• Textile Coloration and Finishing
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• v.16 no.4
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• pp.10-18
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• 2004

In this work, Aqueous sericin solution was prepared by degumming process with electrolytic reduction water. Then, the microfiltration and ultrafiltration systems were applied to the concentration of aqueous sericin solution. The objective of this study was to select the optimum operating condition among the different pressure. The permeate flux and rejection ratio were observed with time, pressure, flow rate and concentration. and, the wastewater and permeated water quality values such as pH, BOD, COD, and NH levels were measured. In order to see the influence of electrolytic reduction water, the flux of pure water and electrolytic reduction water by PVDF22(MF) and PS100(UF) membrane was measured. In microfiltration system, the relative flux reduction decreased rapidly to 0.02 in the 30min, as the concentration polarization and gel layer formation were increased. and then the sericin concentration rejection ratio was 40%. In ultrafiltration system, the permeate flux decreased with time and concentration, and increased with the operating pressure and flow rate. Optimal condition in PS100 membrane system for sericin concentration was operating pressure 1.464kgf/$cm^24, operating flow rate $7\ell/min at\; 40^{\circ}C$. At that time, sericin concentration rejection ratio was 83% respectably. The sericin solution was concentrated from 0.1wt% solution to 0.2 wt % solution during about 2 hrs by the UF filteration membrane system.

• Journal of Sericultural and Entomological Science
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• v.42 no.2
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• pp.104-108
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• 2000

To hydrolyze insolule sericin the enzyme hydrolysis was used, and then obtained the results as given belows. When insoluble sericin was hydrolyzed by enzyme treatment, the solubility was best at pH 7, 60$\^{C}$ and was slightly increased both above 2 hours treatment and above 10% of enzyme concentration. As the results of electrophoresis, the distribution of molecular weight of sericin powder obtained by enzyme hydrolysis was very weak and showed in the wide range having no distinguishable band. Average degree of polymerzations (A.D.P.) of sericin hydrolyzed by enzyme were about 4.1∼6.3, average molecular weight were about 470∼730. The whiteness of the sericin powder obtained by enzyme hydrolysis was high and increased slightly with higher treatment concentration of enzyme. As the results of amino acid analysis, the amino acid analysis, the amino acid composition of the sericin powder from the enzyme treatment were similar to which located at near 230$\^{C}$ and 320$\^{C}$. The peak of near 230$\^{C}$ could not been found in the sericin powder obtained by enzyme hydrolysis.

• Journal of Sericultural and Entomological Science
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• v.31 no.2
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• pp.121-126
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• 1989

Two kinds of solution for the measurement of solubilities of Sericin are prepared as followings at temperature 90 deg. C. One has the total carbonate concentration as 0, 50, 100mg CO2/l prepared with non-carbonate distilled water, sodium hydrogen carbonate and 0.1N HCI and NaOH, the other has total hardness, that is, calcium hardness or magnesium hardness as 0, 20, 50, 100mg CaCO2/l respectively prepared with non-carbonate distilled water, calcium carbonate and magnesium oxide. Solubilities of Cocoon layer Sericin at above solution gives following results ; 1. pH shows little effect on the solubility of Sericin at the non-carbonate solution but at the carbonate solution pH shows a sensitive effect on the solubility of Sericin. These means that pH controls the concentration of H2CO3, HCO3-and CO32- which prevent and promote the solution of Sericin. 2. After the cocoon layer treatment at the solution, the initial pH of 4.0, 7.0, 9.0 of the solution changed to 6.0-6.5 at the lower total carbonate solution. However in the higher total carbonate solution pH did not changed very much. This may be explained by the buffer action of carbonate. 3. The effect of the hardness on the solubility of Sericin was not found in the non-carbonate solution with the standard hardness after treatment of cocoon layer.

• International Journal of Industrial Entomology and Biomaterials
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• v.15 no.2
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• pp.171-174
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• 2007

Sericin beads were prepared from ethanol-precipitated sericin. The addition of ethanol into hot-water extracted sericin solution induced precipitation of sericin and thereby some sericin could be fractionated. The ethanol-precipitated sericin (EpSS) had narrower molecular weight distribution than original sericin. The EpSS had mainly random coil structure with small portion of ${\beta}-sheet$ structure. With the EpSS, spherical beads could be prepared at lower concentration than with original sericin due to higher viscosity. The EpSS beads had better compressive strength than the original sericin beads and had rubber-like property. Our results suggest that EpSS is more compatible in the polymeric field, since it has better mechanical strength than original sericin.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.132-139
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• 2010

Sericin pulverization process was applied by freezing-thawing of sericin protein concentration solution and physicochemical properties of sericin/chitosan blended films were investigated. In sericin pulverization process by freezing-thawing method, the refrigeration storage at $4^{\circ}C$ maximized gelling between sericin molecules, which increased 10% of recovery ratio from sericin concentration solution that using ultrafiltration procedure. In physicochemical properties of sericin/chitosan blended films, the maximum load of chitosan (6.7kgf) had higher than that of sericin (1.2kgf), and the elongation of sericin and chitosan had 96% and 34%, respectively. Also FT-IR analysis of sericin/chitosan blended films showed that both sericin and chitosan films had amide I peak (N-H bond) in $1,521cm^{-1}$ and amide II peak (C=O bond) in $1,630cm^{-1}$. In addition, it could confirm compatibility between both materials as indicated by the decrease in the amide I peak's absorption value as chitosan content increases.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.203-208
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• 2013

Sericin is usually abandoned after the degumming process. However, it could be a valuable bioresource if an economically efficient recovery process could be set up. In this study, sericin was recovered directly from the degummed waste solution by adding calcium chloride, which induced the precipitation of the surfactant, sodium oleate, by charge interaction. The recovery yield was maximum when 10% of calcium chloride was added. Further increase in the calcium chloride concentration induced the precipitation of sericin. The recovered sericin had a molecular weight distribution similar to that of the hot-water-extracted sericin; but some highmolecular- weight sericin could not be recovered. The secondary structure and amino acid composition of the recovered sericin were similar to those of conventional hot-water-extracted sericin. We expect that sericin recovered from the degummed waste solution could be an alternative to the hot-water-extracted sericin, which is widely used in various applications.

• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.37-40
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• 2001

This study was carried out to investigate the optimum condition for silk sericin collection from degumming solution using some aluminium salts with various treatment conditions and examine the thermal properties of silk sericin collected from degumming solution. Silk sericin was precipitated by treatment of aluminium metal compound from degumming solution. The best optimum collecting conditions of silk sericin from degumming solution are the concentration of 2 $m\ell$/l of polyaluminium chloride (PAC), pH range of 5~7 and room temperature. The reduction of water pollution was evaluated by decreasing the chemical oxygen demand (COD) and nitrate ion (NO$_3$￣). Thermal stability of silk sericin collected from degumming solution was a little lower than that of hot water.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.1
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• pp.10-14
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• 2018

A photo-crosslinkable sericin hydrogel has been prepared by introducing methacrylate groups on sericin. Lysine was the amino acid for methacrylation and the degree of methacrylation was increased with the amount of methacrylic anhydride added. When the concentration of methacrylic anhydride was 20% of sericin, 0.635 mmol/g of methacrylate group could be introduced. The storage modulus of sericin hydrogel was increased proportionally with the degree of methacrylation. However, the swelling ratio of sericin hydrogel decreased with the increase of methacrylation.

• Journal of Sericultural and Entomological Science
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• v.26 no.2
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• pp.16-25
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• 1984

The sericin fixation of silk fabrics by epoxy resins was studied in the presence of aqueous salt solution in different solvents at the indicated temperature for the desired time. Heavy weight gains were obtained in the reaction with glycerol diglycidyl ether (EX-313) and ethylene glycol diglycidyl ether (EX-810) catalyzed by potassium thiocyanate in such solvents as carbon tetrachloride and p-chloroethylene. The obtained results were summarized as follows; 1) The tested resins were found similar in reaction behavior to silk fabric. The effect of fixation and weight gains was higher in EX-810 than EX-313. 2) The weight gains were increased with reaction time and temperature, and degumming ratio reached a constant value in 90 min at 70$^{\circ}C$. 3) The weight gains and the degumming ratio reached an equilibrium at 3-5% of epoxy concentration. 4) The weight gains were remarkably influenced and increased by the concentration of salt solution. The degumming ratio reached an equilibrium over 0.5N concentration of salt. 5) The weight gains were increased with the dipping time in gently-sloping. The degumming ratio reached an equilibrium over 15 min dipping. 6) The effect of sericin fixation of hydrophobic solvents, such as Carbon Tetrachloride, p-Chloroeth-ylene, Cyclohexane, Xylene and Toluene, was found suitable. 7) The effect of drying temperature was not remarkable on the weight gains and the degumming ratio. 8) There was a slight decrease in the moisture regain of sericin-fixed silk and it may be possible to maintain the moisture regain in the sericin-fixed silk by the epoxy resins. 9) The results on testing physical properties of sericin-fixed silk fabric were as follows; The crease recovery was almost not different from undegummed fabric, but inferior to degummed fabric. The tensile strength was improving in accordance with the effect of sericin fixation, either the elongation did.

• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.137-141
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• 1995

The sericin fixation of raw silk by glutaraldehyde solutions with catalyst(serifix B) was done and the effect of sericin fixation by catalyst on reaction mechanism, whiteness and physical properties were investigated and discussed. The obtained results were summarized as follows; 1) The complete sericin fixation were obtained by glutaraldyhyde solution regardless the concentration of catalyst. 2) The tenacities of sericin fixed silk increased in comparison with that of nontreated silk. 3) There were not constant tendency in elongation of sericin fixed silk in comparison with nontreated silk. 4) The whiteness of sericin fixed silk treated glutaral-silk in comparison with nontreated silk. 5) FT-IR spectra were quite different from sericin fixed reagent and catalyst.