Amorphous carbon nanocomposites

The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China 

Fillers and Reinforcements for Advanced Nanocomposites. http //dx.dd.oi 0.1016A978-0-08-100079-3.00012 0 

The use of a-C particles from fuel-rich partial combustion for ink, pigment, and tattoos dates back more than 3000 years, but it remains a topic of current research interest (Lee et al., 2006 Yang et al., 2006). a-C particles are highly condensed from incomplete combustion processes to carbonaceous residue formation, which is commonly described as charcoal, black carbon or carbon black, lampblack, coal, and coke (Gustafsson et al., 1996). a-C is apphed in a wide range of applications, including tires, cars, printing, pencils, computers, printers, photocopiers, laboratory tables, etc. 

Carbon black nanoparticle-reinforced polyisoprene applied in electric heating elements and resistors as thermodynamically inactive materials for a high dielectric constant ( 1000) has been studied. The dissipation factor (tanS) of this carbon black nanocomposite was high (Xu and Wong, 2005). However, improving the dispersion of the nanoparticles in polymer lowers the percolation threshold of composites (Raza et al., 2012 Sumfleth et al., 2011). The electrical conductivity of rubbery epoxy/carbon black nanocomposites at 8 wt% filler loading was 2 x 10 S/m, which matched the criterion of electrical conductivity for electrostatic applications (10 S/m) (Ali Raza et al., 2012 Knite et al., 2004 Sasha Stankovich et al., 2006). 

Carbide-derived carbons (CDCs) can be amorphous or crystalline. The various stmc-tures of CDC can be obtained by varying its crystallinity. When chlorine gas extracts 

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Shi, B., Meng, W.J., Daulton, T.L., 2004. Thermal expansion of Ti-containing hydrogenated amorphous carbon nanocomposite thin films. Applied Physics Letters 85 (19), 4352—4354. 

Shieh, J., Hon, M.H., 2002. Plasma-enhanced chemical-vapor deposition of titanium aluminum carbonitride/amorphous-carbon nanocomposite thin films. Journal of Vacuum Science Technology A 20 (1), 87—92. 

Zhang, X., Liang, H., Wu, Z., Wu, X., Zhang, H., 2013. The effect of substrate bias on titanium carbide/amorphous carbon nanocomposite films deposited by filtered cathodic vacuum arc. Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with... 

Carbon-based nanocomposite concepts have been successfully developed to limit or reduce these adverse effects and at the same time enhance the electron or ion transport [8]. CNT is an ideal building block in the carbon-inorganic composite/hybrid due to its mechanical, physical, chemical properties as mentioned above. CNTs are apparently superior to other carbonaceous materials such as graphite or amorphous carbon and are more adaptable to the homogeneous dispersion of nanoparticles than other carbonaceous materials [36],... 

In some instances, subtle changes in the precursor architecture can change the composition and microstructure of the final pyrolysis product. For example, pyrolysis of —[MeHSiNH] — leads to amorphous, silicon carbide nitride (SiCN) solid solutions at >1000°C (see SiCN section). At ca 1500 °C, these material transform to SisN SiC nanocomposites, of interest because they undergo superplastic deformation20. In contrast, chemically identical but isostructural — [F SiNMe] — transforms to Si3N4/carbon nanocomposites on heating, as discussed in more detail below21. 

The method of microwave plasma-assisted deposition allows to form nickel/hydrogenated amorphous carbon (Ni/a-C H) nanocomposite films. As the C2H2 concentration in Ar-C2H2 gas mixtures increased from 0 to 100 % the phase composition and precipitates size of Ni/a-C H films varies in the consequence Ni (15 nm)—>Ni + Ni3C (5-17 nm) Ni3C (17 nm)—> Ni + a-C H (1 nm) nc-G H (4 nm). The lowest friction coefficient and wear rate were obtained for Ni/a-C H amorphous nanocomposite films containing 20 % of sp3 bonds and deposited from the gas mixture with a C2H2 concentration of 60 %. 

Net-structured NiO was prepared via microwave radiation method with Ni(CH3COO)2 as precursor, followed by calcination at 500°C. The as-prepared NiO was dispersed into glucose solution and subsequently carbonized under hydrothermal condition at 180°C, and the net-structured NiO-C nanocomposites were obtained. TEM images show that the NiO network is homogenously filled with amorphous carbon. The electrochemical performance is improved... 

Similarly, C o was converted into MWCNTs above 700°C via amorphous carbon under hydro-thermal conditions [119], SWCNTs under hydrothermal conditions can only survive mild- and short-term treatment in high-temperature, high-pressure water. With time, SWCNTs gradually transform into MWCNTs and polyhedral graphitic nanoparticles [35]. Both carbon filaments and MWCNTs are produced using ferrocene, Fe, or Fe/Pt nanocrystals at supercritical toluene at 600°C and 12.4 MPa. In this study, toluene serves as both the carbon source for nanotube formation and as a solvent [154]. Recently, direct synthesis of MWCNTs/CdS, MWCNT/ZnO, Ti/CNT, FeO/ MWCNTs, and CNT-F-doped Sn02 nanocomposites under hydrothermal process has been used for various applications [155-159]. 

Metal/carbon nanocomposite (Me/C) represents metal nanoparticles stabilized in carbon nanofilm stractures [7-9]. In turn, nanofilm stractures are formed with carbon amorphous nanofibers associated with metal eon-taining phase. As a result of stabilization and assoeiation of metal nanoparticles with carbon phase, the metal chemically active particles are stable in the air and during heating as the strong complex of metal nanoparticles with carbon material matrix is formed. The test results of nanocomposites obtained are given in Table 2.1. 

Metal/carbon nanocomposite (Me/C) represents metal nanoparticles stabilized in carbon nanofilm structures [7, 8]. In turn, nanofilm structures are formed with carbon amorphous nanofibers associated with metal con-... 

Rahman MM, Wang J-Z, Hassan MF et al (2011) Amorphous carbon coated high grain boundary density dual phase Ll4Ti50i2-Ti02 a nanocomposite anode material for li-ion batteries. Adv Energy Mater 1 212-220... 

Han, Z.J., Tay, B.K., Shakerzadeh, M., Ostrikov, K., 2009. Superhydrophobic amorphous carbon/carbon nanotube nanocomposites. Applied Physics Letters 94 (22), 223106. 

Ng, S.H., Wang, J., Wexler, D., Chew, S.Y., Liu, H.K., 2007. Amorphous carbon-coated silicon nanocomposites a low-temperature synthesis via spray pyrolysis and their application as high-capacity anodes for lithium-ion batteries. Journal of Physical Chemistry C 111 (29), 1131-11138. 

In Part Four, Chapter 11 offers the effectiveness of calcium carbonate nanoparticles on the improvements of compressive strength and durabUity of high-volume fly ash concrete. These resulting properties are further correlated with relevant microstructure and crystalline phases by means of X-ray diffraction, mercury intrusion porosimetry, differential thermal analysis, and thermal gravimetric analysis. Chapter 12 reviews current research and relevant techniques for the manufacture and application of amorphous carbon and its nanocomposites. Various applications for the textile, plastic, and healthcare industries, as well as in the fields of gas and water filtering, electrical apphcations, and food packaging, are also discussed based on the superior and unique propoties of... 

Metal nanoparticle-doped sol-gel silica nanocomposites do not possess the required conductivity to fabricate bulk or screen-printed electrodes. Inspired by the well-known resorcinol/formaldehyde sol-gel process, which can be pyro-lyzed to get a conductive amorphous carbon matrix, we have synthesized a nanocomposite material made of a carbon xerogel doped with bismuth nanoparticles and fabricated a carbon paste electrode for heavy metal analysis (Figure 46.11) [24]. The resulting sensor is very sensitive to several heavy metals. Extremely low detection limits for Pb " and Cd of around 0.5 ppb were achieved using a nanocomposite paste electrode containing 6 wt. % of bismuth. 

C.H. Poa, R.G. Lacerda, D.C. Cox, S.R.P. Silva, F.C. Marques, Stress-induced electron emission from nanocomposite amorphous carbon thin films. Appl. Phys. Lett. 81(5), 853-855 (2002)... 

Schematic illustration of a nanocomposite of LiFeP04 with triaxial structure VGCF as the core, LiFeP04 with amorphous carbon as the inner layer, and amorphous carbon coating as the outer layer. (Adapted from Hosono, E. et al., ACS Appl. Mater. Interfaces, 2,2010.)...

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