Synthesis and Characterization of Dumbbell Shaped Calcium Carbonate Induced by Lignin

2010 ◽  
Vol 658 ◽  
pp. 49-52 ◽  
Author(s):  
Wen Kun Zhu ◽  
Xue Gang Luo ◽  
An Kai Luo ◽  
Xuan Liang

Calcium carbonate with various structures and morphologies were prepared under double injection of the CaCl2 and Na2CO3 solutions with molar ratio of 1:1 at 30 °C, taking lignin as the induction agents. They were characterized by scanning electron microscopy, infrared spectroscopy thermal analysis and X-ray diffraction. The synthesis mechanism was also discussed. The results showed that calcium carbonate of different shape were obtained with the concentration of lignin at 10g/L, 20g/L and 30g/L, respectively, under 30°C while CaCl2 and Na2CO3 were kept at the same concentration of 0.5mol/L. The size of the particles was in a range between 3 and 5μm and the particles were calcites. Compared with the normal calcium carbonate, the compound has advanced thermal decomposition behavior. Fourier transform infrared spectroscopy (FT-IR) analysis revealed the presence of lignin and calcite. The electrostatic interaction of Ca2+ with lignin and the complementary of stereo-structure play important roles in the formation of Dumbbell Shaped Calcium Carbonate.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Michael B. Toffolo ◽  
Giulia Ricci ◽  
Luisa Caneve ◽  
Ifat Kaplan-Ashiri

Abstract In nature, calcium carbonate (CaCO3) in the form of calcite and aragonite nucleates through different pathways including geogenic and biogenic processes. It may also occur as pyrogenic lime plaster and laboratory-precipitated crystals. All of these formation processes are conducive to different degrees of local structural order in CaCO3 crystals, with the pyrogenic and precipitated forms being the least ordered. These variations affect the manner in which crystals interact with electromagnetic radiation, and thus formation processes may be tracked using methods such as X-ray diffraction and infrared spectroscopy. Here we show that defects in the crystal structure of CaCO3 may be detected by looking at the luminescence of crystals. Using cathodoluminescence by scanning electron microscopy (SEM-CL) and laser-induced fluorescence (LIF), it is possible to discern different polymorphs and their mechanism of formation. We were thus able to determine that pyrogenic calcite and aragonite exhibit blue luminescence due to the incorporation of distortions in the crystal lattice caused by heat and rapid precipitation, in agreement with infrared spectroscopy assessments of local structural order. These results provide the first detailed reference database of SEM-CL and LIF spectra of CaCO3 standards, and find application in the characterization of optical, archaeological and construction materials.


2020 ◽  
Vol 58 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Jonathan B. Schneider ◽  
David M. Jenkins

ABSTRACT Formation of the feldspathoid sodalite (Na6Al6Si6O24·2NaCl) by reaction of nepheline (NaAlSiO4) with NaCl-bearing brines was investigated at 3 and 6 kbar and at a constant temperature of 750 °C to determine the brine concentration at which sodalite forms with variation in pressure. The reaction boundary was located by reaction-reversal experiments in the system NaAlSiO4–NaCl–H2O at a brine concentration of 0.16 ± 0.08 XNaCl [= molar ratio NaCl/(NaCl + H2O)] at 3 kbar and at a brine concentration of 0.35 ± 0.03 XNaCl at 6 kbar. Characterization of the sodalite using both X-ray diffraction and infrared spectroscopy after treatment in these brines indicated no obvious evidence of water or hydroxyl incorporation into the cage structure of sodalite. The data from this study were combined with earlier results by Wellman (1970) and Sharp et al. (1989) at lower (1–1.5 kbar) and higher (7–8 kbar) pressures, respectively, on sodalite formation from nepheline and NaCl which models as a concave-down curve in XNaCl – P space. In general, sodalite buffers the concentration of neutral aqueous NaCl° in the brine to relatively low values at P < 4 kbar, but NaCl° increases rapidly at higher pressures. Thermochemical modeling of these data was done to determine the activity of the aqueous NaCl° relative to a 1 molal (m) standard state, demonstrating very low activities (<0.2 m, or 1.2 wt.%) of NaCl° at 3 kbar and lower, but rising to relatively high activities (>20 m, or 54 wt.%) of NaCl° at 6 kbar or higher. The results from this study place constraints on the concentration of NaCl° in brines coexisting with nepheline and sodalite and, because of the relative insensitivity of this reaction to temperature, can provide a convenient geobarometer for those localities where the fluid compositions that formed nepheline and sodalite can be determined independently.


2016 ◽  
Vol 675-676 ◽  
pp. 209-212 ◽  
Author(s):  
Wichian Siriprom ◽  
Nirun Witit-Anun ◽  
Auttapol Choeysuppaket ◽  
T. Ratana

In this study were to explore the properties of interaction between cellulose and calcium carbonate particle (CaCO3) which derive from Papia Undulates Shell in procedure of biocomposite synthesis. The structural properties of cellulose powder Papia Undulates Shell and cellulose-calcium carbonate composite film were investigated by using X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) and the compositions of cellulose/CaCO3 biocomposite film were studied by Energy Dispersive X-ray Fluorescence (EDXRF). The experimental results demonstrated the morphology of Papia Undulates Shell were crystalline aragonite phase and the cellulose have structural as amorphous-crystalline but after film forming the composite film between cellulose and Papia Undulates Shell also have amorphous structural. The result of FTIR used to confirmed the formation of bonding between molecular, it indicated that the cellulose/CacO3 biocomposite film had good biocompatibility due to the biocomposite film have both characteristic feature of CO3-2 group (~874 cm-1 and ~713 cm-1) and the glucose of cellulose at ~1635, ~1064 and ~946 cm-1. Another that, the result from EDXRF shown the chemical composition of organic compound of cellulose/CaCO3 biocomposite film was highest with 99.437 while the Papia Undulates Shell have 0.341 Wt% with corresponding with the ratio of filler material which mixture as 1%. So that, the cellulose/calcium carbonate bicomposite film could be candidate for biocomposite film application.


2011 ◽  
Vol 10 (03) ◽  
pp. 441-445 ◽  
Author(s):  
M. KARL CHINNU ◽  
L. SARAVANAN ◽  
R. JAYAVEL ◽  
C. M. RAGHAVAN ◽  
K. VIJAI ANAND ◽  
...  

Cadmium sulfide nanoparticles have been synthesized by hydrothermal method using cadmium acetate, thiosemicarbazide, and sodium hydroxide as precursors with hexamethylene tetramine as the surfactant. From the X-ray diffraction analysis, it is observed that synthesized CdS nanoparticles show cubic phase. The presence of HMTA in CdS was confirmed by FT-IR analysis. The bandgap value of CdS nanostructure has been estimated by DRS–UV-Visible spectral analysis. The formation of flower-like nanoclusters was observed using scanning electron microscopy (SEM). The application of CdS nanoparticles in photocatalytic degradation was also studied.


Author(s):  
Intan Ayu Safitri ◽  
Iis Siti Jahro

This study aims to determine the effect of the Si/Al molar ratio and the number of Na2EDTA additions on the purity and crystallinity levels of the synthesized zeolite X. zeolite X was synthesized by hydrothermal method at 70°C and 120°C for 3 and 6 hours, respectively. In the synthesis of zeolite X used boiler ash and aluminum foil waste. The results of characterization using Fourier Transform Infra Red (FT-IR) and X-Ray Diffraction (XRD) showed that the level of purity and crystallinity of the synthesized zeolite X was influenced by the variation of Si/Al molar rasio and amount of Na2EDTA addition. The zeolite with the best quality was obtained from the synthesis with a Si/Al molar ratio of 1.6 and the amount of Na2EDTA added as much as 3.0 g. The synthesized zeolite X has a purity level of 75% and a degree of crystallinity with a total intensity of 845.


Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1125
Author(s):  
Dovydas Karoblis ◽  
Ramunas Diliautas ◽  
Eva Raudonyte-Svirbutaviciene ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
...  

In this study, the aqueous sol-gel method was employed for the synthesis of (1−x)SrTiO3-xBiMnO3 solid solutions. Powder X-ray diffraction analysis confirmed the formation of single-phase perovskites with a cubic structure up to x = 0.3. A further increase of the BiMnO3 content led to the formation of a negligible amount of neighboring Mn3O4 impurity, along with the major perovskite phase. Infrared (FT-IR) analysis of the synthesized specimens showed gradual spectral change associated with the superposition effect of Mn-O and Ti-O bond lengths. By introducing BiMnO3 into the SrTiO3 crystal structure, the size of the grains increased drastically, which was confirmed by means of scanning electron microscopy. Magnetization studies revealed that all solid solutions containing the BiMnO3 component can be characterized as paramagnetic materials. It was observed that magnetization values clearly correlate with the chemical composition of powders, and the gradual increase of the BiMnO3 content resulted in noticeably higher magnetization values.


2012 ◽  
Vol 217-219 ◽  
pp. 551-554
Author(s):  
Ting Xi Li ◽  
Yu Hua Zhao ◽  
Qian Li ◽  
Cheng Qian Yuan ◽  
Quan Liang Chen ◽  
...  

Abstract. Polyaniline (PANI) and p-phenylenediamine (p-PDA)-aniline copolymer were prepared via a same microemulsion method. The structures of the PANI and p-PDA-aniline copolymer were characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis(TGA). The results revealed the difference of synthesis and characterization between PANI and p-PDA-aniline copolymer. It was shown that structure of the copolymer is almost similar to that of PANI, but the p-PDA-aniline copolymer has a better crystallization than PANI, and the thermal stability of the copolymer is higher than that of pure PANI.


2021 ◽  
pp. 002199832199641
Author(s):  
Ana P de Moura ◽  
Enio HP da Silva ◽  
Vanessa S dos Santos ◽  
Miguel F Galera ◽  
Flaminio CP Sales ◽  
...  

Due to its exceptional biocompatibility, Polyurethane (PU) reinforced with calcium carbonate (CaCO3) is a composite material with significant biomedical applications. However, much of the currently known mechanical and chemical information regarding composites has been obtained at low and moderate CaCO3 content levels. This study employs experimental and theoretical tools to evaluate the structural, morphological, and mechanical properties of pristine polyurethane, and when doped with CaCO3 at 25 and 50 wt.%. In the experiments the samples are characterized using X-ray diffraction (XRD), infrared spectrophotometry (FT-IR), scanning electron microscopy (SEM), and tensile and flexural mechanical tests, while theoretical calculations are performed to evaluate the carbonate-polymer interaction. The XRD and FT-IR results indicate that CaCO3 is at the calcite phase and that PU-CaCO3 materials exhibit a broadening of bands related to the NH2 group. This result is explained using theoretical calculations that demonstrate a weak interaction between those molecules with the CaCO3 surface, where the molecule-calcite interaction occurs primarily through the NH2 molecular link. With respect to mechanical behaviour, the results show less fracture resistance and greater stiffness for the materials containing CaCO3, compared to those containing only PU. These results are explained in terms of the stress concentration due to CaCO3 within the polymer. Finally, the results detailed in this paper show that a high calcium carbonate loading is suitable for increasing the rigidity and decreasing the fracture toughness of the biomaterial, in association with a reduction of the plastic region.


2016 ◽  
Vol 16 (4) ◽  
pp. 3969-3972 ◽  
Author(s):  
Yongde Meng ◽  
Yanjie Sun

In the present study, biosynthesis of silver nanoparticles was carried out using Rosa chinensis flower extract as reducing agent. The characterization of silver nanoparticles was done by UV-VIS spectrum. The morphology and size of silver nanoparticles were determined by transmission electron microscope (TEM) image. The crystallization of silver nanoparticles was confirmed by X-ray diffraction (XRD) measurements. The Fourier transform infrared (FT-IR) analysis was used to confirm the possible involvement in the formation and stabilization of synthesized silver nanoparticles by the extract of Rosa chinensis flower. Antibacterial activity of silver nanoparticles was studied against Gram positive Staphycoccus aureus and Gram negative Escherichia coli.


2011 ◽  
Vol 239-242 ◽  
pp. 1643-1648 ◽  
Author(s):  
Qin Tang ◽  
Xiang Yong Chen ◽  
Wei Bing Hu ◽  
Gui Yun Zhou

Calcium carbonate was obtained by the microwave-assisted hydrothermal synthesized technique using calcium chloride and urea as the raw materials. The uniform aragonite hexagonal columnar-shaped calcium carbonate with a diameter of 3.0~4.0μm and 70~120μm in length were produced without any additives at the molar ratio of urea and calcium chloride 1.5:1, microwave power 600W. The morphology, size and crystal structure were characterized by means of scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR).The formation process of aragonite hexagonal columnar-shaped calcium carbonate was discussed.


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