The Application of a Drift Accessory for Routine Analysis of Liquids and Solids
Alexander N. Shchegolikhin and Olga L. Lazareva
Department of Electronics of Organic Materials, Joint Institute of Chemical Physics
Russian Academy of Science, 4 Kossygina st., Moscow, 117334, Russia
Abstract
A modification of the normal sample stages of two standard Diffuse Reflection (DRIFT) accessories along with relevant changes to the sample application techniques are reported. These simple modifications are shown to increase the applicability of conventional DRIFT accessories, allowing qualitatively correct Diffuse Reflection-Absorption (DRAFT) spectra of liquids and solids to be obtained routinely and with high sample throughput. To illustrate the feasibility of the modified technique for routine identification purposes, DRAFT spectra are compared with those which have been recorded in transmission. The effects of the sampling methods on the quality of the DRAFT spectra are discussed in terms of possible optical distortion of the latter. A phenomenological explanation of the apparently good correspondence between the DRAFT and the standard transmission spectra is proposed.
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Use of in situ Fiber-Optic Raman Spectroscopy to Replace Calorimetry in the Monitoring of Polymer and Composite Curing
Jeffrey F. Aust1, Karl S. Booksh1, Christopher M. Stellman1, Richard S. Parnas2, and
Michael L. Myrick1*
1Department of Chemistry and Biochemistry,
University of South Carolina,
Columbia, SC 29208.
2Polymers Division,
National Institute of Standards & Technology,
Gaithersburg, MD 20899.
* Author to whom correspondence should be addressed. email: Myrick@psc.sc.edu
Abstract
| A method for real time determination of the percent cure of epoxies via in-situ fiber-optic Raman spectroscopy has been developed. This method utilizes a probe design developed for real time monitoring of polymer curing and multivariate analysis to interpret the data and determine percent cure. This method is demonstrated to be reliable to +/- 0.54% of cure in laboratory samples over a 50-99% cure range. A preliminary study measuring cure percentage in an industrial, glass-reinforced composite has been shown to be reliable to +/- 0.82 % in the 40-90% cure range.
Key words: Process monitoring, fiber optic, Raman spectroscopy, in-situ, percent cure, composite, chemometrics
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