Cotton morphology

No shrink-resist polymer developed so far meets all the above requirements [301]. There is clearly some similarity with easy-care finishing of cotton. Although effective crosslinking agents are readily available for application to cotton, the morphological complexity of the wool fibre is such that an equally effective polymer has yet to be identified for wool treatment [304]. 

The term fibrous, as applied to zeolites, does not necessarily indicate flexibility. Flexibility, however, is one of the physical properties of cotton stone found on the Isle of Skye, Scotland. This locality provides a feathery sample of mesolite, (Na2Ca2Al6SigO30 8H2O), whose composition and structure place it in the same group as natrolite. The similarity between appearance of this sample and that of the mountain flax variety of palygorskite emphasizes the difficulty of identifying fibrous minerals based on morphology alone. 

Some natural polymers such as cotton, slik, and cellulose have the extended-chain morphology, but their morphologies are determined by enzymatically controlled synthesis and crystallization processes. Extended-chain morphology is obtained in some synthetic... 

The morphology of silver nanopartilces on the cotton surface and paint samples was observed by field emission scanning electron microscopy (FE-SEM JSM-6700F, JEOL, Japan). The size and shape of the nanoparticles in solution were determined with transmission electron microscopy (TEM) (LEO-912-OMEGA, Carl Zeiss, Germany). 

Electron diffraction patterns from the primary wall of 15-day-old cotton fiber showed sharp, meridional reflections, with d spacings of 0.517 nin and 0.258 nm. Broad maxima on the equator, with spacings of 0.416 nm and 0.570 nm were also observed. On this basis, it was suggested that the primary wall of cotton contains the cellulose IVi polymorph, which is simply a laterally disordered structure of cellulose I. A discussion of the morphology of cellulose in the primary wall was given. 

Raw wood contains 45-60% of cellulose. Morphologically this kind of cellulose is distinguished from cotton cellulose by the smaller size of its fibres. Chemically it is more reactive. 

Refs 1)H.B. Brown, "Cotton History, Species, Varieties, Morphology, Breeding, Culture, Diseases, Marketing and Uses , McGraw-Hill, NY (1938), 605 pp 2) G.R. Merrill, A.R. 

Recently, scanning electron microscopy has been used in our laboratory to investigate the effects of abrasion on the morphology of fibrous cellulose copolymers (36). For example, cotton cellulose was woven into fabric form (print cloth construction and weight). Cellulose copolymer fabrics were prepared by irradiating a sample of this fabric, followed by copolymerization of the irradiated fabric with a binary mixture of acrylo-... 

Cellophane film Is prepared from regenerated cellulose and Is similar to rayon fiber In that It has a lower molecular weight than cotton and contains a small amount of hemlcellulose, as does linen. Cellophane film, therefore, although not a duplicate of any natural fiber, Is similar enough In chemical structure and morphology to make It useful as a model system. Moreover, Its transparency and the precision of Its manufacture make It quite useful for this type of study. 

The morphology of the fibrous cellulose graft copolymers depended on the method of initiation of free radical formation, experimental conditions during the copolymerization, chemical modification of the cellulose before reaction, and the type of monomer used (60). Variations in the shape of the fibrous cross section, in layering effects in the fiber, and in the location and distribution of the grafted copolymer in the fiber were observed by electron microscopy (61). Cotton cellulose—poly (acrylonitrile) copolymer was selected to show the possible variations in location and distribution of the grafted copolymer in the fiber. 

Flax. Flax is also a cellulosic fiber but has a greater degree of crystallinity than cotton. The morphology of flax is quite different from that of cotton. Flax fibers have a long cylindrical shape with a hollow core. The fibers range in length from V2 to 2V2 inches, with a diameter of 12 to 16 microns. Flax staple is comprised of bundles of individual fibers. Historians believe that flax was among the first fibers to be used as... 

Its origin, development, morphology, chemistry, purification, and utilization have been discussed by many authors [2-12]. The chemistry, structure, and reaction characteristics of cellulose, the carbohydrate polymer that forms the fiber, are thoroughly treated in a number of excellent works [8,9,12-19]. This book is intended to provide an overview of the current state of knowledge of the cotton fiber. Much of the information reported here is taken from the references cited at the end of the book, which should be consulted for a more in-depth treatment. 

Each cotton fiber is a single, elongated, complete cell that develops in the surface layer of cells of the cottonseed. The mature cotton fiber is actually a dead, hollow, dried cell wall [4,5,43], In the dried out fiber, the tubular structure is collapsed and twisted, giving cotton fiber convolutions, which differentiate cotton fibers from all other forms of seed hairs and are partially responsible for many of the unique characteristics of cotton. The biosynthesis and morphology of the cotton fiber are discussed in more detail later (see Chapter 2). 

During mercerization, the swelling induced by the caustic is inhibited from outward expansion by the presence of the primary wall of the cotton fiber. The changes observed in fiber morphology by mercerization include deconvolution, decrease in the size of the lumen, and a more circular cross section. 

This brief reference to the morphological architecture of cotton and wool fibers illustrates their complex nature. The use of X-ray diffraction in this investigation was not intended to yield quantitative information on the morphology of the historic fibers, but rather was intended to serve as a diagnostic technique to detect changes in morphology caused by the treatments. Any change induced by a conservation treatment is believed to affect mechanical fiber properties and should be minimized. 

Figure 7 shows schematic reproductions of the shapes of the X-ray diffractive traces of alpaca observed after treatments in water and tetrachloroethylene. The reflections observed at about 9.8° (20) may indicate that the fibers contain ordered components having a specific helical configuration of the polypeptide chains (31). Aqueous treatments caused some changes in the intensities of the traces. In comparison, the nonaqueous treatment in tetrachloroethylene yielded a trace not much different from the control trace. On the basis of these observations, it is postulated that nonaqueous treatments affect the fiber morphology of historic cotton and protein fibers to a lesser degree than aqueous cleaning treatments. 

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