Copper
Copper is one of the few metals that can be found pure in nature (native metals). Due to its natural availability, as well as its malleable and ductile characteristics, it was used by ancient people more than 10,700 years ago. With new technologies, knowledge about this metal and its properties has expanded. Today it is known that copper has the second highest thermal conductivity among pure metals and has a significant electrical conductivity (59.6×106 S/m). Copper reacts with atmospheric oxygen, not with water like iron. In this process, its natural color, that is not common metallic (gray or silver) but reddish-brown, turns into brown-black due to copper oxide. During that time, carbon dioxide (CO2) and hydroxide ions (OH-) from the air create thin, blue-green layers of patina, which make its appearance unique.
Biostatic properties
New technologies have revealed the biostatic properties of copper. Bacteria and other pathogens like viruses, protozoan, viroid, or fungus cannot live and grow on its surface. That’s why many hospitals use copper on the doorknobs and bed rails, reducing intrahospital infections, as bacteria, fungus and viruses are killed instantly upon touching metallic copper surfaces, a process known as contact killing. In fact, the U.S. Environmental Protection Agency has registered it as the first solid, antimicrobial material.
Transdermal absorption of copper
The transdermal absorption of copper attracts the attention of science community. The advantages of copper absorption through skin are mainly observed through side effects of oral copper compounds, like nausea and vomiting, and the limited absorption of copper through oral intake due to: