Morphology and Polymorph Selectivity Control in Calcium Carbonate Mineralization

2004 ◽  
Vol 847 ◽  
Author(s):  
Swaminathan Sindhu ◽  
Parayil K. Ajikumar ◽  
Subbiah Jegadesan ◽  
Suresh Valiyaveettil
Keyword(s):  
Thin Film ◽  
Calcium Carbonate ◽  
Low Temperature ◽  
Aspartic Acid ◽  
Polyacrylic Acid ◽  
Room Temperature ◽  
Amorphous Calcium Carbonate ◽  
Precipitated Calcium Carbonate ◽  
Selectivity Control

ABSTRACTThe present paper describes the mineralization of calcium carbonate at a low temperature (4 °C) and in presence of additives. Aspartic acid immobilized polyacrylic acid (PA-Asp) induced the nucleation of spherical vaterite polymorph at 4 °C. But at room temperature, a thin film of calcite was deposited. Moreover, stable amorphous calcium carbonate was precipitated in presence of magnesium at low temperature. The observed results show that low temperature and presence of additives influence the nucleation, polymorph selectivity and morphology of the precipitated calcium carbonate.

scholarly journals Pure hydroxyapatite synthesis originating from amorphous calcium carbonate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michika Sawada ◽  
Kandi Sridhar ◽  
Yasuharu Kanda ◽  
Shinya Yamanaka
Keyword(s):  
Calcium Carbonate ◽  
Calcium Phosphate ◽  
Room Temperature ◽  
Molar Ratio ◽  
Final Phase ◽  
Amorphous Calcium Carbonate ◽  
Phosphate Compound ◽  
Synthesis Strategy ◽  
Phosphorylation Reaction ◽  
Subsequent Calcination

AbstractWe report a synthesis strategy for pure hydroxyapatite (HAp) using an amorphous calcium carbonate (ACC) colloid as the starting source. Room-temperature phosphorylation and subsequent calcination produce pure HAp via intermediate amorphous calcium phosphate (ACP). The pre-calcined sample undergoes a competitive transformation from ACC to ACP and crystalline calcium carbonate. The water content, ACC concentration, Ca/P molar ratio, and pH during the phosphorylation reaction play crucial roles in the final phase of the crystalline phosphate compound. Pure HAp is formed after ACP is transformed from ACC at a low concentration (1 wt%) of ACC colloid (1.71 < Ca/P < 1.88), whereas Ca/P = 1.51 leads to pure β-tricalcium phosphate. The ACP phases are precursors for calcium phosphate compounds and may determine the final crystalline phase.

Control of Polymorph Selection in Amorphous Calcium Carbonate Crystallization by Poly(Aspartic Acid): Two Different Mechanisms

Small ◽  
2017 ◽  
Vol 13 (21) ◽  
pp. 1603100 ◽  
Author(s):  
Zhaoyong Zou ◽  
Luca Bertinetti ◽  
Yael Politi ◽  
Peter Fratzl ◽  
Wouter J. E. M. Habraken
Keyword(s):  
Calcium Carbonate ◽  
Aspartic Acid ◽  
Amorphous Calcium Carbonate ◽  
Polymorph Selection

Conductivity Study of Initial Stages of β-PdBi2 Formation on Bi/Si(111)

2018 ◽  
Vol 386 ◽  
pp. 110-115
Author(s):  
Maxim Viktorovich Ivanchenko ◽  
Elena Anatolyevna Borisenko ◽  
Maria Valeryevna Ryzhkova ◽  
Dmitry Anatolyevich Tsukanov
Keyword(s):  
Thin Film ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Ultrathin Films ◽  
Room Temperature ◽  
Molecular Beam ◽  
Electrical Conductance ◽  
Layered Material ◽  
Bulk Crystals ◽  
Superconducting Properties

Bulk β-PdBi2 layered material is known as a low-temperature superconductor. Recently, ultrathin films of this material consisting of dozens of triple layers were grown by molecular beam epitaxy and demonstrated structural, electronic and superconducting properties similar to those of bulk crystals. In this paper, we showed that thin film of β-PdBi2 can be grown by alternative palladium and bismuth deposition and its electrical conductance was investigated at room temperature in comparison with the conductivity of bulk β - PdBi2.

Improved room temperature electron mobility in self-buffered anatase TiO2epitaxial thin film grown at low temperature

2014 ◽  
Vol 53 (9) ◽  
pp. 090305 ◽  
Author(s):  
Thantip S. Krasienapibal ◽  
Tomoteru Fukumura ◽  
Yasushi Hirose ◽  
Tetsuya Hasegawa
Keyword(s):  
Thin Film ◽  
Low Temperature ◽  
Electron Mobility ◽  
Room Temperature ◽  
Temperature Electron

scholarly journals Low-Temperature Fabrication of IZO Thin Film for Flexible Transistors

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2552
Author(s):  
Xingwei Ding ◽  
Bing Yang ◽  
Haiyang Xu ◽  
Jie Qi ◽  
Xifeng Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Low Temperature ◽  
Flexible Electronics ◽  
Room Temperature ◽  
Network Formation ◽  
Semiconductor Films ◽  
Uv Treatment ◽  
Indium Zinc Oxide ◽  
Izo Thin Film

Solution-processed thin film transistors (TFTs) used in flexible electronics require them to be fabricated under low temperature. Ultraviolet (UV) treatment is an effective method to transform the solution precursors into dense semiconductor films. In our work, high-quality indium zinc oxide (IZO) thin films were prepared from nitrate-based precursors after UV treatment at room temperature. After UV treatment, the structure of IZO thin films was gradually rearranged, resulting in good M–O–M network formation and bonds. TFTs using IZO as a channel layer were also fabricated on Si and Polyimide (PI) substrate. The field effect mobility, threshold voltage (Vth), and subthreshold swing (SS) for rigid and flexible IZO TFTs are 14.3 and 9.5 cm2/Vs, 1.1 and 1.7 V, and 0.13 and 0.15 V/dec., respectively. This low-temperature processed route will definitely contribute to flexible electronics fabrication.

Strained calcite crystals from amorphous calcium carbonate containing an organic molecule

CrystEngComm ◽  
2020 ◽  
Vol 22 (42) ◽  
pp. 7054-7058
Author(s):  
So Sugiyama ◽  
Mihiro Takasaki ◽  
Yuya Oaki ◽  
Hiroaki Imai
Keyword(s):  
Raman Spectroscopy ◽  
Calcium Carbonate ◽  
Aspartic Acid ◽  
Organic Molecule ◽  
Amorphous Calcium Carbonate

Strained calcite was produced from amorphous calcium carbonate (ACC) containing aspartic acid and characterized by Raman spectroscopy and nanoindentation.

scholarly journals Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for “Mineral Plastics”

2016 ◽  
Vol 55 (39) ◽  
pp. 11765-11769 ◽  
Author(s):  
Shengtong Sun ◽  
Li-Bo Mao ◽  
Zhouyue Lei ◽  
Shu-Hong Yu ◽  
Helmut Cölfen
Keyword(s):  
Calcium Carbonate ◽  
Polyacrylic Acid ◽  
Amorphous Calcium Carbonate
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