• 환경위생공학
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• 제16권2호
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• pp.91-99
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• 2001

Cross linked chitosan beads showed high selective adsorption abilities in order of $Au^{3+}$ > $Hg^{2+}$ > $Cu^{2+}$ > $Cd^{2+}$ > $Pt^{4+}$ > ${UO_2}^{2+}$ ions in mixed solution of various metal ions at pH 4.5. N-methyltyiobenzylated chitosan beads(MTB-chitosan beads) were prepared treating with p-(methylthio) benzaldehyde after cross linking of chitosan beads to give them a high selectivity in adsorption of metal ions. The MTB-chitosan beads demonstrated their selectivity on precious metals among various metal ions distinctively. Particularly, the MTB-chitosan had a peculiar selective adsorption on $Pd^{2+}$, $Au^{2+}$, and $Hg^{2+}$ions whilst the cross linked chitosan beads showed its high adsorption on $Pd^{2+}$ at pH 1.1. On the other hand, the cross linked chitosan beads showed its superiority in selective adsorption on $Au^{2+}$, $Cu^{2+}$, and $Hg^{2+}$ions to the MTB-chitosan at pH 4.5 of the test solution. Thus metal selectivities were given to chitosan beads through chemical modifications.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.171-174
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• 2005

Suspected carcinogen, TCE and PCE, are the most common groundwater pollutants extensively used as a solvent and degreaser. In this study, oxygenases were immobilized in Ca-alginate and chitosan bead. TCE degradation by the immoblized enzyme beads were measured for various size, enzyme addition volume and TCE contact time. The degradation was decreased as increasing the bead size. For overnight , more than 20% of TCE was degraded. The variation of enzyme activity was tested for the repeated use of enzyme beads.

• 상하수도학회지
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• 제33권3호
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• pp.205-213
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• 2019

Batch adsorption tests were performed to evaluate the applicability of adsorption kinetic model by using hydrogel chitosan bead crosslinked with glutaraldehyde (HCB-G) for Cu(II) as cation and/or phosphate as anion. Pseudo first and second order model were applied to determine the sorption kinetic property and intraparticle and Boyd equation were used to predict the diffusion of Cu(II) and phosphate at pore and boundary-layer, respectively. According to the value of theoretical and experimental uptake of Cu(II) and phosphate, pseudo second order is more suitable. On comparison with the value of adsorption rate constant (k), phosphate kinetic was 2-4 times faster than that of Cu(II) at any experimental condition indicating the electrostatic interaction between ${NH_3}^+$ and phosphate is dominated at the presence of single component. However, when Cu(II) and phosphate simultaneously exist, the value of k for phosphate was sharply decreased and then the difference was not significant. Both diffusion models confirmed that the sorption rate was controlled by film mass transfer at the beginning time (t < 3 hr) and pore diffusion at next time section (t > 6 hr).

• 생명과학회지
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• 제21권1호
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• pp.127-133
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• 2011

${\beta}$-galactosidase를 공유결합으로 키토산 담체에 고정화하여 고정화 효소의 특성을 조사하였다. 또한 충진층 반응기에서 연속 조업을 실시하여 공정 최적화를 실시하였다. 키토산 담체에 대한 효소 고정화 효율은 최대 75%을 나타내었다. 고정화 효소에 대한 최적의 pH는 7.0이었고 최적의 온도는 $50^{\circ}C$였다. pH와 온도의 실험 범위에서 고정화 효소가 자유 효소에 비해 넓은 분포를 보여 pH와 온도에 덜 민감하게 작용하였다. 충진층 반응기에서 고정화 효소의 운전에 대한 수학적 모델을 세우고 수치적으로 해를 구하였다. 투입되는 유당의 농도와 유량에 대해서 충진층 반응기의 출구에서 유당의 전환율을 측정하였다. 실험 결과를 경쟁적 저해 효소 반응식과 물질전달 저항을 고려한 수학적 모델의 결과와 비교하였다. 모델의 결과는 실험 결과를 5% 이내의 오차로 잘 예측하였다. 그리고 충진층 반응기의 길이에 따른 유당 전환율과 연속운전 시간에 따른 효소의 비활성화를 고려한 전환율을 모델로부터 예측하였다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1987년도 제2차학술발표초록집
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• pp.59-59
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• 1987

• 공업화학
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• 제30권5호
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• pp.536-545
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• 2019

An experiment was conducted to evaluate the adsorptive removal of Pb(II) from an aqueous solution using a mixture of spent coffee grounds and chitosan on beads (CC-beads). Various parameters affecting the adsorption process of Pb(II) using CC-beads were investigated. Based on the experimental data, the adsorption kinetics and adsorption isotherms were analyzed for their adsorption rate, maximum adsorption capacity, adsorption energy and adsorption strength. Moreover, the entropy, enthalpy and free energy were also calculated by thermodynamic analysis. According to the FT-IR analysis, a CC-bead has a very suitable structure for easy heavy metal adsorption. The process of adsorbing Pb(II) using CC-beads was suitable for pseudo-second order kinetic and Langmuir model, with a maximum adsorption capacity of 163.51 (mg/g). The adsorption of Pb(II) using CC-beads was closer to chemical adsorption than physical adsorption. In addition, the adsorption of Pb(II) on CC-beads was exothermic and spontaneous in nature. CC-beads are economical because they are inexpensive and also the waste can be recycled, which is very significant in terms of the continuous circulation of resources. Thus, CC-beads can compete with other adsorbents.

• Journal of Pharmaceutical Investigation
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• 제27권1호
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• pp.71-77
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• 1997

With the aim of improving periodontal regeneration efficacy, as a biodegradable local drug delivery device, drug releasing chitosan beads were prepared. Chitosan beads were prepared through the formation of intermolecular or intramolecular ionic interaction bewteen chitosan and sodium tripolyphosphate and were loaded with flurbiprofen. The mean diameter of the beads was $250\;{\mu}m$. Drug loading efficiency was improved by regulating the pH of tripolyphosphate solution. The drug release kinetics mainly depended upon the hydrophobic properties of the flurbiprofen, that is, the release of flurbiprofen showed initial burst with rapid release for the first day followed by a levelling off of the release rate. However, the release rate could be controlled by the formulation factor including the pH, concentration of the tripolyphosphate solution, gelation time, drug contents. From these results, flurbiprofen loaded chitosan beads were anticipated as biodegradable local drug delivery devices for periodontal regeneneration.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.317-333
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• 1996

The main goal of periodontal regeneration is to be achieved by epithelial exclusion, periodontal ligament cell activation or alveolar bone regeneration. The purpose of this study was to investigate on the physico- chemical and biological characteristics of biodegradable chitosan beads. Chitosan beads were fabricated by ionic gelation with sodium tripolyphosphate and they had the size in 300um diameter. As therapeutic agent, flurbiprofen was incorporated into the beads by 10, 20% loading contents. The release of drugs from the chitosan beads was measured in vitro. Also, biological activity tests of flurbiprofen loaded chitosan beads including cytotoxicity test, ihhibition of $IL-1{\beta}$ production, suppression to $PGE_2$ production, collagenase inhibition test, the ability of total protein synthesis, and tissue response were evaluated. The amount of flurbiprofen released from chitosan was 33-50% during 7 days. Minimal cytotoxicity was observed in chitosan beads. Flurbiprofen released from chitosan beads significantly suppressed the $IL-1{\beta}$ production of monocyte, $PGE_2$ production and markedly inhibited collagenase activity. Meanwhile, flurbiprofen released from this system showed increased ability for protein synthesis. Throughout 4 -week implantation period, no significant inflammatory cell infiltrated around chitosan bead and also fibroblast like cell types at the beads - tissue interface were revealed with gradual degradation of implanted chitosan beads. From these results, it was suggested that flurbiprofen loaded chitosan beads can be effectively useful for biocompatible local delivery system in periodontal regeneration.

• 공업화학
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• 제10권2호
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• pp.268-274
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• 1999

평균분자량이 $8.2{\times}10^5$, 탈아세틸화도가 85%인 키토산을 2 wt % 초산 수용액에 용해시킨 후 졸-겔법에 의해 키토산 비드를 제조하였다. 졸-겔법에 의해 제조된 키토산 비드는 SEM 사진과, BET 측정으로 다공성임을 확인할 수 있었다. 다공성 키토산 비드에 의한 $Cu^{2+}$의 흡착평형은 Sips식으로 잘 묘사할 수 있었으며, 키토산 비드 내부에서의 확산과정은 세공 및 표면확산 기구로 설명할 수 있었다. 고정층에서 $Cu^{2+}$의 흡착거동은 linear driving force approximation (LDFA)으로 잘 묘사할 수 있었으며, 본 연구에 사용된 다공성 키토산 비드는 $Cu^{2+}$을 회수하는데 우수한 흡착제임을 확인할 수 있었다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2002년도 제9차 국제심포지움 및 추계정기학술발표회
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• pp.52-52
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• 2002

Chitosan is a key compound of shrimp waste. It is a biopolymer, which is widely used in the field of medical Sciences. Chitosan-TPP (Tripolyphosphate) complex has more or less similar physical properties as Ca-alginate which can be used for the production of synthetic seeds. Possibility of the use of Chitosan-TPP complex as a matrix for encapsulation of somatic embryos was tested against the Ca-alginate complex (2.5w/v Na-alginate, 100mM CaCl2 at pH 5.5). Somatic embryos grown in the induction medium (IM) were drawn into the viscous chitosan solution (1%) and mixed well by inverting the tube carefully. Then the mixture was dropped at regular intervals into the tripolyphosphate (TPP) solution kept on a magnetic stirrer for bead formation. Synthetic seeds formed were washed and transferred into the incubation medium, then allowed either to air-dry or freeze-dry.(중략)