Applications of Infrared Absorption Spectroscopy to Investigations of Cotton and Modified Cottons

Abstract

The KBr technique to obtain spectra of cotton cellulose has been applied satisfactorily to an investigation of physical and crystalline modifications and to changes resulting from oxidation. Several experiments to illustrate applications are described. The potential applications to investigations suggested in the literature are reviewed. It has been shown that infrared absorption spectra of cotton cellulose can be used to follow changes in hydrogen bonding by the classical method of observing the exact wavelengths of the O-H stretching vibrations. Degree of crystallinity can be measured quantitatively by use of ratios of intensities of preselected absorption bands. Oxidation changes can be followed only where such processes result in the formation of C = O groups per se in the oxidized cotton.

Structural Evolution of Gossypium hirsutum Fibers Grown under Greenhouse and Hydroponic Conditions

“…In addition, the presence of this band at 1427 cm −1 has been attributed to an increase in the structural organization of cellulose (e.g., crystalline domains) and used in combination with the vibration correspondent to [β(1-4)glucopyranose] linkage to determine the "crystalline index", later referred to as the "later order index" (LOI) [2,20,21]. A similar trend is found for the double band located at 1313 and 1332 cm −1 .…”

Efficient Hydrolysis of Lignocellulose by Acidic Ionic Liquids under Low-Toxic Condition to Microorganisms

“…To investigate the reason behind these different values, we measured the crystallinity of biomass. The crystallinity was determined by Fourier transform infrared (FTIR) spectroscopy by calculating the ratio of absorbance at 1437 and 899 cm −1 , as reported by O'Connor et al [32]. The ratio of absorbance was 0.60 (bagasse), 0.87 (Eucalyptus), and 0.67 (Japanese cedar).…”

Analysis of the physical properties of developing cotton fibres

“…However, such biological techniques have never been used to quantify molecular changes in cotton fibres during development, yet they offer a new method of qualitative and quantitative measurement of changes to the structure of cellulose that occur during the development of cotton fibres. The advantages of this technique are that no changes in crystallinity of the fibre occur during sample preparation, there is potential for increased sensitivity, and the ability to detect crystallinity changes in individual fibres, rather than the bulk of the sample in other analytical O'Connor et al [42] the IR absorption band at 1429 cm -1 as typical of crystalline regions in the polymer and the absorption band at 893 cm -1 typical of amorphous regions; the ratio of these two bands is referred to as the "lateral order index" (LOI). LOI can be used to interpret qualitative changes in cellulose crystallinity; generally, as LOI decreases crystallinity also decreases [42,58].…”

“…The advantages of this technique are that no changes in crystallinity of the fibre occur during sample preparation, there is potential for increased sensitivity, and the ability to detect crystallinity changes in individual fibres, rather than the bulk of the sample in other analytical O'Connor et al [42] the IR absorption band at 1429 cm -1 as typical of crystalline regions in the polymer and the absorption band at 893 cm -1 typical of amorphous regions; the ratio of these two bands is referred to as the "lateral order index" (LOI). LOI can be used to interpret qualitative changes in cellulose crystallinity; generally, as LOI decreases crystallinity also decreases [42,58]. Figure 10 shows indirect immunofluorescence detection of CBM3a binding to the surface of developing cotton fibres in comparison to changes in LOI from ATR-FTIR analysis.…”