The Effect of Solvent Polarity on Phase Transformation of Citrogypsum via Hydrothermal Process

2019 ◽  
Vol 803 ◽  
pp. 351-355 ◽  
Author(s):  
Thanakit Sirimahasal ◽  
Yutthana Kalhong ◽  
Lida Simasatitkul ◽  
Siriporn Pranee ◽  
Samitthichai Seeyangnok

Calcium sulfate dihydrate (CaSO4•2H2O, CSD), gypsum is a by-product in the production of citric acid (citryogypsum). This by-product could neither be exploited nor distributed as a reactant because of its physical properties including those that are not equivalent to natural gypsum. Moreover, the mentioned citrogypsum has been continually increasing environmental problems. Therefore, this research aims at how to recycle gypsum that is synthesized by hydrothermal method at 95oC for 7 hrs under the atmospheric pressure via different solutions (MeOH, EtOH, PrOH, BuOH and Hexane). In order to produce alpha-calcium sulfate hemihydrate (α-CaSO4•0.5H2O, α-CSH) with improved physical properties that will be used for different industries. FT-IR reveals the chemical composition of crystal and the adsorption of methyl group on the surface. Besides, TGA thermogram shows the theoretical crystal water content of CSD and α-CSH 20.9 wt% and 6.2 wt% respectively. The DSC thermogram, shows that endothermic peaks at 151.2 oC and 168.5 oC. There were two steps of loss at 1.5 and 0.5 water molecule respectively. With SEM images of crystal shows the plate-like shape of citrogypsum, while α-CSH shows the hexagonal shape excluding hexane solution. Of all the results, the polarity of solution has an impact on the transition of CSD to α-CSH under this condition.

2019 ◽  
Vol 824 ◽  
pp. 128-133 ◽  
Author(s):  
Thanakit Sirimahasal ◽  
Yutthana Kalhong ◽  
Lida Simasatitkul ◽  
Siriporn Pranee ◽  
Semih Durmus ◽  
...  

The acid purification of calcium citrate from citric acid production using sulfuric acid as a reagent resulted in citrogypsum waste. The identification of citrogypsum by XRD technique indicates that the main component consists of CaSO4∙2H2O (DH). Furthermore, the comparison of the colours between citrogypsum and natural gypsum are also different. Hence, this research mainly focused on the phase transformation of DH to α-CaSO4 ∙0.5H2O (α-HH) due to high strength and heat resistant. The preparation of α-HH carry out in different volume ratios of ethylene glycol (EG): water solutions at 95oC for 7 hrs under atmospheric pressure. The FT-IR spectra of DH and α-HH results reveal that the absorption frequencies at 1700 and 1800 cm-1 of –OH group are 0.5 and 1.5 water molecule in CaSO4 respectively. TGA thermograms show the theoretical crystal water content of DH approximately 20.1 wt% and the converted α-HH about 4-5 wt%. DSC thermograms of the citrogypsums show two endothermic peaks regarding to two steps of water molecule loss at 151.2oC and 168.5oC respectively. In addition, the α-HH shows exothermic peak at 238.7oC. The morphology of citrogypsum and α-HH are observed by SEM, showing the plate-like shape of citrogypsum and hexagonal shape of α-HH. Moreover, the products could be applied to several other industries for increasing the value and reducing the environmental concerns.


2013 ◽  
Vol 690-693 ◽  
pp. 1013-1019
Author(s):  
Xiao Juan Chen ◽  
Liu Chun Yang ◽  
Jun Feng Zhang ◽  
Yan Huang

Calcium sulfate whisker (CSW) was prepared through the method of cooling recrystallization. In an attempt to develop its new application in environmental protection, we investigated the effect of calcination on the material properties and arsenic uptake performance of calcium sulfate whisker anhydrate (CSAW), which was obtained from CSW calcined at 600 °C for 2 h. Moreover, XRD, SEM, optical microscope, and FT-IR were used to characterize CSW samples. It was found that calcination played an important role in the whisker structure through changing the content of crystal water and the morphology. The CSAW material exhibited a high removal rate of As3+/As5+under strongly alkaline condition.


2017 ◽  
Vol 89 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Özlem Dogan ◽  
Cagri Senol Erdemir ◽  
Emel Akyol ◽  
Semra Kirboga ◽  
Mualla Öner

AbstractThe crystallization of scale forming minerals is an important problem in a number of processes. Calcium sulfate dihydrate (CaSO4·2H2O, gypsum) is the most unwelcome deposit in the production of oil and gas, in water cooling systems and in hydrometallurgical processes. Additives have been used in these processes to prevent the formation and deposition of scaling salts. In this study, the effects of additives on the spontaneuos precipitation of CaSO4·2H2O were investigated in aqueous solutions at 30°C. Conductive copolymers with different vinylphosphonic acid (VPA) contents were used as additives. The degree of inhibition of cystallization was measured as an increase in induction time and the reduction in crystallization rate. The crystallization reactions were interpreted in terms of the Langmuir adsorption isotherm. The cystals were characterized by scanning electron microscope (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). The VPA content of the copolymer and the supersaturation of the solution were found to be effective parameters on CaSO4·2H2O crystallization.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Azmi Seyhun Kipcak ◽  
Meral Yildirim ◽  
Sureyya Aydin Yuksel ◽  
Emek Moroydor Derun ◽  
Sabriye Piskin

Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG). The surface morphology was examined by scanning electron microscopy (SEM). B2O3content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O3)3·7(H2O)] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH)6)2·9(H2O)] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%.


2018 ◽  
Author(s):  
John Lauterbach

We undertook a small product survey in which we purchased a range of brand-styles at retail and sent them to commercial laboratories for dimensional and physical tests, including banded and nonbanded area porosities. Other analyses obtained used chemical, chromatographic, and spectrophotometric (FT-IR) techniques to identify main banding agents and additives used with them. One finding from this study was at least at the time the samples were collected, some companies used just one FSC paper for all products while others used multiple FSC papers.<br>


2020 ◽  
Vol 17 (3) ◽  
pp. 246-256
Author(s):  
Kriti Soni ◽  
Ali Mujtaba ◽  
Md. Habban Akhter ◽  
Kanchan Kohli

Aim: The intention of this investigation was to develop Pemetrexed Diacid (PTX)-loaded gelatine-cloisite 30B (MMT) nanocomposite for the potential oral delivery of PTX and the in vitro, and ex vivo assessment. Background: Gelatin/Cloisite 30 B (MMT) nanocomposites were prepared by blending gelatin with MMT in aqueous solution. Methods: PTX was incorporated into the nanocomposite preparation. The nanocomposites were investigated by Fourier Transmission Infra Red Spectroscopy (FT-IR), Differential Scanning Calorimetry (DSC), Scanning Electron Microscope (SEM) X-Ray Diffraction (XRD) and Confocal Laser Microscopy (CLSM). FT-IR of nanocomposite showed the disappearance of all major peaks which corroborated the formation of nanocomposites. The nanocomposites were found to have a particle size of 121.9 ± 1.85 nm and zeta potential -12.1 ± 0.63 mV. DSC thermogram of drug loaded nanocomposites indicated peak at 117.165 oC and 205.816 oC, which clearly revealed that the drug has been incorporated into the nanocomposite because of cross-linking of cloisite 30 B and gelatin in the presence of glutaraldehyde. Results: SEM images of gelatin show a network like structure which disappears in the nanocomposite. The kinetics of the drug release was studied in order to ascertain the type of release mechanism. The drug release from nanocomposites was in a controlled manner, followed by first-order kinetics and the drug release mechanism was found to be of Fickian type. Conclusion: Ex vivo gut permeation studies revealed 4 times enhancement in the permeation of drug present in the nanocomposite as compared to plain drug solution and were further affirmed by CLSM. Thus, gelatin/(MMT) nanocomposite could be promising for the oral delivery of PTX in cancer therapy and future prospects for the industrial pharmacy.


2020 ◽  
Vol 17 ◽  
Author(s):  
Saeid Azimi ◽  
Niloofar Mohamadighader

Abstract: A new solid catalyst was synthesized from an ionic liquid and heterogenised by changing anion reaction. The new heterogeneous acidic catalyst was characterized by SEM images, EDS analysis, AFM images, Ft-IR, HNMR, 13CNMR and Mass Spectroscopy. It was applied to synthesis of tri-arylmethanes throughout one-pot tri-component reactions among aromatic aldehydes, N,N-dimethylaniline and other carbonic nucleophiles such as anisole and indole. Hence, synthesis of convenient and inexpensive micro-heterogeneous catalyst was introduced, the efficiency of which was confirmed. Also, various useful products were synthesized throughout this simple and clean procedure.


2020 ◽  
Vol 10 ◽  
Author(s):  
Amutha Santhanam ◽  
Naveen Kumar Chandrasekharan ◽  
Rajangam Ilangovan

Background: The occurrence of Cancer results in cellular changes that causes the uncontrolled growth and division of cells. Apoptosis removes cells during development and eliminates the potentially cancerous cells. The bioactive compounds present in the herbal plant shows cytotoxic activity that result in apoptosis. The traditional herbal plants are used world-wide both in allopathy and other traditional ways. Objective: The main objective of this study is to extract the bioactive compound Quercetin from the medicinally significant plant Ocimum sanctum and also to develop nanomedicine as Qu-PEG-NiGs. Materials and Methods: Leaf extract of the medicinally significant plant Ocimum sanctum (O. sanctum) has been used for the synthesis of nickel nanoparticles (NiGs) and extraction of quercetin (Qu). The ethanolic extract of Ocimum sanctum is added to 1 mM Nickel Nitrate (Ni(NO3)2) and stirred for 3 hrs at RT and dried at 60°C for 3hrs and calcinated at 400°C for 2hrs and characterized using Uv-Vis Spectrophotometer, FT-IR, SEM, DLS and Zeta potential. The Quercetin is isolated from Ocimum sanctum leaf extract using the reflux condenser method. The bio-polymer is being PEG-coated over NiGs and Quercetin is loaded into it. The apoptosis activity using MCF-7 cells is performed with Qu-PEG-NiGs. The purity of Quercetin is characterized using HPLC. In order to analyse apoptosis efficiency, MTT assay, Reactive Oxygen Species (ROS), Cell cycle analysis has been performed. Results: The NiGs absorption spectrum gives a peak at 408nm. The FT-IR confirms the presence of particular functional groups shifting from the compound NiGs and then coated with PEG-Qu-NiGs. The SEM images show the size of NiGs ranging from 27.3 nm to 40.4 nm with varied morphology such as hexagonal and other irregular shapes. The presence of Quercetin extracted from the leaf powder is approximately 1.5 mg/g. The ROS results show the Qu-PEG-NiGs induced efficiency of the apoptosis, while the increased concentrations promote ROS and lead to activation of the apoptosis. The cell cycle analysis has shown the cytotoxic effect. Conclusion: PEG-coated nickel nanoparticles can be used as a promising chemotherapeutic agent against MCF7 breast cancer cells. It is the evidence to further studies for evaluating Qu-PEG-NiGs anticancer activity on different types of cancer cells.


SynOpen ◽  
2021 ◽  
Author(s):  
Mina Ghassemi ◽  
Ali Maleki

Copper ferrite (CuFe2O4) magnetic nanoparticles (MNPs) were synthesized via thermal decomposition method and applied as a reusable and green catalyst in the synthesis of functionalized 4H-pyran derivatives using malononitrile, an aromatic aldehyde and a β-ketoester in ethanol at room temperature. Then it was characterized by Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) analysis, scanning electron microscopy (SEM) images, thermo gravimetric and differential thermo gravimetric (TGA/DTG) analysis. The catalyst was recovered from the reaction mixture by applying an external magnet and decanting the mixture. Recycled catalyst was reused for several times without significant loss in its activity. Running the one-pot three-component reaction at room temperature, no use of eternal energy source and using a green solvent provide benign, mild, and environmentally friendly reaction conditions; as well, ease of catalyst recovering, catalyst recyclability, no use of column chromatography and good to excellent yields are extra advantages of this work.


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