scholarly journals Microstructure Transitions and Dry-Wet Spinnability of Silk Fibroin Protein from Waste Silk Quilt

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1622 ◽  
Author(s):  
Xin Zhang ◽  
Zhijuan Pan
Keyword(s):  
Silk Fibroin ◽  
Coagulation Bath ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Leading Role ◽  
Regenerated Silk Fibroin ◽  
Spinning Process ◽  
Silk Fabrics ◽  
The Many ◽  
Conformation Transitions

With excellent biocompatibility and biodegradability, silk fibroin has been developed into many protein materials. For producing regenerated silk fibroin (RSF) fibers, the conformation transition of silk fibroin needs to be thoroughly studied during the spinning process. Since the many silk fabrics that are discarded comprise an increasing waste of resources and increase the pressure on the environment, in this paper, waste silk fiber was recycled in an attempt to prepare regenerated fibroin fiber by dry-wet spinning. Ethanol was the coagulation bath. The rheological properties of all the RSF solutions were investigated to acquire rheology curves and non-Newtonian indexes for spinnability analysis. Four stages of the spinning process were carried out to obtain RSF samples and study their conformation transitions, crystallization, and thermal properties by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, and differential scanning calorimetry. Quantitative analysis of the FTIR results was performed to obtain specific data regarding the contents of the secondary structures. The results showed that higher concentration spinning solutions had better spinnability. As the spinning process progressed, random coils were gradually converted into β-sheets and crystallization increased. Among the different influencing factors, the ethanol coagulation bath played a leading role in the conformation transitions of silk fibroin.

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.

Conductive regenerated silk fibroin composite fiber containing MWNTs

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Negin Piri ◽  
Vahid Mottaghitalab ◽  
Shahram Arbab
Keyword(s):  
Silk Fibroin ◽  
General Scheme ◽  
Conductive Filler ◽  
Composite Fiber ◽  
Multiwalled Carbon ◽  
Sem Images ◽  
Chain Entanglement ◽  
Regenerated Silk Fibroin ◽  
Maximum Conductivity ◽  
Spinning Process

Abstract The electrically conductive regenerated silk fibroin (RSF) fiber containing multiwalled carbon nanotubes (MWNTs) was developed through wet spinning process. A general scheme used for extraction of RSF powder as biopolymer matrix for MWNTs conductive filler. The MWNTs inclusion demands for a sophisticated approach to prepare stable, exfoliated and well distributed filler in matrix solution. Dynamic Light Scattering (DLS) was utilized to show the ability of RSF in stabilizing of MWNTs throughout spinning solution. A non-Newtonian shear thinning behavior observed for RSF/MWNTs according to strong chain entanglement, whereas, the neat RSF solution shows a lower dependence on the shear rate. The scanning electron microscopy (SEM) images also confirmed the proper distribution of MWNTs as a continuous fibril media in the RSF matrix. The Fourier transform infrared spectroscopy (FTIR) demonstrated the role of MWNTs inclusion for increasing of the crystalinity compared to bare RSF fiber. The Raman spectra also confirmed the domination of RSF signatures by strong Raman bands of MWNTs most specifically in RBM region regarding to superior nanotube exfoliation. Moreover, the measurement of four-point probe electrical conductivity for different MWNTs content shows a maximum conductivity of 0.12 S/cm at percolation threshold. The higher thermal stability and greater crystalinity were also evidenced by DSC thermal analysis.

Effect of Concentration on Structure and Properties of Concentrated Regenerated Silk Fibroin Solution

2011 ◽  
Vol 311-313 ◽  
pp. 1653-1656 ◽  
Author(s):  
Fang Xie ◽  
Hao Liang
Keyword(s):  
Silk Fibroin ◽  
Conformational Transition ◽  
Random Coil ◽  
Scanning Calorimetry ◽  
Regenerated Silk Fibroin ◽  
Lower Temperature ◽  
Α Helix ◽  
Β Sheet ◽  
Dsc Curves ◽  
Fibroin Solution

The thermal properties and rheological behavior of concentrated regenerated silk fibroin aqueous solution from 15% to 37% was investigated by differential scanning calorimetry (DSC) and rheometer. Also the conformation of solutions was characterized by Raman spectra. It was discovered that the major endothermic peak in the DSC curves shifted toward the lower temperature region with increasing the concentration. This behavior suggests increasing the concentration can accelerate conformational transition of silk fibroin from random coil and α-helix to β-sheet structure. In addition, it was found that the viscosity of solution increased with increasing concentration in favor of spinning.

Ethanol Vapor-Induced Morphology and Structure Change of Silk Fibroin Nanofibers

2010 ◽  
Vol 160-162 ◽  
pp. 1165-1169 ◽  
Author(s):  
Lin Peng Fan ◽  
Zeng Xiao Cai ◽  
Chun Chen Wu ◽  
Xiao Hua Geng ◽  
Hong Sheng Wang ◽  
...  
Keyword(s):  
Silk Fibroin ◽  
Ethanol Vapor ◽  
Structure Change ◽  
Attractive Alternative ◽  
Scanning Calorimetry ◽  
Atomic Force ◽  
Regenerated Silk Fibroin ◽  
Morphology And Structure ◽  
Nanofibrous Membranes ◽  
Silk Fibroin Nanofibers

In this study, regenerated silk fibroin (RSF, from Bombyx mori) nanofibers with smooth surface had been successfully prepared via electrospinning, as shown by SEM and then as-spun fibers were induced under 75% ethanol vapor. We aimed to investigate the morphology and structure change of 75% ethanol vapor-induced silk fibroin nanofibers. To determine any difference in surface topographies, the nanofibers were inspected using atomic force microscope (AFM) and the results showed that after inducement of 75% ethanol vapor for 24 h, the surface of fibers became rough. Differential Scanning Calorimetry (DSC) analysis indicated that electrospun SF nanofibrous membranes typically took silk I form and 75% ethanol vapor-induced SF nanofibrous membranes took silk II structure. These results suggested that 75% ethanol vapor inducement could be an attractive alternative to expand the application of RSF.

Effects of Cu and Zr on the Formation and Thermal Stability of Al–Ni–Zr–Cu–Y Amorphous Alloy

2012 ◽  
Vol 271-272 ◽  
pp. 36-41
Author(s):  
Wei Yuan Yu ◽  
Wen Jiang Lu ◽  
Nai Rui Li
Keyword(s):  
Thermal Stability ◽  
Amorphous Alloy ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
Glass Forming Ability ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Glass Forming ◽  
Spinning Process ◽  
Thermal Stability Of

Al85Ni10Zr3Y2 and Al80Ni10Zr8-xCuxY2（x=1,2,3,5） alloy ribbons had been prepared by single roller melt-spinning process under vacuum conditions. The ribbons were investigated by X–ray diffraction and differential scanning calorimetry (DSC). The results revealed the strong effect of content of Cu、Zr elements on the glass forming ability and the thermal stability of the alloys. The formation of amorphous alloys are sensitive to contens of these two elements. The completely amorphous alloy or the primary amorphous phase alloy can be obtained when the content of Cu or Zr reach an optimization, otherwise only gaining crystal phase. Al80Ni10Zr7Cu1Y2 and Al80Ni10Zr3Cu5Y2 alloys possess the excellent glass forming ability, which can form the completely amorphous alloy or the composite material of the partial crystal in remaining amorphous.

FTIR and WAXD Study of Regenerated Silk Fibroin

2013 ◽  
Vol 677 ◽  
pp. 211-215 ◽  
Author(s):  
Edwin Kamalha ◽  
Yuan Sheng Zheng ◽  
Yong Chun Zeng ◽  
Mutua N. Fredrick
Keyword(s):  
Molecular Weight ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Secondary Structure ◽  
Bombyx Mori ◽  
Silk Fibroin ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Regenerated Silk Fibroin

In this study, regenerated Bombyx Mori (B. Mori ) silk fibroin from two aqueous solvents was analyzed for structural deviations. Results from Fourier transform infrared spectroscopy (FTIR) and Wide angle x-ray diffraction (WAXD) implied great alteration in the secondary structure, crystallinity and molecular weight due to the regeneration process.

Glibenclamide-Nicotinamide Cocrystals Synthesized by The Solvent Evaporation Method to Enhance Solubility and Dissolution Rate of Glibenclamide

2019 ◽  
Vol 9 (01) ◽  
pp. 21-26
Author(s):  
Arif Budiman ◽  
Ayu Apriliani ◽  
Tazyinul Qoriah ◽  
Sandra Megantara
Keyword(s):  
Solvent Evaporation ◽  
Physical Mixture ◽  
Dissolution Profile ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Evaporation Method ◽  
Dissolution Properties ◽  
Mixture Characterization

Purpose: To develop glibenclamide-nicotinamide cocrystals with the solvent evaporation method and evaluate their solubility and dissolution properties. Methods: Cocrystals of glibenclamide-nicotinamide (1:2) were prepared with the solvent evaporation method. The prediction of interactive cocrystals was observed using in silico method. The solubility and dissolution were performed as evaluation of cocrystals. The cocrystals also were characterized by differential scanning calorimetry (DSC), infrared spectrophotometry, and powder X-ray diffraction (PXRD). Result: The solubility and dissolution profile of glibenclamide-nicotinamide cocrystal (1:2) increased significantly compared to pure glibenclamide as well as its physical mixture. Characterization of cocrystal glibenclamide-nicotinamide (1:2) including infrared Fourier transform, DSC, and PXRD, indicated the formation of a new solid crystal phase differing from glibenclamide and nicotinamide. Conclusion: The confirmation of cocrystal glibenclamide-nicotinamide (1:2) indicated the formation of new solid crystalline phases that differ from pure glibenclamide and its physical mixture

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

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