Ionic liquid crystals (ILCs) present a new class of non-molecular soft materials with a unique combination of high ionic conductivity and anisotropy of physicochemical properties. Symmetrically-substituted long-chain imidazolium-based mesogenic ionic liquids exhibiting a smectic liquid crystalline phase were investigated by solid state NMR spectroscopy and computational methods. The aim of the study was to reveal the correlation between cation size and structure, local dynamics, and orientational order in the layered mesophase. The obtained experimental data are consistent with the model of a rod-shaped cation with the two chains aligned in opposite directions outward from the imidazolium core. The alignment of the core plane to the phase director and the restricted conformations of the chain segments were determined and compared to those in single-chain counterparts. The orientational order parameter ~0.5-0.6 of double-chain ionic liquid crystals is higher than that of corresponding single-chain analogues. This is compatible with the enhanced contribution of van der Waals forces to the stabilization of smectic layers. Increased orientational order for the material with Br counterions, which exhibit a smaller ionic radius and higher ability to form hydrogen bonds as compared to that of BF, also indicated a non-negligible influence of electrostatic and hydrogen bonding interactions. The enhanced rod-shape character and higher orientational order of symmetrically-substituted ILCs can offer additional opportunities in the design of self-assembling non-molecular materials.
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http://dx.doi.org/10.3390/ijms21145024 | DOI Listing |
ACS Nano
January 2025
Sauvage Laboratory for Smart Materials, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China.
With the potential to surpass the Shockley-Queisser (S-Q) limitation for solar energy conversion, the bulk photovoltaic (BPV) effect, which is induced by the broken inversion symmetry of the lattice, presents prospects for future light-harvesting technologies. However, the development of BPV is largely limited by the low solar spectrum conversion efficiency of existing noncentrosymmetric materials with wide band gaps. This study reports that the strain-induced reduction of inversion symmetry can enhance the second-order nonlinear susceptibility (χ) of SnPSe crystals by an order of magnitude, which contributes to an extremely high value of 1.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
Institute of Nano Science and Technology, Sector 81, Knowledge City, Manauli, Mohali, Mohali, Punjab, 140306, INDIA.
Two-dimensional (2D) materials hold great promise for the next-generation optoelectronics applications, many of which, including solar cell, rely on the efficient dissociation of exciton into free charge carriers. However, photoexcitation in atomically thin 2D semiconductors typically produces exciton with a binding energy of ~500 meV, an order of magnitude larger than thermal energy at room temperature. This inefficient exciton dissociation can limit the efficiency of photovoltaics.
View Article and Find Full Text PDFPLoS One
January 2025
School of Management, Wuhan University of Technology, Wuhan, Hubei Province, China.
Fraud in medical insurance is a serious problem that threatens the safety and sustainability of medical insurance funds. The process of reducing or even eliminating the impact of fraud is related to maintaining the balance of payments for medical insurance funds and reforming the payment system based on total amount control. As a result of reviewing the policy background of medical insurance fraud in China, combined with the policy evaluation model in the area of public management, this paper develops a conceptual framework of 'Antecedents-Process-Outcomes' that emphasizes the fraud and governance of medical insurance funds.
View Article and Find Full Text PDFLangmuir
January 2025
Departamento de Química, Catedra de Química Biológica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba 5000, Argentina.
The present work focuses on one of the possible target mechanisms of action of the anionic antimicrobial peptide β-lg derived from trypsin hydrolysis of β-lactoglobulin. After confirmation of bactericidal activity against a pathogenic Gram(+) strain and demonstration of the innocuousness on a eukaryotic cell line, we investigated the interaction of β-lg with monolayers and bilayers of dpPC and dpPC:dpPG as model membranes of eukaryotic and bacterial membranes, respectively. In monolayers, compared to zwitterionic dpPC, in the negatively charged dpPC-dpPG, β-lg injected into the subphase penetrated up to higher surface pressures and showed greater extents of penetration with increasing concentration in the subphase.
View Article and Find Full Text PDFNanoscale
January 2025
Department of Materials Science, Institute of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan.
Pyrrole in a cholesteric liquid crystal was discharged using a Tesla coil to generate pyrrole radicals, affording linear-shaped nano-ordered pyrrole oligomers. Subsequently, the electrochemical polymerisation of a pre-oriented pyrrole oligomer having good affinity for liquid crystals was performed to achieve polypyrrole-imprinted asymmetry from the cholesteric liquid crystal structure. The resultant polymers were analysed using polarising optical microscopy observations, scanning electron microscopy, electrochemistry, optical spectroscopy, and electron spin resonance.
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