• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.20 no.1
• /
• pp.37-51
• /
• 1994

Empty cross-linked chitosan microcapsule was prepared by chemical cross-linking reaction using glutaraldehyde(GA). Chitosan bead was also prepared by coacervation method using sodium hydroxide. The technique involves the formation of a chitosan solution in the discontinuous phase of W/O emulsion. The factors influencing the emulsion stability have been examined to establish optimum conditions Chitosan microcapsules were useful for encapsulation of biological materials, and chitosan bead was useful to prepare the biologically active peptide-bound polysaccharide. As a model compound Gly-His-Lys, cell growth factor, was successfully coupled to chitosan bead.

• Journal of environmental and Sanitary engineering
• /
• v.11 no.3
• /
• pp.21-27
• /
• 1996

Chitosan is a natural polyelectrolytic compound. Researches of adsorption capacity using chitosan have been doing actively. We prepared bead type gel, simple modifier of chitosan, And then experimented adsorption test of heavy metals (Cd etc) using it. According to the result adsorption capacity of chitosan bead was five times higher than chitosan powder. Removal rate of cadmium resulted 90% over in the test that initial concentration of Cd was 100mg/L and bead dosage was 6g/100mL. Adsorption type of heavy metals was similar to general adsorption curve. And optical pH range was 4 - 10 in the adsorption test. In the experiments of other heavy metals (Pb, Zn, Cu, Mn) adsorption types had two stages, highly removal rate-stage at the short time (20minutes) and then slow rate-stage at the after. And removal efficiency at the variable pH ranges revealed relatively good.

• Applied Chemistry for Engineering
• /
• v.4 no.2
• /
• pp.324-334
• /
• 1993

Chitin, the natural polymer has been known as harmless and innoxious material to human and has been also known to be biodegradable. Chitosan which was prepared by the deacetylation of chitin, was propionylated to obtain porous bead shaped propionyl chitosan and its possibility as a water-absorbant polymer was investigated. Propionyl chitosan porous bead was synthesized by acylation reaction using emulsion method of acetic acid solution and propionyl chitosan was partially crosslinked using ethyleneglycol diglycidyl ether. Through the experiment varying the moles of propionic anhydride, reaction time and reaction temperature, best results for water-absorption ability was obtained at reaction condition of 5 moles of propionic anhydride, 10 hours of reaction time and $22^{\circ}C$ of reaction temperature. The absorption ability to the distilled water, various salt solutions, artificial urine and artificial blood, absorption time and retention of water of synthesized porous bead were investigated and also mechanical strength after crosslinking was determined.

• KSBB Journal
• /
• v.15 no.4
• /
• pp.352-358
• /
• 2000

Preparation for the simplified separation of chitosandoligosaccharides from enzymatic hydrolysate was investigated. Two different types of chitosan beads as substrate were prepared as organic-based bead by W/O emulsion method and water-based bead by alkaline treatement. The average size of organic-based bead was $200{\mu}m$, and that of water based beads were $4000{\mu}m$, $100{\mu}m$, $30{\mu}m$, in diameter respectively. Enzyme stability was maintained over 80% at PH 6 after 24 hours. The optimal condition for the production of chitosanoligosaccharides was at pH 6.0, $50^{\circ}C$ and 40U (200U/g-chitosan) According to final oligosaccharide concentration water-based bed showed the similar result with that of organic-based bead even through it had smaller surface area attacked by chitosanse than that of organic-based bead. It is probable that the structure of water-based chitosan bead was looser than that of organic-based bead so enzyme penetrated easily into the bead structure. For the oligosaccharide production versus surface area the different size of water-based beads was investigated, Maxiaml production yield was observed in the $30{\mu}m$ beads. Consequently the water-based chitosan bead was better than the organic-based bead in this reaction system.

• Journal of Pharmaceutical Investigation
• /
• v.25 no.1
• /
• pp.37-46
• /
• 1995

The experiment was designed to investigate the sustained release dosage form of silymarin (SL) from chitosan (CS) carrier. Solid dispersed system was prepared by mixing the drug with chitosan. This solid dispersed system was cross-linked by glutaraldehyde, formaldehyde, acetaldehyde and butylaldehyde, respectively. The dissolution rates of these preparations were compared with each other in vitro. The silymarin was mired with anionic alginate gel and bead was prepared by dropping this mixture to cationic chitosan solution including calcium chloride. Chitosan encapsulated alginate bead after drying in the oven was investigated for the dissolution rate. The dissolution rate of SL-CS mixture was delayed with increase in the amounts of CS and the concentration of aldehyde. The effect on the delay of dissolution rate was in the increasing order of formaldehyde, glutaraldehyde, acetaldehyde, butylaldehyde. The dissolution rate of chitosan encapsulated alginate bead was parallel with the concentration of chitosan in diluted hydrochloric acid solution and delayed with increase in the concentration of chitosan in phosphate buffer solution.

• Journal of environmental and Sanitary engineering
• /
• v.10 no.2
• /
• pp.1-12
• /
• 1995

Under accelerated industrial developments environment pollution comes out to be very stirious. Especially the ions of heavy metal from wastewater, even if they are minimal, accumulated in ecology circle and do finally injury to human health. The general process for removal of heavy metals include coagulation and following sedimentation, ion -exchange and active carbon adsorption and sedimentation that applicate in popular, needs the expense of coagulant the additional treatment of sludge on the general process of coagulation and sedimentation. It is also a serious problem that the second pollution caused by coagulant. However chelating adsorption that uses natural chelating high- molecular compound has not pollution problem Among chelating high- molecules, the diminishing chitin that contained in crustaceans as crawfish and crab in our country with affluent water resources are easy to get. So it is advantageous to use this ubiquitous material for removing heavy metals because we could reuse natural resource. In this research, the author tested the effectiveness of the adsorption and removal of heavy metal ions by chitin and its derivatives. Chitin and cellulose became beads and used as flocculant, in this test. The results are as follows . First, bead showed higher removal ratio than powder in the comparative test on adsorbents such as chitin, chitosan and cellulose. Secondly, in the variety test by the kinds of adsorbent and time. chitosan bead and cellulose bead that showed the highest removal ratio. One hour need to remove the ions of heavy metal. Thirdly, the results of the adsorption degree test by pH revealed high removal ratio adsorption of chitin, cellulose and chitosan bead in alkalin condition but chitosan bead in acidic condition.

• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.4
• /
• pp.301-309
• /
• 2021

Chitosan, natural organic polymer, has been applied in water treatment as adsorbent due to non-toxic for human being. The amino group as functional group, can interacts with cation and anion at the same time. The prepared chitosan bead (HCB) was crosslinked to increase chemical stability (HCB-G) and both HCB and HCB-G were prepared to increase physical strength by drying referred to DCB and DCB-G, respectively. The adsorption effect for crosslinking and drying for four types of chitosan bead was tested using pseudo fist order (PFO), pseudo second order (PSO), and intraparticle diffusion model (ID). Regardless of PFO and PSO, the order of K, rate constant, is as followed: HCB > HCB-G > DCB > DCB-G for Cu(II) and phosphate. Drying leading to contraction of bead significantly reduced adsorption rate due to reduce the porosity of chitosan. In addition, crosslingking also negatively effect on adsorption rate. When compared with Cu(II) using hydrogel bead, phosphate showed higher value than Cu(II) for PFO and PSO. The application of ID showed that both hydrogel beads (HCB and HCB-G) obtained a very low R² ranging to 0.37 to 0.81, while R² can be obtained to over 0.9 for DCB and DCB-G, indicting ID is appropriate for low adsorption rate.

• Journal of Applied Biological Chemistry
• /
• v.59 no.1
• /
• pp.75-81
• /
• 2016

Glutaraldehyde was used as a cross-linking agent for immobilization of purified ${\alpha}$-amylase from Exiguobacterium sp. DAU5. Befitting concentration of glutaradehyde and cross-linking time is the key to preparation of cross-linking chitosan beads. Based on optimized immobilization condition for ${\alpha}$-amylase, an overall yield of 56% with specific activity of 2,240 U/g on chitosan beads and 58% with specific activity of 2,320 U/g on chitosan-carbon beads was obtained. The optimal temperature and pH of each immobilized enzyme activity were $50^{\circ}C$ and 50 mM glycine-NaOH buffer pH 8.5, respectively. Those retained more than 75 and 90% of its maximal enzyme activity at pH 7.0-9.5 and after incubation at $50^{\circ}C$ for 1 h, respectively. In addition, the immobilization product showed higher organic-solvent tolerance than free enzymes. The mode of hydrolyzing soluble starch revealed that the ${\alpha}$-amylase possessed high hydrolyzing activity. These results indicate that chitosan is good support and has broad application prospects of enzyme immobilization.

• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.3
• /
• pp.253-259
• /
• 2018

Cu(II) can cause health problem for human being and phosphate is a key pollutant induces eutrophication in rivers and ponds. To remove of Cu(II) and phosphate from solution, chitosan as adsorbent was chosen and used as a form of hydrogel bead. Due to the chemical instability of hydrogel chitosan bead (HCB), the crosslinked HCB by glutaraldehyde (GA) was prepared (HCB-G). HCB-G maintained the spherical bead type at 1% HCl without a loss of chitosan. A variety of batch experiment tests were carried out to determine the removal efficiency (%), maximum uptake (Q, mg/g), and reaction rate. In the single presence of Cu(II) or phosphate, the removal efficiency was obtained to 17 and 16%, respectively. However, the removal efficiency of Cu(II) and phosphate was increased to 50~55% at a mixed solution. The maximum uptake (Q) for Cu(II) and phosphate was enhanced from 11.3 to74.4 mg/g and from 3.34 to 36.6 mg/g, respectively. While the reaction rate of Cu(II) and phosphate was almost finished within 24 and 6 h at single solution, it was not changed for Cu(II) but was retarded for phosphate at mixed solution.

• Applied Chemistry for Engineering
• /
• v.10 no.1
• /
• pp.166-172
• /
• 1999

Fixed-bed adsorption of metal ions on chitosan bead was studied to remove heavy metal ions in waste water. Chitin was extracted from carb shell and chitosan was prepared by deacetylation of the chitin. The chitosan in bead was used as an adsorbent for heavy metal ions. Freundlich and Langmuir isotherm was determined from the experimental results of equilibrium adsorption for individual metal ion ($Cu^{2+}$, $Co^{2+}$, $Ni^{2+}$) on chitosan bead. Adsorption strength of metal ions decreased in the order of $Cu^{2+}$>$Co^{2+}$>$Ni^{2+}$ ion. Breakthrough curves of single and multicomponent adsorption for metal ions were obtained from the experimental results of fixed-bed adsorption. The breakthrough curves were analyzed by simulation with fixed-bed adsorption equation based on LDFA (linear driving force approximation) adopted LAS (ideal adsorbed solution) theory which can predict multi-component adsorption isotherm from individual adsorption isotherm. The behavior of fixed bed adsorption for single and multi-component system could be nicely simulated by the equation.