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The influence of the chain length and the functional group steric accessibility of thiols on the phase transfer efficiency of gold nanoparticles from water to toluene

Soliwoda K., Tomaszewska E., Tkacz-Szczesna B., Rosowski M., Celichowski G., Grobelny J.

Polish Journal of Chemical Technology

2014

Vol. 16, nr 1

86--91

This paper describes the influence of the chain length and the functional group steric accessibility of thiols modifiers on the phase transfer process efficiency of water synthesized gold nanoparticles (AuNPs) to toluene. The following thiols were tested: 1-decanethiol, 1,1-dimethyldecanethiol, 1-dodecanethiol, 1-tetradecanethiol and 1-oktadecanethiol. Nanoparticles (NPs) synthesized in water were precisely characterized before the phase transfer process using Atomic Force Microscopy (AFM) and Transmission Electron Microscopy (TEM). The optical properties of AuNPs before and after the phase transfer were studied by the UV-Vis spectroscopy. Additionally, the particle size and size distribution before and after the phase transfer of nanoparticles were investigated using Dynamic Light Scattering (DLS). It turned out that the modification of NPs surface was not effective in the case of 1,1-dimethyldecanethiol, probably because of the difficult steric accessibility of the thiol functional group to NPs surface. Consequently, the effective phase transfer of AuNPs from water to toluene did not occur. In toluene the most stable were nanoparticles modified with 1-decanethiol, 1-dodecanethiol and 1-tetradecanethiol.

Termoteria mnogogazovyh potokov v skvazinah s fazovymi perehodami

Sarafutdinov R. F., Baliullin R. A., Ramazanov A. S., Sadretdinov A. A.

Prace Instytutu Nafty i Gazu

2008

nr 150 wydanie konferencyjne

515--519

At present time the techniques of investigation and interpretation of thermal research data is formulated mainly on the base of data analysis for one-phase flows of oil, water and gas. But in the real conditions it is observed the multiphase flows in the formation and well. Processes of putting the well in operation and well shut-in, swabbing, and compressor oil well completion and formations are characterized by the unsteady pressure field. And the pressure in the well can increase above the reservoir pressure, and after that decreases below the reservoir pressure and pressure of saturation of oil by gas. Thus, in the formation it is realized the regimes of multiphase flows related to the transfer of water pump from the wellbore to oil saturated formation to the fluid production from the formation with oil degassing. Temperature distribution of the formation in this case is caused by the Joule-Thomson, adiabatic effects and heat of fluid degassing. Oil and water throttling leads to temperature increasing, and oil degassing to temperature decreasing, An informative thermal technique of research of well and formation is based on the regularities of temperature anomaly changes. In this work the main regularities of temperature distribution formation at arbitrary change of bottomhole pressure under the conditions of multiphase flow taking into consideration the thermodynamic effects and oil degassing are numerically researched. The possibility of field problem solution according to thermohydrodynamic well research is shown.

Simulation of condensation in a subcooled bubbly steam-water flow along a large vertical pipe

Lucas D., Prasser H.

Archives of Thermodynamics

2005

Vol. 26, no. 4

49-59

Detailed experimental data obtained at the TOPFLOW facility for steam-water vertical pipe flow were used to test the complex interaction of local bubble distributions, bubble size distributions and local heat and mass transfer. Steam is injected into subcooled water and condenses during the upward flow. The model considers a large number of bubble classes (50). This allows the investigation of the influence of the bubble size distribution. The results of the simulations show a good agreement with experimental data. The condensation process is clearly slower, if large bubbles are injected (4 mm holes). Also the bubble break-up has a strong influence on the condensation process because of the change of the interfacial area. Some unsureness arises from the unknown interfacial area for large bubbles and possible uncertainties of the heat transfer coefficient.