AFM examination

Topographic AFM examination of organic dyes under the appiication of reductive and oxidative potentials appears to be consistent with the above modeling [168], This can be seen in Fig. 2.25 where in situ AFM images from the upper face and sides of crystals of indigo (a) before, and (b) after application of a linear potential step between 0.0 and +0.75 V at a potential scan rate of lOmV/s are shown. Here,... 

Dehydrated calcium pimelate is added (between 0.01 and 0.5 wt %) as the nucleating agent to isotactic polypropylene to produce the (3 modification of iPP [63]. Following molding between two glass plates at 220°C thin films of the polymer are isothermally crystallized at 140°C-143°C in a microscopy hot stage. After the hedritic structures develop, the samples are quenched to room temperature. Prior to AFM examination, the specimens are etched with a 1% solution of potassium permanganate in a mixture of sulfuric and orthophosphoric acid [64, 65]. This procedure is described in detail in the literature Caution consult the literature for safety precautions ) and helps to remove preferentially amorphous phase of PP [64]. Thus, unlike in the many other examples discussed in Sect. 3.2, here the interior of a specimen is analyzed after its exposure. 

This is consistent with data from atomic force microscopy (AFM) examination of Cu-MOF deposits submitted to a cathodic input. As shown in Figure 5.8a, pristine Cu-MOF particles appeared as elongated crystals 100-200 nm in size with a corrugated surface texture. Upon application of a constant potential step at -250 mV... 

The AFM data shows that the deformed molecular and crystal lattice states persist for long times. For RDX, the semi-permanent higher energy deformed states persist for at least five years, which is the time that had elapsed between when some of the RDX shock and impact experiments were done and when they were examined by the AFM. The time elapsed between the impacts on gold and the AFM examination was about 2 to 3 months. Annealing is likely to be the only way to return all of the lattice and molecules to their lowest energy level state. 

Quite in contrast, AFM examination of the excess water in the case of the cationic hexagonal phase reveals no traces of DNA including the smallest fragments detectable by high resolution AFM (Fig. 12.13e), confirming the strong binding of the DNA to the cationic lipids [58]. 

These qualitative deductions, which are based on considering a smooth surface, lead to a contradiction as the polymer surface-treated before metalization appears to be oxidized over an appreciable depth whilst the oxidized polymer layer left on the metal side after the rupture does not screen completely aluminum. Actually an AFM examination has shown that the surfaces obtained after rupture are not smooth. They present a nodular morphology with a rms roughness (measured on 2 x 2 pm ) in the range of 3-7 nm, i.e., of the order of the IMFP. Further analysis of the results would require modeling, nsing the kind of approach described below. 

FTIR-AFM examination of polymer surfaces, morphology, adhesion studies, photooxidative stability, particle size, and helix structure studies. 

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