Nanoparticle synthesis with silylamine reversible ionic liquids (RevILs) has been previously demonstrated to offer unique alternatives to traditional nanoparticle syntheses, allowing for size control and facile deposition onto support surfaces via the switchable nature of the IL. However, the mechanism of nanoparticle synthesis remains uncharacterized. The use of RevILs facilitates the synthesis of size-controlled nanoparticles without the use of additional stabilizing agents (i.e., surfactants, ligands, and polymers) that passivate the nanoparticle surface, which are traditionally required to control the nanoparticle size. Traditional techniques often require harsh activation steps that ultimately impact nanoparticle size and morphology. While RevIL syntheses offer an excellent alternative, as they do not require additional activation steps, the mechanism through which nanoparticles are synthesized in these systems has not been studied previously. Preceding work hypothesized nanoparticles prepared with RevILs are formed via a reverse micelle mechanism, in which nanoparticles are stabilized and templated within the aqueous core of the organized micelle structures. In this work, DOSY-NMR is used to demonstrate that nanoparticles synthesized with 3-aminopropyltriethylsilane RevIL are not formed through a reverse micelle mechanism but rather a switchable aggregation mechanism that affords control over the nanoparticle size via manipulation of the RevIL structure and concentration. Furthermore, it is shown that the addition of water to RevIL systems has detrimental effects on the aggregation behavior of the ionic liquid molecules in solution, causing disassembly of the ion pairs. However, because nanoparticle reduction likely occurs faster than the disassembly of the ion pairs, nanoparticle size is unaffected by the addition of water during nanoparticle reduction.

Synthesis methods for the preparation of monodisperse, supported nanoparticles remain problematic. Traditional synthesis methods require calcination following nanoparticle deposition to remove bound ligands and expose catalytic active sites. Calcination leads to significant and unpredictable growth of the nanoparticles resulting in polydisperse size populations. This undesired increase in nanoparticle size leads to a decrease in catalytic activity due to a loss of total surface area. In this work, we present the use of silylamines, a class of switchable solvents, for the preparation of monodisperse, supported nanoparticles. Silylamines are switchable molecules that convert between molecular and ionic forms by reaction with CO. Upon addition of an alkane, the switchable solvent behaves as a switchable surfactant (SwiS). The SwiS is used to template nanoparticles to aid in synthesis and subsequently used to release nanoparticles for deposition onto a support material. The use of SwiS allowed for the preservation of nanoparticle diameter throughout the deposition process. Finally, it is demonstrated that supported gold nanoparticle catalysts prepared using SwiS are up to 300% more active in the hydrogenation of 4-nitrophenol than their traditionally prepared analogues.

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Examination of the stress-strain curves of vuloanizates containing up to 60 per cent by volume of mineral filler of particle size greater than 1 µ has led to the discovery of a plateau at which the elongation increases several hundred-fold at constant stress. This has been demonstrated for a number of fillers with several rubbers, natural and synthetic. The effect of filler content, particle size, and degree of cure on the stress at which the plateau occurs, and its length, have been investigated. An explanation is suggested and the significance of the observations for the experimental verification of equations relating modulus to filler content is pointed out. The volume changes accompanying the elongation of these vulcanizates have also been investigated at varying filler contents, particle sizes, and degrees of cure, and shown to correlate with the stress-strain curves. The possible bearing of these results on the nature of the rubber-filler bonds, and hence on the reinforcing action of fillers, is briefly discussed.

The effect of incorporating TiO2 nanowires into organic photovoltaics has been studied using impedance spectroscopy. Electron diffusion coefficient and effective lifetime in different devices were simulated and compared.