Adsorption of a Low-Molecular-Weight Polyacrylic Acid on Silica, Alumina, and Kaolin

2002 ◽  
Vol 256 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Abbas A. Zaman ◽  
Ryuta Tsuchiya ◽  
Brij M. Moudgil
Keyword(s):  
Molecular Weight ◽  
Polyacrylic Acid ◽  
Low Molecular Weight ◽  
Silica Alumina

scholarly journals Effect of solution pH on the stability of mixed silica -alumina suspension in the presence of polyacrylic acid (PAA) with different molecular weights

2013 ◽  
Vol 11 (1) ◽  
pp. 101-110 ◽  
Author(s):  
Małgorzata Wiśniewska ◽  
Konrad Terpiłowski ◽  
Stanisław Chibowski ◽  
Teresa Urban ◽  
Vladimir Zarko ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polyacrylic Acid ◽  
System Stability ◽  
Stability Conditions ◽  
Suspension Stability ◽  
Polymer Molecular Weight ◽  
Solution Ph ◽  
Molecular Weights ◽  
Silica Alumina ◽  
The Stability

AbstractThe influence of solution pH (in the range 3–9) on mixed silica-alumina suspension in the absence and presence of polyacrylic acid (PAA) was studied. The composition of the adsorbent was SiO2 (97%) and Al2O3 (3%). The turbidimetry method was applied to record changes in the stability of the investigated systems as a function of time. It was shown that the suspension without the polymer is less stable at pH 3, whereas at pH 6 and 9, the systems were stable. PAA with molecular weights 100 000 and 240 000 at pH 3 (improvement of system stability conditions) and PAA 2 000 at pH 6 (deterioration of suspension stability) have a great effect on the silica-alumina suspension stability. The stabilization-flocculation properties of polyacrylic acid are a result of a specific conformation of its chains on the solid surface where it depends on the solution pH and the polymer molecular weight.

Cation-Induced Collapse of Low-Molecular-Weight Polyacrylic Acid in the Dispersion of Barium Titanate

2002 ◽  
Vol 254 (2) ◽  
pp. 296-305 ◽  
Author(s):  
Nelson S. Bell ◽  
Jürgen Sindel ◽  
F. Aldinger ◽  
Wolfgang M. Sigmund
Keyword(s):  
Molecular Weight ◽  
Barium Titanate ◽  
Polyacrylic Acid ◽  
Low Molecular Weight

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment
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