Carlisle Chambers Research


Carlisle Chambers Research Interests

The overall theme of research in my laboratory is the preparation and use of organized systems that incorporate many molecules. "Multi-molecule" assemblies are known as "supramolecular" systems, and we are interested in systems that achieve some level of molecular self-organization. We primarily work with two systems: self-assemble monolayers(SAMs) and liquid crystals. The focus of our work is the preparation of new systems that have interesting optical and electronic properties. Over the past twelve years I have had many talented undergraduate George Fox University students help me with these research projects. They have contributed their intellect, enthusiasm, and creativity to the research. Their participation has been crucial and I gratefully acknowledge their work.

1. Rational Design and Control of Nanoscale Features in Self-Assembled Monolayers.
The primary goal of this project involves nanotechnology, which is the preparation of molecular-scale systems for applications in computer and information technology. The specific focus of this research is the preparation of surfaces with well-defined, nanometer-scale features. The specific goal is to control the location of sulfur-based molecules (thiols) as they spontaneously bond in a single layer to a gold surface. The fundamental interaction between thiols and a gold surface is well documented. In recent work, we have shown that when different types of thiols are added at the same time to a gold surface, the individual molecules undergo phase separation. In other words, the thiols tend to form discrete domains or clumps with other molecules of the same type. In our work, internal hydrogen-bonding is used to drive nanoscale phase separation of amide-containing thiols from alkane thiols. We have been able to reproducibly evaluate the extent of phase separation of thiols on gold using a rapid, electrochemical technique. While phase separation does occur, it is random and does not generate reproducible thiol patterns on the gold surface. In this project, we are investigating the conditions and factors that govern controlled phase separation during thiol monolayer formation on gold surfaces. By controlling the location of thiols as they spontaneously self assemble on a gold surface, one might be able to prepare reproducible molecular-scale patterns and arrays. This type of system could be used to prepare molecular scale logic devices and switches for minaturized computers. This work is being done in collaboration with Dr. James Hutchison at the University of Oregon.

2. Preparation and Characterization of Polyoxometalate-Based Thin Films. New Materials with Novel Optical and Electronic Properties.
The primary goal of this project is the preparation of molecule-scale devices that behave as optical transistors and switches. An optical transistor, then, is a device in which amplification of an input optical signal results in a magnified optical response. Devices of this type have potential application as components in an optical memory system. One route to materials with these properties is to prepare organized systems where the individual molecules have the necessary optical and electronic characteristics. We have chosen a class of inorganic anionic clusters, polyoxometalates, as the species that imbue the material with their individual electronic and optical properties.

Picture Picture

We have also chosen to use the highly regular architecture of thin films as the organizing influence. To this end we have attached long-chain carbon groups to polyoxometalates so that the clusters take on phospholipid-like character. Along with our collaborator Dr. Elizabeth J.O. Atkinson at Linfield College, we have used the derivatized polyoxometalates to prepare Langmuir-Blodgett (LB) thin films and multilayers. The thin films are well behaved and very stable. We are exploring the experimental conditions and molecular parameters that govern film formation.

3. New Chemical Sensors: Optical Signaling of Receptor-Ligand Binding Using Liquid Crystals.
The primary goal of this project is to prepare liquid crystal displays (LCDs) that signal molecular recognition interactions with visible color changes. WePicturehave designed and synthesized a compound that binds barbiturate analytes. LCDs prepared with this compound change color as the barbiturate guest is added to the system. The color change can be observed in ambient light with the naked eye and without electrical power. We are currently attempting to use this approach in a system that will bind specific proteins. This technology could be extended to detecting threshold levels of specific toxins or other clinically important species. These systems could be employed as diagnostic or clinical assays for use in remote locations.

Recent Publications:
R. Carlisle Chambers, Christina E. Inman, and James Hutchison, "Electrochemical detection of nanoscale phase separation in binary self assembled monolayers" Langmuir 2005, 21, 4615.

R. Carlisle Chambers, Elizabeth J. Osburn Atkinson, David McAdams, Eric J. Hayden and Davida J. Ankeny Brown, "Creating monolayers and thin films of a novel bis(alkyl) substituted asymmetrical polyoxotungstate, {[CH3(CH2)11Si]2OSiW11O39}4- using the Langmuir-Blodgett technique" Chem. Comm, 2003, 2456.

Students:
Ryan Johnson - (Summer 2005)
Alexandra Salter - (Summer 2005)
Whittney Warren - (Summers 2004,2005)
Georgia Lemen - (Summer 2004)
Travis Lund - (Summer 2004)
Roxy Lowry - (Summer 2003)
Sarah Angell -(Summer 2002)
Ryan Hawk - (Summer 2002)
Karen Ragan - (Summer 2002)
Elissa Bell - (Summers 2000,2001)
Davida Ankeny (Summer 2000)
Jake Vickaryous
Wendy Noyes
Tauni Clark - (Summer 1999)
Holly Nelson - (Summer 1999)
Paul Brewer - (Summer 1999)
Christina Cady - (Summer 1998)
Anna McInturf - (Summers 1997,1998)
Wade Neiwert - (Summer 1998)
Kathryn Parent - (Summer 1997)
Rima Butler
Bonnie Leasure - (Summer 1996)
Berkeley Shorthill - (Summer 1996)
Matt Helmboldt
Brian Schmidt - (Summer 1995)
Jon Bingham - (Summer 1995)

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