Structure analysis of regenerated cellulose hydrogels by small-angle and ultra-small-angle x-ray scattering.
Absolute intensities Deltai(q) of small-angle x-ray scattering (SAXS) and ultra-small-angle x-ray scattering (USAXS) were measured in a wide range of scattering vector q from 2x10(-4) to 0.5 A(-1) for transparent (VI-P) and translucent (VI-L) cellulose hydrogels prepared by coagulation and regeneration of viscose in acid solutions with and without acetone, respectively. We obtained the scattering intensities at very small q conveniently by desmearing the combined data measured by SAXS and USAXS. The plot of Deltai(q)q(2) versus log(10) q showed a peak at -2.5<log(10) q<-1.0. By assuming a two-phase model with the high-density phase (phase 1) composed of only cellulose and with the low-density phase (phase 2) composed of cellulose dispersed in water, volume fractions of phase 1 in VI-P and VI-L were determined to be 0.18 and 0.09, respectively, from the mean-square fluctuation of electron density determined as integral of (Deltai(q)q(2)dq). By fitting the observed scattering profile with the theoretical particle scattering functions of spheres, the average diameter of the high-density region including crystallite was determined to be 120 A for VI-P and 80 A for VI-L. Similar analyses were applied also to freeze-dried VI-P. These results were consistent with those obtained by the wide-angle x-ray-diffraction measurement and also with the observation by scanning probe microscopy.
Ando
H
H
Central Laboratory, Rengo Company, Ltd., 186-1-4, Ohhiraki, Fukushima-ku, Osaka 553-0007, Japan.
Konishi
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T
D002482:Cellulose / Q000648:ultrastructure*; D005782:Gels; D018625:Microscopy, Atomic Force; D010316:Particle Size; D012542:Scattering, Radiation; D014961:X-Ray Diffraction; D014965:X-Rays
D005782:Gels; D002482:Cellulose