• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.133.1-133
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• 2003

• 한국세라믹학회지
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• 제28권11호
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• pp.885-891
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• 1991

Calcium hydroxyapatite have been synthesized by a direct precipitation reaction between 0.05 M calcium hydroxide suspension and 0.3 M orthophosphoric acid solution. 0.01 M calcium hydroxide solution was added during the reaction in order to increase the total Ca/P mol ration and reaction pH of the solution. The stoichiometric hydroxyapatite was synthesized over 1.75 as total Ca/P mol ratio, but the calcium-deficient hydroxyapatite was prepared under 1.725 as total Ca/P mol ratio. The nonstoichiometry of the precipitates were interpreted in terms of the pH change during the reaction.

• 한국재료학회지
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• 제14권6호
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• pp.375-378
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• 2004

The samples were prepared with hydroxyapatite(HAp) powder and eugenol (Eugenol/HAp = 15, 20, 25, 30wt%). The samples were dried at room temperature. The higher mechanical properties was observed in HAp sample with 25wt% Eugenol. The average compressive and bending strength in HAp with 25wt% Eugenol are 542 kgf/$\textrm{mm}^2$ and 366 kgf/$\textrm{mm}^2$ respectively. This strength is higher compare to that of the cortical bone.

• 한국세라믹학회지
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• 제41권4호
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• pp.289-296
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• 2004

양론조성에 근접하는 (Ca/P=1.62-1.67, molar ratio) 휘스커 및 짧은 막대형상의 수산화아파타이트 (Ca$_{10}$(PO$_4$)$_{6}$(OH)$_2$를 $\alpha$-Ca$_3$(PO$_4$)$_2$($\alpha$-TCP) 수용액 (pH 11)의 가수분해와 수열반응으로 각각 합성하였다. 생성된 HAp의 입자형상은 합성방법에, 미세구조의 발달은 반응조건에 주로 의존하였다 가수분해의 경우 반응시간의 경과와 더불어 휘스커 입자들의 상호 교차와 장축방향에서의 응집이 일어났다 반면에, 수열처리에 있어서는 반응과정 중 임계크기(길이 0.75$mu extrm{m}$, 지름 0.3$\mu\textrm{m}$) 이상으로의 입성장은 일어나지 않았으며 과다한 반응시간(20$0^{\circ}C$, $\geq$3시간)은 입자들의 심한 응집을 유발하였다.

• Composites Research
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• 제21권3호
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• pp.18-23
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• 2008

쾌속 조형(Rapid Prototyping; RP) 기술은 다양한 분야에서 활용되고 있다. 본 연구에서는 RP 기술을 이용한 나노복합재 적층장치(Nano Composite Deposition System, NCDS)를 사용하여 이식 가능한 약물전달시스템을 제작하였다. 약물전달시스템 복합재는 약물 입자로 5-fluorouracil (5-FU)를 사용하였으며, 생분해 고분자 매트릭스로 PLGA85/15를 사용하였다. 제작된 약물전달시스템은 넓은 표면적을 가질 수 있도록 지지체(scaffold) 형상으로 제작되었으며, in vitro 환경에서의 약물방출실험이 수행되었다. 약물방출제어를 위하여 생체적합재료인 수산화아파타이트(Hydroxyapatite, HA)를 약물-고분자 복합재에 첨가하였다. 약 50일간의 방출실험을 통하여 약물방출의 가능성을 보임을 확인하였다.

• 한국세라믹학회지
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• 제41권8호
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• pp.582-587
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• 2004

수산화아파타이트(HAp) 및 P-인산3칼슘($\beta$-TCP)으로 구성되는 2상 인산칼슘염(BCP)을 고상반응법으로 합성하고, 이를 상압 및 autoclave를 이용한 고압에서 수열반응 시킴으로써 응집입자의 미세화를 시도하였다. 이 과정에서 일어나는 결정 상 및 화학조성, 구성상의 상대적인 양, 비표면적, 미세구조의 변화에 미치는 공정조건의 영향을 XRD, FT-IR, 질소흡착에 의한 BET법, SEM을 이용하여 검토하였다.

• 한국재료학회지
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• 제15권10호
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• pp.652-656
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• 2005

The samples were prepared with hydroxyapatite(HAp) powder and Polycaboxylate (P.C/HAp=10, 15, 20, 25, 30, 35 $wt\%$). The hydroxyapatite green body with Polycaboxylate were obtained by compaction and drying at room temperature for 3hrs. The higher mechanical properties were observed in HAp sample with $35 wt\%$ Polycaboxylate. The average compressive ana bending strength in HAp with $35 wt\%$ Polycaboxylate are $302 kgf/cm^2$ and $213 kgf/cm^2$ respectively. This strength is higher compare to that of the cortical bone.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.757-760
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• 2005

The technology of rapid prototyping (RP) is used for design verification, function test and fabrication of prototype. The current issues in RP are improvement in accuracy and application of various materials. In this paper, a hybrid rapid prototyping system is introduced which can fabricate nano composites using various materials. This hybrid system adopts RP and machining process, so material deposition and removal is performed at the same time in a single station. As examples, micro gears and a composite scaffold were fabricated using photo cured polymer with nano powders such as carbon black and hydroxyapatite. From the micro gear samples the hybrid RP technology showed higher precision than those made by casting or deposition process.

• 한국재료학회지
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• 제13권11호
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• pp.703-707
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• 2003

Hydroxyapatite powders were prepared by oyster shells and phosphoric acid. They were heat treated at the $1300^{\circ}C$ for 2 hrs. Only hydroxyapatite phases were observed by the XRD analysis. XRF confirmed that the prepared hydroxyapatite composed with 63.2wt% CaO and 35.7wt% $P_2$$O_{5}$ . In the ICP test, small amount of heavy metals were detected as low as 0.009 ppm Ti and 0.002 ppm Ba. The test of bone density was done in human body during three months. As the periods of medication progressed, the bone density was increased.

• 대한의용생체공학회:의공학회지
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• 제18권3호
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• pp.217-222
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• 1997

Hydroxyapatite(HA)-coated metal composites were made by the dipping method. The specimen substrates were Ti plates with a thickness of 2 mm. The HA coating was carried out in HA-sol for 1 min by the dipping method. The concentration of HA-sol for the coating ranged from 3.28 to 9.99 wt%. Excellent coating was observed on Ti substrate dipped once in 9.99 wt% sol. Preparation of Ti plates by sandblasting provided the better environment for coating HA on Ti surface than non-treated surface. As the concentration of sol increased, the weight change and the coating thickness increased. Above 7 wt% sol, they increased sharply.