Comparative Analysis of Physicochemical Properties of Rutile TiO2 
with Hierarchical 3D Architecture Prepared by Liquid Hydrolysis 
of TiCl4 and Hydrothermal Method

TiO2 (rutile) samples with a hierarchical 3D nanostructure of the particles were synthesized by two methods: liquid hydrolysis of TiCl4 at 90 °С and atmospheric pressure; hydrothermal synthesis from TiCl4 at 160 °С and different [H2O]/[Ti] ratios. The effect exerted by conditions of the synthesis and post-treatments on the crystallite size, morphology, electronic properties and pore structure of the rutile samples was investigated. It was shown that severe hydrothermal conditions with the ratio [H2O]/[Ti] = 20 provide the formation of a more perfect crystal structure of rutile with a smaller band gap energy (3.00 eV against 3.06 eV for the rutile obtained by liquid hydrolysis at atmospheric pressure). The study revealed the stabilizing effect of cerium cations on the pore structure of rutile, which changes upon thermal treatment.

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The Formation of Plasma Acid at Atmospheric Pressure and its Application in Hydrolysis of Microcrystalline Cellulose

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.1626 ◽

2013 ◽

Vol 750-752 ◽

pp. 1626-1629

Author(s):

Bo Yuan ◽

Ying Wang ◽

Ying Chao Ji ◽

Qiu Hong Wang

Keyword(s):

Microcrystalline Cellulose ◽

Atmospheric Pressure ◽

High Performance ◽

Barrier Discharge ◽

Ph Value ◽

Reducing Sugar ◽

Dielectric Barrier ◽

Integrated Optical ◽

Hydrolysis Of ◽

Single Factor Experiment

In this paper, plasma acid was obtained by treating distilled water with dielectric barrier discharge at atmospheric pressure in order to hydrolyze cellulose. The acidity of plasma acid was studied through a single factor experiment. A plasma acid with pH value of 1.42 was obtained and used to hydrolyze microcrystalline cellulose at 80°C for 60min. Under this condition, the integrated optical density (IOD) of the hydrolysis sample was 0.589. Based on standard glucose curve, the total reducing sugar (TRS) was calculated to be 53.75mg and the TRS yield was 53.75%. The filtrate was evaporated to get the solid hydrolysis sample to be analyzed by High-performance liquid chromatography (HPLC). The results showed that the sample mainly consisted of glucose, which proved that microcrystalline cellulose could be hydrolyzed by plasma acid. Therefore, it could be concluded that it was an environmentally friendly and economical method to hydrolyze the microcrystalline cellulose by plasma acid.

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Influence of Mineralogical Origin of Limestone Powder on the Performance of Complex Binder Material

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.477.136 ◽

2011 ◽

Vol 477 ◽

pp. 136-141

Author(s):

Qin Wang ◽

Jia Long Chen ◽

Chang Cheng Zhang ◽

Wei Niu

Keyword(s):

Crystal Structure ◽

Clay Mineral ◽

Lamellar Structure ◽

Perfect Crystal ◽

Limestone Powder ◽

Elemental Component ◽

Binder Material ◽

Complex Binder ◽

Main Components ◽

Perfect Crystal Structure

The effect of mineralogical origin, elemental component, crystal structure of three types of limestone powder on the fluidity of cement-limestone paste and mortar was investigated. The results show that the limestone powder originated from the mine of limestone and river pebble have better water-reducing effect, which is closely correlated with the main components of Calcite and Dolomite. These two mineral have relatively regular, orderly and perfect crystal structure with few defects and unfilled pores which are liable to adsorb more water and water-reducing agents. On the contrary, the limestone powder derived from the mine of sandstone has nearly no water-reducing effect which is ascribed to the large amount of clay mineral which exhibit lamellar structure leading to the large quantity of consumption of water.

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Topotactic route to synthesis of novel hydroxylated phases: I. Trioctahedral Micas

Clay Minerals ◽

10.1180/claymin.1986.021.2.02 ◽

1986 ◽

Vol 21 (2) ◽

pp. 125-131 ◽

Cited By ~ 6

Author(s):

S. Komarneni ◽

R. Roy

Keyword(s):

Ion Exchange ◽

Alkaline Earth ◽

Water Molecules ◽

Hydration Energy ◽

Hydrothermal Conditions ◽

Potential Applications ◽

Clay Layers ◽

First Time ◽

Hydrolysis Of ◽

Alkaline Earth Cations

AbstractK-depleted phlogopite mica was used as a topotactic precursor and treated with alkali (Li+, K+, , Rb+, Cs+), alkaline-earth (Mg2+, Ca2+, Sr2+, Ba2+) and trivalent (Al3+) cations under hydrothermal conditions of 200°C and 30 MPa pressure. K-, NH4-, Rb- and Cs-aluminosilicate micas were synthesised at 200°C in one day. The synthesis of Cs-aluminosilicate mica, with potential applications in the management of nuclear wastes, has been achieved for the first time by this approach. Ion exchange by Li+, Na+ and alkaline-earth cations under hydrothermal conditions did not produce anhydrous mica phases but resulted in hydrous phases with one or two layers of water molecules between the clay layers. The formation of hydrous phases may be attributed to the high hydration energy of the above cations compared to K+, , RB+ and Cs+. Ion exchange with Al3+ produced a chlorite-like phase because of the hydrolysis of Al3+ under these hydrothermal conditions. These studies are of relevance in the immobilization of wastes where hazardous ions can be fixed in highly stable insoluble phases like mica or chlorite.

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Enzyme-catalyzed reactions in different types of high-pressure enzymatic reactors

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq0603159p ◽

2006 ◽

Vol 12 (3) ◽

pp. 159-163

Author(s):

Mateja Primozic ◽

Maja Habulin ◽

Muzafera Paljevac ◽

Zeljko Knez

Keyword(s):

High Pressure ◽

Atmospheric Pressure ◽

Ceramic Membranes ◽

Stirred Tank ◽

Optimal Temperature ◽

Stirred Tank Reactor ◽

Tank Reactor ◽

Humicola Insolens ◽

Different Types ◽

Hydrolysis Of

The enzyme-catalyzed hydrolysis of carboxy-methyl cellulose (CMC) was performed in three different types of reactors; in a batch stirred-tank reactor (BSTR) operating at atmospheric pressure, in a high-pressure batch stirred-tank reactor (HP BSTR) and in a high-pressure continuous tubular-membrane reactor (HP CTMR). In the high-pressure reactors aqueous SC CO2 was used as the reaction medium. The aim of our research was optimization of the reaction parameters for reaction performance. All the reactions were catalyzed by cellulase from Humicola insolens. Glucose production in the high-pressure batch stirred-tank reactor was faster than in the BSTR at atmospheric pressure. The optimal temperature for the reaction performed in the BSTR at atmospheric pressure was 30?C, while the optimal temperature for the reaction performed in SC CO2 was 32?C. The influence of the application of tubular ceramic membranes in the high-pressure reaction system was studied on the model reaction of CMC hydrolysis at atmospheric pressure and in SC CO2. The reaction was catalyzed by cellulase from Humicola insolens covalently linked to the surface of the ceramic membrane. The hydrolysis of CMC in SC CO2 and at atmospheric pressure was performed for a long time period. The reaction carried out in SC CO2 was more productive than the reaction performed at atmospheric pressure.

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Optical Detection of Band Gap Variations Due to Ordering in Ga0.47In0.53As on InP

MRS Proceedings ◽

10.1557/proc-281-67 ◽

1992 ◽

Vol 281 ◽

Cited By ~ 1

Author(s):

D. J. Arent ◽

K. A. Bertness ◽

Sarah R. Kurtz ◽

M. Bode ◽

J. M. Olson

Keyword(s):

Band Gap ◽

Atmospheric Pressure ◽

Room Temperature ◽

Energy Gap ◽

Growth Conditions ◽

Band Gap Energy ◽

Optical Energy Gap ◽

Lower Growth ◽

Transmission Electron ◽

High Resolution Images

ABSTRACTA reduction in the optical energy gap of more than 65 meV has been observed in In0.53Ga0.47 As grown on (100) InP by atmospheric pressure metalorganic vapor phase epitaxy. The band gap energies were deduced from room temperature photocurrent spectroscopic measurements, accounting for differences in composition and strain. Spontaneous CuPt type ordering of In and Ga atoms on the (111) subplanes of the InGaAs2 was confirmed by transmission electron microscopy. Superlattice signatures in the transmission micrographs were observed only for samples with associated reduced band gap energies, and were confirmed by visible double periodicity in high resolution images. In0.53Ga0.47 As was grown under a variety of conditions, some which promoted ordering. In general, lower growth temperatures and moderate (∼4 μ/hr) growth rates promoted a greater degree of ordering and reduction of the band gap energy. The influence of growth conditions on the ordered structure is considered within the context of current theories.

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Microwave assisted catalytic hydrolysis of fibrous cellulose over framework catalysts: effects of acidity and pore structure

Cellulose ◽

10.1007/s10570-020-03510-1 ◽

2020 ◽

Author(s):

Songshan Jiang ◽

Wei Xiong ◽

Bai He ◽

Min Li

Keyword(s):

Pore Structure ◽

Catalytic Hydrolysis ◽

Microwave Assisted ◽

Fibrous Cellulose ◽

Hydrolysis Of

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Hydrolysis of Acetals in Water under Hydrothermal Conditions.

ChemInform ◽

10.1002/chin.200410060 ◽

2004 ◽

Vol 35 (10) ◽

Author(s):

Kimihiko Sato ◽

Tsutomu Kishimoto ◽

Minoru Morimoto ◽

Hiroyuki Saimoto ◽

Yoshihiro Shigemasa

Keyword(s):

Hydrothermal Conditions ◽

Hydrolysis Of

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Quantitative relationships between boehmite and γ-alumina crystallite sizes

Journal of Materials Research ◽

10.1557/jmr.2004.0200 ◽

2004 ◽

Vol 19 (5) ◽

pp. 1499-1503 ◽

Cited By ~ 11

Author(s):

J. Sánchez-Valente ◽

F. Hernández-Beltrán ◽

M.L. Guzman-Castillo ◽

J.J. Fripiat ◽

X. Bokhimi

Keyword(s):

Pore Diameter ◽

Lower Surface ◽

Order Kinetic ◽

Hydrothermal Conditions ◽

Structural Units ◽

Fresh Sample ◽

First Order ◽

Main Variable ◽

Crystallite Sizes ◽

Hydrolysis Of

Nanocrystalline boehmite obtained by limited hydrolysis of aluminum tri-sec-butoxide or aluminum chloride was aged under different conditions before being calcined above the dehydroxylation temperature. When aging was carried out under hydrothermal conditions, the condensation of the structural units obeyed a first-order kinetic law with apparent activation energy of 12.2 kcal/mol. Under dehydroxylation conditions, the boehmite fragmentation is accounted for by a simple power law that links its volume to that of the resulting γ-alumina. The main variable is the volatile compounds content (water for instance) in the fresh sample. In terms of texture, a better organization of the initial nanoparticles in the boehmite means a lower surface area and larger pore diameter in the corresponding γ-alumina.

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