Nanoparticle Laboratory

Most nanoparticle uptake and translocation research has quantified nanoparticles in vivo using some type of unique particle label. For example, nanoparticle laboratory studies have included radioactive particles [4], trace metals such as gold and iridium [7], and fluorescent particles [8]. However, the population exposures most relevant to health involve the emissions or deliberate release of high-production-volume manufactured nanomaterials and exposures to incidental nanoparticles, such as soot. Combustion emissions and manufactured powders such as fumed silica, ultraflne titanium dioxide (Ti02), and similar industrial materials rarely have a unique and easily detected label. 

Chemical reduction of metal salts in solution is the most widely used method of preparation of metal nanoparticles, especially in laboratories. In general, the reducing reagents are added into the solution of the precursor ions, but in some cases, a solvent works as a reductant. Various reducing reagents have been proposed to prepare metal nanoparticles. Ethanol or small alcohols can reduce precious metal ions such as Au, Pt", Pd, Ag, and so on [3j. Polymer-stabilized precious metal nanoparticles and their alloy particles can be used as good catalysts for various reactions. Polyols, such as ethylene glycol, were... 

As the reader might have noticed, many conclusions in electrocatalysis are based on results obtained with electrochemical techniques. In situ characterization of nanoparticles with imaging and spectroscopic methods, which is performed in a number of laboratories, is invaluable for the understanding of PSEs. Identification of the types of adsorption sites on supported metal nanoparticles, as well as determination of the influence of particle size on the adsorption isotherms for oxygen, hydrogen, and anions, are required for further understanding of the fundamentals of electrocatalysis. 

In this review, the potential uses of sonochemistry for the preparation of monometallic and bimetallic metal nanoparticles and metal-loaded semiconductor nanoparticles have been highlighted. While specific examples available in the literature were discussed, the sonochemical technique seems to offer a platform technique that could be used for synthesizing a variety of functional materials. Most of the studies to date deal with laboratory scale exploration , it would be ideal if the concepts are tested under large scale experimental conditions involving specific applications. The authors sincerely hope that the information provided in this review would prompt such experimental investigation in a new dimension. 

The objective of this monograph is to include all major studies of metal ions in their aqueous solutions as well as some other important studies in their zerovalent metallic state or in alloys, since the nanoparticles of many of these metals have become too important. Besides, the study of the precipitation of metal ions in aqueous solutions, upon sonication, which has been carried out in our laboratory, would also be discussed. Some of such data include unpublished work. The sequence of metallic ions in this chapter are as they come in the sequence of wet chemical analysis of basic radicals, besides the cationic charge has been kept in mind to make groups and sequences that follow the detailed description. 

Olbrich, C. and Muller, R.H., Tabatt, K., Kaiser, O., Schulze, C., and Schade, R., Stable biocompatible adjuvants — a new type of adjuvant based on solid lipid nanoparticles a study on cytotoxicity, compatibility and efficacy in chicken, Alternatives to Laboratory Animals, 2002, 30, 443 158. 

Time courses of dehydrogenation activities with carbon-supported platinum catalyst under superheated liquid-film conditions in laboratory-scale continuous operation. Catalyst platinum nanoparticles supported on granular activated carbon (Pt/C, 5 wt-metal%), 1.1 g. Feed rate of tetralin 0.5 mL/min (superheated liquid-film conditions). Reaction conditions boiling and refluxing by heating at 240°C and cooling at 25°C. (Reproduced from Hodoshima, Sv Shono, A., Satoh, Kv and Saito, Yv Chem. Eng. Trans8,183-188, 2005. With permission.)... 

Ryan M. Richards was raised near Flint, Michigan. In 1994, he completed both B.A. in chemistry and B.S. in forensic science at Michigan State University. He then spent 2 years as an M.S. student at Central Michigan University working on organometallic chemistry with Professor Bob Howell. He was awarded a Ph D. in 2000 for investigating the properties of metal oxide nanoparticles in the laboratory of Professor Kenneth Klabunde at Kansas State University. In 1999, he was an invited scientist at the Boreskov Institute of Catalysis in Novosibirsk,... 

Bimetallic AumPtioo-m nanoparticles with different atomic compositions ranging from OT = 10 to 90% Au have been obtained in our laboratory. On the basis of the correlation between the synthetic bimetallic feeding and the nanoparticle bimetallic composition as determined by DCP-AES, the composition of the nanoparticles is controllable. In this subsection, the results for the size and composition of selected catalysts are described. 

The procedure chosen for the preparation of lipid complexes of AmB was nanoprecipitation. This procedure has been developed in our laboratory for a number of years and can be applied to the formulation of a number of different colloidal systems liposomes, microemulsions, polymeric nanoparticles (nanospheres and nanocapsules), complexes, and pure drug particles (14-16). Briefly, the substances of interest are dissolved in a solvent A and this solution is poured into a nonsolvent B of the substance that is miscible with the solvent A. As the solvent diffuses, the dissolved material is stranded as small particles, typically 100 to 400 nm in diameter. The solvent is usually an alcohol, acetone, or tetrahydrofuran and the nonsolvent A is usually water or aqueous buffer, with or without a hydrophilic surfactant to improve colloid stability after formation. Solvent A can be removed by evaporation under vacuum, which can also be used to concentrate the suspension. The concentration of the substance of interest in the organic solvent and the proportions of the two solvents are the main parameters influencing the final size of the particles. For liposomes, this method is similar to the ethanol injection technique proposed by Batzii and Korn in 1973 (17), which is however limited to 40 mM of lipids in ethanol and 10% of ethanol in final aqueous suspension. 

The prepared nanoparticles can be stored in lyophilized form and resuspended in physiological solutions prior to administration. The procedure developed on the laboratory scale has been found amenable to scale-up productions. 

Indeed, recent results from our laboratory indicate that dendrimer-encapsulated CdS QDs can be prepared by either of two methods [192]. The first approach is analogous to the methodology described earlier for preparing dendrimer-encapsulated metal particles. First, Cd and S salts are added to an aqueous or methanolic PAMAM dendrimer solution. This yields a mixture of intradendrimer (templated) and interdendrimer particles. The smaller, dendrimer-encapsulated nanoparticles may then be separated via size-selective photo etching [193], dendrimer modification and extraction into a nonpolar phase [19], or by washing with solvent in which the dendrimer-encapsulated particles are preferentially soluble. An alternative, higher-yield method relies on sequential addition of very small aliquots of Cd + and S " to alcoholic dendrimer solutions. 

Klupinski et al. (2004) report a laboratory experiment on the degradation of a fungicide, pentachloronitrobenzene (C Cl NO ), in the presence of goethite and iron oxide nanoparticles this study was intended to illustrate the fate of organic agrochemical contaminants in an iron-rich subsurface. To compare the effects of iron with and without a mineral presence, experiments were performed using... 

We summarize here only the laboratory results obtained in this area of supported or unsupported nanoparticles modified by organometallic compounds. We... 

Similar to chemical vapor deposition, reactants or precursors for chemical vapor synthesis are volatile metal-organics, carbonyls, hydrides, chlorides, etc. delivered to the hot-wall reactor as a vapor. A typical laboratory reactor consists of a precursor delivery system, a reaction zone, a particle collector, and a pumping system. Modification of the precursor delivery system and the reaction zone allows synthesis of pure oxide, doped oxide, or multi-component nanoparticles. For example, copper nanoparticles can be prepared from copper acetylacetone complexes [70], while europium doped yttiria can be obtained from their organometallic precursors [71]. 

Mathew Maye, Oleg Gang, and their colleagues at Brookhaven National Laboratory in New York use DNA to help assemble nanoparticles. 

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