Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Thermoresponsive polymers: Positive progress on antifouling

04.08.2014

Heat-responsive polymers that do not breakdown in water may lead to new antifouling coatings and enhanced oil recovery.

Thanks to the positively and negatively charged units in their monomers, zwitterionic polymers have a high affinity for water — a property known as hydrophilicity. This property helps prevent fouling, namely the build-up of contaminants. Current zwitterionic polymers are not effective in water as they use monomers such as commercially available acrylamide and methacrylates that tend to decompose and lose their electrostatic characteristics when wet.


Their high tolerance to salt, pH and temperature cause zwitterionic polymers to become viscous when subjected to high shear forces in brine, making them useful for marine antifouling applications.

© Alexcrab/iStock/Thinkstock

To solve this issue, a team led by Vivek Vasantha from the A*STAR Institute of Chemical and Engineering Sciences in Singapore has now developed zwitterionic polymers based on water-stable monomers that incorporate nitrogen-containing derivatives known as imidazoles[1]. The team introduced the zwitterions to readily accessible, hydrophobic polystyrene to boost its hydrophilicity in water by forming a hydration layer through electrostatic interactions and hydrogen bonding.

To synthesize the monomers, Vasantha’s team reacted styrene precursors with positively charged imidazoles before attaching the negatively charged sulfonate functional groups. The monomers produced polymers with intact zwitterionic properties, meaning that they retained their positive and negative charges.

These new imidazole-based polymers exhibited some novel solubility characteristics: unlike their conventional water-soluble counterparts, they swelled in water and dissolved only in highly concentrated brine. These differences stem from dipole–dipole interactions and the more hydrophobic nature of the new polymers compared to acrylamide and methacrylate.

With high tolerances to salt, pH and temperature, these polymers became increasingly viscous when subjected to higher shear forces in brine. This characteristic — similar to ‘silly putty’, which is malleable in one’s hands but is unchanged when hit with a hammer — makes the polymers attractive for enhanced oil recovery and marine antifouling coatings.

Another advantage of the new polymers is their reversible phase change: between 5 °C and 95 °C, the polymers formed gels that become clear fluids when heated above the so-called critical temperature in brine and that revert to their stable cloudy state on cooling.

“This phase transition results from the disruption of the equilibrium between salt, water and zwitterionic species,” says Vasantha. The polymer chains expand on heating and collapse below the critical temperature. The researchers can control the critical temperature by simply varying either the brine or polymer concentration. For example, the transition occurred at 20 °C at a low polymer concentration but at 40 °C at a higher polymer concentration.

“We are currently designing new zwitterionic polymers and copolymers with salt- and heat-responsive behavior for a wide range of applications, such as enhanced oil recovery, low-temperature protein separation and antifouling,” says Vasantha.

Reference

1. Vasantha, V. A., Jana, S., Parthiban, A. & Vancso, J. G. Water swelling, brine soluble imidazole-based zwitterionic polymers – synthesis and study of reversible UCST behavior and gel–sol transitions. Chemical Communications 50, 46–48 (2014).

Lee Swee Heng | Research SEA News
Further information:
http://www.research.a-star.edu.sg/research/7009
http://www.researchsea.com

More articles from Life Sciences:

nachricht A cell senses its own curves: New research from the MBL Whitman Center
29.04.2016 | Marine Biological Laboratory

nachricht A New Discovery in the Fight against Cancer: Tumor Cells Switch to a Different Mode
29.04.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Tiny microbots that can clean up water

Researchers from the Max Planck Institute Stuttgart have developed self-propelled tiny ‘microbots’ that can remove lead or organic pollution from contaminated water.

Working with colleagues in Barcelona and Singapore, Samuel Sánchez’s group used graphene oxide to make their microscale motors, which are able to adsorb lead...

Im Focus: ORNL researchers discover new state of water molecule

Neutron scattering and computational modeling have revealed unique and unexpected behavior of water molecules under extreme confinement that is unmatched by any known gas, liquid or solid states.

In a paper published in Physical Review Letters, researchers at the Department of Energy's Oak Ridge National Laboratory describe a new tunneling state of...

Im Focus: Bionic Lightweight Design researchers of the Alfred Wegener Institute at Hannover Messe 2016

Honeycomb structures as the basic building block for industrial applications presented using holo pyramid

Researchers of the Alfred Wegener Institute (AWI) will introduce their latest developments in the field of bionic lightweight design at Hannover Messe from 25...

Im Focus: New world record for fullerene-free polymer solar cells

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences (CAS). This work is about avoiding costly and unstable fullerenes.

Polymer solar cells can be even cheaper and more reliable thanks to a breakthrough by scientists at Linköping University and the Chinese Academy of Sciences...

Im Focus: Ultra-thin glass is up and coming

As one of the leading R&D partners in the development of surface technologies and organic electronics, the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP will be exhibiting its recent achievements in vacuum coating of ultra-thin glass at SVC TechCon 2016 (Booth 846), taking place in Indianapolis / USA from May 9 – 13.

Fraunhofer FEP is an experienced partner for technological developments, known for testing the limits of new materials and for optimization of those materials...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

The “AC21 International Forum 2016” is About to Begin

27.04.2016 | Event News

Soft switching combines efficiency and improved electro-magnetic compatibility

15.04.2016 | Event News

Grid-Supportive Buildings Give Boost to Renewable Energy Integration

12.04.2016 | Event News

 
Latest News

Winds a quarter the speed of light spotted leaving mysterious binary systems

29.04.2016 | Physics and Astronomy

Fiber optic biosensor-integrated microfluidic chip to detect glucose levels

29.04.2016 | Health and Medicine

A cell senses its own curves: New research from the MBL Whitman Center

29.04.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>