A quantitative investigation on the X-ray small angle scattering of cellulose fibers. Part II. The scattering power of various cellulose fibers†
A quantitative investigation on the X-ray small angle scattering of cellulose fibers. Part II. The scattering power of various cellulose fibers†
复制标题
纤维素纤维的 X 射线小角散射研究第二部分。各种纤维素定量纤维的散射能力†。
DOI：
10.1002/pol.1959.1203512812
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发表时间：
1959
期刊：
影响因子：
--
通讯作者：
A. Weidinger
中科院分区：
文献类型：
--
作者：
P. Hermans;D. Heikens;A. Weidinger
本文报道了用三狭缝真空照相机和单色辐射定量测量各种人造丝和苎麻纤维的小角散射与含水率的关系。通过测定样品的吸光度和以任意单位测量的透射光束的强度，将散射强度在样品厚度和初级强度上归一化。从这些数据的散射功率所定义的Porod，是均方的波动的电子密度，计算。然后，通过用已知成分的贵金属溶胶曝光并因此具有可计算的散射功率的程序校准，将该量转换成电子单位。实验结果与纤维素纤维的散射功率计算值进行了比较，纤维素纤维被视为亚微米两相系统，由结晶纤维素嵌入在非结晶纤维素和水的均匀混合物组成。在空气干燥状态下，一些人造丝的散射能力与理论一致。大多数产生更高的值，高达6倍（干苎麻也是如此）。这是解释的亚微观空隙的发生，小于0.75%的体积分数，从纤维到纤维的变量。这种解释是由散射功率和纤维的重量密度之间的一个明显的相关性的存在。总之，微孔是干纤维中的主要散射“颗粒”。水溶胀的人造纤维和苎麻的散射功率的值可以解释的基础上的三相模型，与相组成的结晶纤维素，无定形纤维素与水的均匀混合物，和水，分别。
This paper reports on quantitative measurements of the small angle scattering of various rayons and ramie fibers as functions of moisture content using a three slit vacuum camera and monochromatic radiation. The scattered intensity was normalized on sample thickness and primary intensity through determination of the absorbance of the sample and of the intensity of the transmitted beam measured in arbitrary units. From these data the scattering power as defined by Porod, being the mean square of the fluctuations of the electron density, was calculated. This quantity was then converted into electron units through calibration of the procedure with exposures of noble metal sols of known composition and thus of computable scattering power. The exprimental results were compared with the scattering power calculated for cellulose fibers when regarded as submicro tow-phase systems consisting of crystalline cellulose imbedded in a homogeneous mixture of noncrystalline cellulose and water. In the air-dry state a few of the rayon speciman examined exhibited a scattering power of magnitude consistent with theory. The majority yielded much higher values, up to six times larger (so does dry ramie). This is interpreted by the occurrence of submicro voids to a volume fracton of less than 0.75%, variable from fiber to fiber. This explanation is corroborated by the existenc of a distinct correlation between scattering power and gravimetric density of the fiber. In conclusion, microvoids are the principal scattering “particles” in dry fibers. The values of the scattering power of water swollen rayons and ramie can be interpretated on the basis of a three-pahse model, with the phases consisting of crystalline cellulose, a homogeneous mixture of amorphous cellulose with water, and water, respectively.