Three-dimensional hexagonally packed PLLA nanohelices in the PS matrix were formed in the self-assembly of PS-PLLA chiral block copolymer. After hydrolysis of the PLLA blocks, PS with hexagonally packed helical nanochannels can be fabricated and treated as the template for the following sol-gel process. Subsequently, silica precursor mixture was introduced into the PS template by a pore-filling process. Well-defined helical nanocomposites with SiO(2) inorganic nanohelices orderly dispersed in polymeric matrix can be successfully obtained after the sol-gel process. As a result, with the combination of the self-assembly of degradable block copolymers and sol-gel chemistry, we suggest a novel method for the preparation of the helical nanocomposites with ordered texture.
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http://dx.doi.org/10.1021/ja808092v | DOI Listing |
Nanoscale
December 2024
Materials Genome Institute, Shanghai Engineering Research Center of Organ Repair and Shanghai Engineering Research Center for Integrated Circuits and Advanced Display Materials, Shanghai University, Shanghai 200444, China.
Circularly polarized luminescence (CPL) is a fascinating luminescence phenomenon that has garnered significant research attention for chiroptical applications. In this study, we developed a highly sensitive chiroptical sensor by co-assembling G-quartet nanofibers and nonchiral nitrogen sulfur-doped carbon dots (N-S-CDs) for dual ion detection. The N-S-CDs were synthesized using the one-step microwave method, and a helical G-quartet-based nanofiber structure (g-fiber) was simultaneously formed from guanosine 5'-monophosphate (GMP) in the presence of Sr.
View Article and Find Full Text PDFRSC Adv
October 2024
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University Shanghai 200438 P. R. China
We report here on dual shape transformations of the same thermo-responsive hybrid hydrogel sheet under irradiation of a laser with two different wavelengths (808 nm and 450 nm). By etching the silver nanoprisms in the sheet to silver nanodiscs by using chloride ions (Cl), two areas with distinct light extinction properties are integrated in a single sheet. The conversion of photon energy to thermal energy in local areas by the silver nanoprisms or nanodiscs under laser irradiation with an appropriate wavelength heats up the sheet locally and causes a local volumetric shrinkage, and hence a volumetric mismatch in different areas in the sheet.
View Article and Find Full Text PDFAdv Mater
November 2024
Multi-Scale Robotics Lab, Institute of Robotics and Intelligent Systems, ETH Zurich, Tannenstrasse 3, Zurich, 8092, Switzerland.
ACS Nano
October 2024
Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Dynamic macroscopically chiral nanocomposites are prepared by combining silver nanoparticles (AgNPs) and dynamic helical poly(phenylacetylene)s (PPAs) bearing pendants functionalized with amino groups. These amino groups provide the nanocomposite with the ability to disperse in water along with high stability due to the interaction between the ammonium group and the AgNP. Moreover, the equilibrium between NH/NH produces a "blinking" contact between the PPA and the AgNPs, which allows total control of the dynamic helical behavior of the polymer.
View Article and Find Full Text PDFNanoscale
July 2024
Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati 517507, India.
Liquid crystalline materials have attracted significant attention in chiroptical research due to their ability to form long range ordered helical superstructures. Research focus has been on exploiting the unique properties of liquid crystalline materials to demonstrate highly dissymmetric circularly polarised luminescent (CPL) systems. In this study, we present a thermally driven, facile approach to fabricate CPL-active materials utilizing cholesteryl benzoate as the active substrate.
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