Paints and coatings containing bactericidal agent nanoparticles combat marine fouling
Vanadium pentoxide nanoparticles mimic natural enzymes and inhibit surface build-up of algae and bacteria
2012-07-03
(Press-News.org) 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. 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.
Marine fouling is a problem that costs the shipping industry more than 200 billion dollars per year. The accumulation of organisms such as algae, mussels, and barnacles increases the objects' water resistance and, in consequence, fuel consumption. This means additional costs for shipping companies and, even worse, increased environmental damage due to extra CO2 emissions. Within only a few months, an underwater boat hull can be completely covered and overgrown with organisms. According to Lloyds, this means an increase in fuel consumption of up to 28 percent and about 250 million tons of additional CO2 emissions per year. While it is possible to counteract this effect to some extent by means of the use of antifouling paints, conventional biocides are less effective and can have adverse environmental consequences. In addition, microorganisms can develop resistance to them.
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.
INFORMATION: END
ELSE PRESS RELEASES FROM THIS DATE:
2012-07-03
A consortium of nine research centres has obtained the melon genome, a horticultural specie with high economic value around the world. It is the first time that a Spanish initiative that unites private and state-run centres has obtained the complete genome of a higher organism, in this case a plant, which produces flowers and seeds. Also, it has been done by applying massive sequencing technologies.
Besides the complete melon genome, scientists have obtained the particular genomes of seven melon varieties. The study is published in the magazine Proceedings of the National ...
2012-07-03
The industry is interested in establishing a biorefinery sector in Denmark that can replace oil-based products with biofriendly materials, chemicals, energy and fuel. But this requires a larger biomass production than we are currently achieving. Scientists from University of Copenhagen and Aarhus University have published an extensive report that shows how we can increase the production of biomass by more than 200% in an environmentally friendly way.
The report called "The ten-million-tonne plan" shows how we can increase the Danish production of biomass from agriculture ...
2012-07-03
Experts at The University of Nottingham are the first to create a stable version of a 'trophy molecule' that has eluded scientists for decades.
In research published in the prestigious journal Science, the team of chemists at Nottingham has shown that they can prepare a terminal uranium nitride compound which is stable at room temperature and can be stored in jars in crystallized or powder form.
Previous attempts to prepare uranium-nitrogen triple bonds have required temperatures as low as 5 Kelvin (-268 °C) — roughly the equivalent temperature of interstellar space ...
2012-07-03
A new approach to testing medical treatment options could ensure that more patients get the most beneficial treatment for them – but still yield valuable research results that stand up to scientific scrutiny.
The approach tries to overcome a huge chicken-and-egg problem in medical research: Not enough people volunteer for studies of new treatments partly because researchers can't promise the studies will help them -- but without enough volunteers, researchers can't study new treatment options.
But a new "adaptive" way of designing medical studies could help. In a ...
2012-07-03
Researchers at Moffitt Cancer Center and colleagues at the University of South Florida, the German Cancer Research Center in Heidelberg, and the International Agency for Research on Cancer in Lyon, France, conducted a case control study and found associations between having antibodies to certain types of cutaneous human papillomavirus (HPV) and a kind of skin cancer called squamous cell carcinoma (SCC).
Their study, the first case-control study to investigate the association between SCC and cutaneous HPV types belonging to five different genera, appeared in a recent ...
2012-07-03
Amsterdam, NL, July 2, 2012 – After stroke, patients often suffer from dysphagia, a swallowing disorder that results in greater healthcare costs and higher rates of complications such as dehydration, malnutrition, and pneumonia. In a new study published in the July issue of Restorative Neurology and Neuroscience, researchers have found that transcranial direct current stimulation (tDCS), which applies weak electrical currents to the affected area of the brain, can enhance the outcome of swallowing therapy for post-stroke dysphagia.
"Our pilot study demonstrated that ...
2012-07-03
PROVIDENCE, R.I. [Brown University] — What makes laparoscopic surgery "minimally invasive" — instruments enter the patient through narrow tubes — also makes it visually constraining. As they work on different tasks, surgeons all see the same view. What if each surgeon could control a separate view best suited to the specific task? In a new paper, pediatric surgeon Dr. Francois Luks and his team of co-authors at Brown University and Hasbro Children's Hospital report that in a small in vitro trial, surgeons with their own views performed faster and more accurately.
"When ...
2012-07-03
Researchers are closer to understanding the biology behind GHB, a transmitter substance in the brain, best known in its synthetic form as the illegal drug fantasy. These findings have just been published in the scientific journal PNAS.
In the 1960s, gamma-hydroxybutyric acid (GHB) was first discovered as a naturally occurring substance in the brain. Since then it has been manufactured as a drug with a clinical application and has also developed a reputation as the illegal drug fantasy and as a date rape drug. Its physiological function is still unknown. Researchers identify ...
2012-07-03
Amsterdam, NL, July 2, 2012 – Growing evidence suggests that Parkinson's disease (PD) often starts with non-motor symptoms that precede diagnosis by several years. In the first study to examine patterns in the quality of life of Parkinson' disease patients prior to diagnosis, researchers have documented declines in physical and mental health, pain, and emotional health beginning several years before the onset of the disease and continuing thereafter. Their results are reported in the latest issue of Journal of Parkinson's Disease.
"We observed a decline in physical function ...
2012-07-03
(Embargoed) CHAPEL HILL, NC – New research led by a medical geneticist at the University of North Carolina School of Medicine points to an increased risk of autism spectrum disorders (ASDs) among individuals whose parents or siblings have been diagnosed with schizophrenia or bipolar disorder.
The findings were based on a case-control study using population registers in Sweden and Israel, and the degree to which these three disorders share a basis in causation "has important implications for clinicians, researchers and those affected by the disorders," according to a report ...
LAST 30 PRESS RELEASES:
[Press-News.org] Paints and coatings containing bactericidal agent nanoparticles combat marine fouling
Vanadium pentoxide nanoparticles mimic natural enzymes and inhibit surface build-up of algae and bacteria
