技術(shù)文章
Nanobrook Omni測量應(yīng)用案例-67
閱讀:279 發(fā)布時間:2018-12-14
作者:Aleksei N. Kolodin , Vladimir V. Tatarchuk, Alexander I. Bulavchenko, and Evgeniia V. Poleeva
Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, prosp. Akademika Lavrentieva 3, Novosibirsk 630090, Russia
摘要:The kinetics of thiourea synthesis of CdS nanoparticles (NPs) in reverse microemulsions of Tergitol Np-4/n-decane was studied in the temperature range of 313−333 K by spectrophotometry, photon-correlation spectroscopy, and transmission electron microscopy. The formation of NPs is described by the kinetic model, including two consecutive steps: homogeneous nucleation in a solution as the first step and the autocatalytic growth of NPs due to heterogeneous reaction on a continuously increasing surface as the second step. Effective rate constants of the steps (k1 = 1.52 × 10–2–1.75 × 10–3 s–1 and k2 = 4.9 × 10–1–5.1 × 10–2 M–1 s–1) and effective activation energies (Ea1 = 156 and Ea2 = 149 kJ/mol) were estimated in the pseudo-first-order reaction with respect to cadmium (cCd = 0.9 mM, cThio = 9 mM). The obtained constants were used to calculate the dependence of nanoparticle diameter on the synthesis time (d3 ∼ t). The calculated values correlate well with experimental data of photon-correlation spectroscopy and transmission electron microscopy.