scholarly journals Temperature-controlled reversible exfoliation-stacking of titanate nanosheets in an aqueous solution containing tetraalkylammonium ions

RSC Advances ◽  
2014 ◽  
Vol 4 (17) ◽  
pp. 8682 ◽  
Author(s):  
Kai Kamada ◽  
Nobuaki Soh
Keyword(s):  
Aqueous Solution ◽  
Tetraalkylammonium Ions ◽  
Temperature Controlled ◽  
Titanate Nanosheets

Hollow hydrogel networks for temperature-controlled water fluidics

2018 ◽  
Vol 54 (73) ◽  
pp. 10304-10307 ◽  
Author(s):  
Qing Chen ◽  
Shumin Liang ◽  
Xiaodong Song ◽  
Panče Naumov ◽  
Lidong Zhang
Keyword(s):  
Aqueous Solution ◽  
Sodium Alginate ◽  
Direct Conversion ◽  
One Pot ◽  
Temperature Controlled

A simple, yet robust, reproducible and scalable method for direct conversion of sodium alginate (SA) films to multibranched hydrogel tubes (HTs) in “one-pot” reaction of buffered aqueous solution is reported.

Electrochemical Properties of Lithium Titanate Synthesized by Reassembly of Nanosheets

2007 ◽  
Vol 350 ◽  
pp. 139-142 ◽  
Author(s):  
Keigo Sato ◽  
Shinya Suzuki ◽  
Masaru Miyayama
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Ion Exchange ◽  
Electrochemical Properties ◽  
Discharge Capacity ◽  
Lithium Titanate ◽  
Parent Material ◽  
Cyclic Voltammograms ◽  
Oxidation Current ◽  
Titanate Nanosheets

The electrochemical properties of titanate nanosheets and layer-structured lithium titanate obtained by restacking of titanate nanosheets were investigated in comparison with those of layer-structured lithium titanate obtained by ion-exchange. Restacked lithium titanate was synthesized by reassembling titanate nanosheets with LiOH aqueous solution. The nanosheets were 50-200 nm wide and 1.7 nm thick. The crystal structure inside the nanosheets was the same as that the of parent material. The oxidation current peaks observed in cyclic voltammograms of titanate nanosheets and restacked material were 1.6 V (Li/Li+), which was lower than that of ion-exchanged material by 0.3 V. The discharge capacity of restacked material was 96 mAh g-1, indicating that 32% of the titanium ions were reduced.

Effect of Different Washing Treatments on the Formation of Titanate Nanotubes

2010 ◽  
Vol 663-665 ◽  
pp. 1247-1251 ◽  
Author(s):  
Cheng Yan Liu ◽  
Lei Miao ◽  
Rong Huang ◽  
Sakae Tanemura
Keyword(s):  
Aqueous Solution ◽  
Driving Force ◽  
Deionized Water ◽  
Sodium Ion ◽  
Titanate Nanotubes ◽  
Acidic Solutions ◽  
Ph Values ◽  
Acid Washing ◽  
Almost All ◽  
Titanate Nanosheets

Titanate nanotubes were successfully synthesized by means of an alkaline hydrothermal method and further appropriate post-treatments. The effect of different washing treatments on the formation of titanate nanotubes were systematically studied in this paper. It was found that the washing treatments play an important role in the formation of nanotubes. Treating with 0.1M NaCl aqueous solution mainly resulted in titanate nanosheets while treating with deionized water or 0.1M HCl aqueous solution (1 time, PH>7) can obtain highly crystallized titanate nanotubes. Furthermore, if the PH values of solutions after acid washing processes were below 7, trace of nanotubes can be found but almost all of them were damaged. On the basis of all the present experimental results, we can conclude that titanate nanotubes can be prepared as long as the driving force induced by the imbalance of sodium ion (Na+) concentration on two different sides of nanosheets was appropriate, and meanwhile they were instable in acidic solutions.

scholarly journals Fabrication of transition temperature controlled W-doped VO2 nano particles by aqueous solution

2011 ◽  
Vol 119 (1390) ◽  
pp. 522-524 ◽  
Author(s):  
Hidetoshi MIYAZAKI ◽  
Kisena YOSHIDA ◽  
Shiori SASAKI ◽  
Naonori SAKAMOTO ◽  
Naoki WAKIYA ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Transition Temperature ◽  
Nano Particles ◽  
Temperature Controlled

scholarly journals [OPy][BF4] Selective Extraction for Trace Hg2+ Detection by Electrochemistry: Enrichment, Release and Sensing

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1461
Author(s):  
Chenyu Xiong ◽  
Yun Hui ◽  
Ri Wang ◽  
Chao Bian ◽  
Yuhao Xu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Detection Limit ◽  
Environmental Monitoring ◽  
Selective Extraction ◽  
Good Recovery ◽  
Water Safety ◽  
Buffer Solution ◽  
Temperature Controlled ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Trace mercury ion (Hg2+) detection is important for environmental monitoring and water safety. In this work, we study the electrochemical strategy to detect trace Hg2+ based on the preconcentration of temperature-controlled N-octylpyridinium tetrafluoroborate ([OPy][BF4]) dispersive liquid–liquid microextraction. The [OPy][BF4] selectively extracted Hg2+ from aqueous solution by the adsorption of unsaturated N in [OPy][BF4], which increased the concentration of Hg2+ and decreased that of other interference ions. It was noted that the adsorption of [OPy][BF4] to Hg2+ was weakened by aqueous solution. Hence, after extraction, precipitated [OPy][BF4] was diluted by a buffer solution comprising a mixture of water and acetonitrile to release Hg2+ and the single was detected by electrochemistry. Water is proposed to release Hg2+ adsorbed by [OPy][BF4], and the acetonitrile serves as a co-solvent in buffer solution. Sensitivity and anti-inference ability of sensors were improved using the proposed method and Hg2+ releasing procedure. The detection limit (S/N = 3) of the sensor is 0.0315 μg/L with a linear range from 0.1 to 1 μg/L. And the sensor exhibits good recovery with an range from 106 % to 118%, which has great potential for trace Hg2+ determination.

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

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