Investigation of H2S Solubility in Aqueous N- Methyldiethanolamine + Amine Functionalized UiO-66 as a nano solvent

In this paper, the experimental solubility of hydrogen sulfide in aqueous N- Methyldiethanolamine + Amine Functionalized UiO-66 (UiO-66-NH2) was studied. UiO-66-NH2 was produced using solvothermal process, and its physicochemical properties were investigated by different techniques including XRD, TGA, TEM, BET, and FTIR to realize its crystalline structure, morphology, thermal stability, and porous structure. The Zeta potential of the solution was turned out to be about 26.6 mV (millivolt), meaning that UiO-66-NH2 particles are moderately stable in aqueous 40 wt.% MDEA. The solubility of hydrogen sulfide has been carried out using the isochoric saturation / or static method in two concentration grades of 0.1 and 0.5 wt.% of UiO-66-NH2 in the aqueous solution of 40 wt.% MDEA known as nanofluid. Experimental measurements were carried out at temperatures of 303.15 through 333.15 K, and pressures up 1100 kPa. Results showed that the addition of UiO-66-NH2 nanoparticles to the MDEA solution altered the results less than 3% , while the mean value of uncertainty reported in this work is about 4% , meaning that the addition of nanoparticles do not have remarkable effect on H2S solubility. In contrast, it causes an increased capacity of CO2 absorption of that solution up to 10% .

Effects of Process Variables on Properties of CoFe2O4 Nanoparticles Prepared by Solvothermal Process

Controlling the morphology and magnetic properties of CoFe2O4 nanoparticles is crucial for the synthesis of compatible materials for different applications. CoFe2O4 nanoparticles were synthesized by a solvothermal method using cobalt nitrate, iron nitrate as precursors, and oleic acid as a surfactant. The formation of CoFe2O4 nanoparticles was systematically observed by adjusting synthesis process conditions including reaction temperature, reaction time, and oleic acid concentration. Nearly spherical, monodispersed CoFe2O4 nanoparticles were formed by changing the reaction time and reaction temperature. The oleic acid-coated CoFe2O4 nanoparticles inhibited the growth of particle size after 1 h and, therefore, the particle size of CoFe2O4 nanoparticles did not change significantly as the reaction time increased. Both without and with low oleic acid concentration, the large-sized cubic CoFe2O4 nanoparticles showing ferromagnetic behavior were synthesized, while the small-sized CoFe2O4 nanoparticles with superparamagnetic properties were obtained for the oleic acid concentration higher than 0.1 M. This study will become a basis for further research in the future to prepare the high-functional CoFe2O4 magnetic nanoparticles by a solvothermal process, which can be applied to bio-separation, biosensors, drug delivery, magnetic hyperthermia, etc.

Temperature Controlled Evolution of Pure Phase Cu9S5 Nanoparticles by Solvothermal Process

Copper sulphides are one of the most explored semiconductor metal sulphides because of their stoichiometric and morphological dependent optical and electrical properties, which makes them tunable for numerous optoelectronic applications. Stoichiometrically, copper sulphides exist in numerous structures which varies from the copper-rich phase (Cu2S) to the copper-deficient phase (CuS). Within these extreme stoichiometric phases lies numerous non-stoichiometric phases with interesting optical properties. Different solvothermal techniques have been explored for the synthesis of copper sulphides; however, the thermal decomposition of single source precursors provides a facile and tunable route to the synthesis of pure phase copper sulphides of different stoichiometries. In this study, copper (II) dithiocarbamate have been explored as a single source precursor compound to study the evolution of pure phase Cu9S5. Below 240°C, mixed phase of CuS and Cu9S5 were obtained, and as the temperature was increased beyond 240°C, keeping other reaction condition unchanged, the precursor yielded pure phase of Cu9S5. This phase selectivity at high temperature was attributed to the increased reducing ability of oleylamine (used as solvent) which enhance the evolution of the copper rich phase at high temperature. Optical and morphological studies of the pure phase Cu9S5, showed properties that varied considerably with the temperature of synthesis.