In my diploma thesis, I investigated how the drying temperature (50 °C or 70 °C) affects the structure and composition of potassium bis(oxalato)cuprate(II) dihydrate synthesised from hot solutions of copper sulphate and potassium oxalate. The products were analysed by X-ray powder diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and optical microscopy (OM).
The results obtained show that the composition of the product does not change regardless of the drying temperature. From the diffraction peaks in the XRD diffractograms, which appear at the same diffraction angles, I conclude that the same crystalline phase is formed. The FTIR analysis shows characteristic absorption peaks for the synthesised compound. The TGA and DSC results up to 400 °C confirm the main components of the products, 2 water molecules and oxalate ions. Based on the results of the thermal analysis of the product synthesised at 90 °C, I find that the difference is only in the thermal degradation of the water, which could indicate a different bonding of the 2 water molecules. The optical microscope images show identical blue crystals formed as clusters or single crystals. I was able to define the individual crystals as angular bodies and the average size of the crystals was estimated to be 100 µm.
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