Innovative path to novel materials with adaptive electrical and optical properties
A team of researchers has used X-rays from DESY’s research light source PETRA III to explore the amazingly diverse self-organisation of liquid crystals in nanometre-sized pores. The study, led by Patrick Huber from the Hamburg University of Technology (TUHH), shows how liquid crystals arrange themselves in pores of different sizes, exhibiting different electrical and optical properties. These could be of interest for applications such as sensors and novel optical metamaterials, as the group around first author Kathrin Sentker from TUHH reports in the journal Nanoscale. The research, which Huber presented at the annual DESY Users’ Meeting running until this Friday, will be continued within the framework of the planned Centre for Multiscale Materials Systems (CIMMS), in which TUHH, University of Hamburg, Helmholtz-Zentrum Geesthacht and DESY are involved and for which the Hamburg Science Authority has just approved approximately four million euros funding.
The researchers had studied a special liquid crystal material called HAT6 (2,3,6,7,10,11-hexakis(hexyloxy)triphenylene; C54H84O6), whose single molecules are disc-shaped. Below about 70 degrees Celsius, they arrange themselves into a liquid crystal; by heating to about 100 degrees, the order can be broken. The scientists filled this material into pores in an aluminium oxide substrate and cooled it down. The cylindrical pores were 17 to 160 nanometres (millionths of a millimeter) in diameter, 0.1 millimetres long and situated on a regular, hexagonal lattice.
Image: Simulation of the different orders of the liquid crystal, matching the measurements. Simulation: Marco D. Mazza, Max Planck Institute for dynamics and self-organisation and und Loughborough University