Morphologies, investigation techniques

Transmission electron microscopy (TEM) has traditionally been the mainstay of morphological investigations of polyolefins [8], but recent developments in low voltage high-resolution field emission gun scanning electron microscopy (FEG-SEM) [9] and the advent of atomic force microscopy (AFM) and related near-field techniques [10] have challenged its dominance at the length scales of the order of 10 nm, characteristic of both microdeformation (cavitation, fibrils) and structural components of semicrystalline... 

Prepared by the LB Technique and Donor Doping Molecular Orientation and Structure and Morphology Investigated by Infrared Spectroscopy, X-ray Diffraction, and AFM... 

Rheo-optical techniques (46 8) afford information on the strain dependence not only of stress but also of optical quantities associated directly with the structure or molecular morphology. The techniques were developed extensively for crystalline polymers to investigate the molecular deformation mechanism underlying the tensile elongation. In this part, the chain orientation behavior is characterized by infrared dichroism measured simultaneously with tensile deformation at a constant rate of elongation. 

As far as we know, the process of crystallization of low molecular weight substances in polymer matrices has not been studied until now. This problem is complicated because, as is usually the case with multicomponent systems, many factors affect this process. Moreover, small amounts of crystallites in the polymer matrix make most of the direct structural investigation techniques inapplicable. The casting temperature, the properties of the polymer matrix and of the solvent influence the crystallization process and the resultant morphology of the CT complex. On the basis of the results obtained we discuss the conditions which should be fulfilled to obtain low resistivity of the polymer-CT complex systems. 

The development of investigation techniques, particularly the electron scanning microscopy, allowed to differentiate the other morphological types of the calcium... 

Miscibility is one essential concept in polymer science, since blended systems are commonly used to address multiple property optimizations as typical for many applications. Several methods can be used to determine the miscibility of two- and more component systems. Morphological investigations of blend systems can easily been done with microscopic methods. Several electron microscopic techniques are used, that is, scanning electron microscopy (SEM), TEM, AFM, and scanning tunneling microscopy (STM). Inhomogeneities are typically... 

As has already been shown, the method of preparation and the investigation technique for polymers can influence the appearance of morphology of the particular polymer. In addition, one must consider whether varying the preparation methods and microscopic techniques can improve or even deteriorate the visibility of structural details. Some examples of the practical importance of sample preparation and of microscopic technique that can strongly influence the visibility of structures in the micrographs are described in the following sections. 

Near-infrared reflectance analysis is a useful technique for characterizing textile raw materials, fiber, yarns, and fabrics. It is a nondestructive quantitative analysis that is simple to use and allows rapid testing of the sample. Its ability to measure multiple components of the sample simultaneously and eliminate extensive sample preparation are major advantages of NIRA in the characterization of textile materials. Many innovative mathematical treatments, for example, discriminant analysis and spectral reconstruction, have been developed by instrument manufactures and software companies. These instruments not only aid in the quantitative analysis of the data but also allow morphological investigations of fibers and yarns and rapid, qualitative identification of specific sample sets. 

Several preparation and investigation techniques have been developed to overcome these difficulties. Three methods for investigating the morphologies of polymers are generally available (see Fig. 3.20) [1,2,5] ... 

DRS and TSDC were systematically employed in a series of recent papers to investigate the molecular dynamics and ionic conductivity in neat PTE. In many cases, the results were combined with those of morphological characterization techniques, in particular SAXS and DSC, and of water sorption/diffusion... 

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