Nanoparticles, production

Mehnert, W. and Mader, K., Solid hpid nanoparticles production, characterization and applications. Arfv. Drug Deliv. Rev., 47, 165-96, 2001. 

An improved synthesis of this type of phosphine-stabilized gold nanoparticle was necessary to make them convenient for use as synthetic intermediates in materials applications. We developed a safer, more convenient, and more versatile synthesis of phosphine-stabilized nanoparticles analogous to those originally reported by Schmid. The synthesis described here eliminates the use of diborane and can be carried out quickly with minimal concern for inert conditions. The nanoparticle product is comparable to that prepared by the Schmid procedure, possessing a core diameter of 1.5 0.4 nm and the same reactivity. In addition, the new synthesis can be adapted to permit the use of a variety of phosphines as passivating ligands and provide control over particle core size. ... 

Figure 2.2 Illustration of the optical clarity of (a) vitamin E 50% (from DSM Nutritional Products (Kaiseraugst, Switzerland), average particle size 350 nm), (b) vitamin E 15% (from DSM Nutritional Products (Kaiseraugst, Switzerland), a nanoparticle product, average particle size 100 nm), and (c) vitamin E 17% (competitor product average particle size 730 nm). Reproduced from Chen and Wagner (2004) with permission.

M. Sommer, N.J. Wagner, W. Peukert, J. Green, D. Spahr, Fundamental investigations on nanoparticle production by stirred media milling, in Proceedings of the AIChE Annual Meeting San Francisco, CD-ROM, 16—21 November 2003, paper 54f. 

SC-CO2 is also becoming increasingly important as reaction media [7] for a great variety of fundamental chemical reactions ranging from catalysis to polymerization, [8,9] to synthesis and growth of inorganic materials [1,2], to nanoparticle production and preparation processes [1,2,10,11], and to biotechnological applications such as activation and deactivation of enzymes [12], biomass conversion, and biocatalysis [1,2,13],... 

In a continuous system, it was seen that the same trend of size and charge data occurred. The continuous data displayed much clearer trends, however. Continuous processing is thus the preferred method of nanoparticle production, enabling a better quality control. 

Abraxane is a successful paradigm of nanoparticle application. It is an albumin nanoparticle loading paclitaxel developed by American Pharmaceutical Partners (APP) and American BioScience. The outstanding advantage of Abraxane is no significant side effects, not like the traditional paclitaxel preparation with Cremo-phor EL (polyethoxylated castor oil) and ethanol. More nanoparticle products will reach the market in the future. 

In contrast to standard borohydride reductive nanoparticle synthesis, we have developed an alternative strategy to amino acid encapsulated nanoparticles by utilizing a metal nanoparticle (M°-(Ligand))/metal ion (M"+) precursor redox pair with matched oxidation/reduction potentials. Simply, a metal nanoparticle such as Pt°-(Cys) acts as the principal reductant to a complimentary selected metal ion of Au + resulting in a new stabilized metal nanoparticle of Au°-(Cys) and the oxidation product of the original nanoparticle Pt"+. Malow et al. have reported a metathesis/transmetallation type reaction between a platinum colloid and a Au cyanide compound. Similarly, we employed a Pt°-(Cys)/AuCl4 pair and 0.5-2.0 equivalents of Au to Pt -(Cys). XRD analysis of the nanoparticle products revealed differences in crystallinity... 

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