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Prof. Wayne E. Jones Jr. , Dept. of Chemistry, Binghamton University- September 6, 2007
"Molecular Wires and Devices: New Materials for Nanoscale Molecular Electronics " [more...]
Prof. Bradley F. Chmelka, Dept. of Chemical Engineering, University of California- October 11, 2007
"Molecular Wires and Devices: New Materials for Nanoscale Molecular Electronics " [more...]
Prof. Stanislaus Wong, Dept. of Chemistry, SUNY Stony Brook- November 2, 2007
"Chemical Strategies in Nanoscience" [more...]
Prof. Robert J. Stanley, Dept. of Chemistry, Temple University- November 8, 2007
"Photolyase: Binding of Sunburnt DNA and Light-driven Ultrafast Repair" [more...]
Prof. Ashok J. Maliakal, Bell Labs, Alcatel-Lucent- November 15, 2007
"Nanostructured Materials as Flexible High K Dielectrics and Actuators" [more...]
Prof. Wayne E. Jones Jr.
Dept. of Chemistry
Binghamton University
Molecular Wires and Devices: New Materials for Nanoscale Molecular Electronics
The development of ever smaller electronic and photonic devices has recently focused on the preparation of molecular scale devices. There is a continuing need for new synthetic and processing strategies to prepare these nanomaterials. We have been pursuing new approaches to the preparation of sensors and switches in the context of conjugated polymers and molecular wires. Using a combination of organic coupling chemistry and coordination chemistry, new polymers can be prepared which exhibit long range electron and energy transport behaviors. In some cases, these polymers act as fluorescent sensors, responding selectively to analytes in solution. Derivatives of these materials can also be prepared as nanofibers, thin films on fiber optics, and metal-organic hybrid materials to provide a suite of new materials that can be used for future molecular electronic and photonic devices.
References:
• “Studies of Photoinduced Electron Transfer (PET) and Energy Migration in a Conjugated Polymer System for Fluorescence "Turn-on" Chemosensor Applications,” Lijuan Fan, Wayne E. Jones, Jr., J. Phys. Chem., 2006, 110(15), 7777-7782.
• “Fabrication and Thermal analysis for submicron Silver tubes prepared by Electrospun Fiber Templates.” Frederick Ochanda, Wayne E. Jones, Jr., Langmuir, 2007, Langmuir 23 (2): 795-801.
• “Enhanced Conductivity of Thin Film Polyaniline by Self-Assembled Transition Metal Complexes,” David Sarno, Justin Martin, Steve Hira, Clifford Timpson, Wayne E. Jones, Jr., Langmuir, 2007, LANGMUIR 23 (2): 879-884.
Thursday 9/6/07
2:00 PM
Building 6S Room 232
*Refreshments served at 1:45PM
For additional information contact:
Prof. Michal Kruk
718-982-4030
kruk@mail.csi.cuny.edu
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Prof. Bradley F. Chmelka
Dept. Chemical Engineering
University of California
Guest-Host Interactions in Self-Assembling Solutions and Solids: New Molecular Insights on Binding, Encapsulation, & Release Process
Measurement and control of guest molecule distributions in the presence of self-assembling host species are important in many complex fluid solutions and heterogeneous solids. Technologically important systems include micelle or vesicle hosts for drug delivery, proteins that interact with small molecule agents, and functionalized inorganic-organic hybrid materials. In such mixtures, guest host distributions may be influenced by competing dynamic interactions among numerous and diverse hydrophobic, hydrophilic, and/or surfactant species present. These interactions affect guest-host binding, component mobilities, phase behaviors, and macrscopic mixture properties, though are highly system-dependent and are challenging to establish. Scattering, microscopy calorimetry, and optical spectroscopy measurements are sensitve, though often limited in their resolution, especially in the absence of long-range order. By comparison, multidimensional and pulsed-field-gradient diffusion NMR methods provide higher molecular-level resolution and are sensitive to the locations, distributions, and dynamics of different component species. Recent results and new insights will be presented on guest-molecule interactions with self-assembling host species, e.g., block copolymer surfactants, micelles, vesicles, or proteins, in heterogenous solutions and templated solids.
Thursday 10/11/07
2:15 PM
Building 6S Room 232
*Refreshments served at 2:00PM
For additional information contact:
Prof. Michal Kruk
718-982-4030
kruk@mail.csi.cuny.edu
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Prof. Stanislaus Wong
Dept. of Chemistry
SUNY Stony Brook
Chemical Strategies in Nanoscience
We will discuss examples of our research in nanomaterials, structures at the one billionth of a meter scale. In the first part of the talk, we explore covalent chemical strategies for the functionalization of carbon nanotube surfaces. In recent years, nanotubes have been treated as chemical reagents (be it inorganic or organic) in their own right. Indeed, from their inherent structure, one can view nanotubes as sterically bulky, -conjugated ligands or conversely, as electron-deficient alkenes. Hence, herein we seek to understand, from a structural perspective, the breadth and types of reactions SWNTs can undergo in solution phase, not only at ends and defect sites but also along sidewalls. Controllable chemical functionalization suggests that the unique electronic and mechanical properties of SWNTs can be tailored in a determinable manner. Moreover, prevailing themes in nanotube functionalization have been involved with dissolution of tubes. In the second part of the talk, we describe a number of advances that have been made in the reproducible synthesis of ternary metal oxide nanostructures. Nanoscale structures, such as nanoparticles, nanorods, nanowires, nanocubes, and nanotubes, have attracted extensive synthetic attention as a result of their novel size-dependent properties. Ideally, the net result of a successful nanoscale synthesis using environmentally friendly methodologies is the production of structures that achieve monodispersity, stability, and crystallinity with a predictable morphology. Many of the synthetic methods used to attain these goals have been based on principles derived from semiconductor technology, solid state chemistry, and molecular inorganic cluster chemistry.
Thursday 11/2/07
2:15 PM
Building 6S Room 232
*Refreshments served at 2:00PM
For additional information contact:
Prof. Michal Kruk
718-982-4030
kruk@mail.csi.cuny.edu
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Prof. Robert J. Stanley
Dept. of Chemistry
Temple University
Photolyase: Binding of Sunburnt DNA and Light-driven Ultrafast Repair
DNA photolyase is a monomeric flavoprotein that repairs DNA damaged by ultraviolet radiation. The DNA lesion, a cyclobutylpyrimidine dimer (CPD), is bound in a base-flipped form, in which the CPD is extracted from the DNA duplex so that repair can be facilitated by ultrafast electron transfer from the photoexcited reduced flavin cofactor. We have explored the protein: substrate system using ultrafast and steady-state spectroscopic techniques to identify how the protein binds its substrate and what the ultrafast repair mechanism might be.
Thursday 11/8/07
2:15 PM
Building 6S Room 232
*Refreshments served at 2:00PM
For additional information contact:
Prof. Michal Kruk
718-982-4030
kruk@mail.csi.cuny.edu
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Prof. Ashok J. Maliakal
Bell Labs
Alcatel-Lucent
Nanostructured Materials as Flexible High K Dielectrics and Actuators
The ability to control the chemistry and morphology of composite materials on the nanoscale is essential to the understanding and development of these materials. This is especially true for materials related to flexible electronics and actuation in which performance requirements are not satisfied by a single phase material; however homogeneity of the composite on the nanometer scale is essential to performance. The approach we have taken is to synthesize inorganic core polymer shell nanoparticles which blend the properties of these dissimilar materials on the nanoscale in order to achieve “pseudo homogenous” films which successfully combine the mechanical properties of the polymer shell with the electronic properties of the inorganic oxide core. New dielectric films based on these core-shell structures of titanium oxide and polystyrene have been incorporated into capacitors and thin film transistors (TFTs). Mobilities exceeding 1.0 cm 2/Vs have been achieved for pentacene TFTs, indicating good surface properties for pentacene film growth. These core-shell particles are easy to disperse in organic solvents and also polymers. We have successfully incorporated titanium oxide core-poly(butyl acrylate) shell particles into electroactive polymer actuator devices. In our best devices, we are able to achieve compression strains of approximately 10% for films without any prestrain at electric fields of less than 10 V/mm.
Thursday 11/15/07
2:15 PM
Building 6S Room 232
*Refreshments served at 2:00PM
For additional information contact:
Prof. Michal Kruk
718-982-4030
kruk@mail.csi.cuny.edu
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