Charging and colloidal stability of electrostatically stabilized latex particles

2004 ◽  
pp. 108-113
Author(s):  
J. Sefcik ◽  
M. Verduyn ◽  
G. Storti ◽  
M. Morbidelli
Keyword(s):  
Colloidal Stability ◽  
Latex Particles

Mechanical Stability Test for Hevea Latex

1950 ◽  
Vol 23 (4) ◽  
pp. 981-994
Author(s):  
H. G. Dawson
Keyword(s):  
High Speed ◽  
Colloidal Stability ◽  
Mechanical Stability ◽  
Stability Test ◽  
Simple Method ◽  
Latex Particles ◽  
Interfacial Film ◽  
Total Solids ◽  
Stability Time

Abstract The mechanical stability test is a rapid, simple method of estimating the colloidal stability or quality of Hevea latex by high-speed stirring. Latex particles start to agglomerate as soon as the peripheral speed of the agitator reaches a certain minimum value. Progressive flocculation continues until mechanical coagulation occurs. The end point is defined as the time in seconds required to coagulate 0.5 to 1.0 per cent of the total solids. If the shear is constant, the time is proportional to the colloidal stability, which depends upon the interfacial film between the latex particles and the serum. The mechanical stability time depends critically on the size, the total solids, and the temperature of sample.

scholarly journals Effect of Water and Salt on the Colloidal Stability of Latex Particles in Ionic Liquid Solutions

2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Dóra Takács ◽  
Matija Tomšič ◽  
Istvan Szilagyi
Keyword(s):  
Ionic Liquid ◽  
Electrostatic Interactions ◽  
Colloidal Stability ◽  
Interfacial Structure ◽  
Surface Layers ◽  
Latex Particles ◽  
Low Concentrations ◽  
Ethylammonium Nitrate ◽  
Liquid Solutions ◽  
Added Salt

The colloidal stability of sulfate (SL) and polyimidazolium-modified sulfate (SL-IP-2) latex particles was studied in an ionic liquid (IL) of ethylammonium nitrate (EAN) and its water mixtures. Aggregation rates were found to vary systematically as a function of the IL-to-water ratio. Repulsive electrostatic interactions between particles dominated at low IL concentrations, while they were significantly screened at intermediate IL concentrations, leading to destabilization of the dispersions. When the IL concentration was further increased, the aggregation of latex particles slowed down due to the increased viscosity and finally, a striking stabilization was observed in the IL-rich regime close to the pure IL solvent. The latter stabilization is due to the formation of IL layers at the interface between particles and IL, which induce repulsive oscillatory forces. The presence of the added salt in the system affected differently the structure of the interfaces around SL and SL-IP-2 particles. The sign of the charge and the composition of the particle surfaces were found to be the most important parameters affecting the colloidal stability. The nature of the counterions also plays an important role in the interfacial properties due to their influence on the structure of the IL surface layers. No evidence was observed for the presence of long-range electrostatic interactions between the particles in pure ILs. The results indicate that the presence of even low concentrations of water and salt in the system (as undesirable impurities) can strongly alter the interfacial structure and thus, the aggregation mechanism in particle IL dispersions.

Colloidal stability of dextran-modified latex particles toward adsorption of concanavalin A

1998 ◽  
Vol 276 (5) ◽  
pp. 427-433 ◽  
Author(s):  
C. S. Chern ◽  
C. K. Lee ◽  
Y. J. Tsai ◽  
C. C. Ho
Keyword(s):  
Concanavalin A ◽  
Colloidal Stability ◽  
Latex Particles

Impact of Monovalent and Divalent Cations on the Colloidal Stability of Negatively Charged Latex Particles Decorated with Poly(ethylene glycol)

2016 ◽  
Vol 55 (3) ◽  
pp. 606-614 ◽  
Author(s):  
Larissa H. N. Nukui ◽  
Leandro R. S. Barbosa ◽  
Denise F. S. Petri
Keyword(s):  
Ethylene Glycol ◽  
Colloidal Stability ◽  
Divalent Cations ◽  
Poly Ethylene Glycol ◽  
Latex Particles ◽  
Poly Ethylene

Colloidal Stability by Adsorption of Ni2+or Fe3+Cations on Hairy Latex Particles

2012 ◽  
Vol 33 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Carla Cristiane Osawa ◽  
Elizabeth Fátima de Souza ◽  
Alexandre de Castro
Keyword(s):  
Colloidal Stability ◽  
Latex Particles

Colloidal stability of chitosan-modified poly(methyl methacrylate) latex particles

1999 ◽  
Vol 277 (6) ◽  
pp. 507-512 ◽  
Author(s):  
C. S. Chern ◽  
C. K. Lee ◽  
C. C. Ho
Keyword(s):  
Methyl Methacrylate ◽  
Colloidal Stability ◽  
Latex Particles ◽  
Poly Methyl Methacrylate

A Freeze Shadow Technique for the Preparation of Soft Paint Latexes for Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 314-315
Author(s):  
Earl R. Walter ◽  
Glen H. Bryant
Keyword(s):  
Sample Preparation ◽  
High Vacuum ◽  
Vacuum System ◽  
Latex Particles ◽  
New Methods ◽  
Diffusion Pump ◽  
Film Forming ◽  
Routine Basis ◽  
Distribution Studies ◽  
Preparation Techniques

With the development of soft, film forming latexes for use in paints and other coatings applications, it became desirable to develop new methods of sample preparation for latex particle size distribution studies with the electron microscope. Conventional latex sample preparation techniques were inadequate due to the pronounced tendency of these new soft latex particles to distort, flatten and fuse on the substrate when they dried. In order to avoid these complications and obtain electron micrographs of undistorted latex particles of soft resins, a freeze-dry, cold shadowing technique was developed. The method has now been used in our laboratory on a routine basis for several years.The cold shadowing is done in a specially constructed vacuum system, having a conventional mechanical fore pump and oil diffusion pump supplying vacuum. The system incorporates bellows type high vacuum valves to permit a prepump cycle and opening of the shadowing chamber without shutting down the oil diffusion pump. A baffeled sorption trap isolates the shadowing chamber from the pumps.

Increased Protein Synthesis by Human Platelets during Phagocytosis of Latex Particles in Vitro

1976 ◽  
Vol 35 (02) ◽  
pp. 350-357 ◽  
Author(s):  
Hana Bessler ◽  
Galila Agam ◽  
Meir Djaldetti
Keyword(s):  
Protein Synthesis ◽  
Fold Increase ◽  
Human Platelets ◽  
Polystyrene Latex ◽  
Latex Particles ◽  
The Third ◽  
Platelet Protein ◽  
Dose Dependent ◽  
Phagocytotic Activity

SummaryA three-fold increase of protein synthesis by human platelets during in vitro phagocytosis of polystyrene latex particles was detected. During the first two hours of incubation, the percentage of phagocytizing platelets and the number of latex particles per platelet increased; by the end of the third hour, the first parameter remained stable, while the number of latex particles per cell had decreased.Vincristine (20 μg/ml of cell suspension) inhibited platelet protein synthesis. This effect was both time- and dose-dependent. The drug also caused a decrease in the number of phagocytizing cells, as well as in their phagocytotic activity.

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