Ando H, Konishi T
Central Laboratory, Rengo Company, Ltd., 186-1-4, Ohhiraki, Fukushima-ku, Osaka 553-0007, Japan.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Jul;62(1 Pt B):727-33. doi: 10.1103/physreve.62.727.
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.
分别在有无丙酮的酸性溶液中，通过粘胶的凝固和再生制备了透明（VI-P）和半透明（VI-L）纤维素水凝胶，并在2×10⁻⁴至0.5 Å⁻¹的宽散射矢量q范围内测量了小角X射线散射（SAXS）和超小角X射线散射（USAXS）的绝对强度Δi(q)。通过对SAXS和USAXS测量的组合数据进行去模糊处理，我们方便地获得了非常小q值下的散射强度。Δi(q)q²对log₁₀q的作图在-2.5 < log₁₀q < -1.0处出现一个峰值。通过假设一个两相模型，其中高密度相（相1）仅由纤维素组成，低密度相（相2）由分散在水中的纤维素组成，根据作为（Δi(q)q²dq）积分确定的电子密度的均方涨落，确定VI-P和VI-L中相1的体积分数分别为0.18和0.09。通过将观察到的散射轮廓与球体的理论粒子散射函数拟合，确定VI-P中包括微晶的高密度区域的平均直径为120 Å，VI-L中为80 Å。类似的分析也应用于冻干的VI-P。这些结果与广角X射线衍射测量获得的结果一致，也与扫描探针显微镜的观察结果一致。
