We perform transmission electron microscopy, electron diffraction, and Raman scattering experiments on an individual suspended double-walled carbon nanotube (DWCNT). The first two techniques allow the unambiguous determination of the DWCNT structure: (12,8)@(16,14). However, the low-frequency features in the Raman spectra cannot be connected to the derived layer diameters d by means of the 1/d power law, widely used for the diameter dependence of the radial-breathing mode of single-walled nanotubes. We discuss this disagreement in terms of mechanical coupling between the layers of the DWCNT, which results in collective vibrational modes. Theoretical predictions for the breathing-like modes of the DWCNT, originating from the radial-breathing modes of the layers, are in a very good agreement with the observed Raman spectra. Moreover, the mechanical coupling qualitatively explains the observation of Raman lines of breathing-like modes, whenever only one of the layers is in resonance with the laser energy.
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http://dx.doi.org/10.1021/nl2026234 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China.
The involvement of neurons in the peripheral nervous system is crucial for bone regeneration. Mimicking extracellular matrix cues provides a more direct and effective strategy to regulate neuronal activity and enhance bone regeneration. However, the simultaneous coupling of the intrinsic mechanical-electrical microenvironment of implants to regulate innervated bone regeneration has been largely neglected.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, 153-8904, Tokyo, Japan; Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, 153-8505, Tokyo, Japan. Electronic address:
Phase separation, a fundamental phenomenon in both natural and industrial settings, involves the coarsening of domains over time t to reduce interfacial energy. While well-understood for simple viscous liquid mixtures, the physical laws governing coarsening dynamics in complex fluids, such as colloidal suspensions, remain unclear. Here, we investigate colloidal phase separation through particle-based simulations with and without hydrodynamic interactions (HIs).
View Article and Find Full Text PDFChemistry
January 2025
University of Hyderabad School of Chemistry, School of Chemistry, School of Chemistry, University of Hyderabad, 500046, Hyderabad, INDIA.
The amorphous/crystalline (A/C) assembly in molecular solids has a direct bearing on their attributes and applications, including mechanical, pharmaceutical, electronic and photophysical. A systematic analysis of the molecular features and interactions that determine the predilection towards the A, C or bi-stable A-C states is critical. This fundamental problem is addressed through an exhaustive investigation of a large family of alkoxyalkyl diaminodicyanoquinodimethanes (ROR'-DADQs); enhancement of their fluorescence from the solution, to the A, to the C state serves as an excellent signature of the phase preference and temporal stability.
View Article and Find Full Text PDFHeliyon
July 2024
School of Physics, Changchun University of Science and Technology, Changchun, 130022, China.
To analyze the motion laws of a magnetic and elastic coupling system under the influence of various factors, this paper proposes a magnetic coupling pendulum based on spring pieces and magnets-a magnetic-mechanical oscillator. By fixing spring pieces onto two non-magnetic bases and attaching magnets to their upper ends, which repel each other, the potential energy during oscillation is expanded using Fourier series. Subsequently, Lagrange equations are solved to study the effects of the first two terms of potential energy.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Mechanical Engineering, Faculty of Engineering, Urmia University, Urmia, Iran.
This study investigates the nonlinear dynamics of a system with frequency-dependent stiffness using a MEMS-based capacitive inertial sensor as a case study. The sensor is positioned directly on a rotating component of a machine and consists of a microbeam clamped at both ends by fixed supports with a fixed central proof mass. The nonlinear behavior is determined by electrostatic forces, axial and bending motion coupling, and frequency-dependent stiffness.
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