Electron microscopy, monomer film

Another approach to deposit conducting polymers can be achieved by photochemical polymerization of the monomer precursors. This procedure provides a means by which different composites (metals and/or various alloy materials with or without biomolecules) can be deposited from an electrolyte onto a non-conducting surface. Such a procedure was optimized and applied for polymerization of pyrrole in the presence of metal nanoparticles [61]. Photopolymerized films containing metals analyzed by environmental scanning electron microscopy (SEM) appeared to be typical of amorphous polypyrrole in which bright Ag particles were found on the surface (Fig. 7.6). 

Upon degradation, oligomers and monomers of PHA are produced, which are then assimilated by the microorganisms as nutrients. Electron microscopy analysis of PHA films revealed that degradation occurs at the surface via enzymatic hydrolysis. The degradation is therefore a function of the surface area available for microbial colonisation. 

Reversed micelles have very highly dynamic structures and are in rapid equilibrium with surfactant monomers. Therefore, it is usually difficult to observe their real features by microscopy. A freeze-fracture transmission electron microscope (TEM) would probably show the real picture of a reversed micellar solution because a freeze-fracture film of the reversed micelles is made by rapid cooling to — 150°C to stop instantly the dynamic nature of the structure. Figure 2(a) shows an electron micrograph of the AOT reversed micellar solution (5% w/v AOT-iso-octane solution, IV = 1) [44]. The visual observation by a... 

Latex with hydroxyl functionalised cores of a methyl methacrylate/butyl acrylate/2-hydroxyethyl methacrylate copolymer, and carboxyl functionalised shells of a methyl methacrylate/butyl acrylate/methacrylic acid copolymer was prepared by free radical polymerisation. The latex was crosslinked using a cycloaliphatic diepoxide added by three alternative modes with the monomers during synthesis dissolved in the solvent and added after latex preparation and emulsified separately, then added. The latex film properties, including viscoelasticity, hardness, tensile properties, and water adsorption were evaluated as functions of crosslinker addition mode. Latex morphology was studied by transmission electron and atomic force microscopy. Optimum results were achieved by introducing half the epoxide by two-step emulsion polymerisation, the balance being added to the latex either in solution or as an emulsion. 8 refs. 

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