scholarly journals Electrospun nanocomposite fibers from lignin and iron oxide as supercapacitor material

Author(s):  
Pichitchai Butnoi ◽  
Autchara Pangon ◽  
Rüdiger Berger ◽  
Hans-Jürgen Butt ◽  
Varol Intasanta
2021 ◽  
Author(s):  
Abdulrahman Mohmmed AlAhzm ◽  
Maan Omar Alejli ◽  
Deepalekshmi Ponnamma ◽  
Yara Elgawady ◽  
Mariam Al Ali Al-Maadeed

Abstract Piezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun nanocomposite fibers from polyvinylidene fluoride (PVDF) filled Zinc Oxide (ZnO)/Iron Oxide (FeO) nanomaterials. The nanocomposite fiber based flexible PENG showed piezoelectric output voltage of 5.9 V when 3 wt.% of ZnO/FeO hybrid nanomaterial was introduced, which was 29.5 times higher than the neat PVDF. No apparent decline in output voltage was observed for almost 2000 seconds attributed to the outstanding durability. This higher piezoelectric output performance is correlated with the β-phase transformation studies from the Fourier transformation infrared spectroscopy and the crystallinity studies from the differential scanning calorimetry. Both these studies show respective enhancement of 3.79 and 2.16 % in the β-phase crystallinity values of PVDF-ZnO/FeO 3 wt.% composite. Higher dielectric constant value obtained for the same composite (3 times higher than the neat PVDF) confirms the increased energy storage efficiency as well. Thus the proposed soft and flexible PENG is a promising mechanical energy harvester, and its good dielectric properties reveals the ability to use this material as good power sources for wearable and flexible electronic devices.


Author(s):  
Abdulrahman Mohmmed AlAhzm ◽  
Maan Omar Alejli ◽  
Deepalekshmi Ponnamma ◽  
Yara Elgawady ◽  
Mariam Al Ali Al-Maadeed

AbstractPiezoelectric nanogenerators (PENG) with flexible and simple design have pronounced significance in fabricating sustainable devices for self-powering electronics. This study demonstrates the fabrication of electrospun nanocomposite fibers from polyvinylidene fluoride (PVDF) filled zinc oxide (ZnO)/iron oxide (FeO) nanomaterials. The nanocomposite fiber based flexible PENG shows piezoelectric output voltage of 5.9 V when 3 wt% of ZnO/FeO hybrid nanomaterial is introduced, which is 29.5 times higher than the neat PVDF. No apparent decline in output voltage is observed for almost 2000 s attributed to the outstanding durability. This higher piezoelectric output performance is correlated with the β-phase transformation studies from the Fourier transformation infrared spectroscopy and the crystallinity studies from the differential scanning calorimetry. Both these studies show respective enhancement of 3.79 and 2.16% in the β-phase crystallinity values of PVDF-ZnO/FeO 3 wt% composite. Higher dielectric constant value obtained for the same composite (three times higher than the neat PVDF) confirms the increased energy storage efficiency as well. Thus the proposed soft and flexible PENG is a promising mechanical energy harvester, and its good dielectric properties reveals the ability to use this material as good power sources for wearable and flexible electronic devices.


Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.


2018 ◽  
Vol 6 (10) ◽  
Author(s):  
Hosam Zaghloul ◽  
Doaa A. Shahin ◽  
Ibrahim El- Dosoky ◽  
Mahmoud E. El-awady ◽  
Fardous F. El-Senduny ◽  
...  

Antisense oligonucleotides (ASO) represent an attractive trend as specific targeting molecules but sustain poor cellular uptake meanwhile superparamagnetic iron oxide nanoparticles (SPIONs) offer stability of ASO and improved cellular uptake. In the present work we aimed to functionalize SPIONs with ASO targeting the mRNA of Cyclin B1 which represents a potential cancer target and to explore its anticancer activity. For that purpose, four different SPIONs-ASO conjugates, S-M (1–4), were designated depending on the sequence of ASO and constructed by crosslinking carboxylated SPIONs to amino labeled ASO. The impact of S-M (1–4) on the level of Cyclin B1, cell cycle, ROS and viability of the cells were assessed by flowcytometry. The results showed that S-M3 and S-M4 reduced the level of Cyclin B1 by 35 and 36%, respectively. As a consequence to downregulation of Cyclin B1, MCF7 cells were shown to be arrested at G2/M phase (60.7%). S-M (1–4) led to the induction of ROS formation in comparison to the untreated control cells. Furthermore, S-M (1–4) resulted in an increase in dead cells compared to the untreated cells and SPIONs-treated cells. In conclusion, targeting Cyclin B1 with ASO-coated SPIONs may represent a specific biocompatible anticancer strategy.


2019 ◽  
Author(s):  
Suchanuch Sachdev ◽  
Rhushabh Maugi ◽  
Sam Davis ◽  
Scott Doak ◽  
Zhaoxia Zhou ◽  
...  

<div>The interface between two immiscible liquids represent an ideal substrate for the assembly of nanomaterials. The defect free surface provides a reproducible support for creating densely packed ordered materials. Here a droplet flow reactor is presented for the synthesis and/ or assembly of nanomaterials at the interface of the emulsion. Each droplet acts as microreactor for a reaction between decamethylferrocene (DmFc) within the hexane and metal salts (Ag+/ Pd2+) in the aqueous phase. The hypothesis was that a spontaneous, interfacial reaction would lead to the assembly of nanomaterials creating a Pickering emulsion. The subsequent removal of the solvents showed how the Ag nanoparticles were trapped at the interface and retain the shape of the droplet, however the Pd nanoparticles were dispersed with no tertiary structure. To further exploit this, a one-step process where the particles are synthesised and then assembled into core-shell materials was proposed. The same reactions were performed in the presence of oleic acid stabilise Iron oxide nanoparticles dispersed within the hexane. It was shown that by changing the reaction rate and ratio between palladium and iron oxide a continuous coating of palladium onto iron oxide microspheres can be created. The same reaction with silver, was unsuccessful and resulted in the silver particles being shed into solution, or incorporated within the iron oxide micro particle. These insights offer a new method and chemistry within flow reactors for the creation of palladium and silver nanoparticles. We use the technique to create metal coated iron oxide nanomaterials but the methodology could be easily transferred to the assembly of other materials.</div><div><br></div>


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