Description of colloidal particles aggregation in the presence of Hofmeister effects: on the relationship between ion adsorption energy and particle aggregation activation energy

2018 ◽  
Vol 20 (35) ◽  
pp. 22831-22840 ◽  
Author(s):  
Yaxue Luo ◽  
Hang Li ◽  
Xiaodan Gao ◽  
Rui Tian
Keyword(s):  
Activation Energy ◽  
Adsorption Energy ◽  
Colloidal Particles ◽  
Dlvo Theory ◽  
Particle Aggregation ◽  
Ion Adsorption ◽  
The Relationship

Upon extending the DLVO theory by taking into account the Hofmeister effects, the predicted CCC values match well with experimental CCCs.

scholarly journals Self-Assembly of Shape-Tunable Oblate Colloidal Particles into Orientationally Ordered Crystals, Glassy Crystals and Plastic Crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Jiawei Lu ◽  
Xiangyu Bu ◽  
Xinghua Zhang ◽  
Bing Liu
Keyword(s):  
Crystal Structures ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Building Blocks ◽  
Fundamental Question ◽  
The Self ◽  
Plastic Crystals ◽  
Self Assembled ◽  
Glassy Crystals ◽  
The Relationship

The shapes of colloidal particles are crucial to the self-assembled superstructures. Understanding the relationship between the shapes of building blocks and the resulting crystal structures is an important fundamental question....

New experiments on the relationship between light-induced defects and photoconductivity degradation

2001 ◽  
Vol 664 ◽  
Author(s):  
Stephan Heck ◽  
Howard M. Branz
Keyword(s):  
Activation Energy ◽  
Defect Density ◽  
Activation Energies ◽  
Dangling Bond ◽  
Fast Recovery ◽  
Slow Recovery ◽  
Degradation Model ◽  
Induced Defects ◽  
The Relationship ◽  
Hydrogenated Amorphous

ABSTRACTWe report experimental results that help settle apparent inconsistencies in earlier work on photoconductivity and light-induced defects in hydrogenated amorphous silicon (a-Si:H) and point toward a new understanding of this subject. After observing that light-induced photoconductivity degradation anneals out at much lower T than the light-induced increase in deep defect density, Han and Fritzsche[1] suggested that two kinds of defects are created during illumination of a-Si:H. In this view, one kind of defect degrades the photoconductivity and the other increases defect sub-bandgap optical absorption. However, the light-induced degradation model of Stutzmann et al.[2] assumes that photoconductivity is inversely proportional to the dangling-bond defect density. We observe two kinds of defects that are distinguished by their annealing activation energies, but because their densities remain in strict linear proportion during their creation, the two kinds of defects cannot be completely independent.In our measurements of photoconductivity and defect absorption (constant photocurrent method) during 25°C light soaking and during a series of isochronal anneals between 25 < T < 190°C, we find that the absorption measured with E ≤1.1 eV, first increases during annealing, then exhibits the usual absorption decrease found for deeper defects. The maximum in this absorption at E ≤1.1eV occurs simultaneously with a transition from fast to slow recovery of photoconductivity. The absorption for E ≤1.1eV shows two distinct annealing activation energies: the signal rises with about 0.87 eV and falls with about 1.15 eV. The 0.87 eV activation energy roughly equals the activation energy for the dominant, fast, recovery of photoconductivity. The 1.15 eV activation energy roughly equals the single activation energy for annealing of the light-induced dangling bond absorption.

Te Induced AlAs/GaAs Superlattice Mixing

1988 ◽  
Vol 126 ◽  
Author(s):  
P. Mel ◽  
S. A. Schwarz ◽  
T. Venkatesan ◽  
C. L. Schwartz ◽  
E. Colas
Keyword(s):  
Mass Spectrometry ◽  
Activation Energy ◽  
Diffusion Coefficient ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Vapor ◽  
Temperature Range ◽  
The Relationship ◽  
Secondary Ion

ABSTRACTTe enhanced mixing of AlAs/GaAs superlattice has been observed by secondary ion mass spectrometry. The superlattice sample was grown by organometallic chemical vapor deposition and doped with Te at concentrations of 2×1017 to 5×1018 cm−.3 In the temperature range from 700 to 1000 C, a single activation energy for the Al diffusion of 2.9 eV was observed. Furthermore, it has been found that the relationship between the Al diffusion coefficient and Te concentration is linear. Comparisons have been made between Si and Te induced superlattice mixing.

Adsorption of Cu(II) Ions from an Aqueous Solution by Cross-Linked Carboxymethyl Konjac Glucomannan

2011 ◽  
Vol 239-242 ◽  
pp. 2310-2316 ◽  
Author(s):  
Chun Mei Niu ◽  
Shao Ying Li ◽  
Dong Huang
Keyword(s):  
Adsorption Capacity ◽  
Copper Nitrate ◽  
Konjac Glucomannan ◽  
Ion Adsorption ◽  
Adsorption Time ◽  
Isotherm Equation ◽  
Langmuir Isotherm Equation ◽  
Effects Of Ph ◽  
The Relationship ◽  
Carboxymethyl Konjac Glucomannan

Crosslinked Carboxymethyl Konjac Glucomannan(CMKGM) with substitution degrees ofcarboxymethyl group（DS）0.265, 0.457 and 0.586 were prepared through reaction of monochloroacetic acid, konjac glucomannan(KGM) and epichlorohydrin and used to adsorb Cu(II) from the aqueous solutions of copper nitrate. The effects of pH, adsorbent dose, initial concentration of Cu(II), adsorption time and temperature on adsorption capacity were investigated. The results showed that adsorption capacity increased with an increasing DS of the carboxymethyl groups. Equilibrium adsorption time was 20 min or so and was independent on DS. The adsorption followed Langmuir isotherm equation. Ligand ion adsorption between carboxymethyl group and Cu(II) was thought to be predominate in the process of adsorption according to the relationship between DS and thermodynamic parameters. CMKGM can be used as cheaper and more effective adsorbents.

Study on Curing Kinetics of MEP-15/593/660 System

2014 ◽  
Vol 988 ◽  
pp. 31-35
Author(s):  
Jia Le Song ◽  
Chan Chan Li ◽  
Zhi Mi Zhou ◽  
Chao Qiang Ye ◽  
Wei Guang Li
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Conversion Ratio ◽  
Scanning Calorimetry ◽  
Degree Of Cure ◽  
Curing Kinetic ◽  
The Relationship ◽  
Kinetics Of

Curing kinetics of MEP-15/593 system and MEP-15/593/660 system is studied by means of differential scanning calorimetry (DSC). Curing kinetic parameters are evaluated and the relationship between diluent 660 and the curing properties is investigated. The results show that the diluent 660 can not only reduce viscosity and activation energy, but also improve the degree of cure and conversion ratio.

scholarly journals A Simple Method to Determine Critical Coagulation Concentration from Electrophoretic Mobility

2020 ◽  
Vol 4 (2) ◽  
pp. 20 ◽  
Author(s):  
Marco Galli ◽  
Szilárd Sáringer ◽  
István Szilágyi ◽  
Gregor Trefalt
Keyword(s):  
Electrophoretic Mobility ◽  
Dlvo Theory ◽  
Computational Method ◽  
Particle Aggregation ◽  
Critical Coagulation Concentration ◽  
Simple Method ◽  
Interparticle Forces ◽  
Mobility Data ◽  
Key Parameter ◽  
Multivalent Electrolytes

Critical coagulation concentration (CCC) is a key parameter of particle dispersions, since it provides the threshold limit of electrolyte concentrations, above which the dispersions are destabilized due to rapid particle aggregation. A computational method is proposed to predict CCC values using solely electrophoretic mobility data without the need to measure aggregation rates of the particles. The model relies on the DLVO theory; contributions from repulsive double-layer forces and attractive van der Waals forces are included. Comparison between the calculated and previously reported experimental CCC data for the same particles shows that the method performs well in the presence of mono and multivalent electrolytes provided DLVO interparticle forces are dominant. The method is validated for particles of various compositions, shapes, and sizes.

scholarly journals Aggregate Evolution Mechanism during Ion-Adsorption Rare Earth Ore Leaching

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Kui Zhao ◽  
Yulong Zhuo ◽  
Xiaojun Wang ◽  
Wen Zhong
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Rare Earth ◽  
Ammonium Chloride ◽  
Particle Deposition ◽  
Pure Water ◽  
Particle Aggregation ◽  
Ion Adsorption ◽  
Aggregate Formation ◽  
Fine Soil ◽  
Formation And Evolution

The phenomenon of particle aggregation occurs when ammonium chloride is used as a leaching reagent to infiltrate rare earth samples. To reveal the formation and evolution mechanisms of aggregates, a self-developed column leaching experimental device was employed in conjunction with nuclear magnetic resonance technology. The relationships among the amount of rare earth leaching, the evolution of the microscopic pore structure, the porosity, and the leaching time were obtained. A comparative analysis of pure water and ammonium chloride test groups revealed that aggregates were present only in the latter. Consequently, the results of comprehensive analyses indicate that the formation of aggregates is a temporary particle deposition phenomenon caused by the settling of fine soil particles migrating from the top to the bottom of a sample. Furthermore, chemical exchanges constitute the main cause of aggregate formation.

Thermal Stability vs. Crystallization of the Lithiumsilicate Glasses with Addition Zirconium Dioxide and Titanium Dioxide

2008 ◽  
Vol 39-40 ◽  
pp. 399-401
Author(s):  
Viliam Pavlík ◽  
Eugen Jóna ◽  
Martina Sapietová ◽  
Soňa Šnircová
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Analysis ◽  
Titanium Dioxide ◽  
Differential Thermal Analysis ◽  
Structural Analysis ◽  
Zirconium Dioxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Relationship

The glasses with composition of Li2O . 2 SiO2 . n ZrO2 . n TiO2 (where n = 0; 0.015; 0.031; 0.050; 0.075; 0.1; 0.15; 0.2) were prepared and the relationship between structural and selected parameters of thermal stability vs. crystallization has been studied by differential thermal analysis. Structural analysis was provided by X–ray diffraction. The order of thermal stability vs. crystallization representing of activation energy of studied glass systems which increase with higher addition both oxides. The same order was obtained from the values of XRD. On the comparison the glasses with zero addition titanium dioxide their activation energy was much higher.

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