Researchers from the University of Wisconsin have found that defects that run through liquid crystals can serve as miniscule tubes capable of forming new materials and nanoscale structures.
Liquid crystals have properties that lie between those of conventional liquid and those of solid crystal. A liquid crystal may flow just like a liquid but has molecules that are oriented in a crystal-like way.
Contemporary electronic displays often use liquid crystals. Liquid crystals also exist in the natural world. Many cell membranes and proteins are in fact liquid crystals.
For a new study, which was published in the journal Nature Materials on Sept. 21, researchers focused on the use of the topological defects in liquid crystal that are already widely used for organizing colloidal dispersion.
The defects can now also be used for channeling molecules into particular positions to form new materials and nanoscale structures, which could have applications in a range of fields including medicine and electronics.
The researchers explained that controlling the geometry of the system allows for the sending of these channels from any one point to another point, an approach study researcher Nicholas Abbott, from the University of Wisconsin, described as versatile.
"This is an enabling discovery," Abbott said. "We're not looking for a specific application, but we're showing a versatile method of fabrication that can lead to structures you can't make any other way."
Abbott and colleagues have so far been able to assemble phospholipids, molecules capable of organizing into layers in the walls of cells, within the defects in liquid crystal.
It is possible to introduce many defects with the manipulation of the liquid crystalline system's geometry and this can be used to produce nanomaterials in varying shapes.
The researchers have so far had success in producing defects that look like small ropes and have filled them with water and fat loving molecules.
When they link these assemblies of molecules together and remove the templates of liquid crystal, it leaves behind the amphiphilic building blocks in a nanoscale structure that lasts.
"By using fluorescence microscopy, cryogenic transmission electron microscopy and super-resolution optical microscopy, we observed signatures of molecular self-assembly of amphiphilic molecules in topological defects, including cooperativity, reversibility and controlled growth," the researchers wrote in their study.
