Control Crystallization of Calcium Carbonate in Aqueous Solution with In-Situ Radical Polymerization of Sodium Acrylate as a Latent Inductor for Crystal Nucleation and Growth

2004 ◽  
Vol 77 (4) ◽  
pp. 827-833 ◽  
Author(s):  
Kensuke Naka ◽  
Dong-Ki Keum ◽  
Yasuyuki Tanaka ◽  
Yoshiki Chujo
Keyword(s):  
Aqueous Solution ◽  
Calcium Carbonate ◽  
Radical Polymerization ◽  
Nucleation And Growth ◽  
Crystal Nucleation ◽  
Sodium Acrylate ◽  
Control Crystallization

Biomimetic Synthesis of Hydrophobic Calcium Carbonate Nanoparticles In Situ

2010 ◽  
Vol 113-116 ◽  
pp. 807-810
Author(s):  
Yang Xu ◽  
Cheng Yu Wang ◽  
Jian Li
Keyword(s):  
Aqueous Solution ◽  
Contact Angle ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Organic Substrate ◽  
Biomimetic Synthesis ◽  
Dodecanoic Acid ◽  
Caco3 Nanoparticles ◽  
Surface Modified

The hydrophobic CaCO3 nanoparticles were synthesized in situ by mimicking the essential functions of biomineralization. Using this method, CaCO3 nanoparticles were synthesized and were surface modified at the same time in the system of aqueous solution. The organic substrate of dodecanoic acid used here not only induces the nucleation and growth of calcium carbonate but also make the surface of calcium carbonate hydrophobic. The contact angle of the modified CaCO3 nanoparticles reached 110o.

A TEM study of the microstructure of avian eggshells

1992 ◽  
Vol 50 (2) ◽  
pp. 1102-1103
Author(s):  
S. Q. Xiao ◽  
S. Baden ◽  
A. H. Heuer
Keyword(s):  
Electron Microscope ◽  
Calcium Carbonate ◽  
Nucleation And Growth ◽  
Growth Mechanisms ◽  
Shell Surface ◽  
Thin Sections ◽  
Polycrystalline Metals ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms

The avian eggshell is one of the most rapidly mineralizing biological systems known. In situ, 5g of calcium carbonate are crystallized in less than 20 hrs to fabricate the shell. Although there have been much work about the formation of eggshells, controversy about the nucleation and growth mechanisms of the calcite crystals, and their texture in the eggshell, still remain unclear. In this report the microstructure and microchemistry of avian eggshells have been analyzed using transmission electron microscope (TEM) and energy dispersive spectroscopy (EDS).Fresh white and dry brown eggshells were broken and fixed in Karnosky's fixative (kaltitanden) for 2 hrs, then rinsed in distilled H2O. Small speckles of the eggshells were embedded in Spurr medium and thin sections were made ultramicrotome.The crystalline part of eggshells are composed of many small plate-like calcite grains, whose plate normals are approximately parallel to the shell surface. The sizes of the grains are about 0.3×0.3×1 μm3 (Fig.l). These grains are not as closely packed as man-made polycrystalline metals and ceramics, and small gaps between adjacent grains are visible indicating the absence of conventional grain boundaries.

scholarly journals Shape-controlled synthesis and in situ characterisation of anisotropic Au nanomaterials using liquid cell transmission electron microscopy

Nanoscale ◽  
2019 ◽  
Vol 11 (36) ◽  
pp. 16801-16809 ◽  
Author(s):  
Shih-Ting Wang ◽  
Yiyang Lin ◽  
Michael H. Nielsen ◽  
Cheng Yu Song ◽  
Michael R. Thomas ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nucleation And Growth ◽  
Crystal Nucleation ◽  
Controlled Synthesis ◽  
Transmission Electron ◽  
Liquid Cell ◽  
Shape Controlled ◽  
Fundamental Requirement

Understanding the mechanisms behind crystal nucleation and growth is a fundamental requirement for the design and production of bespoke nanomaterials with controlled sizes and morphologies.

scholarly journals Crystallization kinetics of amorphous calcium carbonate in confinement

2019 ◽  
Vol 10 (19) ◽  
pp. 5039-5043 ◽  
Author(s):  
Jack Cavanaugh ◽  
Michael L. Whittaker ◽  
Derk Joester
Keyword(s):  
Steady State ◽  
Calcium Carbonate ◽  
Crystal Nucleation ◽  
Amorphous Calcium Carbonate ◽  
Emulsion Droplets ◽  
Individual Crystal ◽  
Upper Limit ◽  
Kinetics Of

In situ observation of amorphous calcium carbonate (ACC) confined in ∼500 pL emulsion droplets allows determination of the timing of individual crystal nucleation events. Statistical analysis of events in hundreds of droplets establishes an upper limit for the steady-state nucleation rate of 1.2 cm−3 s−1 for the crystallization from ACC.

scholarly journals Characterization of Glycoconjugates of Extracellular Polymeric Substances in Tufa-Associated Biofilms by Using Fluorescence Lectin-Binding Analysis

2010 ◽  
Vol 77 (2) ◽  
pp. 505-516 ◽  
Author(s):  
B. Zippel ◽  
T. R. Neu
Keyword(s):  
Sialic Acid ◽  
Calcium Carbonate ◽  
Extracellular Polymeric Substances ◽  
Lectin Binding ◽  
Laser Scanning Microscopy ◽  
Crystal Nucleation ◽  
Amino Sugars ◽  
Binding Analysis ◽  
Freshwater Tufa

ABSTRACTFreshwater tufa deposits are the result of calcification associated with biofilms dominated by cyanobacteria. Recent investigations highlighted the fact that the formation of microbial calcium carbonates is mainly dependent on the saturation index, which is determined by pH, the ion activity of Ca2+and CO32−, and the occurrence of extracellular polymeric substances (EPS) produced by microorganisms. EPS, which contain carboxyl and/or hydroxyl groups, can strongly bind cations. This may result in inhibition of CaCO3precipitation. In contrast, the formation of templates for crystal nucleation was reported by many previous investigations. The purposes of this study were (i) to characterize thein situdistribution of EPS glycoconjugates in tufa-associated biofilms of two German hard-water creeks by employing fluorescence lectin-binding analysis (FLBA), (ii) to verify the specific lectin-binding pattern by competitive-inhibition assays, and (iii) to assess whether carbonates are associated with structural EPS domains. Three majorin situEPS domains (cyanobacterial, network-like, and cloud-like structures) were detected by FLBA in combination with laser scanning microscopy (LSM). Based on lectin specificity, the EPS glycoconjugates produced by cyanobacteria contained mainly fucose, amino sugars (N-acetyl-glucosamine andN-acetyl-galactosamine), and sialic acid. Tufa deposits were irregularly covered by network-like EPS structures, which may originate from cyanobacterial EPS secretions. Cloud-like EPS glycoconjugates were dominated by sialic acid, amino sugars, and galactose. In some cases calcium carbonate crystals were associated with cyanobacterial EPS glycoconjugates. The detection of amino sugars and calcium carbonate in close association with decaying sheath material indicated that microbially mediated processes might be important for calcium carbonate precipitation in freshwater tufa systems.

scholarly journals Aqueous copper(0) mediated reversible deactivation radical polymerization of 2-hydroxyethyl acrylate

2015 ◽  
Vol 6 (36) ◽  
pp. 6509-6518 ◽  
Author(s):  
Mingmin Zhang ◽  
Michael F. Cunningham ◽  
Robin A. Hutchinson
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Radical Polymerization ◽  
Reversible Deactivation ◽  
Reversible Deactivation Radical Polymerization

Lowering the concentration of adsorbed radicals on the Cu(0) surface, achieved by reducing catalyst and adding NaBr, is the key to the synthesis of well-defined P(HEA) without a high molecular weight shoulder in aqueous solution using two-step Cu(0)in situmediation.

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