Crystallization of vaterite and aragonite on chitin whiskers

2021 ◽  
Vol 16 (2) ◽  
pp. 23-30
Author(s):  
Michael Ikpi Ofem
Keyword(s):  
Calcium Carbonate ◽  
Acrylic Acid ◽  
Room Temperature ◽  
Spherical Shape ◽  
Time Frame ◽  
Sem Images ◽  
Volume Fractions ◽  
Chitin Whiskers ◽  
Calcium Carbonate Polymorphs ◽  
Poly Acrylic Acid

The need for the possibility of producing calcium carbonate crystals by the evaporation method within five minutes and the growth of different calcium carbonate polymorphs on chitin whiskers within the same time frame at room temperature necessitated these report. Chitin whiskers (CHWs) were used as insoluble substrates, while poly (acrylic) acid (PAA) is used as soluble additive. The crystals were grown in chitin whiskers, Poly (acrylic) acid and CHW/PAA composites. The volume fractions for aragonite, vaterite, and calcite are 0.10, 0.25, and 0.65, respectively, in the absence of chitin whiskers or Poly (acrylic) acid. Calcite and aragonite volume fractions decrease in favour of vaterite when PAA and or CHWs were added. SEM images in the absence of CHWs and PAA shows rhombohedral calcites that display steady and step like plane appearances with an average edge of between 1.3 and 1.4 μm. In the presence of only CHWs, the SEM images show a mixture of ellipsoidal and spherical shape vaterites. The spherical vaterites have smooth, rough, and some irregular surfaces. Rod-like aragonite polymorphs were seen when only PAA was used as the template. In the presence of both PAA and CHWs, the rhombohedral shape showed roughness with irregular faces. Keywords: Chitin whisker, Calcium carbonate, Calcium, vaterite aragonite, Polymorph, Mole fraction

Preparation of amorphous calcium carbonate nanoparticles from impure dolomitic marble with the aid of poly(acrylic acid) as a stabilizer

2014 ◽  
Vol 25 (2) ◽  
pp. 591-598 ◽  
Author(s):  
M.M.M.G.P.G. Mantilaka ◽  
R.M.G. Rajapakse ◽  
D.G.G.P. Karunaratne ◽  
H.M.T.G.A. Pitawala
Keyword(s):  
Calcium Carbonate ◽  
Acrylic Acid ◽  
Amorphous Calcium Carbonate ◽  
Dolomitic Marble ◽  
Poly Acrylic Acid

γ-Irradiation Induced Synthesis of Titanium Dioxide/Poly(acrylic acid) (TiO2/PAA) Nanocomposites and Layer-by-Layer Assembly on Glass Substrate

2015 ◽  
Vol 1098 ◽  
pp. 25-30 ◽  
Author(s):  
Lawrence John Paulo L. Trinidad ◽  
Ken Aldren S. Usman ◽  
Leon M. Payawan
Keyword(s):  
Acrylic Acid ◽  
Layer Thickness ◽  
Titania Nanoparticles ◽  
Cross Linking ◽  
Layer By Layer ◽  
Γ Irradiation ◽  
Sem Images ◽  
Nucleation Sites ◽  
Anatase Titania ◽  
Poly Acrylic Acid

Adsorption and encapsulation of the nanoparticles in polyelectrolytes impart stability to the nanometal by preventing aggregation through electrostatic and steric effects. Poly (acrylic acid) (PAA) was employed as a polymer cap to anatase titania nanoparticles. Cross-linking of the polymer was done via free-radical cross-linking using gamma-irradiation. The size of the nanocomposite produced ranged from 40-120 nm. SEM images showed that excess TiO2 in solution becomes nucleation sites for aggregation. Film assembly of the synthesized nanocomposite were done by layer-by-layer deposition with PDDA. Films formed with increasing thickness (5, 10, and 15 layers) were analyzed under AFM and shown to have a thickness of 0.25 μm, 1.1μm and 3.0 μm respectively.The average film layer thickness obtained ranged from 50-200 nm per TiO2/PAA-PDDA layer where as the number of layers deposited increase, the layer thickness increase while the roughness decreases.

scholarly journals Synthesis of nanoporous calcium carbonate spheres using double hydrophilic block copolymer poly(acrylic acid-b-N-isopropylacrylamide)

2018 ◽  
Vol 230 ◽  
pp. 143-147 ◽  
Author(s):  
Sudhina Guragain ◽  
Nagy L. Torad ◽  
Yousef Gamaan Alghamdi ◽  
Abdulmohsen Ali Alshehri ◽  
Jeonghun Kim ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Block Copolymer ◽  
Acrylic Acid ◽  
Copolymer Poly ◽  
Poly Acrylic Acid

Nanosized Amorphous Calcium Carbonate Stabilized by Poly(ethylene oxide)-b-poly(acrylic acid) Block Copolymers

Langmuir ◽  
2006 ◽  
Vol 22 (4) ◽  
pp. 1875-1879 ◽  
Author(s):  
Baptiste Guillemet ◽  
Michael Faatz ◽  
Franziska Gröhn ◽  
Gerhard Wegner ◽  
Yves Gnanou
Keyword(s):  
Calcium Carbonate ◽  
Block Copolymers ◽  
Acrylic Acid ◽  
Ethylene Oxide ◽  
Amorphous Calcium Carbonate ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Poly Acrylic Acid

Long-lived emission at room temperature of harmane dispersed in poly (acrylic acid)-poly (vinyl alcohol) polymer network

1999 ◽  
Vol 81 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Jucimar M de Souza ◽  
Paulo N M. dos Anjos ◽  
Walter M de Azevedo ◽  
Alberto S Marques
Keyword(s):  
Acrylic Acid ◽  
Vinyl Alcohol ◽  
Room Temperature ◽  
Polymer Network ◽  
Poly Vinyl Alcohol ◽  
Poly Acrylic Acid

scholarly journals Inhibition of homogenous formation of calcium carbonate by poly (acrylic acid). The effect of molar mass and end-group functionality

Desalination ◽  
2014 ◽  
Vol 338 ◽  
pp. 93-105 ◽  
Author(s):  
Ali A. Al-Hamzah ◽  
Christopher P. East ◽  
William O.S. Doherty ◽  
Christopher M. Fellows
Keyword(s):  
Calcium Carbonate ◽  
Acrylic Acid ◽  
Molar Mass ◽  
End Group ◽  
Poly Acrylic Acid

scholarly journals Analysis of calcium carbonate polymorphs deposited in water piping system and the effect of tartaric acid additive

2018 ◽  
Vol 159 ◽  
pp. 01054 ◽  
Author(s):  
W. A. Putranto ◽  
Y. Umardhani ◽  
Sulistyo ◽  
Yurianto ◽  
A. P. Bayuseno
Keyword(s):  
Calcium Carbonate ◽  
Tartaric Acid ◽  
Room Temperature ◽  
Rietveld Method ◽  
Piping System ◽  
Chemical Additives ◽  
Eds Analysis ◽  
Increasing Temperature ◽  
Calcium Carbonate Polymorphs ◽  
Water Piping

Calcium carbonate (CaCO3) formed in a water piping system was investigated in the presence of chemical additives tartaric acid (0.00 and 10.00 ppm) and various temperatures ((27 and 50ºC). The flow rate inside pipe (35 ml/min) were selected. Solutions of CaCl2 and Na2CO3 were prepared in water with equimolar to Ca2+ concentration of 3000 ppm. The induction time of scale nucleation varied from 24 min to 44 min. An increasing temperature of the solution resulted in more CaCO3 scale, mass, while the higher tartaric acid made the reduced mass of scales by 90%. SEM/EDS analysis verified CaCO3 with a plate like morphology. Also the XRPD Rietveld method provided the confirmation of a major phase of calcite and vaterite minerals followed by the minor of aragonite in the absence of tartaric acid and at room temperature. However, the presence of 10 ppm tartaric acid yielded the increasing result of calcite, while aragonite precipitation was hampered under the influence of tartaric acid. The presence of tartaric acid at increasing temperature of 50ºC could delay formation of calcite, whereas aragonite could be formed significantly. Thus the study showed the capacity of the tartaric acid in influencing CaCO3 crystallization.

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