Thermal, Structural and Morphological Characterisation of Freeze-dried Copper(II) Acetate Monohydrate and its Solid Decomposition Products

Abstract

In the present study the thermal decomposition of a freeze-dried copper(II) acetate monohydrate powder, (CH 3 COO) 2 Cu . H 2 O, (FDCuAcH 2 O), was analysed by a combination of high-temperature X-ray diffractometry; differential scanning calorimetry and thermogravimetry, up to 700 °C. The structure and morphology of the calcined freeze-dried powders were analysed by scanning electron microscopy and X-ray diffractometry. The results showed that FDAcCuH 2 O decomposes during heating in two stages: I) (25-225 °C) FDCuAcH 2 O dehydrates giving rise to copper(II) acetate, (CH 3 COO) 2 Cu, (AcCu), and II) (225-525 °C) AcCu decomposes to CuO through complex oxidation reactions of Cu and Cu 2 O, simultaneously. SEM showed that FDCuAcH 2 O powder has a scale-like morphology, which is created in the freezing stage and retained after freeze-drying. After calcination at 125 and 225 °C, clusters of elongated tubes (or filaments) compose the resulting powder (AcCu). Subsequent calcination at temperatures above 325 °C resulted in hard clusters of spheroid-like CuO particles.

Polypropylene in the melt state as a medium for in situ synthesis of copper nanoparticles

“…Therefore, the temperature of the mixer (190°C) was high enough to dehydrate the precursor. However, despite the reaction was performed under nitrogen atmosphere and at a temperature below those reported for decomposition of the precursor (between 220 and 325°C), diffraction peaks related with copper oxides were further observed . In particular, tenorite (CuO) and cuprite (Cu 2 O) crystalline phases with peaks at 35.5 and 38.78°, and 36.4 and 42.5°, respectively, appear.…”

“…On the basis of aforementioned, we can summarize the different chemical reactions involved. Initially, the precursor was dehydrated between 125 and 225°C inside the melt mixer forming the anhydride …”

Study of the Interactions Between Copper(ii) Acetate Monohydrate and Orotic Acid and Orotate Ligands

“…Therefore, it is possible suggest that the orotic acid coordinates with Cu(II) ion through this oxygen as it was reported for the complex obtained from Zn(II) acetate and orotic acid 23 . 2 show two maxima between 250-300ºC which can be attributed to loss of acetate ligands and other two maxima peaks between 350-450ºC are due to orotate weight loss 21 (see Figure 2). TGA-DTG of Cu 2 (acetate) 4 (H 3 OR) 4 show two maxima at 265ºC and at 328ºC attributed to weight loss of acetate and orotic acid ligands respectively (see Figure 3).…”

A generalized sample preparation method by incorporation of metal–organic compounds into polymers for electroless metallization

“…53 The decomposition of copper acetate monohydrate is more versatile and the published results are still controversial. [54][55][56][57][58][59][60][61] A multistep thermal decomposition of copper acetate has been proposed depending on the atmosphere. [55][56][57][58] Lin et al 58 have proposed three-step decomposition in air: dehydration step (106-168 C), decomposition step (168-302 C) during which solid Cu, Cu 2 O, and CuO were formed, the third step (302-500 C) was the step where Cu and Cu 2 O were oxidized to CuO as the temperature increased.…”