It poses great problems to our society, making it the subject of investigation for many research groups, which dedicate great efforts to find means to prevent or control this process. The Universidad Autónoma de Madrid has tested a new protection technique that consists of the electrodeposition of a conductive polymer (polypyrrole) over the surface of a material like copper that is easily oxidised.
Copper is widely used for many applications and being a metal that oxidises relatively easily, its conservation represents a great economical benefit. Conventional methods to avoid or minimise corrosion of the material are in many cases short lived, very expensive and involve the use of toxic chemicals.
A recent article by Pilar Herrasti published in the Electrochimica Acta journal describes how copper has been successfully covered with a conductive polymer that creates a barrier with the corrosive environment while leaving the conductive property of the material untouched. Conductive polymers are remarkable materials - plastics with a slightly altered composition that make them capable of conducting electricity. Synthesising these polymers is not complicated and the process can be varied to increase or decrease their conductivity.
When an oxidising potential is applied to a pyrrole solution, it oxidises the compound over the electrode, and a thin film of the material is laid over the metal. In the case of copper, the methodology involves generating a layer of copper oxide over which the polymer is deposited. This layer is conductive like the metal and since it is deposited in an oxidised state it can then be reduced, maintaining the copper in the passivity zone (non corrosion zone), while simultaneously acting as a physical barrier between the copper and the environment. For its effect to be adequate on the material there are two fundamental conditions, the oxide-reductive potential must be high and there should be minimal porosity.
To achieve this goal, a detailed study of electrodeposition has been carried out, using different techniques, and adjusting the different parameters such as environmental composition and potentials or currents applied. The polymer deposited copper was then tested by submerging it in a solution of NaCl, simulating sea water, which is one of the most corrosive environments there are, since it contains large numbers of chloride ions.
These ions are responsible for an extremely localised form of corrosion that leads to the creation of small holes in the metal, known as pitting. The study of the behaviour of these materials had led to the conclusion that by tuning the different parameters, a thin film can be created that withstands the attack of this harsh environment for at least a month.
Novel sensors could enable smarter textiles
17.08.2018 | University of Delaware
Quantum material is promising 'ion conductor' for research, new technologies
17.08.2018 | Purdue University
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
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