Nanoparticle superlattices

Generation of nanoparticles under Langmuir monolayers and within LB films arose from earlier efforts to form nanoparticles within reverse micelles, microemulsions, and vesicles [89]. Semiconductor nanoparticles formed in surfactant media have been explored as photocatalytic systems [90]. One motivation for placing nanoparticles within the organic matrix of a LB film is to construct a superlattice of nanoparticles such that the optical properties of the nanoparticles associated with quantum confinement are preserved. If mono-layers of capped nanoparticles are transferred, a nanoparticle superlattice can be con-... 

Shevchenko, E. V. Talapin, D. V. Murray, C. B. O Brien, S. 2006. Structural characterization of self-assembled multifunctional binary nanoparticle superlattices. J. Am. Chem Soc. 128 3620-3637. 

Murray, C. B. Sun, S. Doyle, H. Betley, T. 2001. Monodisperse 3d transition-metal (Co, Ni, Fe) nanoparticles and their assembly into nanoparticle superlattices. MRS Bulletin 26 985-991. 

On the other hand, if the shape of the particles can be controlled, self-assembly of these shaped particles can lead to crystal orientation of each particle in a self-assembled superlattice. For example, MnFe204 nanoparticles have been made in cube-like and polyhedron shapes, as shown in Fig. 6 [46]. Controlled evaporation of the carrier solvent from the hexane dispersion (about 2 mg/mL) of the particles led to MnFe204 nanoparticle superlattices. 

Figure 7. TEM images of 12 nm MnFe204 nanoparticle superlattices of (A) cube-like and (B) polyhedron-shaped nanoparticles. XRD (Co Ka X = 1.788965 A) of (C) cubelike and (D) polyhedron-shaped nanoparticle superlattice on Si(100) substrates [46].

Figure 8. (A) Schematic illustration of surfactant exchange reaction (B) TEM image of 8 nm nanoparticle superlattice with each particle being surrounded by oleate molecules and interparticle spacing at 4 nm (C) TEM images of 8 nm nanoparticle superlattice after surfactant exchange with dicyanobenzene. The spacing between two particles is at lnm.

Martin JE, Wilcoxon JP, Odinek J, Provencio P (2000) Control of interparticle spacing in gold nanoparticle superlattices. JPhys ChemB 104 9475-9486... 

Figure 3.11 TEM micrographs of nanoparticle superlattices of Au nanoparticles prepared by the inverse micelle method (a) and (b) low-magnification images (c)-(f) regularly shaped nanoparticle superlattices (g) magnified image of a superlattice edge (note the perfect arrangement of the Au nanoparticles).

Most 3d nanoparticle superlattices have a close-packed twofold coordination. Namre forms crystal lattices of lower coordinations in a great variety of ionic crystals. Recently Kalsin et al. (78) assembled an ionic lattice of oppositely charged nanoparticles. The nanoparticles were gold ligated with mercaptoundecanoic acid and silver ligated with A(,A(,A(-trimethyl(l 1-mercaptoundecyl) ammonium chloride salt. The nanoparticles were essentially the same size, each about 5 nm in diameter. 

Sargentis, C., Giannakopoulos, K., Travlos, A., Normand, P., and D. Tsamakis. 2008. Study of charge storage characteristics of memory devices embedded with metalhc nanoparticles. Superlattices and... 

Kostiainen M, Hiekkataipale P, Laiho A, Lemieux V, Seitsonen J, Ruokolainen J, Ceci P (2013) Electrostatic assembly of binary nanoparticle superlattices using protein cages. Nat Nanotechnol 8 52-56... 

Shevchenko EV, Talapin DV, Kotov NA, O Brien S, and Murray CB. 2006. Structural diversity in binary nanoparticle superlattices. Nature 439 55-59. 

Teranishi, T. 2003. Eabrication and electronic properties of gold nanoparticle superlattices. C.R. Chim. 6 (8-10) 979-987. 

A QC (a quasiperiodic crystal) is a form of soHd matter that exhibits order without periodicity. QCs are often associated with classically forbidden rotational symmetries, although strictly speaking, this is not a necessary feature [1]. In this chapter, we are concerned with QCs composed of metal atoms, although quasiperiodicity has also been discovered in block copolymers [4], Hquid crystals [5], and nanoparticle superlattices [6]. Many excellent reviews and books are available that provide an introduction to aU aspects of QCs [7-12]. 

Chen Z, Moore J, Radtke G, Sirringhaus H, O Brien S Binary nanoparticle superlattices in the semiconductor-semiconductor system CdTe and CdSe, J Am Chem Soc 129 15702-15709, 2007. 

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