Nanoparticles polydisperse

For instance, nanoparticles of silver chloride have been synthesized by mixing two mi-croemnlsions, one containing silver ions and the other containing chloride ions. It was shown that the average particle size, the polydispersity and the number of particles formed depend on the intermicellar exchange rate and/or the rigidity of the surfactant shell [228],... 

Figure 6. TEM micrographs representing the transformations of (a) polydispersed nanoparticles upon (b) alkanethiol addition at room temperature and (c) after digestive ripening (inverse micelle system). (Reprinted with permission from Ref [49], 2002 American Chemical Society.)...

When the polydisperse silver nanoparticles are irradiated with a monochromatic light, only the nanoparticles that are resonant with the incident light are excited and the excited electrons are transferred to Ti02, giving rise to liberation of Ag. The resonant particles are thus reduced in size until they become non-resonant. Some of the electrons... 

Silver nanoparticles can be deposited on Ti02 by UV-irradiation. Deposition of polydisperse silver particles is a key to multicolor photochromism. The nanoparticles with different size have different resonant wavelength. Upon irradiation with a monochromatic visible light, only the resonant particle is excited and photoelectrochemically dissolved, giving rise to a decrease in the extinction at around the excitation wavelength. This spectral change is the essence of the multicolor photochromism. The present photoelectrochemical deposition/dissolution processes can be applied to reversible control of the particle size. 

Considerable research effort was focused on systems of colloidal gold of which a broad variety of synthetic procedures were reported [140 b, fj. While native colloidal gold solutions are only stable for a restricted time, Brust et al. [141] were able to overcome this problem by developing a simple method for the in situ preparation of alkyl thiol-stabihzed gold nanoparticles. This synthetic route yields air-stable and easy to handle passivated nanoparticles of moderate polydispersity, and is now commonly employed for the preparation of inorganic-organic core-shell composites. Such composites are used as catalytic systems with principally two different functions of the protective 3D-SAM layer. Either the metal nanoparticle core can be used as the catalytically active center and the thiol layer is only used to stabihze the system [142], or the 3D-SAM is used as a Hnker system to chemically attach further catalytic functions [143]. 

A well-controlled pol5mierization method in terms of pol5mer length, polydispersity, and spatial distribution of functional groups is cmcial for effective nanoparticle assembly (Chiefari et al. 1998 Bielawski and Gmbbs 2000 Coessens et al. 2001 ... 

Arriagada FJ, Osseoasare K (1994) Silica Nanoparticles Produced in Aerosol Ot Reverse Microemulsions - Effect of Benzyl Alcohol on Particle-Size and Polydispersity. J Dispers Sci Technol 15 59-71... 

From these data it is concluded that the size, shape, and polydispersity of nanoparticles depend critically on the colloidal structure in which the synthesis is performed. This is well demonstrated when, by changing the water content, similar colloidal structures (reverse micelles or interconnected cylinders) are obtained ... 

Poly(styrene-fe-butadiene-b-styrene) flower-like nanoparticles having a molecular weight of 56,700 Da with a polydispersity of 1.04 were prepared by Wang et al. (3) using equimolar amounts of triethylamine and butyllithium with butadiene, styrene, and divinylbenzene. 

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