Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

At Smallest Scale, Liquid Crystal Behavior Portends New Materials

04.05.2012
Liquid crystals, the state of matter that makes possible the flat screen technology now commonly used in televisions and computers, may have some new technological tricks in store.

Writing yesterday (May 3, 2012) in the journal Nature, an international team of researchers led by University of Wisconsin-Madison Professor of Chemical and Biological Engineering Juan J. de Pablo reports the results of a computational study that shows liquid crystals, manipulated at the smallest scale, can unexpectedly induce the molecules they interact with to self-organize in ways that could lead to entirely new classes of materials with new properties.

"From an applied perspective, once we get to very small scales, it becomes incredibly difficult to pattern the structure of materials. But here we show it is possible to use liquid crystals to spontaneously create nanoscale morphologies we didn’t know existed," says de Pablo of computer simulations that portray liquid crystals self-organizing at the molecular scale in ways that could lead to remarkable new materials with scores of technological applications.

As their name implies, liquid crystals exhibit the order of a solid crystal but flow like a liquid. Used in combination with polarizers, optical filters and electric fields, liquid crystals underlie the pixels that make sharp pictures on thin computer or television displays. Liquid crystal displays alone are a multibillion dollar industry. The technology has also been used to make ultrasensitive thermometers and has even been deployed in lasers, among other applications.

The new study modeled the behavior of thousands of rod-shaped liquid crystal molecules packed into nano-sized liquid droplets. It showed that the confined molecules self organize as the droplets are cooled. "At elevated temperatures, the droplets are disordered and the liquid is isotropic," de Pablo explains. "As you cool them down, they become ordered and form a liquid crystal phase. The liquid crystallinity within the droplets, surprisingly, induces water and other molecules at the interface of the droplets, known as surfactants, to organize into ordered nanodomains. This is a behavior that was not known."

In the absence of a liquid crystal, the molecules at the interface of the droplet adopt a homogeneous distribution. In the presence of a liquid crystal, however, they form an ordered nanostructure. "You have two things going on at the same time: confinement of the liquid crystals and an interplay of their structure with the interface of the droplet," notes de Pablo. "As you lower the temperature the liquid crystal starts to become organized and imprints that order into the surfactant itself, causing it to self assemble."

It was well known that interfaces influence the order or morphology of liquid crystals. The new study shows the opposite to be true as well.

"Now you can think of forming these ordered nanophases, controlling them through droplet size or surfactant concentration, and then decorating them to build up structures and create new classes of materials," says de Pablo.

As an example, de Pablo suggested that surfactants coupled to DNA molecules could be added to the surface of a liquid crystal droplets, which could then assemble through the hybridization of DNA. Such nanoscale engineering, he notes, could also form the basis for liquid crystal based detection of toxins, biological molecules, or viruses. A virus or protein binding to the droplet would change the way the surfactants and the liquid crystals within the droplet are organized, triggering an optical signal. Such a technology would have important uses in biosecurity, health care and biology research settings.

The new study was supported by the U.S. Department of Energy (DOE) through the Office of Basic Energy Sciences, and the U.S. National Science Foundation. In addition to de Pablo, authors of the new report include former postdoctoral fellows J.A. Moreno-Razo and E.J. Sambriski, now at the Autonomous Metropolitan University of Mexico and Delaware Valley College, respectively; Nicholas L. Abbott, of UW-Madison; and J.P. Hernández-Ortiz of the National University of Colombia.

-- Terry Devitt (608) 262-8282, trdevitt@wisc.edu

Juan de Pablo | Newswise Science News
Further information:
http://www.wisc.edu

Further reports about: DNA DNA molecule Energy Science Liquid Science TV computer simulation liquid crystal

More articles from Materials Sciences:

nachricht Cementless fly ash binder makes concrete 'green'
19.06.2018 | Rice University

nachricht Ground-breaking discoveries could create superior alloys with many applications
19.06.2018 | Chalmers University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>