scholarly journals Mechanism of Morphology Variations in Colloidal CuGaS2 Nanorods

2021 ◽  
Author(s):  
Logan Keating ◽  
Moonsub Shim
Keyword(s):  
Cation Exchange ◽  
Seeded Growth ◽  
Catalytic Growth ◽  
Wide Range

Cu2-XS nanocrystals can serve as templates and intermediates in the synthesis of a wide range nanocrystals through seeded growth, cation exchange, and/or catalytic growth. This versatility can facilitate and accelerate...

scholarly journals Exchange Characteristics of Lead, Zinc, and Cadmium in Selected Tropical Soils

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Tope O. Bolanle-Ojo ◽  
Abiodun D. Joshua ◽  
Opeyemi A. Agbo-Adediran ◽  
Ademola S. Ogundana ◽  
Kayode A. Aiyeyika ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Tropical Soils ◽  
Exchange Capacity ◽  
Exchange Reactions ◽  
Soil System ◽  
Soil Systems ◽  
Wide Range ◽  
Lead Zinc ◽  
High Base

Conducting binary-exchange experiments is a common way to identify cationic preferences of exchangeable phases in soil. Cation exchange reactions and thermodynamic studies of Pb2+/Ca2+, Cd2+/Ca2+, and Zn2+/Ca2+were carried out on three surface (0–30 cm) soil samples from Adamawa and Niger States in Nigeria using the batch method. The physicochemical properties studies of the soils showed that the soils have neutral pH values, low organic matter contents, low exchangeable bases, and low effective cation exchange capacity (mean: 3.27 cmolc kg−1) but relatively high base saturations (≫50%) with an average of 75.9%. The amount of cations sorbed in all cases did not exceed the soils cation exchange capacity (CEC) values, except for Pb sorption in the entisol-AD2 and alfisol-AD3, where the CEC were exceeded at high Pb loading. Calculated selectivity coefficients were greater than unity across a wide range of exchanger phase composition, indicating a preference for these cations over Ca2+. TheKeqvalues obtained in this work were all positive, indicating that the exchange reactions were favoured and equally feasible. These values indicated that the Ca/soil systems were readily converted to the cation/soil system. The thermodynamic parameters calculated for the exchange of these cations were generally low, but values suggest spontaneous reactions.

scholarly journals Quasi-Seeded Growth of Ligand-Tailored PbSe Nanocrystals through Cation-Exchange-Mediated Nucleation

2008 ◽  
Vol 120 (16) ◽  
pp. 3071-3075 ◽  
Author(s):  
Maksym V. Kovalenko ◽  
Dmitri V. Talapin ◽  
Maria Antonietta Loi ◽  
Fabrizio Cordella ◽  
Günter Hesser ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Seeded Growth

Phosphatidic acid-functionalized monolithic stationary phase for reversed-phase/cation-exchange mixed mode chromatography

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 100891-100898 ◽  
Author(s):  
Kun Peng ◽  
Qiqin Wang ◽  
Weijia Chen ◽  
Donghai Xia ◽  
Zhengyin Zhou ◽  
...  
Keyword(s):  
Phosphatidic Acid ◽  
Stationary Phase ◽  
Cation Exchange ◽  
Mixed Mode ◽  
Pharmaceutical Compounds ◽  
Reversed Phase ◽  
Small Peptides ◽  
Wide Range ◽  
Monolithic Stationary Phase

A reversed-phase and cation-exchange mixed-mode poly(MDPA-co-EDMA) monolith was successfully prepared and applied to the separation of a wide range of analytes, such as small peptides, phenols, vitamins B, pharmaceutical compounds.

Octapod-Shaped Colloidal Nanocrystals of Cadmium Chalcogenides via “One-Pot” Cation Exchange and Seeded Growth

Nano Letters ◽  
2010 ◽  
Vol 10 (9) ◽  
pp. 3770-3776 ◽  
Author(s):  
Sasanka Deka ◽  
Karol Miszta ◽  
Dirk Dorfs ◽  
Alessandro Genovese ◽  
Giovanni Bertoni ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Colloidal Nanocrystals ◽  
Seeded Growth ◽  
One Pot ◽  
Cadmium Chalcogenides

Long-lasting phosphorescence with a tunable color in a Mn2+-doped anionic metal–organic framework

2017 ◽  
Vol 5 (31) ◽  
pp. 7898-7903 ◽  
Author(s):  
Xiaogang Yang ◽  
Dongpeng Yan
Keyword(s):  
Cation Exchange ◽  
Metal Organic Framework ◽  
Wide Range ◽  
Yellow Orange ◽  
Metal Organic ◽  
Organic Framework

Based on a facile cation exchange with Mn2+ at different concentrations, the phosphorescence performance of the anionic metal–organic framework could be adjusted across an unusually wide range from blue to violet, white, yellow, orange and red.

Changes in effective cation exchange capacity and exchangeable aluminum with soil pH in lime-amended field soils

Soil Research ◽  
1992 ◽  
Vol 30 (2) ◽  
pp. 177 ◽  
Author(s):  
Z Hochman ◽  
DC Edmeades ◽  
E White
Keyword(s):  
Cation Exchange ◽  
Linear Relationship ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Exchange Capacity ◽  
Exchangeable Cations ◽  
Acidic Soils ◽  
Hydrogen Ion Concentration ◽  
Wide Range

Eleven acidic soils from northern N.S.W., having a wide range of values for ECEC, A1 and soil organic carbon (%C), were treated in the field with five rates of lime. The relationships between soil pH and the effective cation exchange capacity (ECEC), and between pH and exchangeable aluminium (Al), were investigated for the top 10 cm of these soils. Increases in the total exchangeable cations (TEC) calculated as ECEC-Al, were shown to be madelup almost entirely by increases in exchangeable calcium. There were no consistent changes in the amount of exchangeable magnesium, potassium or sodium due to liming these acidic soils. Formulae used to predict changes in A1 and ECEC with pH in the 'Lime-it' model were tested and modified on the 11 soils from northern N.S.W. A strong linear relationship was observed in each soil between Al and pH (transformed to hydrogen ion concentration x 103). The slope of this relationship (SALs) can be predicted from the pH and A1 values of unlimed soils. Strong linear relationships were also observed between pH and TEC, for each of the 11 soils. The SL, (the slope of the linear relationship TEC/pH for any soil 's') was shown by multiple regression analysis to be a function of TECi/pHi (where TECi is the sum of exchangeable cations of unlimed soil 's'; and pHi is the pH value of unlimed soil 's'), %C of the unlimed soil, and SALs. By using the measured values of pH, ECEC, Al and %C of unlimed soils, the values of Al, and TEB can be predicted for any pH value that may be measured (or predicted) after liming. The predictive relationships developed on N.S.W. soils were tested against independent data from New Zealand. The results confirmed the Al/pH predictions (R2 = 0.955), while the TEC/pH predictions were less well matched (R2= 0.62) possibly due to unusual clay mineralogy or organic matter fractions of 3 of the 18 soils tested.

Soil solution chemistry of contrasting soils amended with heavy metals

Soil Research ◽  
1999 ◽  
Vol 37 (5) ◽  
pp. 993 ◽  
Author(s):  
H. J. Percival ◽  
T. W. Speir ◽  
A. Parshotam
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Ions ◽  
Cation Exchange ◽  
Soil Solution ◽  
Solution Chemistry ◽  
Percentage Increase ◽  
Soil Solution Chemistry ◽  
Soil Solutions ◽  
Wide Range

The soil solution chemistry of heavy metal amended soils is of great importance in assessing the bioavailability of heavy metals and their toxicity to the soil biota. Three contrasting soils were amended with Cd(II), Cu(II), Ni(II), Pb(II), Zn(II), and Cr(III) nitrate salts at rates of 10–100 mmol/kg. This concentration range was chosen to encompass a wide range of effects on sensitive soil biochemical properties as part of a larger project. Soil solutions were extracted and analysed for pH, and for concentrations of heavy metals, and major cations and anions. Heavy metal speciation was calculated with the GEOCHEM-PC model. Heavy metal concentrations in the soil solutions increased both in absolute terms and as a percentage of added heavy metal as amendment rates increased. This observation is due to decreasing specific adsorption (caused by decreasing pH induced by the amendments), and to increasing saturation of cation exchange sites. For all 3 soils, the percentage increase commonly follows the order Cr(III) < Pb < Cu < Ni < Cd < Zn. The percentage of each metal held in the soil solution increased from soil to soil as cation exchange capacity, and therefore sorptivity, decreased. Both the concentration and activity of free heavy metal ions were substantially lower than the corresponding total metal concentration. This was ascribed to ion-pairing of metal ions with anions, particularly nitrate introduced in the amending solutions, as well as to increases in ionic strength as a result of amendment. Metal-anion species were mainly inorganic but where Cu and Pb were relatively low in concentration because of strong adsorption by the soils, organic complexation was likely to be significant. Speciation trends were similar for the 3 soils but different in magnitude.

Simple Synthesis of Micrometer Fe3O4 Particles with Controlled Magnetic Behaviors

2011 ◽  
Vol 298 ◽  
pp. 273-277
Author(s):  
Gui Zhe Zhao ◽  
Xing Zhou ◽  
Ya Qing Liu ◽  
You Yi Sun
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Magnetic Properties ◽  
Fourier Transform ◽  
Room Temperature ◽  
High Saturation Magnetization ◽  
Vibrating Sample Magnetometer ◽  
Seeded Growth ◽  
Wide Range ◽  
Ft Ir

Fe3O4 particles were prepared by the co-precipitating method in the presence of polyethylene glycol (PEG). They were characterized by the Transmittance electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscope, which indicate the formation of spherical Fe3O4 particles with a wide range of sizes (up to 200 nm in radius) and the polydispersity of particle size below 20%. Furthermore, the magnetic properties of Fe3O4 particles were measured using a vibrating sample magnetometer (VSM), indicating that the particles possess high saturation magnetization at room temperature. These results are attributed that the Fe3O4 particles were directly coated with PEG in a seeded growth Sto¨ber process.

scholarly journals Quasi-Seeded Growth of Ligand-Tailored PbSe Nanocrystals through Cation-Exchange-Mediated Nucleation

2008 ◽  
Vol 47 (16) ◽  
pp. 3029-3033 ◽  
Author(s):  
Maksym V. Kovalenko ◽  
Dmitri V. Talapin ◽  
Maria Antonietta Loi ◽  
Fabrizio Cordella ◽  
Günter Hesser ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Seeded Growth
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