- About Us
- Career Center
- Nano-Social Network
- Nano Consulting
- My Account
|Polarized light microscopy image of a square microparticle in liquid crystal|
Chemists and physicists have succeeded in getting custom-shaped microparticles to interact and self-assemble in a controlled way in a liquid crystal.
The research, federally funded by the National Science Foundation, appears in the Nov. 20 edition of the journal Science.
"We're learning the rules about how these lithographic particles self-assemble," said Thomas G. Mason, a UCLA professor of chemistry and physics and a member of the California NanoSystems Institute at UCLA. "This method may enable us to cause them to assemble in desired configurations."
The scientists anticipate that their "LithoParticles," which are made of solid polymeric materials, will have significant technological and scientific uses.
"We're examining how pairs of particles interact and come to attach together," Mason said. "If we can get the particles to interact in certain controlled ways, we can build larger-scale assemblies that may have applications in photonics, optical communication networks and a variety of other areas."
Mason and his colleagues — lead author Clayton Lapointe, a postdoctoral scholar at UCLA, formerly at the University of Colorado at Boulder, and Ivan Smalyukh, an assistant professor of physics at the University of Colorado at Boulder — used an optical microscope to study the attractions between the particles, which they custom designed in various shapes, including triangles, squares and pentagons. The particles are too small to see with the unaided eye but are quite clear with the instrument.
"This is a very complex material that we have created," said Mason, whose research is at the intersection of chemistry, physics, engineering and biology. "We have made lithographic particles dispersed in a liquid crystal, and the molecular constituents are aligned."
Particles of different shapes interact in different ways, Lapointe, Mason and Smalyukh report. Those with an odd number of sides, such as triangles and pentagons, interact differently than particles shaped like squares.
"In this environment, the particles have different kinds of interactions that depend on their shapes," Mason said. "We have shown in a systematic way how by changing the number of sides of the particles in a controlled way, we can characterize the differences in their interactions."
The scientists added materials to the liquid crystal to get the particles to attract. They produced the geometric particles using the same method Mason and his UCLA used to design and mass-produce billions of fluorescent microscale particles in the shapes of all 26 letters of the alphabet, as well as geometric shapes, such as triangles, crosses and doughnuts, in 2007. Now they have watched the particles interact.
In another paper, UCLA postdoctoral scholar Kun Zhao and Mason report discovering new states of matter in two dimensions. Their research, which appears in the Nov. 13 edition of the journal Physical Review Letters, focused on a two-dimensional surface with pentagon-shaped particles that were free to move on this surface. Zhao and Mason studied the structures as they increased the area fraction of the pentagons in the confined two-dimensional plane. They used a lithographic technique to make the particles and studied them in water on a flat glass surface.
For information about Mason's research, visit www.chem.ucla.edu/dept/Faculty/Mason.
UCLA is California's largest university, with an enrollment of nearly 38,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university's 11 professional schools feature renowned faculty and offer more than 323 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Five alumni and five faculty have been awarded the Nobel Prize.
For more information, please click here
Copyright © UCLAIf 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.
|Related News Press|
News and information
Accurate design of large icosahedral protein nanocages pushes bioengineering boundaries: Scientists used computational methods to build ten large, two-component, co-assembling icosahedral protein complexes the size of small virus coats July 25th, 2016
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers
Ultrasensitive sensor using N-doped graphene July 26th, 2016
Attosecond physics: Mapping electromagnetic waveforms July 25th, 2016
RMIT researchers make leap in measuring quantum states July 21st, 2016
Graphene photodetectors: Thinking outside the 2-D box July 21st, 2016