Colloid capping

Fig. 4.27 Controlled drug release and delivery system using colloid capping of a mesoporous silica channel. Reprinted with permission from [222], C.-Y. Lai etal.J. Am. Chem. Soc. 2003, 725, 4451. 2003, American Chemical Society.

Guo and co-workers have synthesized trioctyl phosphine oxide (TOPO) stabilized iron nanoparticles by the microemulsion method with an average diameter of 3 nm [192]. The amorphous particles are known to effectively catalyze reactions such as the decomposition of H2O2. A specific advantage of this method is that the presence of O2 does not hamper the electrocatalytic currents obtained for H2O2. Gold colloids capped with a mixed monolayer of alkylthiol and amidoferrocenyl-... 

Kher S S and Wells R L 1996 Synthesis and characterization of colloidal nanoorystals of capped gallium arsenide Nanostruct. Mater. 7 591... 

Oluwafemi, O. S. (2009). A Novel Green Synthesis of Starch-Capped CdSe Nanostructures. Journal of Colloids and Surfaces B Biointerfaces, 73, 382-386. 

Oluwafemi O. S., Revaprasadu N and Adeyemi O. O. (2010). A facile "green" synthesis of ascorbic acid-capped ZnSe nanoparticles. Colloids Surf B Biointerfaces, 79,126-130. 

The reduction of transition metal salts in solution is the most widely practiced method for synthesis of metal colloidal suspensions [7]. In the preparation process, polymer is often used in order to prevent the agglomeration of metal particles as well as to control their size. Ahmadi et al. [5] reported that the concentration of the capping polymer affects the shape of platinum particles obtained by salt reduction. This means that the addition of a... 

Wu YD, Wang LS, Xiao MW, Huang XJ (2008) A novel sonochemical synthesis and nanostructured assembly of polyvinylpyrrolidone-capped CdS colloidal nanoparticles. J Non-Cryst Solid 354(26) 2993-3000... 

Absorption spectra of CdS colloid indicate the formation of quantum sized CdS particles. The particle size increased upon sonication, indicated by the red shift in the onset of absorption. The particle size was highly dependent on the mercaptan used, because of the absorption of the mercaptan on the particle acting as a capping agent and the rate of H2S produced. Study of mercaptan systems revealed that there was also a thermal process responsible for CdS formation. 25% of the total CdS produced sonochemically was formed via a thermal mechanism presumably in the hot shell around the compressed bubble. CdS colloid could be dissolved quite readily by sonicating solutions under air saturated conditions [89] by the following reaction,... 

I. Bedjat, P.V. Kamat, Capped semiconductor colloids. Synthesis and photo-electrochemical behavior of Ti02-capped SnC>2 nanocrystallites, J. Phys. Chem. 99 (1995) 9182-9188. 

Bedja I, Kamat PV (1999) Capped semiconductor colloids synthesis and photoelectrochemical behavior of Xi02 capped Sn02 electrolyte. J Phys Chem 99 9182-9188... 

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