scholarly journals Controlled Morphology of Porous Polyvinyl Butyral Nanofibers

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Daniela Lubasova ◽  
Lenka Martinova
Keyword(s):  
Applied Voltage ◽  
High Efficiency ◽  
Polymer Concentration ◽  
Polyvinyl Butyral ◽  
Solution Concentration ◽  
Solvent Mixture ◽  
Electrospinning Process ◽  
Filter Materials ◽  
One Step ◽  
Poor Solvent

A simple and effective method for the fabrication of porous nanofibers based on the solvent evaporation methods in one-step electrospinning process from the commercial polyvinyl butyral (PVB) is presented. The obtained nanofibers are prevalently amorphous with diameters ranging from 150 to 4350 nm and specific surface area of approximately 2–20 m2/g. Pore size with irregular shape of the porous PVB fibers ranged approximately from 50 to 200 nm. The effects of polymer solution concentration, composition of the solvents mixture, and applied voltage on fiber diameter and morphology were investigated. The theoretical approach for the choice of poor and good solvents for PVB was explained by the application Hansen solubility parameter (HSP) and two-dimensional graph. Three basic conditions for the production of porous PVB nanofibers were defined: (i) application of good/poor solvent mixture for spinning solution, (ii) differences of the evaporation rate between good/poor solvent, and (iii) correct ratios of good/poor solvent (v/v). The diameter of prepared porous PVB fibers decreased as the polymer concentration was lowered and with higher applied voltage. These nanofiber sheets with porous PVB fibers could be a good candidate for high-efficiency filter materials in comparison to smooth fibers without pores.

Research on Electrospinning Process of Pullulan Nanofibers

2012 ◽  
Vol 268-270 ◽  
pp. 198-201 ◽  
Author(s):  
Xiao Bin Sun ◽  
D. Jia ◽  
Wei Min Kang ◽  
Bo Wen Cheng ◽  
Ya Bin Li
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Great Influence ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Diameter Distribution ◽  
Optimal Parameters ◽  
Redistilled Water ◽  
Water As Solvent

A kind of pullulan biopolymer nanofibers with diameter of 100～700nm were obtained using redistilled water as solvent through electrospinning technology in this paper. The effects of the spinning solution concentration, applied voltage, flow rate and capillary–screen distance on morphology and diameter distribution of pullulan nanofiber were studied by SEM. The results show that, different parameters had great influence on nanofibers’ morphology and diameter. The optimal parameters of pullulan nanofibers electrospinning were: 22wt.% spinning solution concentration, 31 kV voltage, 20 cm capillary–screen distance and 0.5ml/h flow rate.

Multi-Bubble Electrospinning of Nanofibers

2013 ◽  
Vol 843 ◽  
pp. 26-33
Author(s):  
Xue Feng Sun ◽  
Yong Liu ◽  
Jian Liu ◽  
Rui Wang ◽  
Yan Li Hu
Keyword(s):  
Applied Voltage ◽  
Large Scale ◽  
Solution Concentration ◽  
Processing Parameters ◽  
Mutual Interference ◽  
Electrospinning Process ◽  
Scale Production ◽  
Large Scale Production ◽  
Theoretical Investigations ◽  
Multiple Bubbles

Multi-bubble electrospinning is considered as one of efficient techniques which have potential for large scale production of nanofibers. However, there is a lack of published research to better understand the formation of bubbles and the mutual interference among these bubbles. In this paper, the formation methods of multiple bubbles on the free liquid surface were examined to determine which ones performed relatively well. The influence of solution concentration, applied voltage, gas pressure, liquid length and the shape of electrode on the process and morphology of nanofibers were also investigated. The results showed that multiple gas tubes in the solution was the best choice to produce stable multiple bubbles though the number of bubbles was less than that obtained by the other methods. Some important processing parameters, such as solution concentration, applied voltage and the shape of electrode, had an important influence on the morphologies of nanofibers. Finally, both experimental and theoretical investigations in this process proved that the mutual interference among bubbles existed during multi-bubble electrospinning process.

Preparation of Chitosan based Nanofibers: Optimization and Modeling

2016 ◽  
Vol 14 (1) ◽  
pp. 283-288 ◽  
Author(s):  
K. Thirugnanasambandham ◽  
V. Sivakumar
Keyword(s):  
Polymer Solution ◽  
Response Surface ◽  
Applied Voltage ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Interactive Effects ◽  
Optimum Process ◽  
Process Conditions ◽  
Good Correspondence ◽  
Nanofiber Diameter

AbstractThe main objective of the present study is to prepare a chitosan based nanofiber and model the electrospinning process using response surface methodology (RSM). The electrospinning parameters such as collector distance, polymer solution concentration and applied voltage were optimized by using three-variable-three-level Box–Behnken design (BBD). Based on RSM analysis, second order polynomial equation was formed and it indicated good correspondence between experimental and predicted values. 3D response surface plots were used to study the individual and interactive effects of process variables on chitosan based nanofiber diameter. The optimum process conditions for the minimum chitosan based nanofiber diameter (0.3 µm) were found to be collector distance of 12 cm, polymer solution concentration of 25% and applied voltage of 6 kV.

Response surface methodology optimization of electrospinning process parameters to fabricate aligned polyvinyl butyral nanofibers for interlaminar toughening of phenolic-based composite laminates

2018 ◽  
Vol 49 (7) ◽  
pp. 858-874 ◽  
Author(s):  
Parvaneh Kheirkhah Barzoki ◽  
Masoud Latifi ◽  
Amir Masoud Rezadoust
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Composite Laminates ◽  
High Speed ◽  
Polyvinyl Butyral ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Optimum Conditions ◽  
Nanofiber Diameter ◽  
Mode Ii Fracture Toughness

In this study and for the first time, aligned nanofibers were produced from low molecular weight polyvinyl butyral. Using response surface methodology, the preparation condition of aligned nanofiber was optimized in terms of nanofiber diameter and its structural stability. Central composite design as a response surface methodology was employed and the effects of process variables and their influence on nanofiber diameter were investigated. Based on a statistical analysis, the use of a model, which was used to determine the nanofiber diameter, proved to be successful because of its low probability value (0.0073) and high correlation coefficient (0.9619). A high-speed cylinder collector was used to fabricate aligned polyvinyl butyral nanofibers. The optimum conditions of 17.5 kV voltage, 10 cm collector distance, 13% solution concentration, and 2100 r/min rotational speed were obtained from experiments. The least diameter of 158.6 nm along with a stable structure was determined for polyvinyl butyral nanofiber prepared under the optimum conditions. An aligned polyvinyl butyral nanoweb was applied on the mid-layer of glass-phenolic laminated composites as an interlaminar reinforcement. The fracture behavior of the laminates was determined by end-notched flexure tests. Excellent toughening property which was observed for the aligned polyvinyl butyral nanofibers caused the mode-II fracture toughness and its maximum force to increase by 25.2 and 40.8%, respectively.

Morphology of Biodegradable Poly(hexamethylene Adipate)(PHMA) Nanofibers Prepared by Electrospinning

2009 ◽  
Vol 87-88 ◽  
pp. 555-560
Author(s):  
Wei Min Kang ◽  
Bo Wen Cheng ◽  
Quan Xiang Li ◽  
Xu Pin Zhuang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flow Rate ◽  
Applied Voltage ◽  
Mixed Solvent ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Solvent Ratio ◽  
Biodegradable Poly ◽  
Scanning Electron

A kind of novel biodegradable poly(hexamethylene adipate) (PHMA) nanofibers with diameter of 100～700nm using a mixed solvent of 1,2-dichloroethane (DCE ) and trifluoroacetic acid (TFA) were obtained by electrospinning process in this paper. The morphology of electropun PHMA nanofibers were investigated by scanning electron microscopy (SEM). The results showed that the morphology, diameter and uniformity of the fibers were influenced by solvent ratio, solution concentration, applied voltage, capillary–screen distance and flow rate greatly. The finer and uniform nanofibers were electrospun from a mixed solvent of DCE and TFA with ratio of 70/30(w/w).

scholarly journals Effect of Changing Solvents on Poly(-Caprolactone) Nanofibrous Webs Morphology

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
A. Gholipour Kanani ◽  
S. Hajir Bahrami
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Glacial Acetic Acid ◽  
Methylene Chloride ◽  
Polymer Concentration ◽  
Average Diameter ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Poly Caprolactone ◽  
Successful Production

Polycaprolactone nanofibers were prepared using five different solvents (glacial acetic acid, 90% acetic acid, methylene chloride/DMF 4/1, glacial formic acid, and formic acid/acetone 4/1) by electrospinning process. The effect of solution concentrations (5%, 10%, 15% and 20%) and applied voltages during spinning (10 KV to 20 KV) on the nanofibers formation, morphology, and structure were investigated. SEM micrographs showed successful production of PCL nanofibers with different solvents. With increasing the polymer concentration, the average diameter of nanofibers increases. In glacial acetic acid solvent, above 15% concentration bimodal web without beads was obtained. In MC/DMF beads was observed only at 5% solution concentration. However, in glacial formic acid a uniform web without beads were obtained above 10% and the nanofibers were brittle. In formic acid/acetone solution the PCL web formed showed lots of beads along with fine fibers. Increasing applied voltage resulted in fibers with larger diameter.

Using Orthogonal Design in Optimizing Parameters for Bubble Electrospinning of Polyvinyl Alcohol (PVA) Nanofibers

2010 ◽  
Vol 29-32 ◽  
pp. 1943-1947 ◽  
Author(s):  
Liang Dong ◽  
Wan Shou ◽  
Yong Liu ◽  
Rui Wang ◽  
Ru Dong Chen
Keyword(s):  
Polyvinyl Alcohol ◽  
Process Parameters ◽  
Applied Voltage ◽  
Orthogonal Design ◽  
Solution Concentration ◽  
Electrospinning Process ◽  
Electrospinning Technique ◽  
Array Design ◽  
Nanofiber Diameter ◽  
Lower Medium

The present work was aimed at studying the effects of process parameters on morphologies of Polyvinyl alcohol (PVA) nanofibers in a novel electrospinning technique, bubble electrospinning. The process was optimized by constructing L 9(34) orthogonal experimental array design. Three factors were investigated and nine tests were run under lower, medium and higher levels of these factors. The results showed that PVA solution concentration plays an important role in affecting the morphologies of PVA nanofibers in bubble electrospinning process. With the increase of the concentration of PVA solution, the morphologies of fibers were changed from beaded fibers to uniform cylinder fibers and the average nanofiber diameter also increased. The optimization process was 12w% for PVA solution, 30kV for applied voltage and 10cm for spinning distance.

scholarly journals Fabrication and characterization of polyvinylidene fluoride nanofibers prepared by electrospinning technique

2021 ◽  
Vol 63 (1) ◽  
pp. 49-54
Author(s):  
Thi Thu Thuy Nguyen ◽  
◽  
The Huu Nguyen ◽  
Thi Hai Trinh ◽  
Thi Thu Trang Bui ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Feed Rate ◽  
Polyvinylidene Fluoride ◽  
Fiber Diameter ◽  
Average Diameter ◽  
Solution Concentration ◽  
Solvent Mixture ◽  
Gas Filtration ◽  
Hydrophobic Property ◽  
Electrospinning Technique

Electrospinning is a technique that produces polymer fibers with diameters in the submicron range. In this study, some electrospinning parameters affecting the morphology, average diameter, and distribution of the diameter of polyvinylidene fluoride (PVDF) fibers were investigated by using scanning electron microscopy (SEM). These electrospinning parameters include solution concentration, applied voltage, the feed rate of solution, distance from the needle to the collector, and solvent mixture. PVDF fibers have a fine structure, narrow distribution of fiber diameter, and average fiber diameter of 736 nm at a solution concentration of 20 wt%, solvent mixture with 60/40 weight of N,N-dimethylacetamide (DMAc) and acetone (Ac), an applied voltage of 11 kV, the feed rate of 1 ml/h, and the distance from the needle to the collector of 17 cm. The hydrophobic property and tensile strength of the PVDF nanofiber membrane were also reported. PVDF nanofibers have the potential to apply in several areas such as water or gas filtration, catalyst, lithium battery, ect.

One-step Separation and Purification of Four Phenolic Acids from Stenoloma chusanum (L.) Ching by Medium-pressure Liquid Chromatography and High-speed Counter-current Chromatography

2019 ◽  
Vol 9 (2) ◽  
pp. 138-143
Author(s):  
Tianyun Li ◽  
Xiling Dai ◽  
Yichen Li ◽  
Guozheng Huang ◽  
Jianguo Cao
Keyword(s):  
Natural Products ◽  
Liquid Chromatography ◽  
Phenolic Acids ◽  
High Speed ◽  
High Efficiency ◽  
Total Phenolic ◽  
Medium Pressure ◽  
Medium Pressure Liquid Chromatography ◽  
One Step ◽  
Counter Current

Background:Stenoloma chusanum (L.) Ching is a Chinese traditional medicinal fern with high total flavonoid and total phenolic content. Traditionally, phenolic compounds were separated by using column chromatography, which is relatively inefficient. </P><P> Objective: This study aims to use an efficient method to separate natural products from S. chusanum by Medium-Pressure Liquid Chromatography (MPLC) and High-Speed Counter-Current Chromatography (HSCCC).Methods:In the present research, firstly, a sample (2.5 g) from the dichloromethane extract of S. chusanum was separated by MPLC. Next, fraction P5 was purified by HSCCC with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 2:4:1:4 (v/v/v/v). </P><P> Result: Four phenolic acids were obtained and their structures were identified by means of NMR and ESI-mass analysis. They were identified as: 1) protocatechuic acid (34 mg, purity 90.1%), 2) syringic acid (66 mg, purity 99.0%), 3) p-hydroxybenzoic acid (5 mg, purity 91.2%) and 4) vanillic acid (6 mg, purity 99.3%).Conclusion:The combination of MPLC and HSCCC is a high-efficiency separation method for natural products. This is the first report with regard to the separation of four phenolic acids in one step by MPLC and HSCCC from S. chusanum (L.) Ching.

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