Polymer nanocomposite, definition

Polymer nanocomposites are combinations of polymers containing inorganic or organic fillers of definite geometries (fibres, flakes, spheres, particulates and so on). The use of fillers, which have one dimension on the nanometre scale, enables the production of polymer nanocomposites. Functional nanocomposites with specific properties can be custom-made by combining metal nanoparticles (MNP) into the polymer matrix. 

As it is well known [1] that the interlacial interaction role in multiphase systems, including polymer composites, is very great. In polymer composites such interactions (interfacial adhesion) absence results in sharp reduction of their reinforcement degree [2]. For polymer nanocomposites interfacial adhesion existence in the first place means the formation of interfacial regions, which are the same reinforcing element for these materials, as nanofiller actually [3], Proceeding from the said above, it is necessary to know the conditions and mechanisms of interfacial regions formation in polymer nanocomposites for their structure control. The present paper purpose is these mechanism definition and the indicated researeh is performed on the example of three particulate-filled nanocomposites on the basis of butadiene-styrene rubber. 

Silicone co-polymer networks and IPNs have recently been reviewed.321 The development of IPNs is briefly described, and the definitions of the main (non-exclusive) classes of the IPNs are cited. Examples of latex IPNs, simultaneous and sequential IPNs, semi-IPNs, and thermoplastic IPNs are provided. The use of silicone-silicone IPNs in studies of model silicone networks is also illustrated. Networks in which siloxane and non-siloxane components are connected via chemical bonds are considered co-polymer networks, although some other names have been applied to such networks. Today, some of the examples in this category should, perhaps, be discussed as organic-inorganic hybrids, or nanocomposites. Silicone IPNs are discussed in almost all of the major references dealing with IPNs.322-324 Silicone IPNs are also briefly discussed in some other, previously cited, reviews.291,306... 

The close fit of the experimental data and the values predicted by the constitutive modified Halpin-Tsai equations I and II (24) and (25), as seen in Fig. 43 (for NR) illustrates the appropriate definition of the IAF. Table 10 also confirms that newly devised equations (24) and (25) provide astounding results because their predictions conform to the experimental data. The introduction of IAF imparts a definitive change to the predicting ability of the constitutive equations for polymer/filler nanocomposites (Fig. 43 Table 10). 

Successful incorporation of magnetic nanoparticles into a conductive polymer matrix will definitely widen their applicability in the fields of electronics, biomedical dmg delivery, and optics. These doubly functionalized nanocomposites will exhibit the magnetic properties of the magnetic particles and the conducting properties of the conductive-polymer matrices. However, one of the challenges so far is the abihty to integrate a high... 

In further quest for development of more efficient materials, clue had been provided by ongoing mixed (interdisciplinary) research. Intelligently the immediate inspiration was drawn from mixed systems (i.e., blends, alloys or composites) based on conventional polymers, metals, and ceramics. Soon it was realized that the already established wide applicability of CPs/ICPs can be further expended by formation of multiscale/multiphase systems, e.g., a wide variety of electronically, electrochemically, and/or optoelec-tronically active blends (BLNs), conjugated copolymers (CCPs) and composites (CMPs) [both bulk or nanocomposites (NCs)] or hybrids (HYBs) [11,14-16,52,109,113,120,128,131,132,191-205]. The next section of the chapter covers the fundamental aspects of CP-based BLNs, CCPs, and NCs/ HYBs. In particular, their definitions (including etymology), types, properties, synthetic routes, and practical applications have been discussed with the help of suitable examples from the open literature. 

In this perspective, inorganic nanocomponents (such as nanoparticles) can be seen as additives to enhance polymer performance and thus they are also termed nanofillers or nano-inclusions . Organic-inorganic nanocomposites can be considered a form of hybrid material, even if the definition of hybrid nanomaterials typically refers to nanocomposites where the organic and the inorganic phases are... 

Atomic and electronic processes that occur at the polymer-nanoparticle interface largely determine the unique properties of nanocomposite. These materials become electrical conductors only at definite component ratios when conducting chain-type coagulated structures are formed instead of matrix systems. In other words, the fractal clusters formed upon cohesion of nanoparticles serve as ciurent-conducting channels. The highest conductivity is attained when the metallopoly-meric material is permeated by interconnected chains of conducting particles that are in contact. This forms an electrical percolation network that exceeds the percolation threshold. As a rule, this is achieved at a nanoparticles content of 50 vol%. 

In general, the dispersion of clay particles in a polymer matrix can result in the formation of three general types of composite materials (Figure 1). Conventional composites contain clay tactoids with the layers aggregated in unintercalated face - face form. The clay tactoids are simply dispersed as a segregated phase. Intercalated clay composites are intercalation compounds of definite structure formed by the insertion of one or more molecular layers of polymer into the clay host galleries and the properties usually resemble those of the ceramic host. In contrast, exfoliated polymer-clay nanocomposites have a low clay content, a monolithic structure, a separation between layers that depends on the polymer content of the composite, and properties that reflect those of the nano-confmed polymer. 

The most widely used reinforcements in nanocomposites are carbon nanotubes, layered clay, and nanoparticles. The most widely used polymer matrices are polyamides, nonpolar polymers, polyesters, epoxies, and polyurethane. However, this chapter will focus on nanocomposites which are made from both biodegradable fiber/fillers and biodegradable matrices, since only these composites truly justify the definition of eco-friendly and green nanocomposites. 

These descriptive terms are used to classify the degree of nauoscale dispersion as well as global micro- and macroscale dispersion of the nanoparticles in the polymer matrix. Since no numerical standards exist for rating the degree of nanoparticle dispersion in the polymer matrix, use of these terms is strictly qualitative and continues to be area of some controversy, as the classification of dispersion is mostly the opinion of the user. Unfortunately, not all researchers in the nanocomposite area use these terms in the same ways. The definition of intercalated comes from an... 

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