Scientists at Johannes Gutenberg University Mainz (JGU) in Germany have discovered that tiny vanadium pentoxide nanoparticles can inhibit the growth of barnacles, bacteria, and algae on surfaces in contact with water, such as ship hulls, sea buoys, or offshore platforms.
a) Biofouling at a boat hull; b) knotted wrack, Ascophyllum nodosum; c) Mode of action of bioinspired under water paints: Like the natural enzyme vanadium bromoperoxidase vanadium pentoxid nanoparticles act as a catalyst for the formation of hypobromous acid from bromide ions (contained in sea water) and small amounts of hydrogen peroxide that are formed upon exposure to sun light. Copyright: Tremel research group, JGU
Their experiments showed that steel plates to which a coating containing dispersed vanadium pentoxide particles had been applied could be exposed to seawater for weeks without the formation of deposits of barnacles, bacteria, and algae. In comparison, plates that were coated only with the ship's normal paint exhibited massive fouling after exposure to seawater for the same period of time.The discovery could lead to the development of new protective, antifouling coatings and paints that are less damaging to the environment than the ship coatings currently used.
It was one of nature's own defense mechanisms that provided the inspiration for the approach now taken by the team of scientists working under Professor Dr. Wolfgang Tremel of the Institute of Inorganic Chemistry and Analytical Chemistry at JGU. Certain enzymes found in brown and red algae produce halogen compounds that have a biocidal potential. It is assumed that these are synthesized by the algae to protect them against microbial attack and predators. The chemists at Mainz University decided to mimic this process using vanadium pentoxide nanoparticles. According to their article published in Nature Nanotechnology, vanadium pentoxide (V2O5) nanoparticles have "an intrinsic biomimetic bromination activity […] which makes them a practical and cost-efficient alternative for conventional chemical biocides." Vanadium pentoxide functions as a catalyst so that hydrogen peroxide and bromide combine to form small quantities of hypobromous acid, which is highly toxic to many microorganisms and has a pronounced antibacterial effect. The required reactants are present in seawater: This already contains bromide ions, while small quantities of hydrogen peroxide are formed when it is exposed to sunlight.
The process has been demonstrated both under laboratory conditions and in natural seawater. It has only very minimal consequences for the environment because the effect is restricted to micro-surfaces. The metallic oxide is particularly potent when it is present in the form of nanoparticles because then, due to the larger surface area, there is an enhanced catalytic effect.
"Vanadium pentoxide nanoparticles, due to their poor solubility and the fact that they are embedded in the coating, are considerably less toxic to marine life than are the tin- and copper-based active substances used in the commercially available products," explains Wolfgang Tremel. In his view, ships' coatings based on vanadium pentoxide could be a practical and cost-effective alternative to conventional chemical biocides. "Here we have an environmentally-compatible component for a new generation of antifouling paints that employ the natural defense mechanism used by marine organisms."
Ron Wever, the team's Dutch cooperation partner from the University of Amsterdam, has been investigating such natural defense mechanisms for the last 15 years. He suggested adding the enzyme involved, i.e., vanadium haloperoxidase, to antifouling paints. The chemists in Mainz are now working together with Wever to develop vanadium pentoxide nanoparticles. "Vanadium pentoxide particles are considerably cheaper and also more stable than genetically produced enzymes," he adds.
A research group headed by Dr. Klaus Peter Jochum of the Max Planck Institute for Chemistry in Mainz has been conducting experiments to determine whether the use of vanadium pentoxide might have a negative effect on the environment. Using a highly sensitive ICP mass spectrometer, the scientists determined the concentration of vanadium in various samples of seawater that had been exposed to the coated material for different lengths of time. The results showed that levels were only slightly elevated above the normal average vanadium concentration in seawater. It can thus be concluded that only very tiny amounts of vanadium migrate from the coating into seawater and will thus have no negative impact on the environment.
Argon is not the 'dope' for metallic hydrogen
24.03.2017 | Carnegie Institution for Science
Researchers make flexible glass for tiny medical devices
24.03.2017 | Brigham Young University
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Health and Medicine
27.03.2017 | Life Sciences
27.03.2017 | Earth Sciences