Parakristalline Gitterstörungen in Kettenrichtung von Cellulose I und II

Zusammenfassung Röntgenweitwinkelmessungen an Ramie sowie an einer Viskosefaser zeigen, daß in Kettenrichtung parakristalline Störungen vong=1,1% bzw.g=1,5% vorliegen. Die mittleren Kristallitgrößen in Kettenrichtung betragen¯D ₀₁₀=485 Å bzw.¯D ₀₁₀=112 Å, senkrecht dazu etwa¯D=52 Å bzw.¯D=41 Å. Aus Röntgenkleinwinkelmessungen ergeben sich kleinste Fibrillendurchmesser von 2R=52 Å bzw. 2R=45 Å. Die gefundenen Fibrillendurchmesser verhalten sich wie 1248.Für die Viskosefaser wird eine Langperiode vonP=168 Å gemessen, woraus mit¯D ₀₁₀=112 Å folgt, daß die ungeordneten Bereiche in Kettenrichtung eine Länge von etwa 56 Å haben.

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Summary Wide angle X-ray diffraction studies on ramie and on a viscose fibre show that paracrystalline distortions exist in chain direction havingg-values ofg=1.1% andg=1.5%, respectively. The mean crystallite sizes in chain direction are¯D ₀₁₀=485 Å and¯D ₀₁₀=112 Å, respectively. Perpendicular to the chain direction mean crystallite sizes of approximately¯D=52 Å and¯D=41 Å, respectively, are measured.Small angle X-ray diffraction studies give the diameters of the cellulose fibrils, the smallest of which are 2R=52 Å and 2R=45 Å, respectively. The diameters of the fibrils are in the ratio of 1248.A long period ofP=168 Å is measured for the viscose fibre implying a length of 56 Å for the disordered domains in chain direction.

     

Acrylonitr1le anion-radical detection by infrared internal reflection spectra

The application of internal reflection spectroscopy to the study of interface boundary layers has been extended over cases in which unstable particles appear at the interface as a result of imposing a negative electrical potential on the germanium hemicylinder, used simultaneously as an optical prism in the internal reflection spectroscopic device and as an electrode. The appearance of the particles is detected by their internal reflection spectrum. The method has been applied in the case of the electrochemically induced polymerization of acrylonitrile. Two particles were found to be generated during electrolysis. They are assigned to the anionradical and to the di-anion of acrylonitrile.     

Gas-chromatographische Bestimmung des Verhältnisses 2-Methylbutanol (2MB): 3-Methylbutanol (3MB) in verschiedenen Weinbrand- und Whiskysorten

Analytical and Bioanalytical Chemistry -     

An ESR study of some organic complexes of tetravalent vanadium

ESR results are reported for solutions and glasses containing vanadyl diethyldithiophosphate, vanadyl and vanadium diethyldithiocarbamates, and vanadium butylxanthogenate. Comparison with compounds of known structure gives the structures of these complexes.