With the aim to meet the greatest challenge facing organic batteries, namely the low conductivity of the electrodes, the electrochemical properties of a series of substituted perylene diimides able to form semi-conductive columnar material are investigated. Depending on the substituent group, a strong influence of this group on the reversibility, redox potential but especially on the gravimetric capacity of the electrodes is observed. In the case of substitution by a simple propyl group, the corresponding diimide shows a complete electrochemical activity with only 10% by mass of conductive additive and even shows a half-capacity activity without any additive and without particular electrode engineering. Extensive research has highlighted the intrinsic reactivity of the columnar material but also its perpetual rearrangement during charge/discharge cycles. This study shows that the amount of conductive additive can be significantly reduced by adapting the design of the molecular material and favoring the assembly of redox units in the form of a conductive column.
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http://dx.doi.org/10.1002/smll.202305701 | DOI Listing |
Nanotechnology
January 2025
Department of Electrical and Computer Engineering, Nazarbayev University, Nazarbayev University, Astana, Kazakhstan, Astana, 010000, KAZAKHSTAN.
Non-equilibrium molecular dynamics (NEMD) simulations reveal the existence of a spontaneous heat current (SHC) in the absence of a temperature gradient and demonstrate ultra-high thermal rectification in asymmetric trapezoid-shaped graphene. These unique properties have potential applications in power generation and thermal circuits, functioning as thermal diodes. Our findings also show the presence of negative and zero thermal conductivity in this system.
View Article and Find Full Text PDFFood Addit Contam Part A Chem Anal Control Expo Risk Assess
January 2025
Shanxi Key Laboratory of Food and Drug Safety Prevention and Control, Inspection and Testing Center of Shanxi Province, Taiyuan, Shanxi, China.
Two novel phosphodiesterase 5 (PDE-5) inhibitors were detected in pressed candy using high-performance liquid chromatography (HPLC)-diode array detection. Following extraction with acetonitrile and sonication, the compounds were isolated and purified semi-preparative liquid chromatography. Structural characterisation was achieved through high-resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopy.
View Article and Find Full Text PDFBackground: Maintenance hemodialysis (MHD) is an effective treatment for patients with end-stage renal disease. Although MHD can prolong the survival of patients, their quality of life is lower and the fatality rate is higher. This work analyzed the factors related to the autogenous arteriovenous fistula (AVF)-like expansion of non-diabetic MHD patients by vascular ultrasound (VUS).
View Article and Find Full Text PDFJ Speech Lang Hear Res
January 2025
Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital, Boston.
Purpose: The Daily Phonotrauma Index (DPI) can quantify pathophysiological mechanisms associated with daily voice use in individuals with phonotraumatic vocal hyperfunction (PVH). Since DPI was developed based on weeklong ambulatory voice monitoring, this study investigated if DPI can achieve comparable performance using (a) short laboratory speech tasks and (b) fewer than 7 days of ambulatory data.
Method: An ambulatory voice monitoring system recorded the vocal function/behavior of 134 females with PVH and vocally healthy matched controls in two different conditions.
Acc Chem Res
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
ConspectusReactions of gas phase molecules with surfaces play key roles in atmospheric and environmental chemistry. Reactive uptake coefficients (γ), the fraction of gas-surface collisions that yield a reaction, are used to quantify the kinetics in these heterogeneous and multiphase systems. Unlike rate coefficients for homogeneous gas- or liquid-phase reactions, uptake coefficients are system- and observation-dependent quantities that depend upon a multitude of underlying elementary steps.
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