On the anomalous shapes of native copper crystals from the Michigan Copper Country

For over a century, the anomalous shapes of Michigan copper crystals from the Michigan Copper Country have been acknowledged. They are well known by mineral collectors and curated in museums from all around the world; still, their particular habits remain enigmatic. These natural crystals do not seem to follow crystal shape theories, based on the internal three-dimensional crystal structure. In this article, we offer a unique perspective on the formation of Michigan copper crystals. Firstly, we review the most common theories of crystal shapes. Then, taking into account the surface reconstructions induced by adsorbed oxygen, detected by ultra-high vacuum techniques, we present evidence of a strong correlation between these oxygen-induced surface reconstructions and the anomalous shapes. Finally, in order to understand why these shapes are not found in copper at other localities, oxygen dosing was performed using NanoSIMS on different natural copper crystals as a preliminary investigation. The higher oxygen content found in the Michigan copper crystal studied compared to others supports the influence of adsorbed oxygen on the anomalous crystal shapes. This result shows which mechanisms could modify crystal shapes and allow the development of strategies to monitor them, due to the presence of oxygen impurities. This new find is of great importance in shape-dependent catalysis, sensor characteristics, or other properties of material such as nanocrystals.

Electronucleation mechanism of copper in wastewater by controlled electrodeposition analysis

To improve the efficiency of copper deposition in wastewater containing polyvinylpyrrolidone surfactant and reveal the mechanism of copper crystals, a controlled electrodeposition process was developed using a low-cost stainless steel cathode and electrochemical methods.

Chemical Method of Receipt of Powder-Like Mixtures of Copper Crystals (Cu) -Nano, Micro Dispersion of for Reinforcement of Polymeric Compositions are Used as Materials for Printing 3D

We consider possibility of the chemical process of obtaining crystals of copper powder mixtures -nano, micro dispersion of for reinforcement of polymeric compositions are used as materials for printing 3D thermo-extrusion method, is given determination the physic and to mechanical properties of the resulting material, depending on the filler, we offer a method to reduce the porosity of products for the SLS technology, DMLS,investigated kinds of crystal structures of copper (Cu) and crystallization process copper (Cu) with -nano phase in solution H2O.

Self-assembled super-hydrophobic multilayer films with corrosion resistance on copper substrate

Micro and nano rough cube copper crystals were modified by 1-dodecanethiol/polydopamine multilayer on smooth copper substrate, which shows good superhydrophobic property and corrosion resistance ability.