Solvent-Induced Crystallization of Polyarylene Sulfide Sulfone

2015 ◽  
Vol 815 ◽  
pp. 529-533
Author(s):  
Su Ying Li ◽  
Yue Wu Gong ◽  
Sheng Ru Long ◽  
Xiao Jun Wang ◽  
Jie Yang

In this paper, N-methyl-2-pyrrolidone (NMP) induced crystallization behavior of PASS was found and studied. To study NMP induced crystallization of PASS, Differential Scanning Calorimeter (DSC), X-Ray Powder Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA) were employed. The results showed that the crystal induced by NMP was consistent with precipitates obtained in solution, and was the eutectic of PASS and NMP. With the induction time increased, crystalline region continued to improve and the crystal size became bigger.

2021 ◽  
Vol 21 (5) ◽  
pp. 2808-2815
Author(s):  
Alessandra Scano ◽  
Francesco Lai ◽  
Francesca Marongiu ◽  
Guido Ennas

X-ray Powder Diffraction, Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimeter were used to study the effect of the manual grinding in an agate mortar of the diclofenac acid polymorphs HD1 and HD2. In particular, we have tried to highlight how the HD2 form is more sensitive than the HD1 to the grinding process to achieve a nanometric crystal size. HD1 shows no change, while in the case of the HD2, changes in the molecular conformation and the formation of a new metastable form of the polymorph are observed after grinding.


2005 ◽  
Vol 879 ◽  
Author(s):  
Navendu Goswami ◽  
P. Sen

AbstractZinc sulfide nanoparticles, prepared employing a non-equilibrium route, are investigated for surface related effects. Water has been shown to induce a structural transformation in nanoparticles prepared this way, which is not related to their particle size. Employing Fourier transform infrared spectroscopy and x-ray powder diffraction, we show here the importance of S-H interaction in the buildup to the final ZnS structure of these nanoparticles. These particles hold promise as water sensors.


2002 ◽  
Vol 749 ◽  
Author(s):  
Kouichi Takayama ◽  
Shigeo Ohshio ◽  
Hidetoshi Saitoh

ABSTRACTChemical-vapor-deposition of titanium tetra-isopropoxide (TTIP) under the atmosphere at low temperature has been conducted. The structure of the obtained films was assessed using Fourier transform infrared spectroscopy, X-ray diffractometry and Raman spectroscopy. These analyses indicated that amorphous TiOxHy films were obtained at gas temperatures in the range of 150–300 °C, and crystalline anatase-TiO2 film was formed at 350 °C. This distinction is accounted for by plausible chemical reactions as follows; the hydroxyl reaction of TTIP below 350 °C promotes the formation of the amorphous TiOxHy. As the temperature goes up to 350 °C, dehydrogenation of the TiOxHy films promotes to form crystalline TiO2. Also the obtained amorphous films were annealed for 10 min under the atmosphere in assessing the transformation proceeding in the solid state. The structural change is shown at 350 °C, indicating that the crystalline phase would be formed via dehydrogenation and polymerization on the surface of the amorphous phase under the atmosphere. The crystal size of the annealed films was evaluated in assessment for the transformation.


2019 ◽  
Vol 3 (1) ◽  
pp. 41 ◽  
Author(s):  
Victoria Tobilko ◽  
Larysa Spasonova ◽  
Iryna Kovalchuk ◽  
Borys Kornilovych ◽  
Yurij Kholodko

Silylation of clay minerals from Cherkasy deposit (Ukraine) montmorillonite (layer silicate) and palygorskite (fibrous silicate) was performed using organosilane (3-aminopropyl)triethoxysilane (APTES). Solvents with different polarity (ethanol, toluene) were used in synthesis. The structure of modified minerals was characterized by complex of methods (X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption at −196 °C and thermal analysis). Studies of adsorption characteristics of APTES-modified clay minerals were carried out in relation to uranium (VI). The results indicated that modified montmorillonite and palygorskite were effective materials for water purification from UO22+.


2015 ◽  
Vol 1119 ◽  
pp. 466-470 ◽  
Author(s):  
Radek Ševčík ◽  
Petra Mácová ◽  
Marta Pérez-Estébanez

CaCO3 polymorphs are intensively studied due to their importance in the nature and the widespread use in the industry as well. This work is dealing with the crystallization of aragonite from vaterite dispersion during the refluxation at 100°C. The characterization of CaCO3 polymorphs during vaterite transformation was performed with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD). The influence of the different refluxing times on the aragonite crystallization was discussed. The purest aragonite, 70.7(2) wt.%, was synthetized in the sample refluxed for 60 minutes. Prolonged refluxation strongly affected aragonite crystals with gradual transformation into calcite.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
G. D. Webler ◽  
M. J. M. Zapata ◽  
G. S. Maciel ◽  
A. Patra ◽  
J. M. Hickmann ◽  
...  

The influence of the presence of barium carbonate (BaCO3) phase on the luminescence properties of barium titanate nanocrystals (BaTiO3) powders was investigated. Structural and optical characterizations of erbium (Er3+) doped BaTiO3synthesized by the sol-emulsion-gel were performed. Using Fourier transform infrared spectroscopy and X-ray powder diffraction, we identified the presence of impurities related to BaCO3and quantified its fraction. It was observed that the presence of BaCO3phase, even at low levels, depletes significantly the infrared-to-visible upconverted luminescence efficiency of the produced nanopowders.


2020 ◽  
Author(s):  
Yoochan Hong ◽  
Hyun Soo Kim ◽  
Taeha Lee ◽  
Gyudo Lee ◽  
Ohwon Kwon

Abstract Polyaniline nanoskein (PANS), which have polyaniline nanofibers, is developed. PANS is formulated via sequential extracting, heating, and swelling processes. The compositions of PANS have been analyzed using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and Brunauer-Emmett-Teller analysis, and the results of which indicate that PANS is composed of solely organic materials. Moreover, PANS have been shown convertible absorbance characteristics according to surrounding acidic environments, and using these characteristics, the possibility of PANS for sensing of surrounding redox states changes is presented.


2021 ◽  
Vol 1 (2) ◽  
pp. 26-33
Author(s):  
Rasidi Roslan ◽  
Muhammad Nor Arifin Yaakob ◽  
Ms Fathihah

Lignin is a sub-product from lignocellulose apart from cellulose and hemicellulose that produced from empty fruit bunch fiber (EFB). Lignin has low solubility and reactivity due to its bulky macromolecule structre. Being one of the wastes that being generated in massive amount, many alternatives has been taken to transform lignin into valuable products. To do so, many reactions are needed for the lignin to go through. In this study, lignin will be extracted from empty fruit bunch (EFB) with the aid of acid hydrotrope concentration of 30 % and microwave assisted with various extraction heating time and temperature. Characterization of lignin is done using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Nuclear magnetic resonance (NMR) while Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD) used to characterize residues. The highest percentage of lignin yield and its purity obtained are 19.47 % and 96.63 % with the reaction time and temperature of the microwave is 30 minutes and 90 °C. From Fourier Transform Infrared Spectroscopy (FTIR), a wide band at 3430.09 cm-1 and 3413.45 cm-1 are observed due to O-H stretching vibration. As for peak at 1123.17 cm-1 and 1051.26 cm-1, it correspond to syringyl and guaicyl unit in both lignin and raw EFB. As for Thermogravimetric analysis (TGA), it shows that lignin decomposes slowly compared to raw EFB due to the aromatic structure of lignin that is very stable, therefore leading to difficulty of decomposing while from Differential Scanning Calorimetry (DSC), after removing cellulose and hemicellulose, glass transition temperature (Tg) obtained from lignin DSC spectroscopy is 193.05 °C at heat flow of 1.15 mW/mg. Next, from Nuclear magnetic resonance (NMR) spectroscopy, the signals observed around 6.5 – 8.0 ppm indicate aromatic H in syringyl and guaiacyl unit only at lignin spectra while at 3.3 – 4.0 ppm, raw EFB has an intense peak compared to lignin which attribute to methoxyl group. When the residue of the lignin as well as the raw EFB powder is characterized using X-ray Powder Diffraction (XRD), the crystallinity index of the lignin with reaction time and temperature of the microwave 30 minutes and 90 °C is the highest, 69.28 %. As a conclusion, an admissible percent of lignin yield and purity is able to be obtained with addition of acid hydrotrope depending on the variables. From the spectroscopies characterization, it is proved that lignin characteristics and properties are compatible for the production of new and value added products.


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