ABSTRACT
This work used a highly flexible, sustainable polyimide tape as a substrate to deposit ductile-natured carbonaceous Ni3N (C/Ni3N@polyimide) material for supercapacitor application. C/Ni3N was prepared using a co-sputtering technique, and this method also provided better adhesion of the electrode material over the substrate, which is helpful in improving bending performance. The ductile behavior of the sputter-grown electrode and the high flexibility of the polyimide tape provide ultimate flexibility to the C/Ni3N@polyimide-based supercapacitor. To achieve optimum electrochemical performance, a series of electrochemical tests were done in the presence of various electrolytes. Further, a flexible asymmetric supercapacitor (NC-FSC) (C/Ni3N//carbon@polyimide) was assembled by using C/Ni3N as a cathode and a carbon thin film as an anode, separated by a GF/C-glass microfiber soaked in optimized 1 M Li2SO4 aqueous electrolyte. The NC-FSC offers a capacitance of 324 mF cm-2 with a high areal energy density of 115.26 µWh cm-2 and a power density of 811 µW cm-2, with ideal bending performance.
ABSTRACT
Conjugated polymers are promising tools to differentiate various types of semiconducting single-walled carbon nanotubes (s-SWCNTs). However, their synthesis is challenging. Insufficient control over molecular weights, and unpredictive/unrepeatable batches hinder possible applications and scale-up. Furthermore, commercial homogeneous catalysts often require inert conditions and are almost impossible to recycle. To overcome these problems, we present a nanocatalyst consisting of magnetic nickel nanowires decorated with highly active palladium nanoparticles. A two-step wet chemical reduction protocol with the assistance of sonochemistry was employed to obtain a heterogeneous catalyst capable of conducting step-growth Suzuki polycondensation of a fluorene-based monomer. Additionally, we enhanced the performance of our catalytic system via controlled microwave irradiation, which significantly shortened the reaction time from 3 d to only 1 h. We studied the influence of the main process parameters on the yield and polymer chain length to gain insight into phenomena occurring in the presence of metallic species under microwave irradiation. Finally, the produced polymers were used to extract specific s-SWCNTs by conjugated polymer extraction to validate their utility.
ABSTRACT
Alzheimer's disease (AD), affecting 5.3 million people in the U.S., impairs portions of the brain controlling memories. In humans, mutations in the amyloid precursor protein (APP) gene has been implicated in increased plaque formation, which can block the communication between nerve cells, decrease dendritic formation and increase cell death, and promote neuroinflammation. As coconut oil has been suggested to alleviate the symptoms in AD patients, we examined the impact of coconut oil on APP expression and secretion of amyloid peptides in N2a cells expressing the human APP gene (N2a/APP695). We found that coconut oil treatment decreased APP expression in N2a cells and reduced the secretion of amyloid peptides Aß40 and Aß42. Moreover, coconut oil treatment promoted differentiation of N2a cells. Our data suggest that ADP-Ribosylation Factor 1 (ARF1) may contribute to the effects of coconut oil on APP expression and secretion of Aß. A high ARF1 expression was also detected in the primary neuronal cells from the mice overexpressing the Swedish mutant APP. Immunostaining results revealed that APP is co-localized with ARF1 in the Golgi apparatus and this interaction is impaired after coconut oil treatment. Furthermore, knockdown of ARF-1 using siRNA decreased secretion of amyloid peptides, confirming the impact of ARF1 on the secretion of amyloid peptides. CONCLUSION: These results suggest that coconut oil decreases intracellular ARF1 expression, thereby resulting in an inhibition of APP and amyloid ß secretion. This study reveals a novel mechanism for intracellular APP processing in neuronal cells.