Construction of sub-5 nm long-range ordered structures through self-assembly has received increasing attention. Herein, a series of ODMS-based thermotropic liquid crystals (LCs) containing perylene diimide (PDI) were designed and synthesized. These LCs can form ordered nanostructures with periodic sizes around 5 nm including smectic J (SmJ), oblique columnar (Col ), and hexagonal columnar (Col ) phases with change in the volume fraction of ODMS, where the layer spacing of the SmJ phase is less than 5 nm. Thin films with parallel oriented nanolines with line width less than 5 nm can be obtained on PDMS-modified silicon substrates by spin-casting and simple thermal annealing processes. Moreover, owing to the strong π-π interaction between PDI cores, these nanolines are long-range ordered with uniaxial orientation in relatively large areas (1.5×1.5 μm ) with over 300 continuous microdomains without pre-patterning. These nanostructures provide the possibility of preparing nanotemplates by oxygen plasma etching.
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http://dx.doi.org/10.1002/chem.202203702 | DOI Listing |
Chemistry
January 2025
Universitat Bielefeld, Chemie, Universitätsstraße 15, 33615, Bielefeld, GERMANY.
This work combines halogen and chalcogen bonding. Short, polarity directed C-X⋅⋅⋅Ch (X = Br or I, Ch = Se or Te) contacts were prepared by in situ low-temperature cocrystallization of liquid mixtures of neutral pentafluorohalogenobenzenes C6F5X and dimethyl chalco-genides Me2Ch. Solid-state structures of Me2Se and Me2Te were determined 150 and 125 years after their first description.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, SUNY Buffalo State University, 1300 Elmwood Ave., Buffalo, New York 14222, United States.
Here, we report a simple method to prepare near-IR (NIR) surface-enhanced Raman scattering (SERS) substrates by quickly freezing a citrate-capped Au nanoparticle (AuNP) solution in liquid nitrogen, followed by thawing it at room temperature. This process aggregates AuNPs in a controlled manner by forming ice crystals with smaller grain sizes when compared to a slow freezing process. The resulting smaller AuNP aggregates remain suspended in solution long enough to conduct high-throughput chemical analysis in a microwell plate using the NIR SERS spectroscopy.
View Article and Find Full Text PDFJ Mol Graph Model
January 2025
Institute of Chemical Physics after A.B. Nalbandyan of NAS RA, 5/2 P. Sevak St., Yerevan, 0014, Armenia.
Liquid crystals (LC) are widely used in various optical devices due to their birefringence, dielectric anisotropy, and responsive behavior to external fields. Enhancing the properties of existing LCs through doping with nanoparticles, including semiconductor quantum dots, offers a promising route for improving their performance. Among various nanoparticles, QDs stand out for their high charge mobility, sensitivity in the near-infrared spectral region, and cost-effectiveness.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
Center for Research on Advanced Fiber Technologies (CRAFT), Materials Research Institute and Huck Institute of Life Sciences, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Molecular composites, such as bone and nacre, are everywhere in nature and play crucial roles, ranging from self-defense to carbon sequestration. Extensive research has been conducted on constructing inorganic layered materials at an atomic level inspired by natural composites. These layered materials exfoliated to 2D crystals are an emerging family of nanomaterials with extraordinary properties.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO 80309, USA.
The current intense study of ferroelectric nematic liquid crystals was initiated by the observation of the same ferroelectric nematic phase in two independently discovered organic, rod-shaped, mesogenic compounds, RM734 and DIO. We recently reported that the compound RM734 also exhibits a monotropic, low-temperature, apolar phase having reentrant isotropic symmetry (the I phase), the formation of which is facilitated to a remarkable degree by doping with small (below 1%) amounts of the ionic liquid BMIM-PF. Here we report similar phenomenology in DIO, showing that this reentrant isotropic behavior is not only a property of RM734 but is rather a more general, material-independent feature of ferroelectric nematic mesogens.
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