scholarly journals Fabrication of Silk Nanofibres with Needle and Roller Electrospinning Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Nongnut Sasithorn ◽  
Lenka Martinová
Keyword(s):  
Formic Acid ◽  
Production Rate ◽  
Calcium Chloride ◽  
Silk Fibroin ◽  
Applied Voltage ◽  
Rotating Cylinder ◽  
Spinning Process

In this study, silk nanofibres were prepared by electrospinning from silk fibroin in a mixture of formic acid and calcium chloride. A needle and a rotating cylinder were used as fibre generators in the spinning process. The influences of the spinning electrode and spinning parameters (silk concentration and applied voltage) on the spinning process, morphology of the obtained fibres, and the production rate of the spinning process were examined. The concentration of the spinning solution influenced the diameter of the silk electrospun fibres, with an increase in the concentration increasing the diameters of the fibres in both spinning systems. The diameters of the electrospun fibres produced by roller electrospinning were greater than those produced by needle electrospinning. Moreover, increasing the concentration of the silk solution and the applied voltage in the spinning process improved the production rate in roller electrospinning but had less influence on the production rate in needle electrospinning.

Preparation of Silk Fibroin Nanofibres by Needleless Electrospinning Using Formic Acid-Calcium Chloride as the Solvent

2016 ◽  
Vol 848 ◽  
pp. 203-206 ◽  
Author(s):  
Nongnut Sasithorn ◽  
Rattanaphol Mongkholrattanasit ◽  
Lenka Martinová
Keyword(s):  
Electron Microscope ◽  
Formic Acid ◽  
Calcium Chloride ◽  
Silk Fibroin ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Silk Fibre ◽  
Needleless Electrospinning ◽  
Spinning Process ◽  
Scanning Electron

In this study, silk nanofibre sheets were prepared by a needleless electrospinning from silk fibroin in a mixture of formic acid and calcium chloride. The influences of the concentration of calcium chloride on the properties of spinning solution, morphology of the silk electrospun fibres and the spinning performance of the spinning process were examined. The results show that calcium chloride can improve the solubility of silk fibroin in formic acid. The morphology of electrospun fibres was characterized by a scanning electron microscope (SEM), which indicates that the morphology of obtained fibres was influenced by the weight ratio of silk fibre to calcium chloride in the spinning solution. It was observed that the concentration of calcium chloride in the spinning solution influenced the diameter of the silk electrospun fibres, with an increase in the concentration of calcium chloride increasing the diameters of the electrospun fibres. The silk nanofibres had diameters ranging from 440 to 1900 nm. However, increasing the concentration of calcium chloride in the spinning solution had a less influence on the spinning performance of electrospinning process.

Large‐area thin films of silk fibroin prepared by two methods with formic acid as solvent and glycerol as plasticizer

2021 ◽  
pp. 50759
Author(s):  
Francisco Vieira Santos ◽  
Sergio Akinobu Yoshioka ◽  
Marcia Cristina Branciforti
Keyword(s):  
Thin Films ◽  
Formic Acid ◽  
Silk Fibroin ◽  
Large Area

scholarly journals Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

2016 ◽  
Vol 20 (3) ◽  
pp. 985-991
Author(s):  
Zhi Liu ◽  
Yuqin Wan ◽  
Hao Dou ◽  
Ji-Huan He
Keyword(s):  
Formic Acid ◽  
Silk Fibroin ◽  
Sodium Carbonate ◽  
High Efficiency ◽  
Lithium Bromide ◽  
Solution Properties ◽  
Acid System ◽  
Acid Dissolution ◽  
Carbonate Concentration ◽  
Degumming Process

Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

Effect of coagulation bath parameters on the morphology and absorption behavior of a skin–core filament based on biomedical polyurethane and native silk fibroin microparticles

2019 ◽  
Vol 90 (3-4) ◽  
pp. 460-468 ◽  
Author(s):  
Yan Zhuang ◽  
Han Wang ◽  
Linfeng Wang ◽  
Changjun Liu ◽  
Yuan Xu ◽  
...  
Keyword(s):  
Drug Release ◽  
Water Absorption ◽  
Silk Fibroin ◽  
Controlled Drug Release ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Electron Microscopy Analysis ◽  
Potential Applications ◽  
Spinning Process ◽  
Biomedical Polyurethane

This study investigates the effect of the constituents and temperature of a coagulation bath on the morphology and water absorption behavior of a skin–core filament, which has potential application in the field of controlled drug release, based on biomedical polyurethane (BPU) and native silk fibroin microparticles (NSFPs). BPU solution and BPU/NSFP blend solution were extruded from the cortex and core channel of a coaxial double injector into a coagulation bath with different constituents and at different temperatures to form filaments. Scanning electron microscopy analysis of the skin–core filament prepared by wet-spinning revealed that the addition of ethanol decreased the exchange speed between the solvent and non-solvent and led to the formation of micropores on the surface. Meanwhile, the interface between the cortex and core became pronounced and the water absorption capability of the filament decreased with increasing ethanol concentration in the coagulation bath. The high temperature of the coagulation bath also improved the exchange speed between the solvent and non-solvent; however, its effect on the morphology of the filament was weak. Thus, a skin–core filament with different morphologies and water absorption behaviors was fabricated by controlling the constituents and temperature of the coagulation bath during the wet-spinning process. This skin–core filament has potential applications in controlled drug release.

Effects of applied voltage on hydrogen production rate of a single reactor BML with Clostridium sp.

2015 ◽  
Vol 98 ◽  
pp. 383-389 ◽  
Author(s):  
Chiung-Yi Cheng ◽  
Kuang-Li Cheng ◽  
Terng-Jou Wan ◽  
Wei-Nung Kuo ◽  
Feng-Jen Chu ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Production Rate ◽  
Applied Voltage ◽  
Hydrogen Production Rate

scholarly journals Multiple-Jet Needleless Electrospinning Approach via a Linear Flume Spinneret

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2052 ◽  
Author(s):  
Liang Wei ◽  
Chengkun Liu ◽  
Xue Mao ◽  
Jie Dong ◽  
Wei Fan ◽  
...  
Keyword(s):  
Process Parameters ◽  
Applied Voltage ◽  
Mass Production ◽  
Solution Concentration ◽  
Average Error ◽  
High Quality ◽  
Needleless Electrospinning ◽  
Nanofiber Diameter ◽  
Multiple Jets ◽  
Spinning Process

There is a great limitation to improving the quality and productivity of nanofibers through the conventional single-needle method. Using needleless electrospinning technology to generate multiple jets and enhance the productivity of nanofibers has attracted lots of interest for many years. This study develops a novel linear flume spinneret to fabricate nanofibers. Multiple jets with two rows can be formed simultaneously on the surface of the spinneret. The solution concentration has a significant impact on the average nanofiber diameter compared with applied voltage and collection distance. The effects of different spinning process parameters on the productivity of nanofibers are investigated. High-quality nanofibers with small nanofiber diameter and error can be fabricated successfully. The average nanofiber diameter is 108 ± 26 nm. The average error is 24%. The productivity of nanofibers can reach 4.85 ± 0.36 g/h, which is about 24 times more than that of the single-needle method. This novel linear flume spinneret needleless electrospinning technology exhibits huge potential for mass production of nanofibers in the field of industrialization.

scholarly journals Plasticity and Swell-Shrink Behaviour of Electrokinetically Stabilized Virgin Expansive Soil using Calcium Hydroxide and Calcium Chloride Solutions as Cationic Fluids

2019 ◽  
Vol 29 (1) ◽  
pp. 128-146
Author(s):  
Jijo James ◽  
Archana James ◽  
Arun Kumar ◽  
Elumalai Gomthi ◽  
Karunakaran Kamal Prasath
Keyword(s):  
Soil Sample ◽  
Calcium Hydroxide ◽  
Calcium Chloride ◽  
Applied Voltage ◽  
Expansive Soil ◽  
Graphite Electrodes ◽  
Stabilization Process ◽  
Stabilized Soil ◽  
Free Swell ◽  
Different Levels

Abstract This investigation focussed on the plasticity and swell-shrink behaviour of an expansive soil that was stabilized using electro kinetic stabilization (EKS) techniques with cationic fluids for enhancement of stabilization. 0.25 M solutions of calcium hydroxide and calcium chloride were used as cationic fluids. An electro kinetic (EK) cell of dimensions 500 mm x 150 mm x 160 mm with inert graphite electrodes of size 140 mm x 160 mm x 5 mm was adopted for the stabilization process, carried out at an applied voltage of 40 V over a period of 6 hours. After the duration of the test, stabilized soil sample was subjected to Atterberg limits and free swell tests to determine its plasticity and swell-shrink characteristics. The results of the investigation found that both fluids were capable of reducing the plasticity and swell-shrink behaviour of the soil with different levels of effectiveness.

scholarly journals Silk Fibroin-Sheathed Conducting Polymer Wires as Organic Connectors for Biosensors

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 103 ◽  
Author(s):  
Yanke Jiang ◽  
Meng Xu ◽  
Vamsi K Yadavalli
Keyword(s):  
Silk Fibroin ◽  
Environmental Sustainability ◽  
Protective Coatings ◽  
High Sensitivity ◽  
Flexible Polymers ◽  
Free Standing ◽  
Organic Systems ◽  
Spinning Process ◽  
Organic Electrode ◽  
Conductive Fibers

Conductive polymers, owing to their tunable mechanical and electrochemical properties, are viable candidates to replace metallic components for the development of biosensors and bioelectronics. However, conducting fibers/wires fabricated from these intrinsically conductive and mechanically flexible polymers are typically produced without protective coatings for physiological environments. Providing sheathed conductive fibers/wires can open numerous opportunities for fully organic biodevices. In this work, we report on a facile method to fabricate core-sheath poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) PEDOT:PSS-silk fibroin conductive wires. The conductive wires are formed through a wet-spinning process, and then coated with an optically transparent, photocrosslinkable silk fibroin sheath for insulation and protection in a facile and scalable process. The sheathed fibers were evaluated for their mechanical and electrical characteristics and overall stability. These wires can serve as flexible connectors to an organic electrode biosensor. The entire, fully organic, biodegradable, and free-standing flexible biosensor demonstrated a high sensitivity and rapid response for the detection of ascorbic acid as a model analyte. The entire system can be proteolytically biodegraded in a few weeks. Such organic systems can therefore provide promising solutions to address challenges in transient devices and environmental sustainability.

Effect of Solvent on the Characteristics of Electrospun Regenerated Silk Fibroin Nanofibers

2007 ◽  
Vol 342-343 ◽  
pp. 813-816 ◽  
Author(s):  
Lim Jeong ◽  
Kuen Yong Lee ◽  
Won Ho Park
Keyword(s):  
Secondary Structure ◽  
Formic Acid ◽  
Silk Fibroin ◽  
Structural Changes ◽  
Effective Means ◽  
Electrospun Nanofibers ◽  
Random Coil ◽  
Regenerated Silk Fibroin ◽  
Silk Fibroin Nanofibers ◽  
Β Sheet

Nonwoven nanofiber matrices were prepared by electrospinning a solution of silk fibroin (SF) dissolved either in formic acid or in 1,1,1,3,3,3-hexafluoro-2-isopropyl alcohol (HFIP). The mean diameter of the electrospun nanofibers prepared from SF dissolved in formic acid was 80 nm with a unimodal size distribution, which was smaller than those prepared from HFIP (380 nm). SF nanofibers were then treated with an aqueous methanol solution, and structural changes due to solvent-induced crystallization of SF were investigated using IR and 13C solid-state CP/MAS NMR spectroscopy. SF nanofibers prepared from formic acid were found to have a higher proportion of β-sheet conformations than those prepared from HFIP. Methanol treatment provided a fast and effective means to alter the secondary structure of both types of SF nanofibers from a random coil form to a β-sheet form. As demonstrated in the present study, this approach to controlling the dimensions and secondary structure of proteins using various solvents may be useful for the design and tailoring of materials for biomedical applications, especially for tissue engineering applications.

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