scholarly journals Tunable Photoluminescence of Polyvinyl Alcohol Electrospun Nanofibers by Doping of NaYF4: Eu+3 Nanophosphor

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Sanjeev Kumar ◽  
Garima Jain ◽  
B. P. Singh ◽  
S. R. Dhakate

NaYF4: Eu+3 nanophosphor/polyvinyl alcohol (PVA) composite nanofibers have been successfully fabricated using the electrospinning technique. The electrospun polymeric nanofibers were characterized by scanning electron microscopy (SEM), high-resolution transmission microscopy (HRTEM), X-ray diffraction (XRD), photoluminescence (PL), and Raman spectroscopy. The flexible polymeric mats exhibited strong red emission at 724 nm at excitation wavelength of 239 nm. 5% concentration of NaYF4: Eu+3 nanophosphor are embedded homogenously inside the PVA matrix. The strong red emission peak attributed to the presence of Eu+3 ions. The characterization of the mats confirmed the uniform dispersion and tunable photoluminescence properties. These photoluminescent nanofibers (PLNs) could be easily fabricated and potentially useful in solid-state lighting applications.

2017 ◽  
Vol 6 (4) ◽  
pp. 77
Author(s):  
N A M Shahin ◽  
S Abd El Mongy ◽  
R Kamal ◽  
A B El- Bially ◽  
A A Shabaka ◽  
...  

Polyaniline (PANI) - Polyvinyl alcohol (PVA) nanocomposite were prepared using laser irradiation method. X-ray diffraction results showed that, (PANI/PVA) nanocomposite exhibited amorphous nature of polymer. The electronic transition will be studied using Ultraviolet-Visible spectrometer (UV-Vis). The real part of dielectric constant (έ) and imaginary part (ε") were studied. Also, the relaxation time was calculated.


Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1501 ◽  
Author(s):  
Jung-Yao Chen ◽  
Chien-You Su ◽  
Chau-Hsien Hsu ◽  
Yi-Hua Zhang ◽  
Qin-Cheng Zhang ◽  
...  

Herein, poly(3-hexylthiophene-2,5-diyl) (P3HT) nanofiber-based organic field-effect transistors were successfully prepared by coaxial electrospinning technique with P3HT as the core polymer and poly(methyl methacrylate) (PMMA) as the shell polymer, followed by extraction of PMMA. Three different solvents for the core polymer, including chloroform, chlorobenzene and 1,2,4-trichlorobenzene, were employed to manipulate the morphologies and electrical properties of P3HT electrospun nanofibers. Through the analyses from dynamic light scattering of P3HT solutions, polarized photoluminescence and X-ray diffraction pattern of P3HT electrospun nanofibers, it is revealed that the P3HT electrospun nanofiber prepared from the chloroform system displays a low crystallinity but highly oriented crystalline grains due to the dominant population of isolated-chain species in solution that greatly facilitates P3HT chain stretching during electrospinning. The resulting high charge-carrier mobility of 3.57 × 10−1 cm2·V−1·s−1 and decent mechanical deformation up to a strain of 80% make the P3HT electrospun nanofiber a promising means for fabricating stretchable optoelectronic devices.


2013 ◽  
Vol 774-776 ◽  
pp. 795-798
Author(s):  
Ting Jin Zhou ◽  
Min Lu ◽  
Ri Yao Chen

Carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA) and chitosan (CS)-polyvinyl alcohol were cross-linked by Fe3+and glutaraldehyde respectively to prepare cation exchange layer and anion exchange layer, and polyvinyl alcohol-sodium alginate (SA)-metal octocarboxyphthalocyanine (MePc (COOH)8, a kind of water splitting catalyst, here, Me stands for Fe3+or Co2+) nanofibers were prepared by electrospinning technique and introduced into the interlayer to obtain the CMC-PVA/PVA-SA-MePc (COOH)8/CS-PVA bipolar membrane (BPM). The experimental results showed that compared with the BPM without the PVA-SA-MePc (COOH)8interlayer, the water splitting efficiency at the interlayer of the CMC-PVA/PVA-SA-MePc (COOH)8/ CS-PVA BPM was obviously increased, and its membrane impedance decreased. When the concentration of FePc (COOH)8in the PVA-SA-FePc (COOH)8nanofibers was 3.0%, the trans-membrane voltage drop (IRdrop) of the CMC-PVA/PVA-SA-FePc (COOH)8/CS-PVA BPM was as low as 0.6V at a high current density of 90 mA/cm2.


2020 ◽  
Vol 15 ◽  
pp. 155892502094645
Author(s):  
Mayza Ibrahim ◽  
Michal Krejčík ◽  
Karel Havlíček ◽  
Stanislav Petrík ◽  
Mohamed Eldessouki

There is a growing public interest in utilizing biomass and biomaterials to obtain products with high sustainability and less harm to the environment. This study reports on using electrospinning technique to produce nanofiber membranes based on homogeneous polymeric blends of gum Arabic, polyvinyl alcohol, and silver nanoparticles. The produced interconnected membranes were cross-linked via heat and plasma treatments, and the membranes were characterized for their chemical and physical characteristics. Fourier transform infrared spectroscopy shows a cross-linking of gum Arabic and polyvinyl alcohol through esterification during the heat treatment, and through graft polymerization with methyl groups after methane plasma treatment. The mechanical performance of the membranes showed an increase in the modulus of elasticity in the longitudinal direction (parallel to electrospun nanofibers) from 85 ± 4 MPa to 148 ± 5 MPa compared with the transverse direction. Also, well-dispersed nanoparticles in the spinning solution tend to increase the elasticity from 41 ± 3 MPa to 148 ± 5 MPa, while the agglomeration of these nanoparticles decreases the mechanical properties of the nanofibers. Results of the biodegradation tests confirmed the significant biodegradable nature of the produced nanofibers, where 99.09% of the material was degraded within 28 days. Moreover, samples showed significant bactericidal activity against Micrococcus luteus with significantly less-observed bacteria in the measured plate, while the inhibition zone for Escherichia coli was 1 cm. The produced biodegradable electrospun membranes have multiple potential applications in many fields; especially for medical, antibacterial, and food packaging. This work reports the results for moisture and oxygen transfer of the membranes as a proposed application in food wrapping.


2006 ◽  
Vol 45 ◽  
pp. 735-740 ◽  
Author(s):  
W. Nuansing ◽  
S. Maensiri

This paper reports on the fabrication of nanofibres of ceramic compounds using electrospinning technique. In a typical process, ceramic nanofibres are fabricated by electrospinning a precursor mixture of appropriated metal sources, polymer and solvent, followed by calcination treatment of the electrospun composite nanofibres. In this work, the electrospinning set up as well as experimental procedure are described in detail. The fabrication of thermoelectric oxide NaCo2O4, ferroelectric Ba1-xSrxTiO3 and semiconductor TiO2 nanofibres with diameter of ~20-200 nm are demonstrated. The characterization of the fabricated nanofibres using TG-DTA, X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy is also investigated.


2002 ◽  
Vol 736 ◽  
Author(s):  
Yu Wang ◽  
Jorge J. Santiago-Avilés

ABSTRACTWe have synthesized Pb(Zr0.54Ti0.48)O3 fibers with diameter ranging from 500 nm to several microns using electrospinning and metallo-organics decomposition (MOD) techniques. By a refinement of our electrospinning technique, i.e. by increasing the viscosity of the precursor solution, and by adding a filter to the tip of the syringe, the diameter of synthesized PZT fibers has been reduced to the neighborhood of a hundred nanometers. The complex thermal decomposition was characterized using Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD). It was found that alcohol evaporated during electrospinning and that the organic groups had pyrolized before the intermediate pyrochlore phase was formed. There is a good correspondence between XRD and FTIR spectra. It was also found that a thin film of platinum coated on silicon substrate surface not only seems to have catalyzed the phase transformation to PZT but also favored the formation of 110 texture in the synthesized PZT fibers.


2021 ◽  
Vol 8 ◽  
Author(s):  
Qi Liu ◽  
Wen-Chong Ouyang ◽  
Xiu-Hong Zhou ◽  
Tao Jin ◽  
Zheng-Wei Wu

In this study, nanofibers with different ratios of poly(vinyl alcohol) and chitosan incorporated with moxifloxacin hydrochloride (MH/PVA/CS) were fabricated through the blending electrospinning, and the morphological features were tested using scanning electron microscopy (SEM). Further characterization of the new nanofiber was accomplished by Thermogravimetric analysis (TG), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Antibacterial activity of the MH-loaded nanofibers at different drug loading were tested and compared with the blank group. Experimental results show that the MH/PVA/CS nanofibers exhibited the good antibacterial properties against Staphylococcus aureus and Pseudomonas aeruginosa due to the MH incorporation. Compared with blank nanofibers, MH/PVA/CS nanofibers have significantly better antibacterial properties, and different proportions of PVA and CS have a certain effect on the antibacterial activity of nanofibers. The conclusions in this paper show that MH/PVA/CS composite nanofibers may have great potential in antibacterial materials.


2015 ◽  
Vol 74 (11) ◽  
Author(s):  
Azizul Mohd Zahari ◽  
Abdull Rahim Mohd Yusoff ◽  
Nor Aziah Buang ◽  
Palanivel Satishkumar ◽  
M Jasmin Fathi Jasni ◽  
...  

This research is about the investigation of the pure water flux property of composite polyvinylidene fluoride (PVDF) nanofibers. Electrospinning technique was used to prepare the composite electrospun nanofibers. PVDF was dissolved in N,N-dimethylformamide (DMF) solvent and blended together with activated carbon (AC) and polyvinylpyrrolidone (PVP). The nanofibers were characterized to determine the morphologies, wettability property, and its tensile strength. The fabricated nanofibers diameter was found in the range between 20 to 180 nm. The presence of AC deteriorates the mechanical properties of the nanofibers as the size of AC is larger than the external diameter of the nanofibers. The results of contact angle confirmed that the fabricated nanofiber exhibit less hydrophobic in the presence of PVP and AC. The less hydrophobic nature of proposed nanofiber might be useful for the water treatment process.


2019 ◽  
Vol 34 (4-5) ◽  
pp. 401-411
Author(s):  
Rajalakshmi Ramamoorthy ◽  
Muthumanickkam Andiappan ◽  
Murugesan Muthalagu

The polyherbal-loaded polycaprolactone nanofibrous mat was prepared by electrospinning technique, and physical and chemical characteristics of nanofibrous mats were studied using scanning electron microscopy, x-ray diffraction, thermogravimetric analyzer, and Fourier transform infrared spectroscopy. The presence of various phytochemicals in the crude monoherbal and polyherbal extracts was analyzed. The antimicrobial activity and biocompatibility of the polyherbal-loaded nanofibrous mats were studied. The drug release pattern of the polyherbal-loaded nanofibrous mats was studied at different time intervals. The 5% drug-loaded nanofibrous mat shows higher sustainable drug release rate than 1% and 3% drug-loaded nanofibrous mats. The cell viability was found to be 98.91%, 98.77%, 98.5%, and 98.22% for polycaprolactone and 1%, 3%, and 5% for polyherbal-loaded nanofibrous mats, respectively.


2016 ◽  
Vol 701 ◽  
pp. 307-311
Author(s):  
Umma Habiba ◽  
Amalina Muhammad Afifi ◽  
Bee Chin Ang

In this study, Polyvinyl Alcohol /Zinc Hidroxide composite was synthesised via film casting method. Fourier transform infrared and X-Ray diffraction was undertaken to analyze the interaction between polyvinyl alcohol and zinc hydroxide.Morphology of the resulting PVA/Zn(OH)2 composite structure was observed by Field Emission Scannig Electron Spectroscopy. FTIR and XRD results showed interaction between PVA and zinc hydroxide. These interaction are responsible for change in the thermal behavior of the composite.


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