The Role of Crystal Control Agent in the Formation of Needlelike Calcium Carbonate Nano Particles

2011 ◽  
Vol 236-238 ◽  
pp. 2150-2159
Author(s):  
Yu Qian Ye ◽  
Xue Mei Chen
Keyword(s):  
Calcium Carbonate ◽  
Aspect Ratio ◽  
Crucial Role ◽  
Average Diameter ◽  
Morphological Characterization ◽  
Control Agent ◽  
Nano Particles ◽  
Precipitated Calcium Carbonate ◽  
Nanometer Particles

In this work, needlelike precipitated calcium carbonate (PCC) nanometer particles were synthesized by industrial carbonation route using EDTA as crystal control agent. The morphological characterization shows that the as-synthesized needlelike PCC particles have an average diameter of 52 nm and an aspect ratio of around 14:1. The results indicate that EDTA plays a crucial role in the formation of needlelike PCC nanometer particles. A possible mechanism for the formation of needlelike PCC particles assisted by the crystal control agent EDTA is also proposed.

Role of additives to improve adsorption of xylan on precipitated calcium carbonate

Cellulose ◽  
2018 ◽  
Vol 25 (3) ◽  
pp. 1583-1598 ◽  
Author(s):  
Indrasena Ghosh ◽  
Chhaya Sharma ◽  
Rita Tandon
Keyword(s):  
Calcium Carbonate ◽  
Precipitated Calcium Carbonate

scholarly journals Effect of PCC crystallization and morphology on flocculation with microfibrillated cellulose, on sheet densification and liquid absorption behavior

Cellulose ◽  
2020 ◽  
Vol 27 (17) ◽  
pp. 10151-10166
Author(s):  
Teija Laukala ◽  
Johanna Lyytikäinen ◽  
Katriina Mielonen ◽  
Kaj Backfolk
Keyword(s):  
Calcium Carbonate ◽  
Material Flow ◽  
Microfibrillated Cellulose ◽  
Precipitated Calcium Carbonate ◽  
Floc Structure ◽  
Liquid Absorption ◽  
Sheet Structure ◽  
Flocculation Aid ◽  
Flocculating Agent

Abstract Composite sheets consisting of elongated and aggregated cationically charged precipitated calcium carbonate (PCC) and native microfibrillated cellulose (MFC) were prepared with a wet laying method. The furnishes were prepared with and without an anionic flocculating agent (polyacrylamide) in order to adjust the structure of the sheet. The samples were compressed (densified) in order to determine the particle and microfibrillated cellulose-PCC structure coalescence and densification, as well as its subsequent influence on liquid absorption behavior. The densification affected both the vertical and lateral distribution of PCC, but the flocculating agent enhanced the compression stability and stabilized the sheets against PCC material flow. The differences between the sheets made with and without the flocculation aid affected the absorption of an anionic dye-based fluid ink, which was evident as a higher print density and less print bleeding. The absorption behavior was dependent on the sheet structure, especially on the PCC distribution within the sheets. Finally, the role of MFC on floc structure and floc formation is discussed. Graphic abstract

Preparation and Characterization of Sodium Hexatitanate Whiskers

2012 ◽  
Vol 602-604 ◽  
pp. 1339-1343
Author(s):  
Xiao Yu Zhang ◽  
Yu Jun Zhang ◽  
Hong Yu Gong ◽  
Yun Na Song
Keyword(s):  
Aspect Ratio ◽  
Heating Temperature ◽  
Average Diameter ◽  
Potassium Fluoride ◽  
Growth Behavior ◽  
Molar Ratio ◽  
Morphological Observation ◽  
Industrial Grade

Sodium hexatitanate (Na2O•6TiO2) whiskers with an average diameter and aspect ratio of 1-3 µm and 10-20 respectively were synthesized by calcinating mixtures of industrial grade sodium carbonate (Na2CO3), anatase TiO2 and potassium fluoride (KF). The growth of sodium hexatitanate whiskers was obtainable in a range of TiO2/Na2CO3 molar ratio from 4 to 6, heating temperature from 940 °C to 1000 °C and content of KF from 5 wt.% to 7 wt.% with different morphologies and aspect ratio of the products. The role of KF on the growth behavior of Na2O•6TiO2 whiskers was demonstrated by structural and morphological observation.

Study of Preparation and the Influencing Factors of Chrysanthemum-Shaped Calcium Carbonate Applied to Paper Industry

2012 ◽  
Vol 621 ◽  
pp. 111-116 ◽  
Author(s):  
Ze Li Chen ◽  
Hua Jing Zhu
Keyword(s):  
Calcium Carbonate ◽  
Influencing Factors ◽  
Shape Control ◽  
Paper Industry ◽  
Carbon Dioxide Concentration ◽  
Control Agent ◽  
Optimum Conditions ◽  
Precipitated Calcium Carbonate ◽  
Carbonation Process ◽  
Carbonate Filler

This paper describes the precipitated calcium carbonate filler applied to paper industry, which was prepared by adding a specific crystal control agent. And a series of influencing factors in carbonation process was studied, such as carbonization temperature, concentration of milk of lime, carbon dioxide concentration and the crystal shape control dosage. Therefore the optimum conditions for preparation of chrysanthemum-shaped crystalline calcium carbonate were determined.

Crystal Growth of Aragonite Precipitated Calcium Carbonate by Seeded Method

2007 ◽  
Vol 544-545 ◽  
pp. 693-696
Author(s):  
Woon Kyoung Park ◽  
Ji Whan Ahn ◽  
Sang Jin Ko ◽  
Choon Han
Keyword(s):  
Crystal Growth ◽  
Calcium Carbonate ◽  
Aspect Ratio ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Gas Flow ◽  
Precipitated Calcium Carbonate ◽  
Co2 Gas ◽  
Carbonation Process ◽  
Co2 Flow

Characteristics of nucleation and crystal growth of aragonite precipitated calcium carbonate in Ca(OH)2 – MgCl2 – CO2 system via a carbonation process is investigated. Aragonite precipitated calcium carbonate with high aspect ratio was synthesized at high reaction temperature and concentration of Ca(OH)2 slurry. The increase in crystal size with decreased in CO2 gas flow rate can be explained by a decrease in the nucleation rate and an increase in the crystal growth rate caused by a decrease in the dissolution rate to CO3 2- ion. In this study, crystal growth of aragonite was investigated by adding aragonite seed. It was found that crystal growth of aragonite precipitated calcium carbonate could be controlled by three-step carbonation process using reactants as the Ca(OH)2. Aragonite with an aspect ratio from 5 to 27 and diameter from 3μm to 24μm was thereby grown at a reaction temperature of 80°C and a CO2 flow rate of 50ml/min. It was also found that MgCl2 aqueous solution can be used again in the carbonation process for the synthesis of aragonite precipitated calcium carbonate.

Aspect Ratio Evaluation of Carbon Nanotubes Grown on Calcium Carbonate Substrate for Different Temperatures and Precursor Flow Times

2009 ◽  
Vol 4 ◽  
pp. 127-133 ◽  
Author(s):  
K.N. Pati ◽  
Chetan S. Solanki
Keyword(s):  
Carbon Nanotubes ◽  
Calcium Carbonate ◽  
Aspect Ratio ◽  
Average Diameter ◽  
Maximum Diameter ◽  
Analysis Software ◽  
Iron Cobalt ◽  
Average Aspect Ratio ◽  
Different Temperatures

Carbon Nanotubes (CNTs) are excellent material with a variety of physical, electrical, and mechanical properties. The average aspect ratio is evaluated for samples synthesized at different temperature and time of precursor flow. The experiments were conducted on calcium carbonate (CaCO3) substrate with iron-cobalt (Fe-Co) as a catalyst. Acetylene (C2H2) was used as a precursor gas and argon (Ar) as a carrier gas. The experiments were performed at temperatures ranging from 600 0C to 900 0C in step of 100 0C with time of precursor flow varying from 15 minutes to 75 minutes in the step of 15 minutes. The partial pressure of C2H2 and Ar kept constant during synthesis of CNT. The mass flow rate of C2H2 and Ar were 2 liters/hour and 60 liters/hour respectively during synthesis of CNT. The characterization of CNT was done with SEM, EDX, and TEM microscopes. Average aspect ratio of CNT is estimated using image analysis software. Most of nanotubes grown present an average diameter of 40 nm. The minimum and maximum diameter found are12.5 nm and 106 nm respectively. It is observed that average aspect ratio ranges from 25 to 58.

Epitaxial YBa2Cu3O7-8 films : Crucial role of growth-induced linear defects in microwave properties

2001 ◽  
Vol 11 (PR11) ◽  
pp. Pr11-47-Pr11-52
Author(s):  
V. M. Pan ◽  
V. S. Flis ◽  
V. A. Komashko ◽  
O. G. Plys ◽  
C. G. Tretiatchenko ◽  
...  
Keyword(s):  
Crucial Role ◽  
Microwave Properties ◽  
Linear Defects
Sign in / Sign up

Export Citation Format

Share Document