Basic Properties of Starfish Derived Calcium Carbonate and its Phase Transformation to Carbonate Apatite

2012 ◽  
Vol 529-530 ◽  
pp. 40-43
Author(s):  
Daiki Honda ◽  
Akari Takeuchi ◽  
Ishikawa Kunio
Keyword(s):  
Aqueous Solution ◽  
Phase Transformation ◽  
Calcium Carbonate ◽  
Porous Structure ◽  
Pore Size ◽  
Hydrothermal Treatment ◽  
Bone Substitute ◽  
Source Material ◽  
Carbonate Apatite ◽  
Porous Calcium Carbonate

Feasibility of starfish bone to be a source material for apatite bone substitute was investigated in the present study because starfish bone is known to be porous calcium carbonate. Starfish bone was assembly of Mg containing calcite granules. And the calcite granules had fully interconnected porous structure with approximately 20 µm of pore size. After the hydrothermal treatment of the calcite granules in Na2HPO4 aqueous solution, the granules were gradually transformed to apatite. Therefore, starfish derived calcium carbonate would be a candidate of a source material for carbonate apatite bone substitute.

Comparison of PLGA Reinforcement Method for Carbonate Apatite Foam

2012 ◽  
Vol 529-530 ◽  
pp. 417-420 ◽  
Author(s):  
Girlie M. Munar ◽  
Melvin L. Munar ◽  
Kanji Tsuru ◽  
Ishikawa Kunio
Keyword(s):  
Compressive Strength ◽  
Porous Structure ◽  
Cancellous Bone ◽  
Bone Substitute ◽  
Vacuum Infiltration ◽  
Carbonate Apatite ◽  
Potential Candidate ◽  
Bone Substitute Material ◽  
Substitute Material ◽  
Scanning Electron

Carbonate apatite (CO3Ap) foam with interconnecting porous structure is a potential candidate as bone substitute material owing to its similarity to the cancellous bone with respect to composition, morphology and osteoclastic degradation. However, it is brittle and difficult to handle. This is thought to be caused by no organic material in the CO3Ap foam. The aim of this study is to reinforce the CO3Ap foam with poly (DL-lactide-co-glycolide) (PLGA). Immersion and vacuum infiltration methods were compared as reinforcing methods. Compressive strength of unreinforced CO3Ap foam, (12.0 ± 4.9 kPa) increased after PLGA reinforcement by immersion (187.6 ± 57.6 kPa) or by vacuum infiltration (407 ± 111.4 kPa). Scanning electron microscopy (SEM) showed the preservation of full interconnecting porous structure of CO3Ap foam after PLGA reinforcement using immersion or vacuum infiltration. Interface between the PLGA and CO3Ap foam, however revealed that no gap was found between the PLGA and CO3Ap foam interface when vacuum was used to reinforce the PLGA whereas a gap was found when simple immersion was used. Strong interface between PLGA and CO3Ap foam is therefore thought to be the key for higher compressive strength. In conclusion, vacuum infiltration is a more efficient method to reinforce the CO3Ap foam with PLGA for improving the mechanical strength without sacrificing the cancellous bone-type morphology.

scholarly journals Reentrant phase transformation from crystalline ikaite to amorphous calcium carbonate

CrystEngComm ◽  
2018 ◽  
Vol 20 (21) ◽  
pp. 2902-2906
Author(s):  
Zhaoyong Zou ◽  
Luca Bertinetti ◽  
Wouter J. E. M. Habraken ◽  
Peter Fratzl
Keyword(s):  
Phase Transformation ◽  
Calcium Carbonate ◽  
Porous Structure ◽  
Amorphous Calcium Carbonate ◽  
Multi Level

Micrometer-sized metastable amorphous calcium carbonate with a multi-level interconnected porous structure is transformed from highly hydrated crystalline ikaite by fast dehydration.

Fabrication of Carbonate Apatite Block from Calcium Sulfate by Hydrothermal Treatment

2011 ◽  
Vol 493-494 ◽  
pp. 139-142 ◽  
Author(s):  
Shunsuke Nomura ◽  
Kanji Tsuru ◽  
Alireza Valanezhad ◽  
Shigeki Matsuya ◽  
Ichiro Takahashi ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Bone Substitute ◽  
Calcium Sulfate ◽  
Treatment Temperature ◽  
Carbonate Content ◽  
Precipitation Reaction ◽  
Carbonate Apatite ◽  
X Ray Diffraction ◽  
Hydrogen Carbonate ◽  
Calcium Sulfate Hemihydrate

Carbonate apatite (CO3Ap) is expected to be an ideal bone substitute since it can harmonize with the bone remodeling cycle. The aim of this study is to fabricate a CO3Ap bone substitute from gypsum (calcium sulfate, CaSO4·2H2O) hardening bodies based on dissolution-precipitation reaction. Calcium sulfate hemihydrate mixed with water at a water-to-powder ratio of 0.5 was packed in a split stainless mold and kept at room temperature for 24 hours to obtain set CaSO4·2H2O. The set CaSO4·2H2O was hydrothermally treated in the presence of disodium hydrogen phosphate (Na2HPO4) and sodium hydrogen carbonate (NaHCO3). The results of powder X-ray diffraction and Fourier transform infrared spectroscopy indicated that CO3Ap block could be fabricated from the set CaSO4·2H2O block by hydrothermal treatment with Na2HPO4 and NaHCO3. When the treatment temperature was increased, the conversion rate to CO3Ap increased. However, the carbonate content decreased with increasing treatment temperature.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

1990 ◽  
Vol 48 (4) ◽  
pp. 1094-1095
Author(s):  
Eduardo A. Kamenetzky ◽  
David A. Ley
Keyword(s):  
Aqueous Solution ◽  
Affinity Chromatography ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Coverage ◽  
Vacuum Impregnation ◽  
Thin Sections ◽  
Selective Staining ◽  
Low Viscosity ◽  
Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

scholarly journals A Novel Resorbable Composite Material Containing Poly(ester-co-urethane) and Precipitated Calcium Carbonate Spherulites for Bone Augmentation—Development and Preclinical Pilot Trials

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 102
Author(s):  
Claudia Rode ◽  
Ralf Wyrwa ◽  
Juergen Weisser ◽  
Matthias Schnabelrauch ◽  
Marijan Vučak ◽  
...  
Keyword(s):  
Composite Material ◽  
Calcium Carbonate ◽  
Bone Substitute ◽  
Pilot Trial ◽  
Carbonate Content ◽  
Precipitated Calcium Carbonate ◽  
Degradation Behaviour ◽  
Biodegradable Composite ◽  
Loss Of Mass

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.

Effects of Surface Properties and Solvent PH Values on the Adsorption/Desorption Abilities of Mesoporous SBA-15 to Methylene Blue Molecules

2012 ◽  
Vol 518-523 ◽  
pp. 352-355
Author(s):  
Hui Liu ◽  
Hong Liang Li ◽  
Meng Xue Wang ◽  
Jing Jing Sang ◽  
Xiu Song Zhao
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Surface Properties ◽  
Weak Base ◽  
Adsorption Ability ◽  
Ph Values ◽  
Model Molecule ◽  
Adsorption Desorption

Methylene blue (MB) was used as model molecule to investigate the effects of surface properties and solvent pH values on the adsorption and desorption (or release) behaviors of mesoporous SBA-15 materials. It was found that the treatment of SBA-15 with a pH 7.8 aqueous solution can enhance the adsorption rate and capacity in comparison with the pristine SBA-15. The effect of pH values on MB releasing from the weak base treated SBA-15 and the pristine one have been studied and been compared in pH values range from 0.5 to 7.0. Both of them showed a maximum releasing rate at about pH 2 and all of the treated SBA-15 samples showed a higher releasing quantity than the pristine ones. The influence mechanisms of base treatment on the adsorption ability and that of pH values on the releasing properties of SBA-15 samples have been analyzed and been discussed based on the composition, the morphology, the surface area and pore size distribution and adsorption/desorption measurements.

Tobacco stalk-derived carbon prepared by one-step molten salt carbonization for supercapacitor

2021 ◽  
pp. 2151021
Author(s):  
Yuxuan Liu ◽  
Xinhua Cheng ◽  
Shenghui Zhang
Keyword(s):  
Aqueous Solution ◽  
Energy Density ◽  
Porous Structure ◽  
Molten Salt ◽  
Electrode System ◽  
Rate Performance ◽  
Heteroatom Doping ◽  
Hierarchically Porous Structure ◽  
One Step ◽  
Tobacco Stalk

High-performance capacitive carbon materials, derived from tobacco stalk, were prepared by a one-step carbonization process in molten carbonate. Owing to the high specific surface area (SSA) (1165.9 m2 g[Formula: see text] and heteroatom doping by the activation effect of molten salt medium for 3 h, the as-obtained carbon material with hierarchically porous structure exhibits an ideal capacitive property with delivering specific capacitances of 219.8, 188.0, 176.4, and 168.4 F g[Formula: see text] at 0.2, 0.5, 1, and 2 A g[Formula: see text], respectively, acceptable rate performance with 76.6% capacitance retention in range of 0.2–2 A g[Formula: see text], and good cyclic stability with 93% capacitance retention after 3000 charge–discharge cycles at 1 A g[Formula: see text], as well as energy density of 30.5 Wh kg[Formula: see text] at 0.2 A g[Formula: see text] and power density of 989.6 W kg[Formula: see text] at 2 A g[Formula: see text] in 1 mol L[Formula: see text] H2SO4 aqueous solution using a three-electrode system. Moreover, it delivers specific capacitances of 143.3, 140.2, 137.4, and 134.3 F g[Formula: see text] at 0.2, 0.5, 1, and 2 A g[Formula: see text], respectively, and excellent rate performance with 93.7% capacitance retention in range of 0.2–2 A g[Formula: see text], as well as energy density of 4.9 Wh kg[Formula: see text] at 0.2 A g[Formula: see text] and power density of 488.6 W kg[Formula: see text] at 2 A g[Formula: see text] in 6 mol L[Formula: see text] KOH aqueous solution using a symmetrical two-electrode system. The correlation between hierarchically porous structure with heteroatom doping and capacitive performance is also discussed.

scholarly journals Effect of Soaking Time on the Phase Transformation of Porous Biphasic β-Tricalcium Phosphate/Carbonate Apatite Scaffold

2019 ◽  
Vol 30 (Supp.2) ◽  
pp. 65-75
Author(s):  
Nur Nadhirah Muhaime ◽  
◽  
Ira Artillia ◽  
Nurazreena Ahmad ◽  
◽  
...  
Keyword(s):  
Phase Transformation ◽  
Tricalcium Phosphate ◽  
Carbonate Apatite ◽  
Soaking Time ◽  
Phosphate Carbonate
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