Research Equipment Proposal: Acquisition of a Fourier Transform Infrared Spectrometer with a Microscope Attachment.

Cuny City College, New York NY

Investigators

Abstract

ABSTRACT CTS-0079677 A. Couzis CUNY @ City College This is an engineering equipment proposal for the acquisition of a Nicolet Nexus-670 Fourier Transform Infrared Spectrometer. The instrument is an advanced FTIR device with features that allow operation in the near, mid and far regions of the IR and infrared sources, and an infrared microscope (Nicolet Continum infrared microscope) which will allow surface mapping experiments with minimum x-y resolution of less that .1 um. the total cost for this instrument is approximately $115,000 of which City College has agreed to a one third cost share, thus the requested amount from NSF is approximately $76,500. The Instrument will be used by four faculty (A. Couzis, C. Maldarelli, D. Rumschitski and L. Gilchrist) all of the Department of Chemical Engineering at City College in a series of five projects, some of which are collaborative. These projects are: Water restructuring and monolayer phase behavior of surfactants at the hydrophobic solid - aqueous interface (Couzis). "Superspreading" trisiloxane surfactant systems allow water to spread on hydrophobic surfaces. How these systems work is unknown. We have posited a mechanism in which the siloxane displaces water as it adsorbs onto the hydrophobic/water interface to form a dense hydrophobic domain adjacent to the solid, which lowers the solid/water tension and facilities spreading. Total internal reflection in the infrared will be used to follow restructuring and chain coherence in an effort to establish this mechanism, and this information will be used to design mixed hydrocarbon surfactant systems with superspreading ability. The direct measurement of the surfactant equation of state of the air-aqueous interface (Maldarelli). The equation of state describes the dependence of the surface tension on the surface concentration. For soluble surfactants this equation has not been measured directly since surface concentrations are unknown. Infrared reflection adsorption spectrometry will be sued to obtain directly the surface concentration by measuring the infrared adsorbance and suing a calibration with an insoluble surfactant. Nano-engineered templates for a controlled crystallization (Maldarelli and Couzis) Functionalized self-assembled monolayers on a solid support are being designed to serve as template foe selective crystallization of one polymorph over another. The templating is a form of epitaxy in which the functionalized template surface mimics a face of the desired crystal polymorph. Total internal reflection in the infrared will be used to follow structural changes in the template as crystallization proceeds providing insight into how to optimize the epitaxy. Characterization of biomimetic surfaces (Gilchrist) Biomimetic surfaces will be constructed form cellular components such as polypeptides, structural proteins and phospholipids. Internal reflection spectroscopy in the infrared will be used on IR tags on these components to study the structure of the assembling surface. The dynamic of protein folding (Rumschitski) The process of protein folding involves a series of kinetic paths in a transition from a random coil to a native configuration. Folding times are usually complete in times well below a millisecond. Structural studies of the folding process provide insight into the relationship between the protein's sequence and its native conformation, but are currently difficult to obtain because of the long scan times of techniques such as x-ray crystallography and solution state NMR. We propose a new technique in which the protein folding is initiated in a miniature well-mixed flow cell at steady state, with different ages or protein intermediates states present. IR spectroscopy, together with a kinetic model, is used to identify these states.