Polymer nanocomposites micrographs

Fig. 12 TEM micrograph of Au-polymer nanocomposite prepared via in situ microemulsion polymerization...

A dispersion of nanoparticles of Au or other metals in a polymer matrix may also be obtained by a one-pot process of microemulsion polymerization. For instance, the UV-polymerization of a microemulsion of 35 wt% MMA, 35 wt% AUDMAA and 30 wt% of 0.1 M HAUCI4 aqueous solution would produce a Au-polymer nanocomposite, as shown in Fig. 12 [104]. This TEM micrograph shows a microtoned thin film of the sample. It is clearly apparent that Au particles of about 10-15 nm are well dispersed in the polymer matrix. 

The optical micrographs in Figure 5 show the effect of oxygen plasma exposure to pure nylon 6 and a nylon 6/7.5wt% layered silicate nanocomposite. Both are melt-processed samples recast from the 1,1,1,3,3,3-hexa-fluoro-2-propanol solution. The nylon 6 sample experiences almost complete deterioration after 8 hours (480 minutes) of continuous exposure. In contrast, deterioration of the nanocomposite is minimal, with no significant decrease in thickness. Buckling of the nanocomposite sample after exposure arises from differences in thermal expansivity of the self-generating ceramic surface and the bulk polymer nanocomposite. 

TEM. However, this observation is in all cases qualitative and highly localised. A general idea of the morphology of polymer nanocomposites can also be obtained by SEM. The dispersion pattern of the nanomaterial in the polymer matrix may be visualised from SEM micrographs. In addition to topographical information, this also provides the chemical composition near the surface of the nanocomposites or nanomaterials (energy dispersive X-ray spectroscopy, EDX system). 

Living or controlled polymerization techniques have also been frequently used for the in-situ synthesis of polymer nanocomposites. Figure 1.20 shows the example of styrene polymerization in the presence of modified filler. The filler modification consisted of ammonium cation bearing a notroxide moiety [44]. Styrene was polymerized in bulk at 125 °C for 8h. No diffraction peaks were observed in the XRD confirming extensive exfoliation of the filler. TEM micrographs also confirmed the uniform distribution of filler in the matrix. Generation... 

Figure 2.11. SEM micrographs of the nanocomposites containing 2.5 vol% of the (a) polymer grafted nanotubes and (b) as received nanotubes. Reproduced from reference 49 with permission from Elsevier.

Figure 9.34 Scanning electron micrographs showing the tensile fracture surfaces of (a) neat polymer, (b) 10 phr NT-Al O, nanocomposites, and (c) 10 phr APTES-AI2O3 nanocomposites. A - mirror zone, B - mist zone, C - hackle zone. Reprinted from [97] with permission from Elsevier.

TEM micrographs of the PP nanocomposites containing filler modified with ammonium salt of copolymer of styrene and vinylbenzene chloride. (Reproduced from Su, S. et al., Polym. Degrad. Stabil, 83,321,2004.)... 

TEM micrograph of nanocomposite obtained by in situ ethylene polymerization with precatalyst B immobilized on D72T following route 2. (Adapted from Leone, G. et al., /. Polym. Sci., Part A Polym. Chem., 47,548,2009.)... 

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