title: Comparative analysis of crystallinity changes in cellulose I polymers using ATR-FTIR, X-ray diffraction, and carbohydrate-binding module probes.
abstract: Cotton fiber cellulose is highly crystalline and oriented; when native cellulose (cellulose I) is treated with certain alkali concentrations, intermolecular hydrogen bonds are broken and Na-cellulose I is formed. At higher alkali concentrations Na-cellulose II forms, wherein intermolecular and intramolecular hydrogen bonds are broken, ultimately resulting in cellulose II polymers. Crystallinity changes in cotton fibers were observed and assigned using attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and X-ray diffraction (XRD) subsequent to sodium hydroxide treatment and compared with an in situ protein-binding methodology using cellulose-directed carbohydrate-binding modules (CBMs). Crystallinity changes observed using CBM probes for crystalline cellulose (CBM2a, CBM3a) and amorphous cellulose (CBM4-1, CBM17) displayed close agreement with changes in crystallinity observed with ATR-FTIR techniques, but it is notable that crystallinity changes observed with CBMs are observed at lower NaOH concentrations (2.0 mol dm(-3)), indicating these probes may be more sensitive in detecting crystallinity changes than those calculated using FTIR indices. It was observed that the concentration of NaOH at which crystallinity changes occur as analyzed using the CBM labeling techniques are also lower than those observed using X-ray diffraction techniques. Analysis of crystallinity changes in cellulose using CBMs offers a new and advantageous method of qualitative and quantitative assessment of changes to the structure of cellulose that occur with sodium hydroxide treatment.
authors: Sustainable Materials Research Group, Centre for Technical Textiles, University of Leeds, Leeds LS2 9JT, UK.
authors: Alenka
authors: A
authors: Kljun
authors: Thomas A S
authors: TA
authors: Benians
authors: Florence
authors: F
authors: Goubet
authors: Frank
authors: F
authors: Meulewaeter
authors: J Paul
authors: JP
authors: Knox
authors: Richard S
authors: RS
authors: Blackburn
mesh_terms: D001665:Binding Sites; D002482:Cellulose / Q000737:chemistry*; D003460:Crystallization; D003368:Gossypium / Q000737:chemistry; D006860:Hydrogen Bonding; D010446:Peptide Fragments / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012972:Sodium Hydroxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D010446:Peptide Fragments; D012972:Sodium Hydroxide; D002482:Cellulose