Improvement of Electrical Properties

Kaolin also serves as functional filler in wire and cable insulation. As with other applications, surface-treated kaolin offers the best improvement in performance, 

Mineral type Mineral loading (wt%) Tensile yield strength (MPa) Tensile elongation (%) Tensile modulus, MPa (1% Secant) Flexural modulus (GPa) Izod impact strength iiM 

Type Loading (phr) Tensile strength (MPa) Elongation at break (%) elongation (after 168hat120°C in air) Power ftictor % (aftier 168 h in water at 75 °C) 

Note Satintone 5 and Translink 77 are BASF Corp. kaolin grades. 

Metakaolin is an effective functional filler in plasticized PVC wire insulation at loadings of about 10 phr. It better protects the insulation from cracking or treeing, a term that describes the physical breakdown of the cable polymer matrix due to moisture or other external influences. Volume resistivity greatly improves when metakaolin is incorporated compared to other minerals (see Table 13.9) [15], although the color is not as white as with higher temperature fully calcined kaolin. In addition, 

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Lee, H. et al. 2008. Improvements of electrical properties containing carbon nanotube in epoxy/graphite bipolar plate for polymer electrolyte membrane fuel ceBs. Journal of Nanoscience and Nanotechnology 8 5464-5466. 

Lee JY, Shin HY, Kang SW, Park C, Kim SW. Improvement of electrical properties via glucose oxidase-immobilization by actively turning over glucose for an enz3mie-based biofuel cell modified with DNA-wrapped single walled nanotubes. Biosens Bioelectron 2011 26 2685-2688. 

The crystal quality of the InGaN QWs becomes poor mainly due to the lattice-constant mismatch and the difference of the thermal expansion coefficient between InN and GaN with increasing the In composition [4,5]. Therefore, in order to improve the external quantum efficiency (i/ext) of the InGaN-based LEDs and LDs, it is important to elucidate and optimize the effects of the various growth conditions for the InGaN active layer on the structural and optical properties. Recently, we reported a fabrication of efficient blue LEDs with InGaN/GaN triangular shaped QWs and obtained a substantial improvement of electrical and optical properties of the devices [6,7]. 

The maintenance and improvement of current properties and the creation of new material properties are the important reasons for the functionalisation of textiles with sol-gel organosilica coatings with particle diameters smaller than 50 nm (nanosols).25 Coating with nanosols enables the manifold alteration of their physico-mechanical, optical, electrical and biological properties of a textile surface (Figure 4.28). 

Fig. 10.13 l-V for Ta-AI-O-N compared to Ta-O, showing that Al improves the electrical properties (based on depositions in the same sputtering system). The composition of this film was about Ta0.8AI0.2O1.45N0.05 ... 

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. 

As carbon nanotubes present exceptional mechanical, superior thermal and electrical properties in general, by using them as reinforcing elements there are high expectations for improvement of quality of nano- and microcomposites [14-18]. As shown from earlier measurements, through carbon nanotube addition a 15-37% improvement of mechanical properties (elastic modulus and strength) can be achieved in comparison to other carbon-filled samples [19]. 

Antimony appeared in all notes at a low level and was rubbed off both front and back, indicating its presence in the inks. If it was not added deliberately, it might have been present as an impurity in lead. Antimony frequently is alloyed with lead to increase its strength and to improve the electrical properties of lead plates in storage batteries and often is present in reclaimed lead. 

In summary we have reviewed the progress in the characterization of electrical properties of ZnO. Improved ohmic and Schottky contacts have been fabricated, the latter suitable for depletion layer spectroscopy. The shallow and deep donor levels have been identified for ZnO from various sources. Further control of deep donors seems necessary for achieving p-conductivity. 

While PECVD has demonstrated utility for halide precursors [29], the ability of small quantities of fluorine to improve the electrical properties of Si02 has prompted investigation of the use of SiF4 as a suitable source [30]. Although high quality films were deposited, H2 or SiH4 were required as an additive. 

At any given interface between two phases the properties of both phases close to the interface and, in particular, those of the topmost layers are different from those in the bulk. In order to separate this special portion of a system from both bulk phases the term interphase has been coined for this quasi-phase in between the bulk phases. This term considerably expands the two-dimensional view of the phase boundary as a simple interface between two completely homogenous phases. The particular properties of these interphases are of pivotal importance for their behavior in many areas of science and technology. In applied sciences an improvement of these properties is possible only with knowledge of these properties that is as broad and deep as possible. In electrochemistry the interphase properties are further complicated by the involvement of charged particles and extremely high electric fields. A broader overview of the electrochemical interface will identify further adjacent domains ... 

BeryUiuin oxide-filled resins gain high conductivity without loss of electrical properties. Metal particles have heen used as fillers for plastics to improve or impart certain properties. Thus, aluminum has heen used for applications ranging from making a decorative finish to improving thermal conductivity. Copper particles are used in plastics to provide electrical conductivity. Lead is used because it dampens vibrations, acts as barrier to gamma-radiation, and has high density. 

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