Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Impregnating plastics with carbon dioxide

This propeller was dyed yellow in only five minutes at 90 degrees Celsius and 200 bar. At this pressure, the yellow dye powder dissolved in the CO2 which transferred it into the plastic. ( Fraunhofer UMSICHT)
This propeller was dyed yellow in only five minutes at 90 degrees Celsius and 200 bar. At this pressure, the yellow dye powder dissolved in the CO2 which transferred it into the plastic. ( Fraunhofer UMSICHT)

Abstract:
Everyone has heard that carbon dioxide is responsible for global warming. But the gas also has some positive characteristics. Researchers are now impregnating plastics with compressed CO2 in a process that could lead to new applications ranging from colored contact lenses to bacteria-resistant door handles.

Impregnating plastics with carbon dioxide

Munich, Germany | Posted on January 4th, 2011

CO2 is more than just a waste product. In fact, it has a variety of uses: the chemical industry makes use of this colorless gas to produce urea, methanol and salicylic acid. Urea is a fertilizer, methanol is a fuel additive, and salicylic acid is an ingredient in aspirin.

Researchers at the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT in Oberhausen are pursuing a new idea by testing how carbon dioxide can be used to impregnate plastics. At a temperature of 30.1 degrees Celsius and a pressure of 73.8 bar, CO2 goes into a supercritical state that gives the gas solvent-like properties. In this state, it can be introduced into polymers, or act as a "carrier" in which dyes, additives, medical compounds and other substances can be dissolved. "We pump liquid carbon dioxide into a high-pressure container with the plastic components that are to be impregnated, then steadily increase the temperature and the pressure until the gas reaches the supercritical state. When that state is reached, we increase the pressure further. At 170 bar, pigment in powder form dissolves completely in the CO2 and then diffuses with the gas into the plastic. The whole process only takes a few minutes. When the container is opened, the gas escapes through the surface of the polymer but the pigment stays behind and cannot subsequently be wiped off," explains Dipl.-Ing. Manfred Renner, a scientist at Fraunhofer UMSICHT.

In tests, the researchers have even managed to impregnate polycarbonate with nanoparticles that give it antibacterial properties. E-coli bacteria, placed on the plastic's surface in the institute's own high-pressure laboratory, were killed off completely - a useful function that could be applied to door handles impregnated with the same nanoparticles. Tests conducted with silica and with the anti-inflammatory active pharmaceutical ingredient flurbiprofen were also successful. "Our process is suitable for impregnating partially crystalline and amorphous polymers such as nylon, TPE, TPU, PP and polycarbonate," states Renner, "but it cannot be applied to crystalline polymers."

The process holds enormous potential, as carbon dioxide is non-flammable, non-toxic and inexpensive. Whilst it shows solvent-like properties, it does not have the same harmful effects on health and on the environment as the solvents that are used in paints, for example. Painted surfaces are also easily damaged and are not scratch-resistant. Conventional processes for impregnating plastics and giving them new functions have numerous drawbacks. Injection molding, for instance, does not permit the introduction of heat-sensitive substances such as fire retardants or UV stabilizers. Many dyes change color; purple turns black. "Our method allows us to customize high-value plastic components and lifestyle products such as mobile phone shells. The best about it is that the color, additive or active ingredient is introduced into layers near the surface at temperatures far below the material's melting point, in an environ mentally friendly manner that does away with the need for aggressive solvents," says Renner. The process could, for example, be used to dye contact lenses - and lenses could even be enriched with pharmaceutical compounds that would then be slowly released to the eye throughout the day, representing an alternative to repeated applications of eye drops for the treatment of glaucoma. According to the scientist, this new impregnation method is suitable for a broad range of new applications.

####

For more information, please click here

Copyright © Fraunhofer Institute

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

Chains of nanogold forged with atomic precision September 23rd, 2016

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

Nanotech Grants Options September 22nd, 2016

Coffee-infused foam removes lead from contaminated water September 21st, 2016

Possible Futures

Chains of nanogold forged with atomic precision September 23rd, 2016

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

Coffee-infused foam removes lead from contaminated water September 21st, 2016

Towards Stable Propagation of Light in Nano-Photonic Fibers September 20th, 2016

Academic/Education

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

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Nanotech Security Featured by Simon Fraser University: Company's Anti-Counterfeiting Technology Developed With the Help of University's 4D LABS Materials Research Institute August 21st, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Materials/Metamaterials

Chains of nanogold forged with atomic precision September 23rd, 2016

Coffee-infused foam removes lead from contaminated water September 21st, 2016

Containing our 'electromagnetic pollution': MXene can protect mobile devices from electromagnetic interference September 13th, 2016

New material to revolutionize water proofing September 12th, 2016

Announcements

Chains of nanogold forged with atomic precision September 23rd, 2016

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

Nanotech Grants Options September 22nd, 2016

Coffee-infused foam removes lead from contaminated water September 21st, 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