The Nanoscience Paradigm: “Size Matters!”

Abstract

The essential feature of nanomaterials is that their physical and chemical properties are size dependent, making it possible to engineer the material properties not only by defining its chemical composition, but also by tailoring the size and shape of the nanostructures, and the way in which individual building blocks are assembled. This chapter addresses the origin of the size dependence of the properties of nanomaterials, which can be traced to two fundamental nanoscale effects: (a) the increase in the surface/volume ratio with decreasing size, and (b) spatial confinement effects. Furthermore, the definition and classification of nanomaterials is introduced, and the techniques used to fabricate and study them are briefly discussed, with emphasis on nanoparticles of inorganic materials.

Evidence of exchange interaction of localized carriers and transition metals in diluted II‐VI nanostructures: ODMR study

“…Figure 3 shows the high-frequency electron spin echo (ESE) detected EPR and electron-nuclear double resonance (ENDOR) spectra, measured in ZnO:Co quantum dots using the techniques described in Ref. [6]. The shallow donor (SD) signals appeared only after UV excitation.…”

“…ZnO quantum dots, which consist of a ZnO nanocrystal core and Zn(OH) 2 shell can be effectively studies by magnetic resonance techniques [6]. Cobalt doped ZnO quantum dots were prepared by chemical wet method and had a diameter of 2 to 6 nm.…”

“…Colloidal ZnO nanocrystals, or quantum dots (QDs) are widely studied with magnetic resonance techniques [6]. ZnO QDs doped with cobalt present a promising class of DMS for spintronics applications.…”

Surface Photochemistry of Quantum Dot-Porphyrin Nanoassemblies for Singlet Oxygen Generation

“…Thus, the realization of FRET with a quantum efficiency of 100% is not the case for the nanoassembly under study. (2). A small tail rest of QD emission in the porphyrin fluorescence spectral range has been subtracted.…”

“…Based on evident progress in the synthesis of colloidal semiconductor QDs with relatively narrow size distributions within a few percent, rational shape-engineering, compositional modulation, electronic doping, and tailored surface chemistries, these nanoobjects as well as nanoassemblies based on QDs and functionalized organic compounds (including proteins) have become an important class of naomaterials with great potential for applications ranging from electronic and optoelectronic devices (1)(2)(3)(4)(5)(6)(7)(8)(9)(10) to material science (11)(12)(13)(14)(15), sensorics (16)(17)(18)(19) and nanomedicine (14,(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). The science and technology of nearly all QD-based materials, drug delivery systems, diagnostic methods, controlled release systems, organic-inorganic nanoassemblies, etc., involve on every length scale, from the molecular to the macro, surface and interfacial phenomena that can be tuned by varying the surface and interfacial energy and by varying the specific chemical interactions and chemical groups populating such surfaces and interfaces.…”