Important Morphology Observations

In this part, we will discuss important observations made in OPV. Different material systems will be discussed and important processing methods and related morphology optimization will be compared and analyzed. 

---

The Colli Albani volcano has long attracted the attention of scientists, who reported important field observations and clarified several first-order vol-canological, petrological and morphological features of the volcano (e.g. Sabatini 1900). However, the extensive study by Fomaseri et al. (1963)... 

Inhibitions of Cell Wall Biosynthesis. All bactericidal modes of action involve the alteration or destruction of some component (s) of the cell whose physiological function is of vital importance and cannot be compensated for or repaired by other cell constituents. This has been described above for the bacterial chromosome (DNA) and for the total population of bacterial ribosomes. The most prominent bactericidal effect, however, is caused by interferences with the biosynthesis of the cell wall polymer. Such a mode of action was proposed for penicillin on the basis of morphological observations in 1946s°)when the underlying biochemistry was still unknown. 

Nitrogen physisorption analysis reveals important morphological differences between the solids. So, BET surface area decreases as the calcining temperature increases, being the surface area 101.7, 29.4 and 16.93 m /g for the solids calcined at 400"C, 600 C and 800"C, respectively. The porous structure (Fig. 4) is also clearly different in these materials, especially for the solid calcined at 400"C, for which pore diameters are markedly lower than for the other two materials. Comparing the solids calcined at 600 and 800"C, it is observed that their porous structure is similar, although the peaks are sharper in the case... 

Furthermore, with PES5003P, xcp 0.40 and the particles are also smaller than with NFBN. We also see an effect of the viscosity and of the reactive chain ends of the thermoplastic. But because is 180 °C, which is lower than the Tg of the thermoplastic, one important effect is certainly also the vitrification of the dispersed particles when phase separation occurs. The consequence is that only with thermoplastic additives is an evolution of the morphology observed between precuring and postcuring processes. 

Enhanced interphase interactions, deduced from thermal and dynamic mechanical properties and morphology observed by SEM, demonstrate the efficient compatibilizing effect of iPS-fo-iPP copolymer on iPS-iPP blends. Each sequence of the iPS-fc-iPP diblock copolymer can probably penetrate or easily anchor its homopolymer phase and provide important entanglements, improving the miscibility and interaction between the iPS and iPP phases. This is in good agreement with what is inferred from the mechanical properties of the iPS-fo-iPP-iPS-iPP polyblends. 

The first observations clearly show that polyols modify the equilibrium morphology of boehmite particles, as it has been reported in the case of gibbsite crystallization [20, 21]. The use of polyols allows to obtain departures of the diamond shaped morphology observed at pH ll. If boehmite particles synthesized in presence of C2 to C4 polyols are always diamond shaped, the proportion of (101) and (010) planes is modified (table 1). The highest proportion of (101) face is reached for boehmite synthesis in presence of mesoerythritol (C4). Xylitol (C5) causes much important changes as the particle morphology is isotropic in this case. 

The three mechanisms described above briefly contribute to the overall dilatation of the material under tension, and it is not easy to assign to each process its relative importance in the recorded damage rate A. However, some authors like Keskkula and Schwarz (37) for HIPS, showed from detailed morphological observation that the crazing in the PS matrix is not the only active source of damage, but that the decohesion at the PS/PB interface and cavitation in the PB nodules play a significant role as well. 

There is however, still some doubt about this interpretation of the morphological observations and it is difficult to estimate what the quantitative importance of this type of transport is (Lacy and Taylor 1962 Millington and Finean 1962). It is quite possible that the pinocytotic mechanism is relevant mainly to the uptake of the droplets from the oil phase, described above. The micellar... 

On the other hand, we can recognize the advantage of the spot measurements, which actually reveal a real picture of the inner structure, but we have to admit that the way how we see it, that is the entire selection of insight windows and their multiplicity, is often in the hands of the observer and his experience as to what is more and less important to bring to his view and then observe in more details. Therefore, such a morphological observation, on the contrary, can be equally questioned as being based on a very localized and... 

The correct preparation of the sample and the use of adequate grids to support the material for analysis are important for observing two-dimensional images with high quality and resolution. However, an alternative is the ultramicrotome. The particles are embedded in a polymer resin and cut in thin sections of about 20 nm with a diamond knife. It is specially recommended for zeolite materials. The observation of these thin sections allows to observe the internal morphology of the particles and the dispersion of metals on the microporous structure material [32]. 

Nanomodification creates improved fibre characteristics, e.g. mechanical strength, thermal stability, the enhancement of barrier properties, fire resistance, ion exchange capability, etc., for use in different application fields. In order to follow modification efficiency, various characterization techniques can be used, e.g. X-ray analysis to study composite structure, morphological observations by electron microscopy, mechanical tests, determination of electrokinehc properties, calorimetric measurements. The dispersion of particles within the hybrid system is of fundamental importance, and thus to observe particles a method based on selective etching of the polymer using a plasma... 

---