Here, we describe a strategy to obtain nanoporous liquid-crystalline (LC) membranes by incorporating a photocleavable -nitrobenzyl group in polymerizable columnar liquid crystals. Two derivatives were synthesized with propylene and nonylene spacers, respectively, between the ionic and the photocleavable moieties to introduce various size nanopores after photocleavage. The membranes were prepared by photopolymerization in the LC states, followed by photocleavage and washing with methanol. The resulting membranes show a virus rejection of 99.99%. Although the rejection value remained almost the same for the two membranes, water flux increased with increasing the length of the alkyl spacers. These membranes were found to be almost free from pinhole defects. The present study offers a new methodology for the development of nanoporous membranes with organized nanostructures for separation technologies.
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http://dx.doi.org/10.1021/acsmacrolett.9b00513 | DOI Listing |
J Am Chem Soc
January 2025
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia.
Designing molecular receptors that bind anions in water is a significant challenge, and an even greater difficulty lies in using these receptors to remove anions from water without resorting to the hazardous liquid-liquid extraction approach. We here demonstrate an effective and synthetically simple strategy toward these goals by exploiting ion-pair assembly of macrocycles. Our anion binding ensemble consists of an octa-chloro tetra-urea macrocyclic anion receptor (ClTU), which forms water-dispersible aggregates, and a tetra-cationic fluorescent dye 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP4), which provides Coulombic stabilization and fluorescence reporting of anion binding in an ion-pair assembly.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Dankook University, 119, Dandae-ro, Chungnam 448-701, Korea.
This paper presents the reversible transformation between two polymorphs of a hexacatenar liquid crystal () with distinct fluorescence colors at room temperature (RT). This method utilizes mechanical pressure (mechanochromism) and an electric field (E-field-chromism). The molecule (), designed with a pyrene core and 1,2,3-triazole linkers, exhibits a blue-emissive crystalline (CRY) polymorph () and a green-emissive liquid crystalline (LC) polymorph () at RT, depending on the cooling rate from the liquid phase.
View Article and Find Full Text PDFBeilstein J Org Chem
December 2024
Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), F-67034 Strasbourg, France.
The high potential of non-covalent arene-fluoroarene intermolecular interactions in the design of liquid crystals lies in their ability to strongly promote self-assembly, improve the order and stability of the supramolecular mesophases, and enable tuneability of the optical and electronic properties, which can potentially be exploited for advanced applications in display technologies, photonic devices, sensors, and organic electronics. We recently successfully reported the straightforward synthesis of several mesogens containing four lateral aliphatic chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SFAr) of various types of commercially available fluoroarenes with the electrophilic organolithium derivatives 2,2'-dilithio-4,4',5,5'-tetraalkoxy-1,1'-biphenyl (2Li- ).
View Article and Find Full Text PDFSmall
December 2024
Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
This paper discusses the controlled morphology of hierarchical liquid crystalline DNA assemblies. Through a process of heating and slow cooling, double-stranded DNAs (dsDNAs) having 23 complementary bases and two base overhangs (a pair of 25mer oligonucleotides) spontaneously assemble into micro-sized hexagonal platelets in a solution containing poly(ethylene glycol) (PEG) and salt. Remarkably, the addition of a shorter dsDNA with AA/TT overhangs (a pair of 18mer oligonucleotides) to a PEG-salt solution of 25mer DNA with AA/TT overhangs results in the formation of molecular tubes, each with a central blockage.
View Article and Find Full Text PDFCommun Chem
December 2024
Department of Chemistry, Universitat de les Illes Balears, Palma de Mallorca, Spain.
Supramolecular self-assembly is an advanced approach for constructing ordered nanoscale architectures with broad applications. While the principles of supramolecular polymerization have been thoroughly explored in artificial small molecules, polymer transformations remain barely explored, likely due to the lack of suitable reference models presenting well-defined and reversible transitions between aggregates. In this study, we introduce a series of bisdendronized squaramides (SQs) 1-3, showcasing complex self-assembly behaviours involving four distinct aggregates, three different interaction patterns, and various thermodynamically controlled polymorph transformations.
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