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Source: NASA/Goddard Space Flight Centre
PUBLISHED:  Nov. 20 2011

PLANT WITH 'EGGBEATER' TEXTURE INSPIRES
WATERPROOF COATING

Optical micrograph of eggbeater-shaped hairs on the leaf surface of the aquatic plant Salvinia molesta. The hairs reduce friction and help the plant stay afloat. Ohio State University engineers have replicated the surface in a plastic coating that could reduce drag and boost buoyancy on boats and submarines. (Credit: Image courtesy of Ohio State University)
A floating weed that clogs waterways around the world has at least one redeeming feature: It's inspired a high-tech waterproof coating intended for boats and submarines.

The Brazilian fern Salvinia molesta has proliferated around the Americas and Australia in part because its surface is dotted with oddly shaped hairs that trap air, reduce friction, and help the plant stay afloat.

In the November 1 issue of the Journal of Colloid and Interface Science, Ohio State University engineers describe how they recreated the texture, which resembles a carpet of tiny eggbeater-shaped fibers. The plastic coating they created in the laboratory is soft and plush, like a microscopic shag carpet.

In nature, air pockets trapped at the base of Salvinia's hairs reduce friction in the water and help the plant float, while a sticky region at the tips of the eggbeaters clings lightly to the water, providing stability.

Bharat Bhushan
Ohio Eminent Scholar
Howard D. Winbigler Professor of Mech Eng 
Bharat Bhushan Ohio Eminent Scholar Howard D. Winbigler Professor of Mech Eng "It's the combination of slippery and sticky surfaces that makes the texture so special. The Salvinia leaf is an amazing hybrid structure. The sides of the hairs are hydrophobic in nature, they're covered with wax which prevents water from touching the leaves and traps air beneath the eggbeater shape at the top. The trapped air gives the plant buoyancy, but the tops of the hairs are hydrophilic. They stick to the water just a tiny bit, which keeps the plant stable on the water surface. With commercial development, the coating could reduce drag and boost buoyancy and stability on boats and submarines. I've studied the gecko feet, which are sticky, and the lotus leaf, which is slippery. Salvinia combines aspects of both. With this study, we've gotten deep insight into a very simple concept how the Salvinia leaf works. That's where the fun is. Besides, I've already moved on to studying shark skin.""It's the combination of slippery and sticky surfaces that makes the texture so special. The Salvinia leaf is an amazing hybrid structure. The sides of the hairs are hydrophobic in nature, they're covered with wax which prevents water from touching the leaves and traps air beneath the eggbeater shape at the top. The trapped air gives the plant buoyancy, but the tops of the hairs are hydrophilic. They stick to the water just a tiny bit, which keeps the plant stable on the water surface. With commercial development, the coating could reduce drag and boost buoyancy and stability on boats and submarines. I've studied the gecko feet, which are sticky, and the lotus leaf, which is slippery. Salvinia combines aspects of both. With this study, we've gotten deep insight into a very simple concept how the Salvinia leaf works. That's where the fun is. Besides, I've already moved on to studying shark skin."

In tests, the coating performed just as the Salvinia hairs do in nature. The bases of the hairs were slippery, while the tips of the hairs were sticky. Water droplets did not penetrate between the hairs, but instead clung to the tops of the eggbeater structures -- even when the coating sample was turned on its side to a 90-degree vertical.

Bhushan and master's student Jams Hunt compared the stickiness of their plastic coating to the stickiness of the natural Salvinia leaf using an atomic force microscope. The two surfaces performed nearly identically, with the plastic coating generating an adhesive force of 201 nanoNewtons (billionths of a Newton) and the leaf generating 207 nanoNewtons.

That's a very tiny force compared to familiar adhesives such as transparent tape or even masking tape. But the adhesion is similar to that of another natural surface studied by Bhushan and other researchers: gecko feet.

Bhushan develops biomimetic structures -- artificial structures created in the lab to mimic structures found in nature. The gecko feet inspired him to investigate a repositionable, "smart" adhesive, and the lotus leaf inspired the notion of glass that repels water and dirt.

He came to study Salvinia through a colleague in the university's Biological Sciences Greenhouse, who provided samples of the plant for the study.

Salvinia molesta, also known as giant salvinia, is native to Brazil, and is a popular plant for home aquariums and decorative ponds around the world. It needs no dirt, but lives solely in the water -- even moving water such as rivers and lakes.

At some point, the hearty plant escaped from people's homes into the wild. Now it has proliferated into commercial waterways in North America, South America, and Australia, where it has become an invasive species.

While the plant is a nuisance to ships today, it could ultimately provide a benefit if a commercial coating based on its texture became available. Bhushan has no plans to commercialize it himself, though.


Source: Ohio State University. The original article was written by Pam Frost Gorder.

Journal Reference:
James Hunt, Bharat Bhushan. Nanoscale biomimetics studies of Salvinia molesta for micropattern fabrication. Journal of Colloid and Interface Science, 2011; 363 (1): 187 DOI: 10.1016/j.jcis.2011.06.084
PLANT WITH EGGBEATER TEXTURE INSPIRES WATERPROOF COATING - WATERWAYS NEWS - 20 NOVEMBER 2011

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Valier Galy WHOI Researcher "The relatively long carbon residence time in the Ganges system was a surprise, primarily because of the region's dynamically high rates of physical erosion and sediment transport. We thought it was likely that the organic matter there was young, but what gets exported there sits in the soil for quite some time -- 3,000 years on average. That's pretty old. The good news is that the Ganges-Brahmaputra basin "is not contributing rapidly to CO2 in the atmosphere. The bad news is that makes the region more susceptible to global warming. That has "big implications for the global carbon cycle, because the longer it is stored in the soil, the longer it is kept away from the atmosphere as CO2. The buildup of CO2 in the atmosphere is thought to be largely responsible for global warming. Future environmental changes may dictate that carbon will not stay as long in the soil. If this happens, the net source of CO2 in the atmosphere will increase. Even though there have been few similar studies in other low latitude regions, the results of the WHOI study could portend global warming effects elsewhere in the world. Our study shows that ancient soil carbon exists in a globally significant tropical system. We therefore hypothesize that similar stocks of ancient carbon may exist elsewhere at low latitude. Global warming would likely destabilize this ancient carbon, generating an extra flux of CO2 to the atmosphere, hence further warming. This may not be too important over the short-term -- decades, for example, but over a longer time scale -- tens of thousands of years -- it can be important." Ramon Farreny UAB Co-Author "It is important to consider the collection of rainwater when planning and designing cities, as this is an alternative water source with many different uses, it can even be used to save drinking water. One such project, published in the journal Water Research, indicates that roofs "are the first choice for collecting rainwater in urban areas, but not all roofs function in the same way and it is necessary to select the most appropriate ones."Farreny explains: "The inclusion of criteria related to the slope and roughness of roofs in urban planning may be useful in promoting the harvesting of rainwater as an alternative water source. This could also contribute to preventing flooding and water shortages." Bharat Bhushan Ohio Eminent Scholar Howard D. Winbigler Professor of Mech Eng "It's the combination of slippery and sticky surfaces that makes the texture so special. The Salvinia leaf is an amazing hybrid structure. The sides of the hairs are hydrophobic in nature, they're covered with wax which prevents water from touching the leaves and traps air beneath the eggbeater shape at the top. The trapped air gives the plant buoyancy, but the tops of the hairs are hydrophilic. They stick to the water just a tiny bit, which keeps the plant stable on the water surface. With commercial development, the coating could reduce drag and boost buoyancy and stability on boats and submarines. I've studied the gecko feet, which are sticky, and the lotus leaf, which is slippery. Salvinia combines aspects of both. With this study, we've gotten deep insight into a very simple concept how the Salvinia leaf works. That's where the fun is. Besides, I've already moved on to studying shark skin." Celia Churchill Graduate Student University of Michigan "We had a pretty good idea that that janthinids evolved from snails that live on the sea floor. The question was, which specific group of snails gave rise to the janthinids, and how did the janthinid lineage make the transition from bottom dwellers to surface surfers? We thought of two possibilities. The first was that bubble rafting evolved from juvenile droguing. I started to dissect it, and when I pulled the float away I noticed that there were tiny Recluzia on the float and egg capsules of the large female. These hitchhiking juveniles suggested a life history consistent with the egg mass hypothesis. They also suggested an explanation for how the rare Recluzia manages to survive. Immediately we started thinking about dwarf males, which are known from a variety of molluscan groups. If Recluzia has a life history strategy where males remain with females, that might explain how Recluzia can persist at such low densities. When there aren't very many females, remaining with one of them may be the best mating strategy for a male." Scott Borg Director NSF Antarctic Sciences "The project aims to determine the underlying causes behind why Pine Island Glacier has begun to flow more rapidly and discharge more ice into the ocean," "This could have a significant impact on global sea-level rise over the coming century." Robert Bindschadler Emeritus Glaciologist NASA's Goddard Space Flight Center "The Pine Island Glacier ice shelf continues to be the place where the action is taking place in Antarctica. It only can be understood by making direct measurements, which is hard to do. We're doing this hard science because it has to be done. The question of how and why it is melting is even more urgent than it was when we first proposed the project over five years ago."

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About 1.8 million people in Cambodia and Vietnam are currently suffering from the worst flooding in a decade. The situation has received far less media coverage then the floods in Thailand. . .




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The highly endangered sturgeons of the Danube river basin are at risk because of the persistent illegal trade in their caviar involving Bulgaria and Romania, according to a newly published TRAFFIC report compiled for WWF.
EU Fisheries Commissioner Maria Damanaki has suggested that fish that ends up as discards should be given to the poor or used as feed at fish farms. An estimated 1 million tones of fish are tossed back into the North Sea alone.Thanawat Jarupongsakul, a lecturer at the faculty of science's Unit for Disaster and Land Information Studies Thailand has proposed 11 flood preventive measures to permanently deal with flood disasters including an 'express super water highway.'
Thanawat Jarupongsakul, a lecturer at the faculty of science's Unit for Disaster and Land Information Studies Thailand has proposed 11 flood preventive measures to permanently deal with flood disasters including an 'express super water highway.'

1.8M HIT BY FLOODS IN CAMBODIA AND VIETNAM

ANTIGUA SEEKS MEGA YACHTS REGISTRY

MERCY SHIP HOSPITAL IN WEST AFRICA

P&I CLUB WARNS
TOO MUCH TECHNOLOGY ON SHIPS CAN BE DANGEROUS

A BLUEPRINT FOR OCEAN SUSTAINABILITY

Volvo Ocean Race
First Leg – Alicante to Cape Town – 12000 Km
UPDATES -VIDEOS


ILLEGAL CAVIAR TRADE
POSES MAJOR THREAT TO STURGEONS

GIVE FISH DISCARDS TO THE POOR

BANGKOK
SUPER WATERWAY TO CONTROL FLOODS?
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Jutta Jahrl Sturgeon Expert WWF "The EU has a major responsibility to regulate the caviar trade because EU member states are the largest consumer of caviar from Romania and the second largest consumer of caviar from Bulgaria. The EU must close every loophole in order to save sturgeons from extinction. It is crucial that traders and consumers do not buy unlabelled caviar - this simple act would strike a major blow against the illegal trade.”
Baldwin Spencer Prime Minister Antigua and Barbuda Yacht Registry “The Antigua and Barbuda Department of Marine Services and Merchant Shipping currently has yachts on its registry, although the merchant shipping aspect of the operations enjoys the most success. This official launch therefore is the commencement of a programme of expansion focusing on the mega-yacht class of the market. Antigua & Barbuda is growing in importance in the ship registry business, with the nation’s flag ranking within the top 20 international ship registries worldwide. It is ranked number eight in the merchant ships section and it is growing steadily. The country is now poised to move more aggressively in the market to attract the mega-yachts.”
Tito Morales-Pinzón Author of the study Researcher at UAB and Pereira Technological University (Colombia) "However, the costs and environmental impact of these systems have yet to be assessed, because although one material may be efficient in collecting or storing the rainwater, it may also be too expensive or cause contamination. Under the Water Framework Directive, local water prices will increase to include the real supply costs and this could lead to an interest in rainwater-collection strategies from the economic point of view.”

EVEN THE CLEANEST WASTEWATER
CONTRIBUTES TO MORE 'SUPER BACTERIA'

INTERNATIONAL TEAM TO
DRILL BENEATH MASSIVE ANTARCTIC ICE SHELF

PLANT WITH 'EGGBEATER' TEXTURE
INSPIRES WATERPROOF COATING

EXPERTS RECOMMEND THE INCLUSION OF
RAINWATER-COLLECTION SYSTEMS IN CITIES

IN BUBBLE-RAFTING SNAILS
THE EGGS CAME FIRST

LONG-TERM CARBON STORAGE IN GANGES BASIN
MAY PORTEND GLOBAL WARMING WORSENING
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