scholarly journals Nanofibrousp-nJunction and Its Rectifying Characteristics

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jian Fang ◽  
Xungai Wang ◽  
Tong Lin

Randomly oriented tin oxide (SnO2) nanofibers and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)/polyvinylpyrrolidone (PEDOT:PSS/PVP) nanofibers were prepared by a two-step electrospinning technique to form a layered fibrous mat. The current-voltage measurement revealed that the fibrous mat had an obvious diode-rectifying characteristic. The thickness of the nanofiber layers was found to have a considerable influence on the device resistance and rectifying performance. Such an interesting rectifying property was attributed to the formation of ap-njunction between the fibrous SnO2and PEDOT:PSS/PVP layers. This is the first report that a rectifying junction can be formed between two layers of electrospun nanofiber mats, and the resulting nanofibrous diode rectifier may find applications in sensors, energy harvest, and electronic textiles.

2015 ◽  
Vol 1805 ◽  
Author(s):  
Juan Manuel Rodríguez ◽  
Amanda Watson ◽  
Ildeman Abrego ◽  
José Domingos Ardisson ◽  
Carlos Ariel Samudio ◽  
...  

ABSTRACTTin oxide is of great interest due to their potential technological applications, such as: gas sensors, energy conversion, catalysts and others. Appropriate doping can further enhance the conductivity of the SnO2 material with little loss of transparency. Isolated tin iron oxide fibers (Sn1-xFexO2-δ) with x (molar %) = 0, 2, 4, 6, 8 and 10 were prepared by the electrospinning technique. Anhydrous SnCl4, FeCl3·6H2O, different alcohols, chloroform and a polymer (PEO) were used as precursor materials. Appropriate mixture of these reagents defines the deposition solution. The samples were deposited on glass substrates and annealed at 500o C. The fibers are characterized by scanning electron microscopy (SEM), impedance spectroscopy and temperature dependence current-voltage measurements. The fibers with diameters between 2 to 12 microns were used for sensorial purpose. Thus, water vapor sensor responses were also measured and the experimental results are tested using the Freundlich isotherms model.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1245
Author(s):  
Sofia El-Ghazali ◽  
Muzamil Khatri ◽  
Mujahid Mehdi ◽  
Davood Kharaghani ◽  
Yasushi Tamada ◽  
...  

Recently, bio-based electrospun nanofiber mats (ENMs) have gained substantial attention for preparing polymer-based biomaterials intended for use in cell culture. Herein, we prepared poly(ethylene-glycol 1,4-Cyclohexane dimethylene-isosorbide-terephthalate) (PEICT) ENMs using the electrospinning technique. Cell adhesion and cell viability of PEICT ENMs were checked by fibroblast cell culture. Field emission electron microscope (FE-SEM) image showed a randomly interconnected fiber network, smooth morphology, and cell adhesion on PEICT ENM. Fibroblasts were cultured in an adopted cell culturing environment on the surface of PEICT ENMs to confirm their biocompatibility and cell viability. Additionally, the chemical structure of PEICT ENM was checked under Fourier-transform infrared (FTIR) spectroscopy and the results were supported by -ray photoelectron (XPS) spectroscopy. The water contact angle (WCA) test showed the hydrophobic behavior of PEICT ENMs in parallel to good fibroblast cell adhesion. Hence, the results confirmed that PEICT ENMs can be potentially utilized as a biomaterial.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jin Yeong Song ◽  
Hyun Il Ryu ◽  
Jeong Myeong Lee ◽  
Seong Hwan Bae ◽  
Jae Woo Lee ◽  
...  

AbstractElectrospinning is a common and versatile process to produce nanofibers and deposit them on a collector as a two-dimensional nanofiber mat or a three-dimensional (3D) macroscopic arrangement. However, 3D electroconductive collectors with complex geometries, including protruded, curved, and recessed regions, generally caused hampering of a conformal deposition and incomplete covering of electrospun nanofibers. In this study, we suggested a conformal fabrication of an electrospun nanofiber mat on a 3D ear cartilage-shaped hydrogel collector based on hydrogel-assisted electrospinning. To relieve the influence of the complex geometries, we flattened the protruded parts of the 3D ear cartilage-shaped hydrogel collector by exploiting the flexibility of the hydrogel. We found that the suggested fabrication technique could significantly decrease an unevenly focused electric field, caused by the complex geometries of the 3D collector, by alleviating the standard deviation by more than 70% through numerical simulation. Furthermore, it was experimentally confirmed that an electrospun nanofiber mat conformally covered the flattened hydrogel collector with a uniform thickness, which was not achieved with the original hydrogel collector. Given that this study established the conformal electrospinning technique on 3D electroconductive collectors, it will contribute to various studies related to electrospinning, including tissue engineering, drug/cell delivery, environmental filter, and clothing.


2021 ◽  
Vol 11 (15) ◽  
pp. 6929
Author(s):  
Ewin Tanzli ◽  
Andrea Ehrmann

In biotechnology, the field of cell cultivation is highly relevant. Cultivated cells can be used, for example, for the development of biopharmaceuticals and in tissue engineering. Commonly, mammalian cells are grown in bioreactors, T-flasks, well plates, etc., without a specific substrate. Nanofibrous mats, however, have been reported to promote cell growth, adhesion, and proliferation. Here, we give an overview of the different attempts at cultivating mammalian cells on electrospun nanofiber mats for biotechnological and biomedical purposes. Starting with a brief overview of the different electrospinning methods, resulting in random or defined fiber orientations in the nanofiber mats, we describe the typical materials used in cell growth applications in biotechnology and tissue engineering. The influence of using different surface morphologies and polymers or polymer blends on the possible application of such nanofiber mats for tissue engineering and other biotechnological applications is discussed. Polymer blends, in particular, can often be used to reach the required combination of mechanical and biological properties, making such nanofiber mats highly suitable for tissue engineering and other biotechnological or biomedical cell growth applications.


2021 ◽  
pp. 152808372199746
Author(s):  
Tittaya Thairin ◽  
Patcharaporn Wutticharoenmongkol

Herein, ciprofloxacin (CIP)-loaded alginate/poly (vinyl alcohol)/gelatin (SPG) (CIP–SPG) nanofiber mats were successfully fabricated by electrospinning. The average fiber diameters of the mats before and after crosslinking were in the range of 190–260 and 385–484 nm, respectively. The chemical integrity of CIP remained intact after encapsulation into the mats. The degree of weight loss and water swelling decreased with an increase in the gelatin content of the electrospun nanofiber mats. A release study was carried out by total immersion and diffusion methods using phosphate buffer as a release medium. Burst release of CIP was observed in case of the total immersion method, while a more sustained release was observed in case of the diffusion method. The maximum amounts of CIP released during total immersion and diffusion were in the range of 70–90% and 72–85%, respectively. For both the total immersion and diffusion methods, the released amounts of CIP decreased and the release slowed down with an increase in the gelatin content; this result is consistent with the weight loss and water swelling values. The Young’s modulus increased, while the tensile strength and strain at break decreased with an increase in the gelatin content. The CIP–SPG nanofiber mats were slightly toxic to L929 mouse fibroblasts as evaluated by indirect cytotoxicity assay. The electrospun CIP–SPG nanofiber mats exhibited excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. These results reveal that the electrospun CIP–SPG nanofiber mats are potentially promising materials for wound healing applications.


2013 ◽  
Vol 10 (12) ◽  
pp. 4509-4526 ◽  
Author(s):  
S. Khansari ◽  
S. Duzyer ◽  
S. Sinha-Ray ◽  
A. Hockenberger ◽  
A. L. Yarin ◽  
...  

Photonics ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 412
Author(s):  
Takaho Asai ◽  
Seigo Ito ◽  
Takayuki Makino

We applied room-temperature photoluminescence (PL) spectroscopy for the compositional engineering of a CH3NH3Pb(Cl,I)3 light harvester in an alloy-based perovskite solar cell. This spectroscopic characterization determines the optimal Cl concentration where the power conversion efficiency shows its maximum in a contactless and non-destructive manner. The PL quenching ratio evaluated from the comparative PL studies between the films grown on glass/ZrO2 and SnO2:F/TiO2 substrates exhibited its maximum at a Cl concentration of 10 mol%, which agrees with the Cl concentration determined from the current–voltage measurement-based device performance. We also discuss the possible reasons for the coincidence mentioned above regarding the charge extraction effect induced by Cl incorporation.


2017 ◽  
Vol 5 (28) ◽  
pp. 5580-5587 ◽  
Author(s):  
Michael L. Tanes ◽  
Jiajia Xue ◽  
Younan Xia

Gradients of bioactive proteins on mats of electrospun nanofibers were generated by masking with bovine serum albumin.


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