Metallic nanoparticle composites

Hu, X., et ah, A general route to prepare one- and three-dimensional carbon nanotube/metal nanoparticle composite nanostructures, hangmuir, 2007. 23(11) p. 6352-6357. 

Water-solubilized aminoclay-metal nanoparticle composites and their novel properties... 

In the present study the property of the aminociays wherein protonation of the amino groups in water is accompanied by exfoliation has been exploited.15 Thus metal nanoparticle composites formed by the exfoliated aminoclay sheets by carrying out the reduction of metal precursors in the presence of the clay have been investigated. Besides being entirely water soluble, the exfoliated sheets of aminoclay-Au nanoparticle composites move to the organic/aqueous interface in the presence of an alkanethiol. 

Fig. 2 Optical images of aminoday-metal nanoparticle composites forming clear transparent solutions in water (a) aminoclay solution, and aminoclay with (b) Au, (c) Ag, (d) Pt and (e) Pd nitnopartides.

Fig. 2 shows how the aminoday -metal nanoparticle composites form clear transparent solutions in water. The solutions are pink and yellow for Au and Ag respectively and dark brown in the cases of both Pt and Pd. The reddish-brown colour observed for Au-clay nanoparticle composites immediately after the addition of NaBH4 changed to pink with time. The solutions exhibit characteristic piasmon bands for the Au- and Ag-day suspensions at 520 nm and 410 nm respectively as shown in Fig. 3. In the cases of Pt and Pd, the characteristic absorption band for the precursor s around 260 to 280 nm was absent thereby confirming the formation of Pt and Pd nanoparticles. 7,18 TEM images of the aminoday-metal nanoparticle composites deposited on a carbon coated copper grid are shown in Fig. 4. The histograms show the average particle sizes to be around 3.5 and 5 nm respectively in the cases of Au and Ag nanoparticles. We could see the layered arrangements in the cases of Pt and Pd with the interspacing of 1.5 nm commensurate with the bilayer arrangement of aminoclays (see top right inset of Fig. 4b).

Smith, D.D., Fischer, G., Boyd, R., Gregory, D.A. Cancellation of photoinduced absorption in metal nanoparticle composites through a counterintuitive consequence of local field effects. J. Opt. Soc. Am. B 14, 1625-1631 (1997)... 

Takeda, Y., Lu, J., Plaksin, O.A., Kono, K., Amekura, H., Kishimoto, N. Control of optical nonlinearity of metal nanoparticle composites fabricated by negative ion implantation. Thin Sol. Films 464-465, 483-486 (2004)... 

Copper nanoparticles have been synthesized in silica by 50 keV Cu ion implantation with doses of 8.0x10 ion/cm. N anoparticles were c haracterized by absorption band of surface plasmon resonance in the visible range. Metal nanoparticle composite glasses were analyzed by the Z-scan method at the IR wavelength of NdiYAG laser radiation 1064 nm. The third order nonlinear susceptibility in the analyzed medium with simultaneous nonlinear refraction and absorption were considered as complex values. It is suggested that the samples with nonlinear absorption is perspective ones for optical applications. 

Pringle, J. M., Winther-Jensen, 0., Lynam, C., Wallace, G. G., Forsyth, M., and MacFarlane, D. R. (2008). One-step synthesis of conducting polymer-noble metal nanoparticle composites using an ionic liquid. Adv. Fund Mater., 18, pp. 2031-2040. 

Fu, Y., et al. One pot preparation of polymer-enzyme-metallic nanoparticle composite films for high performance biosensing of glucose and galactose. Adv. Funct. Mater. 19(11), 1784-1791 (2009)... 

Zhou, X., Dom, M., Vogt, J., Spemann, D., Yu, W, Mao, Z., Estrela-Lopis, I., Donath, E., Gao, C., 2014. A quantitative study of the intracellular concentration of graphene/noble metal nanoparticle composites and their cytotoxicity. Nanoscale 6, 8535-8542. 

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