Fabrication of Nanofibers via Crater-Like Electrospinning

2011 ◽  
Vol 332-334 ◽  
pp. 1257-1260 ◽  
Author(s):  
Yuan Yuan Wang ◽  
Yong Liu ◽  
Wei Liang ◽  
Ming Ma ◽  
Rui Wang

Nanofibers, with its excellent performance, have played a significant role in the fields of filtration materials, medical materials, biomaterials, etc. In this work, a novel electrospinning technique, carter-like electrospinning, was presented and used to produce nanofibers. Multiple jets, which have the potential to increase the yield of nanofibers, were found in our experiments. The geometric properties, such as fiber diameter, diameter distribution, and surface morphology of the produced Nanofibers via this process, were characterized using a field emission scanning electron microscopy (FESEM). The results showed that the diameters of nanofibers ranged from several nanometers to one micron, and the nanofibers had average diameter of 84-550nm.

2011 ◽  
Vol 332-334 ◽  
pp. 1063-1066 ◽  
Author(s):  
Qiu Ting Zheng ◽  
Yi Zhang ◽  
Meng Xing Yang ◽  
Hua Wu Liu

Rabbit hair has been expected to be a partial replacement of cashmere, due to its excellent performance and relatively cheaper price. However, the attempt has not been successful, since the morphological structure of the rabbit hair is quite different from other animal hairs. The literature regarding rabbit hair is fairly rich, but the morphology of rabbit hair is too complex to make a very certain conclusion. Hence, the morphological structure of rabbit hair was investigated again in this study, using optical microscopy and the scanning electron microscopy. The basic shape of the hair scale, the cortex distribution and the medulla of different fineness were studied. It was founded that no medulla existed when the diameter was less than 10um. When the fiber diameter was between 10um and 20um, there was normally one medulla layer. Two and three medulla layers occurred when fiber diameter was between 20um and 30um. When the diameter was more than 50um, multi-layers of medulla presented. Keywords: Rabbit Hair, Morphological Structure, Scale Layer, Cortex Layer, Medulla Layer.


2016 ◽  
Vol 20 (3) ◽  
pp. 961-966
Author(s):  
Yan Zhang ◽  
Chuan-Zheng Zhang ◽  
Fu-Juan Liu ◽  
Fei-Yan Wang ◽  
Ping Wang

In this paper, the surface morphologies of polyvinyl alcohol/milk nanofibers produced via electrospinning technique were investigated. The electrospinning process was performed at various processing parameters (flow rate, applied voltage) and different polyvinyl acetate to milk ratios (100/0, 90/10, 80/20, 70/30, and 60/40). The scanning electron microscopy and Image J software were used to characterize the surface morphologies, especially the diameter distribution of electro spun nanofibers. The results of scanning electron microscopy show that the diameter of polyvinyl acetate/milk nanofibers increases with the increase of the spinning speed and spinning voltage but decreases with the increase of the weight percentage of milk in the spinning solution. The potential applications of this bicomponent nanofibers are numerous and diverse. The research results in present paper can contribute to better control of the electrospinning process and thus expanding the applicabilities, such as dressings for wound healing in sports.


2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>


2020 ◽  
Vol 11 (3) ◽  
pp. 10801-10811

This paper reported the fabrication of starch-based nanofibers derived from various weight ratios (w:w) of native sago starch (SS) and poly (vinyl alcohol) (PVA) (0:100, 1:100, 3:100, and 5:100) using the electrospinning technique. The effects of electrospinning operation parameters on the surface morphology of SS/PVA nanofibers were observed by using Scanning Electron Microscopy (SEM). The smooth and bead-free SS/PVA nanofibers with fiber diameters within the range of 90 nm to 150 nm were produced under the optimized conditions. The paracetamol (PCM) was encapsulated into the SS/PVA nanofibers via the blending process. The SS/PVA nanofibers exhibited a maximum PCM loading capacity of 0.9573 mg.mg-1, and PCM was observed to release out from SS/PVA nanofibers slowly and steadily for 72 hours.


2019 ◽  
Vol 14 ◽  
pp. 155892501984322 ◽  
Author(s):  
Chengbo Huang ◽  
Ying Liu ◽  
Zhiguang Li ◽  
Rong Li ◽  
Xuehong Ren ◽  
...  

The main objective of this study was to develop antibacterial materials based on polyacrylonitrile for potential application in protective face masks to combat airborne pathogens. To achieve biocidal properties, 1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone as a kind of N-halamine was introduced into the polyacrylonitrile nanofibers by an electrospinning technique to form nanofibers by an electrospinning technique to form polyacrylonitrile/1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone-5% nanofibers. Scanning electron microscopy and Fourier transformed infrared spectroscopy were employed to characterize the structure of nanofibers. The antimicrobial efficacies of electrospinning nanofibers with 1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone against both Staphylococcus aureus and Escherichia coli O157:H7 were evaluated at different contact times. The antimicrobial efficacies against bioaerosol of S. aureus were also performed. The polyacrylonitrile/1-chloro-2, 2, 5, 5-tetramethyl-4-imidazolidinone-5% nanofibers possess excellent antimicrobial efficacies against bacteria bioaersol, and it has good air permeability.


2016 ◽  
Vol 46 (8) ◽  
pp. 1598-1615 ◽  
Author(s):  
M Gouda ◽  
AA Hebeish ◽  
AI Aljaafari

A radically new innovation was established for development of electromagnetic interference shielding. The innovation emphasis synthesis of carboxymethyl cellulose (CMC), carboxymethyl cellulose composite containing different metal nanoparticles (CMC-MNPs), and carboxymethyl cellulose nanofiber mat (CMC-NF) and carboxymethyl cellulose containing metal nanofiber mat (CMC-MNPs nanofiber mat) by electrospinning technique. Metal nanoparticles used include copper nanoparticles, iron nanoparticles, zinc nanoparticles, cadmium nanoparticles, and cobalt nanoparticles. Synthesized CMC–MNPs were characterized by using scanning electron microscopy coupled with high-energy dispersive X-ray and UV–visible spectroscopy that was used for confirmation of nanoparticles formation. The scanning electron microscopy images clearly showed regular flat shape with semiporous surface. All metal nanoparticles were well distributed inside the backbone of the cellulose without aggregation. The average particle diameter was 29–39 nm for zinc nanoparticles, 29–33 nm for cadmium nanoparticles, 25–33 nm for cobalt nanoparticles, 23–27 nm for copper nanoparticles, and 22–26 nm for iron nanoparticles. Electrospun carboxymethyl cellulose and CMC–MNPs nanofiber mats were synthesized by electrospinning technique and characterized using scanning electron microscopy, energy dispersive X-ray, and transmission electron microscopy. Scanning electron microscopy images of electrospun carboxymethyl cellulose and CMC–MNPs nanofibers reveal smooth and uniformly distributed nanofibers without bead formation with average fiber diameters in the range of 300–450 nm. Moreover, the diameters of electrospun carboxymethyl cellulose nanofiber mat were not affected by the presence of metal nanoparticles. Metal nanoparticles’ content inside the electrospun CMC–MNPs nanofibers was investigated by using atomic absorption spectroscopy. Electromagnetic interference shielding of electrospun carboxymethyl cellulose and CMC–MNPs nanofiber mats was evaluated. Data showed that the EMI-SE was increased in presence of metal nanoparticles and depending on both the metal nanoparticle contents and the electrical conductivity of metal nanoparticles.


Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1321 ◽  
Author(s):  
Bruna Sinjari ◽  
Gianmaria D’Addazio ◽  
Edit Xhajanka ◽  
Sergio Caputi ◽  
Giuseppe Varvara ◽  
...  

Adhesive restorations have been shown to guarantee excellent performance and longevity, although this comes with some disadvantages. Among these, the vulnerability of dentine to different agents has been widely evaluated. The aim of this study was to evaluate the possible penetration of impression materials into freshly cut dentine. Dentine from 27 teeth was impressed with polyether (Impregum Penta L) (nine teeth) and with polyvinyl siloxane (Aquasil Ultra LV) (nine teeth). The surface of nine teeth after the impressions were used as the control. Specifically, the extroflections caused by the imprinting of the dentinal tubules on the impression material, the so-called impression tags, were measured. Furthermore, the presence of the material inside the tubules was examined. Scanning electron microscopy analysis showed material tags for all of the experimental groups. The mean lengths (±SD) were 22.6 (±11.0) µm for polyether, 21.8 (±12.8) µm for polyvinyl siloxane and 11.3 (±7.0) µm for the tooth control, with mean diameters (±SD) of 2.8 (±0.5), 2.4 (±0.7) and 3.1 (±0.7) µm, respectively. Fractal analysis showed fractal dimensions of 1.78 (±0.03), 1.77 (±0.03) and 1.71 (±0.03), respectively. These data demonstrated that the impression materials can remain inside the dentinal tubules, which can adversely affect the adhesive procedures.


2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.


2012 ◽  
Vol 591-593 ◽  
pp. 1042-1045 ◽  
Author(s):  
Si Yu Li ◽  
Yan Wei Wang ◽  
Tan Wen Jun

PAN and P(AN-co-MA) nanofibers have been successfully prepared by electrospinning. The mass concentration is 6%-12%, voltage of 15-25 kV, tip-to-collector distance is 25 cm. The morphology of the obtained samples was measured by a Scanning electron microscopy (SEM). The results showed that there were some large beads distributed on the PAN fiber skeleton when the spinning solution concentration is low. With the spinning solution concentration increased, the bead structure is gradually reduced. The fiber diameter increased with the concentration. For the synthetic reaction mixture P(AN-co-MA), it could obtain uniform nanofibers easily


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