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This paper considers the uniaxial orientation effect on the structure and piezoelectric properties of vinylidene fluoride-tetrafluoroethylene copolymer ferroelectric films. The films were exposed to uniaxial orientation stretching in a temperature range from 20 °C to 60 °C; then, they were contact polarized under normal conditions. The temperature dependence of the electric strength was determined. The longitudinal piezoelectric coefficient values were measured by the quasi-static Berlincourt method. The piezoresponse force microscopy (PFM) method was used to investigate the film domain structure before and after polarization, and the local piezoelectric coefficient values were also calculated. Phase composition was studied using differential scanning calorimetry and infrared spectroscopy with the Fourier transform. It was found that uniaxial orientation stretching contributed to an increase in the piezoelectric coefficient from 5 pC/N to 16-20 pC/N. The results obtained indicate the importance of the amorphous phase contribution to the formation of the piezoelectric properties in polymeric materials.
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http://dx.doi.org/10.3390/ijms26136309 | DOI Listing |
ACS Omega
September 2025
Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé (ICPEES), UMR-7515 CNRS-Université de Strasbourg, 25 rue Becquerel, 67087 Strasbourg, France.
For photodetection applications using 3D hybrid perovskites (HPs), dense and thick films or compacted powders in wafer form are needed and generally require large amounts of HPs. HPs are also often combined with a graphene/carbon layer to improve their conductivity. Among HP synthesis methods, mechanosynthesis, a green synthesis method, provides a large amount of powders, which are furthermore easily densified in compact wafers due to their mechanical activation.
View Article and Find Full Text PDFJ Chem Phys
September 2025
Department of Chemistry, University of Victoria, Victoria, British Columbia V8W 3V6, Canada.
Order parameters provide a useful qualitative and quantitative description of the distribution of molecules in ordered materials as they are independent of the shape of the orientation distribution. For samples that exhibit uniaxial ordering with no twist preference, extracting ⟨P2⟩ from polarized IR absorption data is common and obtaining ⟨P2⟩ and ⟨P4⟩ from Raman data has also been well-described. However, such an approach is not routine in the analysis of surface sum-frequency generation (SFG) spectra.
View Article and Find Full Text PDFActa Biomater
August 2025
STRETCH Lab, Virginia Tech, 330A Kelly Hall, 325 Stanger Street, Blacksburg, 24061, VA, USA. Electronic address:
This study presents quantitative applications of label-free imaging methods to characterize the structure of the uterosacral ligaments (USLs) before, during, and after loading. Rat USLs (n=14) were excised with their spinal and cervical attachments, clamped at these attachment sites, and pulled uniaxially in a custom-built tensile testing machine along their main in vivo loading direction. During uniaxial testing, optical coherence tomography (OCT) images were recorded, revealing the re-arrangement and failure of the structural components of the USLs.
View Article and Find Full Text PDFJ Mech Behav Biomed Mater
August 2025
Trinity Centre of Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, 2, Ireland; Department of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin, Dublin, 2, Ireland; Advanced Materials and Bioengineering Re
Porcine pericardium and bovine pericardium are commonly used materials in medical devices, most notably in the leaflets of bioprosthetic valves. The mechanical and fatigue behaviour of pericardium is influenced primarily by its collagen fibre architecture. Multiple methods exist in the literature for determining the collagen fibre architecture of pericardium, including inspecting the tissue by eye using a light source.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
State Key Laboratory of Synergistic Chem-Bio Synthesis, School of Chemistry and Chemical Engineering, New Cornerstone Science Laboratory, Frontiers Science Center for Transformative Molecules, Zhang Jiang Institute for Advanced Study and National Center for Translational Medicine, Shanghai Jiao Tong
Surface-confined DNA computing has emerged as a powerful information processing paradigm, offering enhanced specificity and accelerated reaction kinetics. Artificially designed DNA origami serves as a key enabler for such systems by providing a highly programmable platform for positioning computational components with nanometer resolution. However, conventional monolayer DNA origami circuits often exhibit non-negligible signal leakage, attributed to structural fluctuation-induced crosstalk between surface-confined molecules.
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