We demonstrate the controlled growth of high aspect ratio anatase TiO2 nanorods by hydrolysis of titanium tetraisopropoxide (TTIP) in oleic acid (OLEA) as surfactant at a temperature as low as 80 degrees C. Chemical modification of TTIP by OLEA is proven to be a rational strategy to tune the reactivity of the precursor toward water. The most influential factors in shape control of the nanoparticles are investigated by simply manipulating their growth kinetics. The presence of tertiary amines or quaternary ammonium hydroxides as catalysts is essential to promote fast crystallization under mild conditions. The novelty of the present approach relies on the large-scale production of organic-capped TiO2 nanocrystals to which standard processing of colloidal nanocrystals, such as surface ligand exchange, can be applied for the first time. Concentrated colloidal titania dispersions can be prepared for a number of fundamental studies in homogeneous solutions and represent a new source of easily processable oxide material for many technological applications.

Nanocrystals of LaPO 4 :Eu and CePO 4 :Tb with a mean particle size of 5 nm and a narrow size distribution have been prepared by reacting the corresponding metal chlorides, phosphoric acid, and a base at 200°C in tris(ethylhexyl) phosphate. Highly crystalline material was obtained as confirmed by X-ray powder diffraction measurements and high-resolution transmission electron microscopy. Successful doping with europium was evident from the splitting and the intensity pattern of the luminescence lines. Luminescence lifetime measurements were used to confirm doping and energy transfer in both materials. Colloidal solutions of CePO 4 :Tb exhibit an overall luminescence quantum yield of 16%.

Novel applications in nanotechnology rely on the design of tailored nano-architectures. For this purpose, carbon nanotubes and nanoparticles are intensively investigated. In this work we study the influence of non-functionalized carbon nanotubes on the synthesis of CdSe nanoparticles by means of organometallic colloidal routes. This new synthesis methodology does not only provide an effective path to attach nanoparticles non-covalently to carbon nanotubes but represents also a new way to control the shape of nanoparticles.There is an increasing number of potential applications for materials with dimensions in the nanometer range. Such systems show improved or even new properties emerging as a result of electronic confinement. In particular, carbon nanotubes (CNTs) find applications as transistors [1, 2], conductive layers [3], field emitters [4,5], and mechanical components [6,7,8]. At the same time, the knowledge acquired from well-established synthetic procedures has facilitated the tailoring and optimization of semiconductor nanoparticles (NPs) with efficient, photostable luminescence properties controlled by quantization [9,10,11].

Optical fibers have revolutionized the telecommunications industry to such an extent that the network capacity available today was unthinkable 20 years ago. Even so, with the advent of the datawave, and the exponential increase of network traffic predicted to continue indefinitely, the generation of bandwidth remains a challenge. One of the major limitations to the implementation of future high-capacity, ultra-broadband optical networks is the expansion of the fiber bandwidth beyond that available from the current state-of-the-art signal amplification device-the erbium-doped fiber amplifier (EDFA). Although there is currently a large effort to expand the flat-gain bandwidth of the EDFA, most of these efforts involve sophisticated engineering, exotic glass fibers, or multicomponent cascaded systems. In a radically different approach, we are attempting to use the unique properties of semiconductor nanocrystals, or quantum dots, as "designer atoms" in order to produce an ultra-broadband optical amplifier with complete coverage of the telecommunications wavelengths. In this paper we review the synthesis of thiol-stabilized mercury chalcogenide nanocrystals via an aqueous colloidal route, which demonstrate extremely intense photoluminescence all the way across the spectral region of interest, i.e., from 1000 to over 1700 nm.

Positively and negatively charged nanoparticles have been mixed together in order to obtain superlattice formation. The interaction between the particles was controlled by adjusting the ionic strength of the solutions. The self-assembly was studied with absorption spectroscopy, powder X-ray diffraction, and high-resolution transmission electron microscopy.