Filler nanotube

Many researchers have shown that incorporation of nanoscale dimension particles (inorganic fillers, nanotubes, nanofibers etc) into a polymer matrix enhances the mechanical properties of the polymer without significantly raising its density or sacrificing its light transmission property. For instance, the Toyota research groups... 

The electrical conductivities of various fillers (nanotubes) in the solid phase were measured by a Keithley 2002 digital multimeter and an Agilent 34401 DMM. 

Hollow tubes extracted from the silica/alumina clay halloysite exist naturally as particles roughly 500 nm long, and they do not have the exfoliation issues of platy nanoclays. Thus, these nanofillers do not require the same specialized equipment and processing that nanoclays require for proper dispersal. As fillers, nanotubes provide high properties because of their very high aspect ratios. 

This chapter focuses on the non-linear viscoelastic behavior of rubber composites and nanocomposites. Here, we have discussed about the effect of individual fillers (mineral fillers, nanotubes, carbon nanofillers, fibrous nanofiUers, biofillers, special structured fillers viz. nanorods, nanowires, nanoflowers etc.) on the linear/ nonlinear viscoelastic behavior of rubber composites. Moreover, as this chapter is more concerned on the non-linear viscoelastic behavior, we have also discussed the effect of hybrid fillers on the nonUnear viscoelastic behavior of rubber composites in more detail. 

There is currently considerable interest in processing polymeric composite materials filled with nanosized rigid particles. This class of material called "nanocomposites" describes two-phase materials where one of the phases has at least one dimension lower than 100 nm [13]. Because the building blocks of nanocomposites are of nanoscale, they have an enormous interface area. Due to this there are a lot of interfaces between two intermixed phases compared to usual microcomposites. In addition to this, the mean distance between the particles is also smaller due to their small size which favors filler-filler interactions [14]. Nanomaterials not only include metallic, bimetallic and metal oxide but also polymeric nanoparticles as well as advanced materials like carbon nanotubes and dendrimers. However considering environmetal hazards, research has been focused on various means which form the basis of green nanotechnology. 

Fillers with extremely high aspect ratios (1000-10,000) such as carbon nanotubes (Figure 32.5) have a much lower percolation threshold (lower amount is required for equivalent reinforcement). 

Meng J, Kong H, Xu HY, Song L, Wang CY, Xie SS (2005) Improving the blood compatibility of polyurethane using carbon nanotubes as fillers and its implications to cardiovascular surgery. Journal of Biomedical Materials Research Part A 74A 208-214. 

Encapsulation of different entities inside the CNT channel stands alone as an alternative noncovalent functionalization approach. Many studies on the filling of carbon nanotubes with ions or molecules focus on how the presence of these fillers affects the physical properties of the tubes. From a different point of view, confinement of materials inside the cylindrical structure could be regarded as a way to protect such materials from the external environment, with the tubes acting as a nanoreactor or a nanotransporter. It is fascinating to envision specific reactions between molecules occurring inside the aromatic cylindrical framework, tailored by CNT characteristic parameters such as diameter, affinity towards specific molecules, etc. 

G. Beyer, Filler blend of carbon nanotubes and organoclays with improved char as new flame retardant system for polymers and cable applications, Fire and Materials, vol. 29, pp. 61-69, 2005. 

C. Zhi, Y. Bando, T. Terao, C. Tang, H. Kuwahara, D. Golberg, Towards thermoconductive, electrically insulating polymeric composites with boron nitride nanotubes as fillers, Adv. Fund. Mater, vol. 19, p. 1857-1862, 2009. 

The filler route has proved to be very efficient to obtain isotropic composites with relatively large improvements in matrix properties at small mass (volume) fractions of nanocarbon. For example, electrical percolation in epoxy has been obtained with only 0.0025 wt% of multi-wall nanotubes (MWNTs) [12]. Similarly, a 2.7-fold increase in matrix modulus has been observed on addition of 0.6 vol% MWNTs to polyvinyl alcohol (PVA) [13]. Although more modest compared to the previous two examples, a... 

For applications where only mechanical properties are relevant, it is often sufficient to use resins for the filling and we end up with carbon-reinforced polymer structures. Such materials [23] can be soft, like the family of poly-butadiene materials leading to rubber or tires. The transport properties of the carbon fibers lead to some limited improvement of the transport properties of the polymer. If carbon nanotubes with their extensive propensity of percolation are used [24], then a compromise between mechanical reinforcement and improvement of electrical and thermal stability is possible provided one solves the severe challenge of homogeneous mixing of binder and filler phases. For the macroscopic carbon fibers this is less of a problem, in particular when advanced techniques of vacuum infiltration of the fluid resin precursor and suitable chemical functionalization of the carbon fiber are applied. 

Carbon nanotubes can be employed either as electrode materials or conductive fillers for the active materials in various electrochemical energy-storage systems [20]. For energy generation and storage, nanotubes hold promise as supercapacitors. 

In order to produce high-performance elastomeric materials, the incorporations of different types of nanoparticles such as layered silicates, layered double hydroxides, carbon nanotubes, and nanosilica into the elastomer matrix are now growing areas of rubber research. However, the reflection of the nano effect on the properties and performance can be realized only through a uniform and homogeneous good dispersion of filler particles in the rubber matrix. 

Lin Q, Harb JN. Implementation of a thick-film composite Li-ion microcathode using carbon nanotubes as the conductive filler. J Electro chem Soc 2004 151 A1115-A1119. 

Nanocarbon material (NCM), containing both the ordered carbon structures (carbon nanotubes (CNT), the particles of nanographite) and the particles of the disordered carbon phase, is known to be promising for using as elements of the nanodimensional devices and as fillers, for example, of lithium batteries. Structure and phase composition of NCM depend essentially on the methods of their obtaining and the regimes of the subsequent temperature and chemical treatment. Therefore, finding the correlation between the structural and phase composition and transport properties of NCM as well the description of the mechanisms of their conductivity are the important problems. 

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