Organic specimen preparation

The infonuation that can be extracted from inorganic samples depends mainly on tlie electron beam/specimen interaction and instrumental parameters [1], in contrast to organic and biological materials, where it depends strongly on specimen preparation. 

External quality assessment schemes involve the distribution by the organizer, to participating laboratories, of aliquots from the same sample. Participants analyze the received specimen and send the results back to the organizer who prepares a report to summarize all data. 

Banks, PM. Technical aspects of specimen preparation and special studies. In Surgical Pathology of the Lymph Nodes and Related Organs, ed. ES Jaffe, pp. 1-21. Philadelphia W. B. Saunders, 1985. 

Finally, the localizations of low-molecular-weight compounds requires special specimen preparation techniques, as these compounds are often diffusible, water- or organic-solvent soluble, and solubilized by conventional fixation and dehydration procedures. The reader is referred to ref. (12) for the processing of cells and tissues for the cytochemical and histochemical localization of these compounds. 

There are three important sources of data and information on RPs. Obtain data from products your organization previously fabricated there is the data sheet compiled by a manufacturer of the material and derived from tests conducted in accordance with standardized specifications. If suppliers data were to be applied without a complete analysis of the test data for each property, the result could prove costly and embarrassing. Final source is preparing your own test specimens and conducting your own tests. Either one or both specimen preparation and test evaluation could be conducted by an outside source. If the fabricator prepares the specimens a duplicate of the fabricating process to be used will be produced or as close to the process as possible. The amount and degree of testing is usually related to factors such as (I) if a prototype is to be prepared and tested and (2) product requirement such as safety. 

Figure 12 Cryo-transmission electron micrographs of vitrified thin films of lamellar phase (brine 0.5 M-SDS 9%-pentanol 7%). Dark lines correspond to the contrast produced by the surfactant membranes. Micrographs a-c display a lamellar order with a variable characteristic distance, which is interpreted as the sign of strong fluctuations of the membranes. Micrograph d displays a disorganized structure that could be due to a modification of the labile lamellar organization by shear or during specimen preparation. Bar = 100 nm. (From Ref. 136.)...

What then are the key specimen preparation methods for studying polymer materials by microscopy techniques This topic could be organized in one of two ways, that is by each specific microscopy technique or by each preparation method. The approach that has been chosen is to describe each specimen preparation type for all microscopies in order to minimize overlap and also to make it simpler to use for reference. Those preparation methods chosen for discussion are the typical ones found to be of major utility in the industrial laboratory. They cover the full range of study of the industrial scientist, that is everything from rapid failure analysis to process optimization studies and fundamental research. The fundamental studies must often be fitted into a limited time framework that requires good choices of methods and techniques on a wide range of materials. 

Chapter 1 provides a brief introduction to polymer materials, processes, morphology and characterization. Chapter 2 is a concise review of the fundamentals of microscopy, where many important terms are defined. Chapter 3 reviews imaging theory for the reader who wants to understand the nature of image formation in the various types of microscopes, with particular reference to imaging polymers. All of these chapters are mere summaries of large fields of science, to make this text complete. They contain many references to more specialized texts and reviews. Chapters 4 and 5 contain the major thrust of the book. Chapter 4 covers specimen preparation, organized by method. 

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