Films of Metal Nanocrystals Formed at Aqueous−Organic Interfaces

Abstract

Nanocrystalline films of Au, Ag, and Cu have been prepared at the toluene-water interface by the interaction of metal-triphenylphosphine complexes in the organic layer with partially hydrolyzed tetrakishydroxymethylphosphonium chloride in the aqueous layer. The nanocrystals have been characterized by a host of microscopic and spectroscopic techniques. The free-standing films could be transferred from the interface onto solid supports. Furthermore, films could be dissolved to yield either a hydrosol or an organosol with the help of appropriate surfactants.

Di-(2-ethylhexyl) dithiophosphoric acid surface protected gold nanoparticles: micellar synthesis, stabilization, isolation, and properties

“…Among a number of the methods of their preparation, rather widespread one is chemical reduction of gold species in solutions including homogeneous [6,7], heterogeneous [8][9][10], and colloidal [11,12] systems. Synthesis in reverse micelles is one of the efficient methods of obtaining nanoparticles with a narrow size distribution due to the possibility of purposeful adjustment of micelle structure through dosed solubilization of the disperse aqueous phase (DAP) [12][13][14][15].…”

Toward Greener Nanosynthesis

“…A wide range of substrates may be used as supports for assembled nanoparticles, ranging from simple planar substrates such as glass (including the SiO 2 windows of novel TEM grids, see Figure 34), silicon wafers, and gold, 90,243,281,284,293,294,297 to interfacial substrates found at the liquid-liquid and liquid-gas boundaries, [298][299][300][301][302][303][304][305][306] to more exotic supports such as biomolecules.…”

Synthesis and Characterisation of Nanomaterials

“…With appropriate choice of metal precursors and reducing agents, a variety of nanocrystalline films can be fabricated, and some of the typical results obtained by this method are presented to illustrate its versatility. Nanocrystalline films of Au, Ag, and Cu have been prepared at the toluene-water interface by the interaction of their metal-triphenyl complexes in the organic layer with partially hydrolyzed tetra-kis-hydroxymethyl-phosphonium chloride (THPC) in the aqueous layer 19 . In a typical preparation, 10 ml of 1.5 mM solution of Au(PPh 3 )Cl in toluene was allowed to stand in contact with 16 ml of 6.25 mM aqueous alkali in a 100 ml beaker under ambient conditions.…”