Xylene Lab Report

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Fig. 1 Cell for the electrosynthesis of CdSe nanoparticles and simultaneous extraction in xylene The resulting colloidal solution was mixed with thermotropic liquid crystal of cadmium caprylate and heated at 150°C. The boiling temperature of xylene (138°C) is within the temperature range of the mesophase existence of cadmium caprylate (98-165°C) [15]. Due to the evaporation of xylene, the CdSe nanoparticles were uniformly distributed throughout the volume of the mesophase of cadmium caprylate, and on cooling this melt, a glassy nanocomposite was formed. The structure of CdSe powders has been investigated by X-ray phase analysis on a DRON-4 diffractometer, using CuKα radiation (wave length 1.5418 Å). 2θ measuring range: 10 - 70○ with a step…show more content…
Using this electrolyte with a surface layer of xylene under continuous –electrolysis conditions, one can obtain extracts of CdSe nanoparticles with a content of 0,3 mol/L in xylene. The same colloidal solutions were used to fabricate optical nanocomposites based on thermotropic liquid-crystalline matrix. During electrosynthesis without the use of anticoagulating agents, CdSe nanoparticles as powder or dendrite-like deposits are formed on the cathode. The presence of water-immiscible xylene and vigorous hydrogen evolution result in the formation of an electrolyte-xylene emulsion in the cathode layer. In the layer of this emulsion, the synthesis and simultaneous extraction of CdSe nanoparticles take place. Being extracted into xylene, they do not yield anymore to action of the acid medium in the electrolyte. Since xylene is a nonpolar solvent, and coagulate very little, if at all. For small nanoparticles, xylene is stabilizing additive, whereas larger nanoparticles precipitate within some time after extraction. This may be due to interaction between the π-bonds of xylene molecules and CdSe nanoparticles [16]. Owing to this interaction, small nanoparticles do not yield to the action of gravitational force and do not precipitate, whereas for larger nanoparticles, the interaction…show more content…
The shift of the curve 2 in Fig. 3 forward more negative values relative to the curve 1, which is responsible for hydrogen evolution from the supporting electrolyte, indicates inhibition of the hydrogen evolution reaction on the reduction of selenious acid. Since the shift of the curve 4 in Fig. 3 towards more negative values relative to the curve 1 for the process of electroreduction of Cd2+ ions is still larger than for the formation process (curve 3 in Fig. 3 ), we assume that the synthesis of CdSe in this supporting electrolyte may take place by an electrochemical-chemical

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