Scanning electron microscopy affected

Scanning electron microscopy indicated that the zeolites crystals are homogeneously dispersed in the surface and the core of the composites. Figure 2 presents micrographs of cross-sections of the chitosan-zeolite spheres and shows that the morphology of the zeolite crystals has not been affected by the gelling of chitosan. 

The shape and fimction of cytomembranes are intriguing and challenging research areas, inasmuch as their heterogeneous composition and size make them technically very difficult to study. Usually, we have to rely on experimental probes that inevitably perturb the sample - such as electron microscopy (EM) - to study their structures. The preparation techniques used for biological specimens often affect the shape of the membranes. Even if these obstacles can be overcome, the result is a two-dimensional impression of a three-dimensional structure. Serial sections or scanning electron microscopy (SEM), as well as tilting and rotation of the sample, will of course improve the result. 

Polymea mictocapsules containing 0,0-3,5,6-trichloro-2-pyridyl phosphorothioate (Dursban) were prepared by reacting a polyisocyanate and a poly amine and the factors affecting the formation of the microcapsule wall examined. The formation of polyurea was confirmed by FTIR spectroscopy, the thermal properties of the microcapsules were investigated by DSC and the morphology of the microcapsules detenninedby scanning electron microscopy. Optimum conditions for the formation of a thin surface l er and a porous matrix were established. 9 lefs. 

The main factor in beam analysis that affects the reliability of the analytical information is the reproducibility of the surfaces. When using scanning electron microscopy (SEM), the apparati are connected to the computer, which makes it possible to obtain quite a bit of information about the sample, especially by X-ray and AES. However, the apparati cannot assure the same length for beam penetration on the surface, which means that the analytical information can be uncertain. Because the beam analysis is rapid, it requires very fast detectors, e.g., Ge/Li or Si/Li. The LA can be successfully used in surface analysis. An automated system has been constructed, laser-induced breakdown spectrometry (LIBS).213 This is an alternative to other surface techniques — secondary ion mas spectroscopy (SIMS), SEM, X-ray photoelectron spectroscopy (XPS) — and it increases the lateral and depth resolution. 

---