Clay nanofillers

Fig. 38 WAXD patterns of stearic acid, clay, and swollen clay. The swollen clay was prepared by mixing stearic acid and organically modified clay (Nanofil-15) at the ratio of 1 1...

The model described in Figure 13.5 takes into account both the physical and chemical effects of the interlayers but the chemical ones, which are reflected, for example, in the ignition time, have not yet been discussed. A number of cone calorimetric investigations reported a decrease of the time to ignition (TTI) in presence of clay nanofillers. Such results can be seen in Table 13.2 for MMT and sepiolite (SEP) clay types. 

Nanoclays. Nanocomposites are materials that contain nanofillers, or fillers of nanometer dimensions. The successful synthesis of nylon-clay nanocomposites (57-59) ushered in nylon nanocomposites that could attain high modulus, heat distortion temperature, dimensional stabiUty, impermeabiUty, and strength with only a few percent modified clay nanofillers. Although it has been long known that poljuners could be mixed with appropriately modified clay minerals and synthetic clays, the field of polymer-layered silicate nanocomposites has gained... 

Nanoclay fillers are categorized as platelet-like nanoclays or layered silicates and tubular nanoclays in terms of filler shape. With the configuration of two tetrahedral sheets of silicate and a sheet layer of octahedral alumina, platelet-like nanoclays or phyllosilicates are formed, which include smectite, mica, vermiculite, and chlorite. In particular, smectite clays are widely employed with further subcategories of MMT, saponite, hectorite, and nontronite. The typical MMT clays are regarded as one of the most effective nanofillers used in polymer/clay nanocomposites due to their low material cost and easy intercalation and modification (Triantafillidis et al., 2002). On the other hand, the fundamental structure of tubular nanoclays contains an aluminum hydroxide layer and a silicate hydroxide layer. They are also known as dio-ctahedral minerals with two different types of halloysite nanotubes (HNTs) and imo-golite nanotubes (INTs). Notwithstanding their material role as clay minerals, these two types of tubular nanoclays resemble the hollow tubular structure of carbon nanotubes (CNTs). In this section, three different types of clay nanofillers, namely MMTs, HNTs, and INTs are reviewed in detail along with the development of clay modification. 

The effect of clay nanofiller on mechanical and thermal properties... 

There are many types of nanofillers including carbon black nanofillers, carbon nanotube nanofillers, carbon fiber nanofillers, activated clay nanofillers, natural clay nanofillers (mined, refined, and treated), clay (synthetic) nanofillers, natural fiber nanofillers, zinc oxide nanofillers and silica nanofillers. Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio which is significantly larger than any... 

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