scholarly journals Cellulose of Salicornia brachiata

2010 ◽  
Vol 5 (4) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Naresh D Sanandiya ◽  
Kamalesh Prasad ◽  
Ramavatar Meena ◽  
Arup K Siddhanta
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Magic Angle Spinning ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Salicornia Brachiata ◽  
Whatman Filter Paper ◽  
Angle Spinning ◽  
C Nmr

Cellulose was extracted from the roots, stems and stem tips of Salicornia brachiata Roxb. Each crude cellulose sample obtained was fractionated into α- and β-celluloses. The yields of crude cellulose from the stems and stem tips were greatest and lowest, respectively, while the yields of α- and β-celluloses were in the order, roots > stems > stem tips. The cellulose samples were characterized by Fourier transform infrared spectroscopy (FTIR), solid state cross polarisation magic angle spinning carbon-13 nuclear magnetic resonance spectroscopy (CP/MAS 13C NMR), X-ray diffraction pattern (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The data were compared with those of the celluloses (predominantly α-cellulose) isolated from Whatman filter paper No. 4 (WFP).

Sol-gel synthesis of a nanoparticulate aluminosilicate precursor for homogeneous mullite ceramics

2006 ◽  
Vol 21 (5) ◽  
pp. 1279-1285 ◽  
Author(s):  
Jarkko Leivo ◽  
Mika Lindén ◽  
Cilâine V. Teixeira ◽  
Janne Puputti ◽  
Jessica Rosenholm ◽  
...  
Keyword(s):  
Spinel Phase ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Density ◽  
Angle Spinning ◽  
Sol Gel Synthesis

An amorphous nanoparticulate aluminosilicate 3/2-mullite precursor has been synthesized and carefully characterized. The sol contained 2-nm particles of Q3(3Al) silica species together with six-coordinated alumina, which suggested an allophane-like structure of the nanoparticles. The sol remained stable for years, and formed an easily redispersible physical gel upon solvent evaporation. The gel crystallized to mullite at temperatures below 1000 °C, without going through any intermediate spinel phase. Thus, the nanoparticulate precursor is regarded as a homogeneous high-purity mullite precursor with a high Si–O–Al bond density, which is useful in the preparation of various nanostructured Al-rich aluminosilicate materials. The sols and gels were characterized by small-angle x-ray scattering, dynamic light scattering, x-ray diffraction, 27Al and 29Si magic-angle spinning (MAS) nuclear magnetic resonance spectroscopy, and differential thermal analysis.

Adsorption of cetyltrimethylammonium ions on an acid-activated smectite and their thermal stability

Clay Minerals ◽  
2005 ◽  
Vol 40 (2) ◽  
pp. 233-243 ◽  
Author(s):  
F. Kooli ◽  
P. C. M. M. Magusin
Keyword(s):  
Surfactant Solution ◽  
Significant Degree ◽  
Magic Angle Spinning ◽  
Basal Spacing ◽  
Resonance Spectroscopy ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
Intercalated Compounds ◽  
Angle Spinning ◽  
Acid Activated Clay

AbstractThe intercalation of the cationic surfactant cetyltrimethylammonium (C16TMA) into the interlayer of an acid-activated clay in the presence of different anions has been studied in detail. When Br or OH anions were used, the basal spacing increased significantly, the increase being related to the loading concentration of the surfactant solution. For intercalated compounds prepared from the hydroxide form, the basal spacing at room temperature varied from 1.6 to 3.8 nm. However, for organoclays prepared from the surfactant bromide, the basal spacing is almost loading- independent (1.9 nm). The use of hydroxide and bromide at higher pH is crucial to intercalating larger amounts of C16TMA cations and, hence, to improving the exfoliation of the silicate sheets. Magic-angle spinning 13C nuclear magnetic resonance spectroscopy indicates that the intercalated surfactants exhibit a significant degree of gauche conformation. According to in situ powder X-ray diffraction, an increase of the basal spacing to 4.08 nm is observed at intermediate temperatures of 50 to 150°C for organoclay with an initial basal spacing of 3.7 nm. At higher temperatures, decomposition of the surfactant occurs and the basal spacing decreases to ~1.4 nm.

Chemical Evolution of the Volcanic Tuff from the Santa Mónica Church in Guadalajara, Mexico

2012 ◽  
Vol 1374 ◽  
pp. 195-203
Author(s):  
Nora A. Pérez ◽  
Enrique Lima
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Nitrogen Adsorption ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Gravimetric Analysis ◽  
Structural Level ◽  
Volcanic Tuff ◽  
Santa Monica ◽  
Angle Spinning ◽  
Adsorption Desorption

ABSTRACTThe Santa Mónica Church is one of the most representative buildings in Guadalajara, Mexico as it is the finest Solomonic Baroque temple in the city. The church was built in the XVIII century with different types of volcanic tuffs, which have been studied from the macroscopic level to the structural level with the aim to determine the deterioration degree of the church’s tuffs.Textural, morphological and structural properties of Tuff were characterized using X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR ATR) and 29Si and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR), nitrogen adsorption-desorption techniques, scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), compressive strength tests were also performed.Characterization data has provided a comprehensive view of the alterations on the volcanic tuff of Santa Mónica Church. Then the study focused on proposing the best strategy for the understanding and conservation of Churches and other buildings in Guadalajara which have been built with the same stone. Currently, siliceous materials doped with aluminum are being tested as consolidate.

scholarly journals Preparation of Li3PS4–Li3PO4 Solid Electrolytes by Liquid-Phase Shaking for All-Solid-State Batteries

2021 ◽  
Vol 2 (1) ◽  
pp. 39-48
Author(s):  
Nguyen H. H. Phuc ◽  
Takaki Maeda ◽  
Tokoharu Yamamoto ◽  
Hiroyuki Muto ◽  
Atsunori Matsuda
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Liquid Phase ◽  
Room Temperature ◽  
Reaction Medium ◽  
Magic Angle Spinning ◽  
Resonance Spectroscopy ◽  
Synthesis Methods ◽  
Magic Angle ◽  
Angle Spinning

A solid solution of a 100Li3PS4·xLi3PO4 solid electrolyte was easily prepared by liquid-phase synthesis. Instead of the conventional solid-state synthesis methods, ethyl propionate was used as the reaction medium. The initial stage of the reaction among Li2S, P2S5 and Li3PO4 was proved by ultraviolet-visible spectroscopy. The powder X-ray diffraction (XRD) results showed that the solid solution was formed up to x = 6. At x = 20, XRD peaks of Li3PO4 were detected in the prepared sample after heat treatment at 170 °C. However, the samples obtained at room temperature showed no evidence of Li3PO4 remaining for x = 20. Solid phosphorus-31 magic angle spinning nuclear magnetic resonance spectroscopy results proved the formation of a POS33− unit in the sample with x = 6. Improvements of ionic conductivity at room temperature and activation energy were obtained with the formation of the solid solution. The sample with x = 6 exhibited a better stability against Li metal than that with x = 0. The all-solid-state half-cell employing the sample with x = 6 at the positive electrode exhibited a better charge–discharge capacity than that employing the sample with x = 0.

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