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A study of the structure of cotton fibres is described, the objective being to determine whether differences in properties between cotton types can be attributed to differences in structure, primarily at the molecular or supramolecular level of organization. It is concluded that there are no obvious differences in the nature of the crystallographic units or the supramolecular 'crystalline aggregates' between cotton varieties and that the observed differences in mechanical properties must have been due to the arrangement of these units (e.g., orientation) or to differences at higher levels of structural organization. [ABSTRACT FROM AUTHOR]

This paper describes a quantitative X-ray-diffraction investigation into the effects of the time of heating native and mercerized cotton fibres at 220°C on the crystallographic order. It is concluded that thermally induced structural modifications are time-dependent and that dissimilar mechanisms operate in the two specimens examined. For example, it appears that an initial recrystallization occurs in native fibres, whereas in mercerized specimens degradation of order increases continuously with the time of heating. [ABSTRACT FROM AUTHOR]

An investigation is described in which a scanning electron microscope was used to assess the efficiency of certain chemical solutions in imparting electrical conductivity to synthetic-polymer fibres. It is shown that the technique provides a sensitive method for ranking the efficiency of anti-static agents only under conditions of high vacuum. It also enables minimum concentration levels of anti-static agents required to provide adequate dissipation of electrical charge to be determined. [ABSTRACT FROM AUTHOR]

An account is given of an investigation in which the low-sulphur S-carboxy-methylkerateine fractions (SCMK-A) from wool, human hair, and ovine horn were dried from, solution at various pH values and the films so formed examined in the electron microscope, both negative-staining and platinum-shadowing techniques being used. Rod-shaped particles, spheroidal aggregates, and filaments were observed. At pH 25-3-5, spheroids predominated, and al pH 90 the rod-shaped particles predominated, whereas filament formation was favoured near neutrality. The filaments had diameters of 20-50 Å; the rod-shaped particles had diameters of about 20 Å and lengths ranging from less than 200 Å to about 800 Å, the most favoured lengths having a common factor of about 160 Å. The spheroids ranged in diameter from about 100 Å to about 600 Å and were usually flattened. The helix-rich fractions obtained by partial digestion of SCMK-A with Pronase P or chymotrypsin appeared to consist chiefly of rod-shaped particles at pH 6-9. The size of these particles (160-170 Å x 20 Å) was in good agreement with hydrodynamic measurements. [ABSTRACT FROM AUTHOR]

The paucity of information about the fine structure of cuticle cells, in animal hair and wool fibres, has been a major factor in the general failure to advance a theory capable of explaining quantitatively the origin of the Directional Frictional Effect. Electron microscope studies have been made covering : (i) surface replications, (ii) examination of fibre profiles, and (iii) thin sectioning. Significant differences have been found between the surface textures of replicas of various wool fibres. However, because of the lack of equipment for the quantitative interpretation of stereo electron-micrographs, the direct examination of fibre profiles was undertaken. Thus, information was obtained about the height and frequency of the distribution of cuticle cell edges along the fibre axis, together with other information about the surface asperities. Thin sections (both transverse and longitudinal) yielded information about the type and extent of radial and peripheral overlapping of cuticle cells ; also, the various ways in which they are attached to their neighbours. The idealized model of a cuticle cell, emerging from these studies, could account for the two distinctly different mechanisms of deformation, namely buckling and compression, under forces acting in the direction of fibre-root and fibre-tip respectively. Evidence was obtained providing further, if not conclusive, proof of the "ploughing" action, operative during motion in the tip-to-root direction. [ABSTRACT FROM AUTHOR]

A letter to the editor that focuses on a study on electron-diffraction of keratin cells is presented.

The article discusses the morphology of the cuticle layer in wool fibers and other animal hairs. After examining surface textures, fiber profiles and thin sections using electron microscopes, significant differences between the surface textures of replicas of various wool fibers were found. Direct examination of fiber profiles obtained information on surface asperities, height and frequency of the distribution of cuticle cell edges along the fiber axis. Type and extent of radial and peripheral overlapping of cuticle cells and their attachments to other was examined using transverse and longitudinal thin sections. The author concludes that the two distinct mechanisms of deformation are buckling and compression supported by the idealized model of a cuticle cell.