Category: winter

Never Scrape Again: Windshield Coating Repels Frost

On By A.P.In ACS Nano, frost, frosting, hydrophilic, hydrophobic, Massachusettes, materials science, Michael Rubner, MIT, Science, Technology, windshield, winterLeave a comment

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A fogged-up camera lens can ruin a perfect shot, and a frosty car window can lead to potentially deadly accidents. To help keep glass clear in harsh weather, scientists are developing an advanced new coating that resists both fogging and frosting.

Glass fogs up and frosts because of water. So you might assume so-called hydrophobic materials, which repel water, provide the best method of fighting such moisture. However, these solutions tend only to make water bead up, scattering light and obscuring views.

Researchers have also experimented with the opposite tactic, attempting to prevent fogging and frosting using hydrophilic materials, which attract water. Here, researchers hope to smear water across the glass surfaces in uniform sheets, to keep the moisture from distorting light. Although these materials work against fog, they can’t prevent frosting. When cold glass encounters humid air, the layer of water that develops simply freezes.

However, the new coating possesses both water-repelling and water-attracting properties, so it works against both fog and frost. The material contains organic compounds with both hydrophilic and hydrophobic components. The hydrophilic ingredients love water so much they absorb moisture, trapping it and keeping it from easily forming ice crystals. This lowers water’s usual freezing temperature and dramatically reduces frosting.

Meanwhile, the material’s hydrophobic components help repel contaminants that might spoil the hydrophilic effect.

“We have no freezing of water, even at low temperatures. It remains completely clear,” researcher Michael Rubner, a materials scientist at MIT, told TechNewsDaily.

When the new coating warms up from the freezing cold, it releases the water, “which just evaporates,” Rubner added.

The new coating does have its limits. “If it’s overwhelmed with water, any excess water can freeze,” Rubner said. “You wouldn’t want this on an airplane wing that constantly gets water on it, but an application like eyeglasses or windshields, it can be amazing.”

The researchers are now seeking to enhance the material’s durability to mechanical stresses. They detailed their findings online Jan. 29 in the journal ACS Nano.

http://www.livescience.com/27611-never-scrape-again-windshield-coating-repels-frost.html

Motorists waste £50m a year while defrosting their cars

On By A.P.In fuel efficiency, winterLeave a comment

Motorists who leave their car engine idle while defrosting their windscreen will waste nearly £50m in fuel this winter, according to Direct Line Car Insurance.

While the average person takes only three minutes to defrost their car, high fuel costs mean even using this small amount of petrol or diesel will see their money go up in exhaust fumes. The wasted fuel equates to over 300 million road miles, and would enable someone to drive an average sized car more than 13,000 times around the world.

However, fuel waste should not be the only worry for motorists. Of those regular drivers who took part in the study, 42pc admitted to having left their car unattended with the keys in the ignition. This makes them the perfect target for thieves, and they risk invalidating their insurance policy as well, should the vehicle get stolen.

Steve Price, head of Direct Line Car Insurance, said: “With fuel prices having risen more than 40 pence per litre since 2007, it makes more sense than ever to consider alternative methods of defrosting your car on icy days. It is really important that drivers never leave their cars unattended with the keys in the ignition under any circumstances, but particularly when defrosting their cars.

“Many of us are pressed for time in the mornings and so leaving your car to warm up whilst running back indoors to tie up some loose ends can seem like a clever use of our time. However, if a theft occurs under these circumstances, policyholders may not be covered.”

http://www.telegraph.co.uk/finance/personalfinance/insurance/motorinsurance/9674396/Motorists-waste-50m-a-year-while-defrosting-their-cars.html