Researchers develop molecular switch that changes liquid crystal colors

August 26, 2013

Dartmouth researchers have developed a molecular switch that changes a liquid crystal's readout color based on a chemical input. This new development may open the way for using liquid crystals in detecting harmful gases, pathogens, explosives and other chemical substances.

The findings appear in the journal Angewandte Chemie.

One of the challenges in the field of molecular switches and machines is the translation of molecular level motion into macroscopic level events by harnessing light or chemical energy—think of a molecular-sized light switch that can be turned on and off. With an actual light switch, this can be easily done by hard wiring the switch to a light source, but doing this at the nanoscale is challenging.

In their study, the Dartmouth researchers used liquid crystals such as the ones in LCD (liquid crystal display) monitors and TV screens to address this challenge. They synthesized a pH activated that can control the long range assembly of a commercially available liquid crystal called NP5. This manipulation changed the readout color of NP5 from purple to green depending on the applied pH, confirming the molecular level motion is responsible for the change in the photophysical properties of the liquid crystal.

The findings open the way for researchers to design molecular switches that produce different readout colors when harmful chemical substances are detected. If these liquid crystals are used as pixels – similar to the ones in LCD screens – researchers may be able to bunch them together and develop groups of sensors that can quickly analyze and detect hazardous materials.

Explore further: Mobius strip ties liquid crystal in knots to produce tomorrow's materials and photonic devices

Related Stories

Making efficient color filter for display applications

August 29, 2012

Flat panel displays, mobile phones and many digital devices require thin, efficient and low-cost light-emitters for applications. The pixels that make up the different colors on the display are typically wired to complex ...

Researchers slow light to a crawl in liquid crystal matrix

August 13, 2013

(Phys.org) —Light traveling in a vacuum is the Universe's ultimate speed demon, racing along at approximately 300,000 kilometers per second. Now scientists have found an effective new way to put a speed bump in light's ...

Recommended for you

Two teams independently test Tomonaga–Luttinger theory

October 20, 2017

(Phys.org)—Two teams of researchers working independently of one another have found ways to test aspects of the Tomonaga–Luttinger theory that describes interacting quantum particles in 1-D ensembles in a Tomonaga–Luttinger ...

Using optical chaos to control the momentum of light

October 19, 2017

Integrated photonic circuits, which rely on light rather than electrons to move information, promise to revolutionize communications, sensing and data processing. But controlling and moving light poses serious challenges. ...

Black butterfly wings offer a model for better solar cells

October 19, 2017

(Phys.org)—A team of researchers with California Institute of Technology and the Karlsruh Institute of Technology has improved the efficiency of thin film solar cells by mimicking the architecture of rose butterfly wings. ...

Terahertz spectroscopy goes nano

October 19, 2017

Brown University researchers have demonstrated a way to bring a powerful form of spectroscopy—a technique used to study a wide variety of materials—into the nano-world.

0 comments

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.