Nanopartide

Xylan-based micro- and nanoparticles have been produced by simple coacervation (Garcia et al., 2001). In the study, sodium hydroxide and chloride acid or acetic acid were used as solvent and non-solvent, respectively. Also, xylan and surfactant concentrations and the molar ratio between sodium hydroxide and chloride acid were observed as parameters for the formation of micro- and nanoparticles by the simple coacervation technique (Garcia et al., 2001). Different xylan concentrations allowed the formation of micro- and nanoparticles. More precisely, microparticles were found for higher concentrations of xylan while nanopartides were produced for lower concentrations of the polymer solution. When the molar ratio between sodium hydroxide and chloride acid was greater than 1 1, the partides settled more rapidly at pH=7.0. Regarding the surfactant variations, an optimal concentration was found however, at higher ones a supernatant layer was observed after 30 days (Garda et al., 2001). 

Anton, N., Benoit, J. P. Saulnier, P. (2008). Design and production of nanopartides formulated from nano-emulsion templates - A review. Journal of Controlled Release, Vol. 128, 3, (June 2008), pp. (185-199), ISSN 0168-3659... 

SW- waxy corn starch, SWNPs- starch nanopartides. Cel- microcrystaUine cellulose, CelNPs- cellulose nanopartides, CB- carbon black, SWAcNPs- waxy starch acetate nanopartides, CelAcNPs cellulose acetate nanopartides. 

Bimetallic nanoparticles, either as alloys or as core-shell structures, exhibit unique electronic, optical and catalytic properties compared to pure metallic nanopartides [24]. Cu-Ag alloy nanoparticles were obtained through the simultaneous reduction of copper and silver ions again in aqueous starch matrix. The optical properties of these alloy nanopartides vary with their composition, which is seen from the digital photographs in Fig. 8. The formation of alloy was confirmed by single SP maxima which varied depending on the composition of the alloy. 

Fig. 8. Digital photograph of starch capped metallic and bimetallic nanopartides in aqueous medium. A Cu B-D Cu-Ag E Ag.

Fig. 9. Comparison of mode of action against E.coli starch capped copper nanopartides vs. amphicilin...

The presence of nanopartides suspended within the starch matrix would ensure continuous release of ions into the nutrient media. Copper ions released by the nanopartides may attach to the negatively charged bacterial cell wall and rupture it, thereby leading to protein denaturation and cell death [31]. The attachment of both ions and nanopartides to the cell wall caused accumulation of envelope protein precursors, which resulted in dissipation of... 

Among all semiconductor NPs, metal selenides have been the focus of great attention due to their importance in various applications such as thermoelectric cooling materials, optical filters and sensors, optical recording materials, solar cells, superionic materials, laser materials and biological labels. Many synthetic methods have been developed for the preparation of relatively monodispersed selenide nanopartides (Murray et al., 1993 Korgel... 

This chapter is organised as follows Following this introduction as section 1, a brief description of the synthesis and characterisation techniques used for the as-synthesised polymer capped selenide nanopartides is given as section 2. In section 3, the mechanism of the reaction, results and discussion of the different selenide nanocomposites obtained using different polymers are given. Section 4, the last section gives a summary of the whole process, followed by references. Acknowledgements are cited before references. 

Scheme 1. Proposed chemical reactions involved in the formation of starch capped MSe nanopartides...

Tang, Z. Kotov, N. A. and Giersig, M. (2002). Spontaneous Organization of Single CdTe Nanopartides into Luminescent Nanowires. Science, 297, 237-240. 

Yang, Y. J. and Xiang, B. J. (2005). Wet synthesis of nearly monodisperse CdSe nanopartides at room temperature. /, Cryst. Growth, 284,453-458. 

Broqvist, P., Molina, L.M., Gronbecka, H. and Hammer, B. (2004) Promoting and poisoning effects of Na and Cl coadsorption on CO oxidation over MgO-supported Au nanopartides. Journal of Catalysis, 227, 217-226. 

Hakkinen, H., Moseler, M., Kostko, O., Morgner, N., Hoffmann, M.A. and Issendorff, B. v. (2004) Symmetry and Electronic Structure of Noble-Metal Nanopartides and the Role of Relativity. Physical Review Letters, 93, 093401-1-093401-4. 

Ge, Q., Song, C. and Wang, L. (2006) A density functional theory study of CO adsorption on Pt—Au nanopartides. Computational Material Science, 35, 247-253. 

Gold biochemistry has seen much development in recent years. The interaction of gold complexes with proteins and mitochondria, the possible role(s) of gold(III) in vivo, and the potential for developing future therapies using gold nanopartides are... 

Thompson, D.T. (2007) Using gold nanopartides for catalysis. Nano Today, 2, 40-Ai. 

Catalytically active gold from nanopartides to ultrathin films. Accounts of Chemical Research, 39, 739—746. 

Daniel, M.-C. and Astruc, D. (2004) Gold nanopartides assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology. Chemical Reviews, 104, 293-346. 

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