Bubble-Liquid Membrane Method for Preparing Spherical Calcium Carbonate Nanoparticles

2021 ◽  
Vol 21 (10) ◽  
pp. 5241-5246
Author(s):  
Jun-Xian Ma ◽  
Xue-Feng Lei ◽  
Sha Jiang ◽  
Jian-Chun Wang ◽  
Yue-Hui Wang

In this work, we describe the principle and operation of a bubble-liquid membrane reactor, and use of the reactor to prepare spherical calcium carbonate nanoparticles. The products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and laser particle size analysis. The effects of additives to control crystal morphology, coating agents, and the stirring speed of the bubble-liquid membrane reactor were investigated. Spherical calcium carbonate nanoparticles with uniform dispersion and no agglomeration were obtained when a disodium hydrogen phosphate/ethylenediaminetetraacetic acid disodium salt mixture (1:1 mass ratio) was used as the additive, oleic acid was used as the coating agent (1.5 wt%), and the stirring speed was 5000–6000 r/min. The results indicate that the bubble-liquid membrane reactor may be suitable for continuous industrial production of calcium carbonate nanoparticles.

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3033-3042
Author(s):  
Liubin Shi ◽  
Mingde Tang ◽  
Yaseen Muhammad ◽  
Yong Tang ◽  
Lulu He ◽  
...  

Herein, calcium carbonate hollow microspheres with a micro–nano hierarchical structure were successfully synthesized using disodium salt of ethylenediaminetetraacetic acid (EDTA-2Na) as an additive, by bubbling pressurized carbon dioxide and calcium hydroxide at 120 °C.


2019 ◽  
pp. 382-391
Author(s):  
Karin Abraham ◽  
Liza Splett ◽  
Eckhard Flöter

The effects of high and low molecular mass dextran (T2000 and T40) on the size and shape of particles precipitated during carbonatation and their correlation with filtration performances were key to this study. Varying contents of T2000 and T40 dextran in sugar solutions corresponding to DS contents of thin juice were investigated. For particle size and shape analysis, static image analysis and laser particle size analysis were used. Both methods, static image analysis and laser diffraction, revealed that the presence of T2000 and T40 dextran leads to a higher amount of large-sized particles at the expense of small-sized particles, indicating pronounced agglomeration. The additional evaluation of shape parameters (circularity, roundness, solidity) obtained from static image analysis indicates that the agglomeration is oriented in the absence and in the presence of lower T40 dextran levels. Besides, non-oriented agglomeration, resulting in more round agglomerates with smoother surfaces, was found for samples loaded with T2000 dextran and high T40 dextran levels. Only the latter samples have shown to negatively affect the filtration performance. Thus, in the presence of T2000 dextran and high T40 dextran levels, the filtration was hampered. This appears to be mainly caused by a tighter packing of more round calcium carbonate agglomerates in the porous structure of the filter cake.


Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2045 ◽  
Author(s):  
Dapeng Zheng ◽  
Haibin Yang ◽  
Feng Yu ◽  
Bo Zhang ◽  
Hongzhi Cui

The effect of graphene oxide (GO) on the crystallization of calcium carbonate (CaCO3) is explored in this paper. Precipitation of CaCO3 was carried out by bubbling carbon dioxide (CO2) through tricalcium silicate (C3S) hydration solution with different graphene oxide admixture contents (0.2%, 1% and 2% mass ratios based on C3S). The polymorph, morphology, crystal size and particle size of CaCO3 were evaluated using X-ray diffraction (XRD), an environmental scanning electronic microscope (ESEM), and laser particle size analysis. The results showed that addition of GO was able to promote the conversion of CaCO3 to a calcite crystal phase with higher thermal stability and crystallinity than the control. However, as the dosage of GO increased, the growth of the calcite crystal particles was somewhat suppressed, resulting in a decrease in the crystal particle size and a narrow particle size distribution. When the amount of GO was 0.2%, 1% and 2%, the crystal size of the calcite was 5.49%, 12.38%, and 24.61% lower than that of the sample without GO, respectively, while the particle size of the calcite also decreased by 17.21%, 39.26%, 58.03%, respectively.


Author(s):  
Bindia Sahu ◽  
M. Sathish ◽  
G. C. Jayakumar

Fatliquoring is an important step of post tanning process of leathermanufacturing where incorporation of self-emulsified oil (lubricant)makes the leather soft. There are several methods which introducepolarity into oil and provide the path where reactive species ofmodified oil can interact with water which leads to form a fatliquor.The aim of this work is to introduce an extra polarity into the fattyacid moiety through chemical modification of castor oil by carbeneintermediate. The spectroscopic characterisation such as FTIR,1H-NMR and 13C-NMR of fatliquor have been carried out. Particle size analysis of fatliquor has also been done. The experimental leathers have been tested for physical strength characterisation such as tensile and tear strength verses control and found to have better properties than control. SEM analysis for morphological study of experimental leather were also carried out which clearly indicates the uniform dispersion of fiber bundles due to the fine distribution of the novel and self-emulsifying fatliquor throughout the matrix.


Author(s):  
EL- Assal I. A. ◽  
Retnowati .

Objective of the present investigation was enthused by the possibility to develop solid lipid nanoparticles (SLNs) of hydrophilic drug acyclovir. Also study vitro and vivo drug delivery. Methods: Drug loaded SLNs (ACV-SLNs) were prepared by high pressure homogenization of aqueous surfactant solutions containing the drug-loaded lipids in the melted or in the solid state with formula optimization study (Different lipid concentration, drug loaded, homogenization / stirring speed and compritol 888ATO: drug ratio). ACV - SLN incorporated in cream base. The pH was evaluated and rheological study. Drug release was evaluated and compared with simple cream- drug, ACV – SLN with compritol 888ATO and marketed cream. The potential of SLN as the carrier for dermal delivery was studied. Results: Particle size analysis of SLNs prove small, smooth, spherical shape particle ranged from 150 to 200 nm for unloaded and from 330 to 444 nm for ACV loaded particles. The EE% for optimal formula is 72% with suitable pH for skin application. Rheological behavior is shear thinning and thixotropic. Release study proved controlled drug release for SLNs especially in formula containing compritol88 ATO. Stability study emphasized an insignificant change in SLNs properties over 6 month. In-vivo study showed significantly higher accumulation of ACV in stratum corneum, dermal layer, and receptor compartment compared with blank skin. Conclusion: AVC-loaded SLNs might be beneficial in controlling drug release, stable and improving dermal delivery of antiviral agent(s).


Circular ◽  
1985 ◽  
Author(s):  
Lawrence J. Poppe ◽  
A.H. Eliason ◽  
J.J. Fredericks

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