Liquid crystal samples were found to exhibit up to four levels of chirality, despite being made up of achiral molecules. The work sheds light on how molecular properties and competing interactions “propagate” order from the molecular level up to the microscale, leading to complexity similar to that found in biological materials. Read more »
ALS Work Using RSoXS
Resonant soft x-ray scattering (RSoXS) combines conventional small-angle x-ray scattering (SAXS) with soft x-ray absorption spectroscopy (XAS) for a chemically sensitive structure probe that unambiguously deciphers the complex morphologies of mesoscale materials. The scattering contributions from the different components can be selectively enhanced by tuning the x-ray photon energy to match the absorption spectrum of different chemical components. RSoXS has been applied to structured polymer assemblies, organic electronics, functional nanocomposites, liquid crystals, and bio/biohybrid materials.
Resonant x-ray scattering and x-ray absorption spectroscopy with elemental sensitivity unravel structural features tied to water–ion domains and discern sulfur-containing groups in sulfonated ionomers, which help delineate chemical factors controlling their phase-separated morphology and governing ion transport. Read more »
Researchers untangled connections between structure and behavior in a class of liquid crystals consisting of flexible, chain-like molecules that self-organize into twisting patterns. The study opens up new possibilities for designing novel liquid-crystal molecules that allow greater control of nanoscale behavior for technological applications. Read more »
Researchers have established a new quantitative model that connects molecular interactions in organic solar-cell materials to device performance. The work suggests a way to quickly identify ideal material mixtures and processing methods, bypassing trial-and-error strategies and minimizing labor-intensive synthesis. Read more »
The spontaneous formation of chiral structures from achiral molecules could shed light on the origin of biological homochirality—how one type of chirality dominated the other in certain biological molecules. Here, resonant soft x-ray scattering (RSoXS) has been used to explore helical phases that emerge from achiral asymmetric dimers. Read more »
Resonant soft x-ray scattering revealed liquid crystal structures that cannot be probed using diffraction, including chiral liquid crystal systems such as the “blue phase” and the twist-bend nematic phase. Information on how individual molecules form functional structures in these systems is key to developing new applications. Read more »
Resonant soft x-ray scattering (RSoXS) at the carbon K-edge was used to probe periodic structures of phases with orientational molecular order but homogeneous electron density distribution. This approach can be applied to structures with periodicities below the optical wavelength, to which neither optical nor classical x-ray diffraction techniques are sensitive. Read more »
With the help of four different ALS beamlines, scientists were able to understand and improve the morphology of the main device structure in organic photovoltaic cells. Read more »
For the first time, researchers have directly measured the helical pitch of twisted liquid crystals composed of achiral bent-core molecules. The work opens the door to understanding the interplay between structure and property in important organic materials, including liquid crystals, lipid tubules, and peptoids. Read more »
A new measurement technique developed at the ALS is helping guide the semiconductor industry in next-generation nanopatterning techniques. NIST and IBM researchers collaborated on the technique, which allows scientists to evaluate the 3D buried features inside a film. The ALS is currently the only place in the world that has such capability.