Conductivity Of Mixed Surfactants Reverse Microemulsion And Electrodeposition Of Nanoparticles In The System

Nowadays, the nanomaterial has become a major research area due to its characteristic which is different from the conventional material and single molecule. In the preparation methods of nanomaterial, the soft templet such as microemulsion and reverse micelles have attracted more attentions recently. Microemulsion is a transparent, isotropic, thermodynamically stable dispersion which is stabilized by surfactant and cosurfactant molecules and its nanopools can be used in the preparation of controllable nanomaterials. However, due to the defect of electrical conductivity, conventional reverse microemulsion can not be used as electrolyte in electrochemistry research.P-octyl polyethylene glycol phenyl ether (Triton X-100) was used with cetyltrimethylammonium bromide (CTAB) and bis(2-ethylhexyl) sulfosuccinate sodiumsalt (AOT) respectively to form mixed surfactants. Then microemulsions were prepared with the mixed surfactants, n-hexane, n-hexanol and water. We studied the effects of surfactant weight ratio, temperature, concentrations of water and cosurfactant on the conductivity of mixed surfactants reverse microemulsion. And the electrochemical behavior of potassium ferricyanide [K3Fe(CN)6]/potassium ferrocyanide [K4Fe(CN)6] in the two systems was investigated by cyclic voltammetry(CV). The results indicate that the conductivity of the mixed surfactants reverse microemulsion is greatly higher than that of the single surfactant system. In the Triton X-100/CTAB system, the conductivity increases with the increase of surfactant weight ratio w(w=mTriton X-100:mCTAB) and stabilized when w reaches 2.3. Also in the Triton X-100/AOT system, the conductivity increases with the increase of surfactant weight ratio w(w=mAOT:mTrito X-100) and stabilizes when w reaches 0.6. Simultaneously, the increase of water concentration and temperature enhances the conductivity while the increase of cosurfactant concentration decreases the conductivity obviously. The CV result shows the redox peak potentials of Fe(CN)63-/Fe(CN)64- are almost constant with the change of scan rate, and the redox potential gaps are about 70 mV-75 mV in the mixed surfactants reverse microemulsion. Furthermore, the ratios of redox peak currents at all scan rates are close to 1.The oxidation peak current increases linearly with the square root of scan rate. The electrochemical reaction of Fe(CN)63-/Fe(CN)64-is reversible and is controlled by diffusion in the system. Based on the ideal conductivity of the mixed surfactants reverse microemulsion, it can be used as soft templet directly in the electrochemistry research. The Triton X-100 and CTAB were mixed with n-hexane, n-hexanol and AgNO3 solution to prepare reverse microemulsion. The obtained system was used in the electrodeposition of Ag nanoparticles. The morphology and electrocatalytic capability of the Ag nanoparticles were investigated. The results indicate that the Ag nanoparticles prepared in the mixed surfactants reverse microemulsion exhibit remarkable catalytic properties for the reduction of benzyl chloride. And the current density, the concentration of Ag+ and the electrodeposition method have effects on electrocatalytic properties of Ag nanoparticles.