The effects of isopropyl alcohol, tert butyl alcohol, isopentyl alcohol, benzaldehyde on the first order rate constant k 1 of the basic hydrolysis reaction of 2,4 dinitrochlorobenzene in the solution of cetyltrimethylammonium bromide(CTAB) are studied. The results show that k 1 decreases with increasing the concentration of small organic additive. It was found that the smaller the alcohol solubility in water and the larger the binding constant with the micelles, the faster the reaction rate decreases. The pseudophase ion exchange model is applied to quantitatively treat the experimental data. The above results are consistent with that obtained from dynamic light scattering, and are interpreted in terms of the change in micellar structure.
Gold nanoparticles modified with C10NH2, C12NH2, C16NH2 and C18NH2 respectively have been prepared by the reverse micelle method. Nanoparticles stability and their two-dimensional (2D) ordered arrangement were studied by UV-Vis absorption spectra and LB technique. The factors, such as the chain length and the size distribution of particles, which affect the 2D ordered arrangement formation, are discussed. Experimental results show that the longer the chain length of surfactants capping the gold nanoparticles, the more stable the nanoparticles, and the more ordered 2D arrangement of gold nanoparticles.