Polymer nanocomposites applications

FIGURE 9 Clay-polymer nanocomposite application. (From Ref. 174.)... 

DPPES was grafted onto the surface of GNO by condensation to form a synergistic phosphorus/silicon-containing GNO flame retardant (DPPES-GNO). A series of nanocomposites that contained 0,1,5, and 10 wt% DPPES-GNO was prepared. XPS, FTIR, Raman spectroscopy, and TEM verified that DPPES covalently bonded to GNO. Furthermore, the addition of DPPES-GNO (up to 10 wt%) to neat epoxy significantly increased its thermal stability and improved the char yield and LOI by 42% and 80%, respectively. The phosphorus, silicon, and GNO layer stmctures of DPPES-GNO caused the continuous and insulating char layer to protect the inner polymer matrix. The approach that is described herein has great potential for the development of a novel synergistic phosphorus/silicon—GNO flame retardant with polymer nanocomposite applications. 

Godovsky, D. Y.-. Device Applications of Polymer-Nanocomposites. Vol. 153, pp. 163-205. Godovsky, D. Y.-. Electron Behavior and Magnetic Properties Polymer-Nanocomposites. Vol. 119,pp. 79-122. 

Fischer, H. (2003). Polymer nanocomposites from fundamental research to specific applications. Materials Science and Engineering C, 23, 763-772. 

Tomasko DL, Han XM, Liu DH, Gao WH (2003) Supercritical fluid applications in polymer nanocomposites. Curr Opin Solid State Mater Sci 7 407 112... 

Horrocks, A.R. and Kandola, B.K. 2007. Potential applications of nanocomposites for flame retardancy. InFlame Retardant Polymer Nanocomposites, Morgan, A.B. and Wilkie, C.A. (Eds.), Wiley-VCH, Verlag GmbH Co, KGaA, Hoboken, NJ, Chapter 11. 

CNT nanocomposites morphological and structural analysis is often done by TEM but an extensive imaging is required then to ensure a representative view of the material. Moreover, carbon based fillers have very low TEM contrast when embedded in a polymer matrix. The application of microscopy techniques is very useful to control the status of CNTs at any time during the preparation process of CNT/polymer nanocomposites, and moreover, to gain insights on parameters important for a better understanding the performance of the final nanocomposite material based on CNTs. 

The main drawbacks of this approach are the low availability of such instruments in laboratories, and the fact that many samples are sensitive to ion beam damage, require specific preparation (95), and can induce low contrast. Moreover, the imaging between two milling periods is typically performed in the backscattered electrons mode, which is not always favorable this is the case for carbon nanotubes in a polymer matrix as the atomic number contrast is low. This is probably the reason why, even if the FIB/SEM approach is used on polymer nanocomposites, it not used in the literature for carbon nanotubes in polymer matrix. In this last application, the tomo-STEM technique is a good alternative to obtain images of relatively thick samples with high contrast and resolution (91). 

Among the applications discussed in this chapter, the most prominent in recent years is CNT-reinforced polymer nanocomposites. The use of CNTs in polymers can provide superior mechanical properties (60). For instance, the addition of 1% CNTs might increase the stiffness of polymers by 10% and increase their resistance to fracture however, improvements in the properties of CNT-reinforced polymers largely depend on the dispersion of CNTs within the polymer matrix and the polymer-CNT interfacial properties. The following section highlights several studies regarding the processing of PLA-CNT nanocomposites. 

S. Gong, L.-S Turng, C.B. Park, and L. Liao, "Microcellular Polymer Nanocomposites for Packaging and Other Applications", in A. Mohanty, M. Misra and H.S. Nalwa, eds., Packaging Nanotechnology, American Scientific Publishers, 2008. 

---