%0 Journal Article
%T Temperature Evolution of Cluster Structures in Ethanol
%A P. Golub
%A I. Doroshenko
%A V. Pogorelov
%A V. Sablinskas
%A V. Balevicius
%A J. Ceponkus
%J Dataset Papers in Science
%D 2013
%R 10.1155/2013/473294
%X The dependence of FTIR spectrum of pure ethanol on the temperature was investigated. The measurements were performed for frozen (the minimum temperature £¿180¡ãC) and liquid ethanol (the maximum temperature 40¡ãC). All changes in IR spectrum of ethanol during gradual warming were detected and analyzed. On the bases of preset observations, the conclusions concerning the evolution of cluster structures in ethanol during transition from solid (frozen) state to liquid state were made. 1. Introduction The alcohols belong to the specific kind of species since their molecules can form hydrogen bonds and arrange in different structures named clusters. Numerous works were devoted to the investigation of these substances. Special attention was paid to the investigation of monohydric alcohols among which methanol [1¨C5] and ethanol [6¨C9] were the most popular as the simplest ones. The main competitive structures are ring and chainlike clusters. In the first type of clusters, all hydroxyl groups of alcohol molecules are H-bonded with neighboring molecule until the conditionally last molecule would bond with the first one. In chainlike structures, the last molecule is not bonded with the first one, thus leaving one hydroxyl group free. But the situation is still not obvious, and different authors postulate different sets of clusters that exist in liquid phase on the basis of different experimental and theoretical techniques [1¨C11]. Also the evolution of cluster structures during the change of ambient conditions has not been followed yet. In the first stage of such type of investigations, we decided to choose infrared spectroscopy as the experimental tool since any changes in clusters sizes and types may be clearly detected by IR spectrum. Ethanol was chosen as the object of investigation. 2. Methodology Registration of the presented spectra was performed in the laboratory of Fourier transform infrared absorption spectroscopy in the Faculty of Physics of Vilnius University, Lithuania. All spectra were recorded using Bruker¡¯s FTIR-spectrometer VERTEX 70 equipped with LINKAM cryostat (model FTIR 600). The spectra were recorded in the spectral range from 750 to 4000£¿cm£¿1 and in temperature range from £¿180 to 40¡ãC. Liquid-N2-cooled mercury cadmium telluride (MCT) was used as a detector. Spectral resolution was set to 1£¿cm£¿1, and in order to increase signal-to-noise ratio, each spectrum was taken as an average of£¿£¿128 scans. Liquid ethanol with purity greater than 99.9 from Fluka was used as received. In Figure 1, the registered FTIR spectra of ethanol at different
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