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 Aromatic couple makes new chemical bonds
30.06.2015 | Institute of Transformative Bio-Molecules (ITbM), Nagoya University

nachricht Breaking through a double wall with a sledgehammer
29.06.2015 | Max-Planck-Institut für Entwicklungsbiologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Iron: A biological element?

Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and a half billion years ago.

Think of an object made of iron: An I-beam, a car frame, a nail. Now imagine that half of the iron in that object owes its existence to bacteria living two and...

Im Focus: Thousands of Droplets for Diagnostics

Researchers develop new method enabling DNA molecules to be counted in just 30 minutes

A team of scientists including PhD student Friedrich Schuler from the Laboratory of MEMS Applications at the Department of Microsystems Engineering (IMTEK) of...

Im Focus: Bionic eye clinical trial results show long-term safety, efficacy vision-restoring implant

Patients using Argus II experienced significant improvement in visual function and quality of life

The three-year clinical trial results of the retinal implant popularly known as the "bionic eye," have proven the long-term efficacy, safety and reliability of...

Im Focus: Lasers for Fast Internet in Space – Space Technology from Aachen

On June 23, the second Sentinel mission was launched from the space mission launch center in Kourou. A critical component of Aachen is on board. Researchers at the Fraunhofer Institute for Laser Technology ILT and Tesat-Spacecom have jointly developed the know-how for space-qualified laser components. For the Sentinel mission the diode laser pump module of the Laser Communication Terminal LCT was planned and constructed in Aachen in cooperation with the manufacturer of the LCT, Tesat-Spacecom, and the Ferdinand Braun Institute.

After eight years of preparation, in the early morning of June 23 the time had come: in Kourou in French Guiana, the European Space Agency launched the...

Im Focus: Superslippery islands (but then they get stuck)

A simple reversible process that changes friction in the nanoworld

(Nano)islands that slide freely on a sea of copper, but when they become too large (and too dense) they end up getting stuck: that nicely sums up the system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference on Regenerative Medicine in Leipzig: Last chance to submit abstracts until 2 July

25.06.2015 | Event News

World Conference on Regenerative Medicine: Abstract Submission has been extended to 24 June

16.06.2015 | Event News

MUSE hosting Europe’s largest science communication conference

11.06.2015 | Event News

 
Latest News

Aromatic couple makes new chemical bonds

30.06.2015 | Life Sciences

Extreme makeover: Mankind's unprecedented transformation of Earth

30.06.2015 | Earth Sciences

Large-scale field-effect transistors based on solution-grown organic single crystals are fabricated

30.06.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>