Particles capping

FIG. 11 TEM images of 2.8-nm-diameter silver particles capped by dodecanethiol that were horizontally transferred from the water surface at a surface pressure just below that at which the film would collapse. The top figure is a higher-resolution image of this phase of particles. (Reprinted with permission from Ref. 121. Copyright 1997 American Chemical Society.)... 

Explosive Pure Explosive Grit Particles/Cap Initiation Sensitization Gas Senslti... 

Most evidence about the effects of airborne particular matter on human health has been produced by epidemiology. Additionally laboratory studies have been published, that involved both animals and human volunteers using concentrated ambient particles (CAPs). Toxicological studies on animals using instilled particles in high concentrations complete our knowledge on health effects of particular... 

Maciejczyk P, Chen LC (2005) Effects of subchronic exposures to concentrated ambient particles (CAPs) in mice VIII. Source related daily variations in in vitro responses to CAPs. Inhal Toxicol 17 243-253... 

The first work on the self-assembly of gold colloid particles capped with alkanethiols was done by Brust and coworkers [Netzer, L, 1983]. This routine has been adopted by other scientists for the deposition of self-assembled monolayers of different colloid nanopartides (e.g., Ag, CdS, CdSe, and ZnS), which were prepared using mercapto-alcohols, mercaptocarboxylic acids, and thiophenols as capping agents. Self-assembled nanopartides usually show well-ordered lateral structures, proved by numerous observations with SEM, STM, and AFM [Collier. C, 1997, Lover. T, 1997, Rogach. A. L, 1999 and Vogel. W, 2000]. 

Fig. 13 Absorption spectrum of an aqueous suspension of nanocrystalline, size-quantized PbS particles (capped with polyvinylalcohol). A HR-TEM image of a typical PbS nanocrystal is shown in the insert the diameter of the nanocrystals is about 6.5 nm (from Ref 122).

The collision responses are affected by the nature of interactions between the collided NPs and the electrode. The adhesion of NPs to the electrode is a complex process that is still poorly understood. The adhesion may depend on many factors, such as the electrode material, particle material, particle capping agent, point of zero charge, electrode surface treatments, the electrolyte solution composition, and the electrode reaction. Therefore, chemical modification of the NPs or the UME can change the particles adhesive as well as nature of the electron transfer during the experiment. 

Colloidal zinc phenylphosphonate can be prepared by stirring the microcrystalline solid in a solution containing a substoichiometric amount of Z1OCI2 (15,16). A mole ratio of 1 Zif25 Zn is sufficient to prepare colloidal suspensions of the zinc salts. These zinc phenylphosphonate particles, capped with Zr, adhere readily to gold surfaces primed with a monolayer of 4-mercaptobutylphosphonic acid. Gold QCM electrodes derivatized in... 

Figure 5 (A) Light micrograph of airways from a normal rat exposed to concentrated ambient particles (CAPs) (B) a chronic bronchitic rat exposed to CAPS that died following exposure for 6 hr/day for 3 days. Note the slight visible buckling of the epithelium in the normal rat exposed to CAPs. In contrast, note the severe bronchoeonstrietion in the airway of the chronic bronchitic, CAP-exposed rat and the cellular infiltrate in the airway lumen.

Clarke R, Catalano P, Krishna Murthy G, Sioutas C, Wolfson M, Koutrakis P, Godleski J. Inhalation of concentrated ambient particles (CAPs) induces pulmonary function alterations in normal and chronic bronchitic animals. Inhalation Tox 1999. In press. 

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