interactions
David Pine, New York University: Structured Colloids: Patches, Packmen, and Helices
Maria Santore, University of Massachusetts: Using Patchy Surfaces for Selective Particle and Cell Adhesion and Dynamic Motion Control
Joachim Spatz, Max Planck Institute: Nanopattern Surfaces for Molecular Engineering of Cellular Environments
Darrell Velegol and H.A. Jerri, Pennsylvania State University: Fabrication of Anisotropic Focus-Released Microcapsules