Poly scanning electron microscopy

Microspheres were monitored by scanning electron microscopy (SEM JEOL 35C), and their diameters were determined from the corresponding SEM microphotographs. Typically, ca. 500 particles in randomly sampled areas of microsphere specimens were analyzed. Molecular weight of poly(L-Lc) was determined by GPC. A system consisting of a LKB 2150 pump, Ultrastyragel 1,000, 500, 100, 100 columns, and Wyatt Optilab 903 interferometric refractometer was used for the measurements. GPC traces were analyzed by using calibration with narrow polydispersity < 1.15)... 

The polymers chosen for the initial stages of our studies were poly-(methyl methacrylate) and polystyrene. There were several reasons for this choice, the most important being (1) well-characterized, low-molecular-weight monodisperse samples of poly(methyl methacrylate) and polystyrene are readily available, or at least relatively easy to synthesize and (2) the poly (methyl methacrylate) /polystyrene system is especially amenable to study by scanning electron microscopy, as we... 

Bootz, A., et al. (2004), Comparison of scanning electron microscopy, dynamic light scattering and analytical ultracentrifugation for the sizing of poly(butyl cyanoacrylate) nanoparticles, Eur. J. Pharm. Biopharm., 57(2), 369-375. 

Brendle described a process which he called polymer grafting, in which particles of molybdenum disulphide or other solid lubricants were coated with various polymers, including polystyrene, polymethylmethacrylate and poly-isobutylvinyl ether. The process was most conveniently carried out by grinding coarse molybdenum disulphide powder in a 20% - 30% solution of the appropriate monomer in a solvent. The quantity of polymer added to the molybdenum disulphide particles was very small, and could not be detected by scanning electron microscopy or infrared spectroscopy. The carbon content (1-4%) indicated a polymer content up to 6% maximum. Brendle considered that the polymer was preferentially grafted onto surface freshly exposed by grinding. This may be partly true, but in view of later... 

Fig.29. Fibrillar microstructure of stress-whitened zones in poly(ethylene terephthalate) as revealed by scanning electron microscopy...

Suspensions of polypyrrole were prepared by the FeCls oxidation of pyrrole in an aqueous solution of methylcellulose (49). The product was dried and yielded films with conductivities of 0.2 S/cm. Scanning electron microscopy revealed globular polypyrrole embedded in the methylcellulose matrix. After several months, these suspensions remained stable with no detectable precipitation. Similarly, the electropolymerization of 3-methyl-thiophene in solutions of poly(methyl methacrylate) and poly(vinyl chloride) was reported (50, 51). 

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