Chloroaquo complexes of titanium(III). The 2T2g→2Eg absorption band

1967 ◽  
Vol 20 (11) ◽  
pp. 2357 ◽  
Author(s):  
HJ Gardner
Keyword(s):  
Equilibrium Constants ◽  
Eutectic Mixture ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ligand Field ◽  
Ion Content ◽  
Formation Curve ◽  
Octahedral Environment ◽  
Wave Numbers ◽  
Titanium Trichloride

If the chloride ion content of aqueous titanium(III) solutions is gradually increased there is a continuous shifting of the 2T2g → 2Eg peak from c. 20100 cm-1 to c. 14500 cm-1. By applying the rule of average environment it is possible to draw a ?formation curve? for the number of chloride ions complexed to the central titanium(III) ion and hence to determine the equilibrium constants of the successive chloroaquo complexes as chloride ion replaces water in the octahedral environment. Of these, the first, K1 = {Ti(H2O)5Cl2+}aw/{Ti(H2O)3/6+}{Cl-}, was determined to be 0.07-0.2. The reflectance spectra of purple titanium trichloride hexahydrate (TiCl3,6H2O) and a 5% solution of a-titanium trichloride in KCl-LiCl eutectic mixture at 25� are shown to give ligand field bands in agreement with the above range of wave numbers.

Penetration Behavior of Chloride Ions into Concrete in Coastal Areas

2006 ◽  
Vol 302-303 ◽  
pp. 584-590
Author(s):  
Yoshihiro Masuda ◽  
F.-R. Wu ◽  
S. Nakamura ◽  
S. Sato
Keyword(s):  
Chloride Ion ◽  
Concrete Specimen ◽  
Chloride Ions ◽  
Ion Content ◽  
Exposure Test ◽  
Total Chloride ◽  
Chloride Ion Penetration ◽  
Apparent Diffusion ◽  
Penetration Behavior ◽  
Ion Penetration

Exposure test on chloride ion penetration behavior into Concrete in coastal area was implemented. The distances between concrete specimens and coast were changed in the range from 50 to 150 meters, and water-cement ratios (W/C) were 45, 55, 60 and 65 %. The total chloride ion content at each different depth from surface of concrete specimen was measured at the age of 1, 2, 3, 5, 7, 8 and 10 years. In this paper, apparent diffusion coefficient (D) and chloride ion content on surface of concrete (C0) were calculated by inverse analyses from the measured total chloride ion content, and the chloride ion penetration behavior was simulated using the calculated D and C0. As a result, the chloride ion penetrated in concrete with a W/C of 60 % at a point 50 m from the sea for 10 years was estimated approximately 0.2 kg/m3.

Resistance to the Penetration of Chloride Ions of Concrete with Intensified Recycled Aggregates

2011 ◽  
Vol 71-78 ◽  
pp. 1572-1577
Author(s):  
Wen Ge Chai ◽  
Wen Li Li ◽  
Wen Xia Gao
Keyword(s):  
Chloride Ion ◽  
Chloride Ions ◽  
Recycled Concrete ◽  
Mineral Admixture ◽  
Recycled Aggregates ◽  
Ion Content ◽  
High Quality ◽  
Total Chloride ◽  
High Efficient ◽  
Electric Flux

In order to study on methods for and effect of improving performances of recycled concrete, this paper has adopted the recycled aggregates intensified by dipping in the chemical grout, on which basis, the recycled concrete is prepared through the double admixing technology, i.e. mixing of the high-quality mineral admixture and the high-efficient water reducer. The chloride ion permeability of the recycled concrete is researched in the laboratory. In the test, the electric flux, the total chloride ion content and the free chloride ion content at different depths of the recycled concrete have been obtained. The research has shown that dipping in the chemical grout is an effective way to intensify recycled aggregates and that recycled concrete prepared with the intensified recycled aggregates, high-quality mineral admixture and high-efficient water reducer features favorable permeability resistance.

Study on the Threshold Value and Test Methods for Chloride Ion Content in Sea Sand

2016 ◽  
Vol 680 ◽  
pp. 482-485
Author(s):  
Fei Long Sun ◽  
Shuai Wu ◽  
Quan Jiang ◽  
Ting Ting Liu
Keyword(s):  
Early Stage ◽  
Chloride Ion ◽  
Threshold Value ◽  
Test Methods ◽  
Chloride Ions ◽  
International Standards ◽  
National Standards ◽  
Ion Content ◽  
River Sand ◽  
Sea Sand

The building sand is mainly composed of river sand at early stage. Recently, with the depletion of river sand, the new mined river sand cannot meet the demands for building sand. The sea sand is resourceful and can remedy the deficiency of sand for construction. However, the sea sand contains high content of chlorine salt, shell and lightweight matters. They are harmful for the strength and durability of concrete and will lead to premature corrosion of rebar. This will endanger the safety of construction. The studies demonstrate that high content of chlorine salt in sea sand is the main factor led to the deterioration of sea sand concrete. Therefore, in order to ensure the safety of construction, the threshold value of chloride content is specified in standards about concrete and aggregate. And methods testing the content of chloride ions are provided. However, the criterion in different standards differs from one another, which means their different viewpoints about the harm of chloride ions. In this work, the threshold value and test methods of chloride ion content for the building sand in the national standards and the international standards are summarized. The research has great significant for setting standards about sea sand, determining the rational threshold value of chloride ion content and improving the method testing the content of chloride ions.

scholarly journals Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

2021 ◽  
Vol 11 (12) ◽  
pp. 5322
Author(s):  
Yang Ding ◽  
Tong-Lin Yang ◽  
Hui Liu ◽  
Zhen Han ◽  
Shuang-Xi Zhou ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Penetration Depth ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Finite Element Software ◽  
Chloride Resistance ◽  
Simulation Calculation ◽  
Marine Concrete ◽  
Resistance Performance

Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

scholarly journals Broadband dielectric spectroscopy for monitoring temperature-dependent chloride ion motion in BiOCl plates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Adrian Radoń ◽  
Dariusz Łukowiec ◽  
Patryk Włodarczyk
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Spectroscopy ◽  
Low Frequency ◽  
Chloride Ion ◽  
Ion Source ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Broadband Dielectric Spectroscopy ◽  
Free Chloride ◽  
Structure Rebuilding

AbstractThe dielectric properties and electrical conduction mechanism of bismuth oxychloride (BiOCl) plates synthesized using chloramine-T as the chloride ion source were investigated. Thermally-activated structure rebuilding was monitored using broadband dielectric spectroscopy, which showed that the onset temperature of this process was 283 K. This rebuilding was related to the introduction of free chloride ions into [Bi2O2]2+ layers and their growth, which increased the intensity of the (101) diffraction peak. The electrical conductivity and dielectric permittivity were related to the movement of chloride ions between plates (in the low-frequency region), the interplanar motion of Cl− ions at higher frequencies, vibrations of these ions, and charge carrier hopping at frequencies above 10 kHz. The influence of the free chloride ion concentration on the electrical conductivity was also described. Structure rebuilding was associated with a lower concentration of free chloride ions, which significantly decreased the conductivity. According to the analysis, the BiOCl plate conductivity was related to the movement of Cl− ions, not electrons.

scholarly journals Layered Double Hydroxides Precursor as Chloride Inhibitor: Synthesis, Characterization, Assessment of Chloride Adsorption Performance

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2537 ◽  
Author(s):  
Lin Chi ◽  
Zheng Wang ◽  
Youfang Zhou ◽  
Shuang Lu ◽  
Yan Yao
Keyword(s):  
Removal Rate ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Ions ◽  
Ion Removal ◽  
Hydraulic Concrete ◽  
Adsorption Behaviors ◽  
The Stability ◽  
Inhibition Performance ◽  
Double Hydroxides

In this study, the chloride adsorption behaviors of CaAl-Cl LDH precursors with various Ca:Al ratios were investigated. The optimal chloride ion removal rate was 87.06% due to the formation of hydrocalumite. The chloride adsorption products of CaAl-Cl LDH precursors were further characterized by X-ray diffraction analysis and atomic structure analysis, the adsorption mechanism was considered to be co-precipitate process. The chloride adsorption behaviors of cementitious materials blended with CaAl-Cl LDH precursors were further investigated. Leaching test according to Test Code for Hydraulic Concrete (SL352-2006) was performed to testify the stability of chloride ions in the mortar. The results show that more than 98.3% chloride ions were immobilized in cement mortar blended with CaAl-Cl LDH precursor and cannot be easily released again. The inhibition performance of steel in the electrolytes with/without CaAl LDH precursor was investigated by using electrochemical measurements. The results indicate that CaAl LDH precursor can effectively protect the passive film on steel surface by chloride adsorption. Considering the high anion exchange capacities of the LDHs, synthesized chloride adsorbent precursor can be applied as new inhibitors blended in cementitious materials to prevent the chloride-induced deterioration. Moreover, the application of chloride adsorption on CaAl-Cl LDH could also be of interest for the application of seawater blended concrete.

GABA responses in rat dentate granule neurons are mediated by chloride

1988 ◽  
Vol 66 (5) ◽  
pp. 637-642 ◽  
Author(s):  
Timothy J. Blaxter ◽  
Peter L. Carlen
Keyword(s):  
Granule Cells ◽  
Hippocampal Slices ◽  
Reversal Potential ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Ion Concentration ◽  
Aminobutyric Acid ◽  
Granule Neurons ◽  
Nernst Equation ◽  
Central Neurons

The dendrites of granule cells in hippocampal slices responded to γ-aminobutyric acid (GABA) with a depolarization. The response was blocked by picrotoxin in a noncompetitive manner. Reductions in the extracellular chloride ion concentration changed the reversal potential of the response by an amount predicted from the Nernst equation for chloride ion. Chloride-dependent hyperpolarizing responses were sometimes also found in the cell body of the granule cells. Since the reversal potential followed that predicted from the Nernst equation for chloride, we conclude that the response was mediated by chloride ions alone with no contribution from other ions. This has not previously been shown for the depolarizing response to GABA in central neurons.

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