Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Novel Clay-based Coating May Point the Way to New Generation of Green Flame Retardants

Using a testing device called a cone calorimeter, NIST researchers measure the heat-release rate and other flammability properties of materials. Above, untreated polyurethane foam 'catches fire' from a nearby heat source. Below, foam treated with a novel clay-filled coating did not ignite when exposed to the same heat source. Instead, a fast-growing protective layer called char forms on the surface.
Credit: NIST
Using a testing device called a cone calorimeter, NIST researchers measure the heat-release rate and other flammability properties of materials. Above, untreated polyurethane foam 'catches fire' from a nearby heat source. Below, foam treated with a novel clay-filled coating did not ignite when exposed to the same heat source. Instead, a fast-growing protective layer called char forms on the surface.

Credit: NIST

Abstract:
In searching for better flame retardants for home furnishings—a large source of fuel in house fires—National Institute of Standards and Technology (NIST) researchers defied the conventional wisdom and literally hit a wall, one made of clay.

Novel Clay-based Coating May Point the Way to New Generation of Green Flame Retardants

Gaithersburg, MD | Posted on June 28th, 2012

It wasn't a dead end, but rather a surprising result that may lead to a new generation of nonhalogenated, sustainable flame retardant technology for polyurethane foam. The thick, fast-forming coating that the NIST team created has a uniformly high concentration of flame-inhibiting clay particles, and it adheres strongly to the Swiss cheese-like surface of polyurethane foam, which is used in furniture cushions, carpet padding, children's car seats, and other items.

"In effect, we can build the equivalent of a flame-retarding clay wall on the foam in a way that has no adverse impact on the foam manufacturing process," explains NIST fire researcher Rick Davis. "Our clay-based coatings perform at least as well as commercial retardant approaches, and we think there's room for improvement. We hope this new approach provides industry with practical alternative flame retardants."

Davis and his NIST colleagues describe the new coating and the process they used to make it in the journal ACS Macro Letters.*

To date, researchers have built up coatings by stacking thin layers in pairs that are held together by basic electrical attraction. With no clay present, just a pure polymer, a thick coating is formed rapidly, but it isn't a fire retardant. With clay in every other layer, either the coating is too thin or the clay content is too low to be an effective fire retardant.

The NIST team tried something you would expect not to work: trilayers consisting of a positively charged bottom topped by two negatively charged layers. Under most circumstances, the two negative layers would repulse each other, but it turns out that hydrogen bonds formed between the two negative layers and overcame this repulsive force.

The resulting trilayer yields a unique result: a thick, fast-forming, and high concentration clay coating on polyurethane foam. This nanocomposite coating is 10 times thicker, contains 6 times more clay, and achieves this using at least 5 times fewer total layers than the traditional bilayer coatings.

"The eight trilayer system thoroughly coated all internal and external surfaces of the porous polyurethane foam, creating a clay brick wall barrier that reduced foam flammability by as much as 17 percent of the peak heat release rate," the team reported. Only a few hundred nanometers thick, the final coating is transparent and the foam still has the same softness, support and feel.

Compared with amounts of current flame retardant applied to polyurethane foam, only half as much of the new clay-based coating was required to achieve comparable levels of performance.

* Y.S. Kim, R. Harris and R. Davis. Innovative approach to rapid growth of highly clay-filled coatings on porous polyurethane foam. ACS Macro Letters, 2012, 1, 820−824. .dx.doi.org/10.1021/mz300102h

####

About National Institute of Standards and Technology (NIST)
The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

For more information, please click here

Contacts:
Mark Bello
301-975-3776

Copyright © National Institute of Standards and Technology (NIST)

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Harris & Harris Group Notes Announcements by Its Portfolio Companies During the Third Quarter of 2016 September 30th, 2016

INVECAS to Enable ASIC Designs for Tomorrow’s Intelligent Systems on GLOBALFOUNDRIES' FDX™ Technology: INVECAS to Collaborate with GLOBALFOUNDRIES to Provide IP and End-to-End ASIC Design Services on 22FDX® and 12FDX™ Technologies September 30th, 2016

How to power up graphene implants without frying cells: New analysis finds way to safely conduct heat from graphene to biological tissues September 30th, 2016

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Laboratories

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

NIST Patents Single-Photon Detector for Potential Encryption and Sensing Apps September 16th, 2016

Electron beam microscope directly writes nanoscale features in liquid with metal ink September 16th, 2016

World's most powerful X-ray takes a 'sledgehammer' to molecules September 14th, 2016

Govt.-Legislation/Regulation/Funding/Policy

How to power up graphene implants without frying cells: New analysis finds way to safely conduct heat from graphene to biological tissues September 30th, 2016

Crystalline Fault Lines Provide Pathway for Solar Cell Current: New tomographic AFM imaging technique reveals that microstructural defects, generally thought to be detrimental, actually improve conductivity in cadmium telluride solar cells September 26th, 2016

Tattoo therapy could ease chronic disease: Rice-made nanoparticles tested at Baylor College of Medicine may help control autoimmune diseases September 23rd, 2016

PHENOMEN is a FET-Open Research Project aiming to lay the foundations a new information technology September 19th, 2016

Discoveries

How to power up graphene implants without frying cells: New analysis finds way to safely conduct heat from graphene to biological tissues September 30th, 2016

Nanosensors could help determine tumors’ ability to remodel tissue: Measuring enzyme levels could help doctors select appropriate treatments September 29th, 2016

Fighting cancer with sticky nanoparticles September 27th, 2016

Gold nanoparticles conjugated quercetin inhibits epithelial-mesenchymal transition, angiogenesis and invasiveness via EGFR/VEGFR-2 mediated pathway in breast cancer September 27th, 2016

Announcements

Harris & Harris Group Notes Announcements by Its Portfolio Companies During the Third Quarter of 2016 September 30th, 2016

INVECAS to Enable ASIC Designs for Tomorrow’s Intelligent Systems on GLOBALFOUNDRIES' FDX™ Technology: INVECAS to Collaborate with GLOBALFOUNDRIES to Provide IP and End-to-End ASIC Design Services on 22FDX® and 12FDX™ Technologies September 30th, 2016

How to power up graphene implants without frying cells: New analysis finds way to safely conduct heat from graphene to biological tissues September 30th, 2016

Innovation in Nanotechnology is Focus of Symposium: Annual event brings international experts to Northwestern Oct. 6 September 29th, 2016

Home

New flexible material can make any window 'smart' August 23rd, 2016

Industrial Nanotech, Inc. Provides Shareholder Update August 22nd, 2016

Lucintel identifies and prioritizes opportunities for alumina trihydrate (ATH) fillers in the global composites industry August 3rd, 2016

Industrial Nanotech, Inc. Expands Distribution Network in US and Internationally May 9th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic