TEM/AIA

Rubber microcomposites based on different matrices (BR, NR, SBR) and loaded with the same amount of unmodified silica were analysed by TEM/AIA following a procedure optimized in order to achieve, in a reasonably short time, quantitative information on the filler dispersion by considering several morphometric descriptors. ... 

Also in this case, the aspect ratio/ of the GNP particles dispersed in NR was quantified with a TEM/AIA approach. An excellent fit was found between experimental and theoretical (evaluated on the basis of Equation (23.1) by using the measured /) modulus values. 

Since a conventional TEM produces a projected three-dimensional (3D) image on a two-dimensional (2D) plane, quantitative information on the filler dispersion can be attained by using AIA techniques. 97,99,102,115,125,127,134 this way, it is possible to recognize, select, measure and compare size and shape of the complex structures dispersed in the matrix through the use of descriptors based on geometrical parameters, such as area, perimeter, diameter and morphometric parameters, such as shape ratio and roundness (Figure 23.3). However, TEM image analysis of filler microdispersions is more difficult to... 

Some examples of filler distribution quantitatively evaluated by 2D and 3D-TEM combined with AIA in rubber-based microcomposites will be reported in Section 23.5.1. 

The combination of TEM and AIA techniques makes it possible to obtain quantitative and representative information on the filler distribution in the elastomer matrix (homogeneity of the dispersion, size and shape distribution of the aggregates) and, consequently, on the filler-elastomer interactions. 

By applying AIA techniques analogous to those discussed in Section 23.5.1, the aspect ratio of the clay particles in a rubber matrix can be determined.For example, the high aspect ratio of stacked and distorted fluorohectorite layers was observed in TEM micrographs and was correlated with the reinforcing effect brought about by this silicate. 

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