• 약학회지
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• 제37권1호
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• pp.66-75
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• 1993

Dental abrasive, dicalcium phosphate dehydrate (DCPD) was prepared and the several important factors affecting on the quality of toothpaste were investigated by means of set test, glycerine absorption, Coulter counter test, color difference, BET adsorption, mercury porosimetery, and rheogram comparing with two foreign DCPDs, MFO4 and Dentphos K. Sample DCPD was prepared by reaction between 85% H$_{3}$PO$_{4}$ and 15% milk of lime at $39^{\circ}C$ (pH6.5), and stabilized with TSPP and TMP. The physicochemical properties of Sample DCPD were obtained as follows: whiteness (98.99), average particle size (15.5 $\mu\textrm{m}$), pH (7.9), remainder particle weight (0.49w/w%), glycerine absorption value (64 ml), and set test (passed). N$_{2}$ adsorption curves (BET) of three kinds of DCPD showed non-porous type III isotherm. BET adsorption parameters of sample DCPD showed that surface area was 24.9 m$^{2}$/g, total pore volume 0.09 cm$^{3}$/g and average pore radius 72.0 $\AA$. The rheogram of the toothpaste containing each DCPD showed bulged plastic flow with yield vlaue and thixotropic behavior. These results meet standard requirements as abrasive standard, and suggested that synthesized sample DCPD could be used a dental abrasive such as a high quality grade in practice as foreign DCPDs.

• 공업화학
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• 제10권2호
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• pp.183-189
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• 1999

$H_2S$를 제거를 위한 아연계 복합금속산화물 탈황제를 제조하고 반응특성을 연구하였다. 최적 황화반응 온도인 $650^{\circ}C$의 고정층에서 탈황-재생의 연속 cycle에 따른 반응성을 관찰하였다. 내마모성 향상을 위한 구형입자의 탈황제를 제조하기 위해 Granulation방법을 이용하였다. XRD와 XPS분석에 의해 zinc titanate결정생성을 확인하였고 소성조건에 따른 탈황제의 특성을 분석하기 위해 mercury porosimetry와 BET분석을 행하였다. Cycle이 증가함에 따라 고온에서의 zinc loss와 sintering, cracking, 그리고 spalling에 의한 탈황제의 확산저항의 증가로 인해 반응성은 떨어졌다.