Nanoparticle-based coating helps stop water from beading

Jul 01, 2014 by Marcia Wood
A nanoparticle-based coating from ARS, applied to the right half of this plastic container, prevents water from beading and reducing visibility. Credit: Sanghoon Kim.

When rain falls on a glass window or a plastic skylight cover, it often forms beads. That's because these surfaces typically are hydrophobic, meaning they repel water.

But a transparent, nanoparticle-based coating developed by Agricultural Research Service scientists can quickly change surfaces from hydrophobic to hydrophilic, so that rain doesn't bead up, and your visibility isn't impaired.

When raindrops come in contact with the spray-on coating, they spread, instead of beading, explains chemist Sanghoon Kim, who headed the nanoparticle studies.

Besides its potential use on windows, the coating might also be applied to solar panels, to help keep dirt from interfering with their performance.

What's more, Kim and colleagues have observed that the coating works well on other materials, including Plexiglas and metals such as stainless steel.

Kim, chemist Atanu Biswas, and physical scientist Kervin Evans—all at the ARS National Center for Agricultural Utilization Research in Peoria, Illinois—created the coating's nanoparticles using only a few off-the-shelf laboratory chemicals, including an ag-sourced protein.

From start to finish, production of the nanoparticles takes less than an hour, involves simple procedures with inexpensive chemicals, and doesn't require specialized equipment or costly heating.

In a proof-of-concept experiment, the researchers used as their protein and ethyl cyanoacrylate as the starting material that's key to creating the nanoparticles. Bovine is a cattle industry coproduct. Ethyl cyanoacrylate is a major component of what's commonly known as "super glue."

Simply stated, the nanoparticles were formed when ethyl cyanoacrylate reacted with albumin in a solution of acidified ethanol. Spinning this mixture in a centrifuge removed any byproducts of the reaction, resulting in suspended in the solution.

Applying the coating is quick and easy. All that's needed is to spray it onto clean glass or other recommended surface, then rinse with water.

Kim, Biswas, and Evans documented their results in a peer-reviewed scientific article published in 2013 in Colloids and Surfaces B: Biointerfaces.

In a followup study, Kim and colleague Yeon Seok Kim, of the National Institute of Standards and Technology, used gliadin—a protein from wheat—to demonstrate that their process is applicable to both plant- and animal-derived proteins. An article published this year in the Journal of Nanoparticle Research has details.

Typically, plant proteins are less expensive than those from animal sources. Regardless of which agricultural source is chosen, informal cost estimates suggest that the new coating could be made at the same or less cost than hydrophilic coatings already on the market.

The fact that the Peoria is rain-ready in about a minute apparently makes it unique. ARS is seeking a patent for the research, and the scientists are looking for industry partners, such as manufacturers of window-cleaning products, to commercialize the invention.

Explore further: Scientists create clearer glass with permanent, superhydrophilic ceramic coating

add to favorites email to friend print save as pdf

Related Stories

Bovine blood keeps gold nanoparticles stable

May 14, 2013

(Phys.org) —A protein from cow blood has the remarkable ability to keep gold nanoparticles from clumping in a solution. The discovery could lead to improved biomedical applications and contribute to projects ...

A new anti-frost and anti-fog coating for glass

Feb 27, 2013

In an advance toward glass that remains clear under the harshest of conditions, scientists are reporting development of a new water-repellant coating that resists both fogging and frosting. Their research ...

Recommended for you

The latest fashion: Graphene edges can be tailor-made

Jan 23, 2015

Theoretical physicists at Rice University are living on the edge as they study the astounding properties of graphene. In a new study, they figure out how researchers can fracture graphene nanoribbons to get ...

Nanotechnology changes behavior of materials

Jan 23, 2015

One of the reasons solar cells are not used more widely is cost—the materials used to make them most efficient are expensive. Engineers are exploring ways to print solar cells from inks, but the devices ...

Gold 'nano-drills'

Jan 22, 2015

Spherical gold particles are able to 'drill' a nano-diameter tunnel in ceramic material when heated. This is an easy and attractive way to equip chips with nanopores for DNA analysis, for example. Nanotechnologists ...

The importance of building small things

Jan 22, 2015

Strong materials, such as concrete, are usually heavy, and lightweight materials, such as rubber (for latex gloves) and paper, are usually weak and susceptible to tearing and damage. Julia R. Greer, professor ...

Graphene brings quantum effects to electronic circuits

Jan 22, 2015

Research by scientists attached to the EC's Graphene Flagship has revealed a superfluid phase in ultra-low temperature 2D materials, creating the potential for electronic devices which dissipate very little ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.