scholarly journals Evaluation of Nb2O5 Ceramic Nanofibers Efficacy to Promote CO2 Photoconversion

2021 ◽  
Author(s):  
Ana Prado ◽  
Joao Malafatti ◽  
Jessica Oliveira ◽  
Caue Ribeiro ◽  
Miryam Rincón ◽  
...  
Keyword(s):  
Global Warming ◽  
Average Diameter ◽  
Homogeneous Surface ◽  
Electrospinning Method ◽  
Ceramic Nanofibers ◽  
Photocatalytic Processes

The increase in global warming due to NOx, CO2, and CH4 harmfully different ecosystems and significantly prejudice world life. A promising methodology in this sense is the pollutant conversion into valuable chemicals from photocatalytic processes by reusable photocatalyst. In this way, the present work aimed to produce a Nb2O5 photocatalyst nanofibers system to convert CO2 by the electrospinning method. Based on the collected data, the nanofibers calcination at 600°C for 2 h resulted in the best condition to obtain a homogeneous surface with an average diameter of 84 nm. As a result, the Nb2O5 nanofibers converted CO2 mostly into CO and CH4, reaching values around 8.5 μmol g−1 and 0.55 μmol g−1, respectively.

scholarly journals Preparation and Application of Nb2O5 Nanofibers in CO2 Photoconversion

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3268
Author(s):  
A. C. F. Prado ◽  
J. O. D. Malafatti ◽  
J. A. Oliveira ◽  
C. Ribeiro ◽  
M. R. Joya ◽  
...  
Keyword(s):  
Global Warming ◽  
Average Diameter ◽  
Photocatalytic Processes

Increasing global warming due to NOx, CO2, and CH4, is significantly harming ecosystems and life worldwide. One promising methodology is converting pollutants into valuable chemicals via photocatalytic processes (by reusable photocatalysts). In this context, the present work aimed to produce a Nb2O5 photocatalyst nanofiber system by electrospinning to convert CO2. Based on the collected data, the calcination at 600 ∘C for 2 h resulted in the best condition to obtain nanofibers with homogeneous surfaces and an average diameter of 84 nm. As a result, the Nb2O5 nanofibers converted CO2 mostly into CO and CH4, reaching values around 8.5 μmol g−1 and 0.55 μmol g−1, respectively.

An Ultrasound Transducer by Lead Zirconate Titanate (PZT) Nanofibers

2011 ◽  
Author(s):  
Guitao Zhang ◽  
Yong Shi
Keyword(s):  
Lead Zirconate Titanate ◽  
Acoustic Waves ◽  
Average Diameter ◽  
Lead Zirconate ◽  
Ultrasound Transducer ◽  
Resonant Frequencies ◽  
Pulse Delay ◽  
Zirconate Titanate ◽  
Electrospinning Method ◽  
Assumed Mode

In this paper, we demonstrate Lead zirconate titanate (PZT) nanofibers as a transducer to generate and detect ultrasound acoustic waves. PZT nanofibers with average diameter of 102nm were fabricated by the electrospinning method. The as-fabricated nanofibers were collected and aligned across a 10 μm silicon trench with Au electrodes. After annealing, the device was tested with the pulse/delay method. Two resonant frequencies, 8 MHz and 13MHz, were detected respectively. By using the Hamilton’s principle for coupled electromechanical systems with properly assumed mode shape, the resonant frequency was caudated. Base on the current testing result, a broadband ultrasound transducer was envisioned.

scholarly journals SINTESIS DAN KARAKTERISASI NANOFIBER KOMPOSIT Zn-PVDF KOPOLIMER

2014 ◽  
Vol 16 (1) ◽  
pp. 49-52
Author(s):  
Yelfira Sari ◽  
Muhamad Nasir ◽  
Chandra Risdian ◽  
Syukri Syukri
Keyword(s):  
Crystal Structure ◽  
Phase Structure ◽  
Research Study ◽  
Fiber Diameter ◽  
Average Diameter ◽  
Nanofiber Composite ◽  
Β Phase ◽  
Α Phase ◽  
Structure Morphology ◽  
Electrospinning Method

Sintesis nanofiber komposit Zn-PVDF kopolimer dengan metoda elektrospinning telah berhasil dilakukan. Proses pembuatan nanofiber komposit serta  morfologi yang terbentuk dipengaruhi oleh penambahan Zn-asetat dengan perubahan diameter rata-rata serat dari 357,13 nm menjadi 777,24 nm. Analisis FTIR menunjukkan bahwa struktur kristal nanofiber komposit Zn-PVDF kopolimer didominasi oleh strukturβ-phase, dengan bilangan gelombang 1190,08 cm-1 dan 487,99 cm-1 untuk struktur α-phase dan 1404,18 cm-1; 1280,73 cm-1; 1074,35 cm-1; 881,47 cm-1; dan 840,96 cm-1 untuk struktur β-phase.Kata kunci :nanofiber komposit, Zn-PVDF kopolimer komposit, elektrospinning,kristal struktur, morfologi, diameter fiber The fabrication of Zn-PVDF copolymer nanofiber composite has been investigated in this research study by using electrospinning method. Fabrication and morphology of nanofiber composite is influenced by the addition of Zn-acetate. The average diameter of nanofiber composites increase with an addition of Zn-acetate, from 357,13 to 777,24nm. FTIRanalysisshowedthat thecrystalstructure ofPVDFnanofiberis dominatedby β-phase , thewave number 1190,08 cm-1 and 487,99 cm-1 for α-phase structure and 1404,18cm-1; 1280,73cm-1; 1074,35cm-1; 881,47cm-1and840,96cm-1 for β-phase structure respectively.Key words : nanofiber composite, Zn-PVDF copolymer composite, electrospinning, crystal structure,  morphology, fiber diameter

Preparation of PCL/PVP/Ag Nanofiber Membranes by Electrospinning Method

2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng
Keyword(s):  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Composite Nanofibers ◽  
Average Diameter ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Nanofiber Membranes ◽  
Poly Vinyl Pyrrolidone

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.

Electrospun Tin Oxide Nanofibers with Different Precursor Solution

2011 ◽  
Vol 675-677 ◽  
pp. 275-278
Author(s):  
Xue Bai ◽  
Di Jia ◽  
Bo Wen Cheng ◽  
Wei Min Kang ◽  
Quan Xiang Li
Keyword(s):  
Crystal Structure ◽  
Tin Oxide ◽  
Precursor Solution ◽  
Average Diameter ◽  
Surface Element ◽  
Rutile Structure ◽  
Inorganic Hybrid ◽  
Hybrid Nanofibers ◽  
Electrospinning Method ◽  
Crystalline Forms

In this paper, electrospinning method was adopted to prepare tin oxide nanofibers membrane with three kinds of novel precursor solution PVP/C12H24O4Sn, PVP/ C4H10OSn and PVP/SnCl4. The morphology, surface element, thermal analysis and crystal structure of the fibers membrane were investigated by SEM, EDS, TG-DTA and XRD. The results showed that the organic/inorganic hybrid nanofibers with an average diameter of 300～700 nm can be obtained by electrospinning. But after calcined at 600°C, the loose and porous tin oxide nanofibers membrane with an average diameter of 100～250 nm can be obtained only by using PVP/SnCl4 as preceusor solution, moreover, it showed good fiber forming property. From XRD spectra, it was found that the rutile structure tin oxide finally obtained without other crystalline forms.

Actuation Behavior of Polylactic Acid Fiber Films Prepared by Electrospinning

2016 ◽  
Vol 16 (4) ◽  
pp. 3343-3348 ◽  
Author(s):  
Taiki Nobeshima ◽  
Yuya Ishii ◽  
Heisuke Sakai ◽  
Sei Uemura ◽  
Manabu Yoshida
Keyword(s):  
Electric Field ◽  
Film Thickness ◽  
Polylactic Acid ◽  
Spin Coating ◽  
Electrostatic Force ◽  
Average Diameter ◽  
Field Region ◽  
Thickness Direction ◽  
Electrospinning Method ◽  
Electric Field Induced Strain

A poly-DL-lactide (PLA) fiber film was prepared using the electrospinning method. This film consisted of randomly oriented PLA nanofibers. Consequently, it had sponge-like structure and was quite soft compared to PLA films prepared by spin coating. The average diameter of the fibers and the density of the film were 730 nm and 20%, respectively. By applying a voltage, the PLA film was subjected to electric-field-induced strain: expansion and compression in the thickness direction. When a voltage of −200 V was applied to the film, its thickness shrank from 13.5 μm to 10.0 μm (a 26% reduction). Electric-field-induced strain can occur via two different mechanisms: The first is electrostrictive behavior. That is, in a highly electric field region, a change of film thickness occurs (compression only) from the electrostatic force between electrodes. The second mechanism is piezoelectric-like behavior that occurs in racemic PLA, wherein a PLA nanofiber is expanded and compressed by applying positive and negative voltage. Such piezoelectric-like behavior was not observed in spin-coated PLA films.

scholarly journals Preparation of ceramic nanofibers of iron vanadate using electrospinning method

2019 ◽  
Vol 37 (4) ◽  
pp. 645-651
Author(s):  
Yasaman Khaksarfard ◽  
Hakimeh Ziyadi ◽  
Akbar Heydari
Keyword(s):  
Sol Gel ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ammonium Vanadate ◽  
Polymer Nanofiber ◽  
Electrospinning Method ◽  
Ft Ir ◽  
Ceramic Nanofibers ◽  
Polymeric Template

AbstractBecause of special characteristics of vanadate compound, such as its sustainability, magneticity, high selectivity in reactions and catalytic character, this study aimed to preparation and analyzing novel ceramic iron vanadate (FeVO4) nanofibers. The ceramic nanofibers of iron vanadate were made by the combination of sol-gel and electrospinning methods. First, polyvinyl alcohol (PVA), as a matrix polymer, was mixed separately with ammonium metavanadate (NH4VO3) and iron (III) nitrate (Fe(NO3)3). As a result, the spinnable polymeric gel was obtained from the controlled mixture of these two precursors of ceramic material. Electrospinning of PVA/iron (III) nitrate/ammonium vanadate solution was done using an Electroris setup that enabled preparation of polymeric template nanofiber. Finally, iron vanadate nanofiber was obtained by calcination of polymer nanofiber at controlled temperature. The products were characterized with scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and Brunauer-Emmett-Teller (BET) surface area analysis.

scholarly journals Microstructure properties of lead silicate glasses

2019 ◽  
Vol 13 (28) ◽  
pp. 91-99
Author(s):  
Dunia K. M. Al-Nasrawy
Keyword(s):  
Lead Oxide ◽  
Average Diameter ◽  
Silicate Glasses ◽  
Lead Silicate ◽  
Oxide Content ◽  
Homogeneous Surface ◽  
X Ray ◽  
Silica Dioxide ◽  
Alo4 Tetrahedron ◽  
Structure Properties

In the present work, lead silicate glasses have been prepared withdifferent amount of lead oxide content. Structure properties such asX-ray diffraction, AFM, and FTIR analyses have been done. Theexceeding of PbO content more than 25wt% revealed a decreasing indensity. The X- ray revealed that the strongest peak related toHexagonal silica dioxide and the other crystal phases formed wererelated to silica oxide (SiO2) and lead oxide (PbO). Growth anddecayed phases in X-ray have been observed with changing leadoxide content. Homogeneous surface was obtained using AFManalyzer with an average diameter around 100 nm. Infrared spectrumis characterized by the presence of large absorption band between1200 and 900cm-1 and have its maximum at 1080 cm-1 which istypical to stretching vibrations of Si–O–Si bonds, another bandsnoticed were attributed to Pb–O–Pb, Pb–O–Si, [AlO4]-tetrahedron,and to Si–O–Al bond.

The Effect of Needle Diameter on Optical Properties and Morphological Structure of La2O3- PVA Phosphor Nanofibers Prepared by Electrospinning Method

2020 ◽  
Vol 301 ◽  
pp. 18-26
Author(s):  
Hasma A. Wahab ◽  
Zainuriah Hassan ◽  
Naser Mahmoud Ahmed
Keyword(s):  
Optical Properties ◽  
Energy Gap ◽  
Uv Light ◽  
Light Emitting Diode ◽  
Morphological Structure ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
Electrospinning Method ◽  
Needle Diameter

Lanthanum Oxide-Polyvinyl alcohol (La2O3-PVA) phosphor nanofibers were prepared by electrospinning and investigation of the effect of needle diameter on the optical properties and morphological structure at the nanofibers was carried out. The average diameter of phosphor nanofibers have been evaluated for five different needle diameters. The resulting phosphor nanofibers were observed and anaylzed by X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM), Ultraviolet-visible Spectroscopy (UV-Vis) and HPC-2 Lightsource Colorimeter. The La2O3-PVA phosphor nanofibers were used in light down-conversion of UV light (365 nm) for the white light-emitting diode (WLED) application. The chromaticity coordinates (CIE) and correlated colour temperature (CCT) were measured for different phosphor nanofibers with different sizes of needle diameter (0.45,0.55,0.65,0.75,1.1) mm. The results revealed that the phosphor nanofibers formed by needle diameter of 0.65 mm places macromolecule in a better order and the average diameter increase from 40.08 nm to 87.27 nm after annealing followed by increasing in atomic percentage of lanthanum. The energy gap of resulting phosphor nanofibers is 3.5365 eV. An optimum colour rendering index (CRI) value of 70.20 is obtained. The white phosphor exhibited CIE values of 0.3536, 0.407 and CCT of 4890 K.

Influence of Molecular Weight on the Morphology and Structure of Electrospun Polyvinylidene Fluoride (PVDF)

2021 ◽  
Vol 1025 ◽  
pp. 293-298
Author(s):  
Aminatul Sobirah Zahari ◽  
Muhammad Hafiz Mazwir ◽  
Izan Izwan Misnon
Keyword(s):  
Molecular Weight ◽  
Polyvinylidene Fluoride ◽  
Analytical Techniques ◽  
Average Diameter ◽  
Pvdf Membrane ◽  
Β Phase ◽  
Membrane Morphology ◽  
Electrospinning Method ◽  
High Flexibility ◽  
Morphology Characterization

Polyvinylidene fluoride (PVDF) reveals outstanding properties such as lightweight, high flexibility and temperature independence material compared to other polymers. In this study, PVDF as a function of molecular weight was prepared by using an electrospinning method in order to study the influences of the molecular weight of the PVDF membrane on the morphology. Analytical techniques such as field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD) were used to characterize the electrospun PVDF membranes. FESEM was used for morphology characterization and also to measure the diameter of fibers while XRD and FTIR were employed to examine crystalline phase membranes. The lowest molecular weight has the smallest average diameter of fibers. Besides, a combination of both α-phase and β-phase crystalline was showed by XRD and FTIR results. This is because the crystalline phases and membrane morphology depend on the polymer molecular weight. In this research, it was found that the largest β-phase fraction for the electrospun PVDF membrane is 80.25 % with a molecular weight at 180,000 g/mol.

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