The Effect of Hydrothermal Holding Time on The Characterization of Hydroxyapatite Synthesized from Green Mussel Shells

Author(s):  
Rifky Ismail ◽  
Muhammad Bagus Laroybafih ◽  
Deni Fajar Fitriyana ◽  
Sri Nugroho ◽  
Yanuar Iman Santoso ◽  
...  

Hydroxyapatite is generally utilized in medical fields especially as a substitute to bone and teeth. Hydroxyapatite nanoparticles have been succesfully synthesized from green mussel shells as a source of calcium carbonate by hydrothermal method. The green mussel shells were calcined, hydrated, and undergone carbonation to form Precipitated Calcium Carbonate (PCC). The PCC of shells was then added with (NH4)2HPO4 with the mole ratio of Ca/P = 1.67. Hydrothermal reaction was carried out at 160oC with variations of the holding time (14, 16, and 18 hrs). The formation of hydroxyapatite was characterized using XRD and SEM-EDX. The XRD patterns showed that the products were hydroxyapatite crystals. The morphology of hydroxyapatite observed using SEM showed that the crystal uniformity of hydroxyapatite. The best result was obtained at 18 hrs holding time of hydrothermal because the hydroxyapatite produced has the highest purity without any impurities phase.

2012 ◽  
Vol 15 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Michele Regina Rosa Hamester ◽  
Palova Santos Balzer ◽  
Daniela Becker

2006 ◽  
Vol 510-511 ◽  
pp. 1026-1029
Author(s):  
Jin Sang Cho ◽  
Sung Min Joo ◽  
Sang Hwan Cho ◽  
Young Hwan Yu ◽  
Im Ho Kim ◽  
...  

The effect of the impurity ions Al3+, Fe3+ and Mg2+ on the formation yield and crystal properties of precipitated calcium carbonate(PCC) produced by the carbonation process was investigated in Ca(OH)2-H2O-CO2 system. The effect of the impurity ions Al3+, Fe3+ and Mg2+ on the formation yield using particle size distribution and morphology of PCC were discussed. The particle size distribution of PCC was increased with increase of impurity ions. The morphology was transformed in order of spheroidal, scalenohedral, rhombohedral calcite for Al3+, Fe3+ and rhombospheroidal, spherical, scalenohedral for Mg2+ with increase of impurity ions.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


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