ISSN:
1435-1536
Keywords:
Coagulation
;
flocculation
;
polymer bridging
;
particle adhesion
;
adhesive force
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The adhesive forces between solid particles mutually attached during coagulation or bridging flocculation are important for modelling floc stability. Results are presented in this study which are obtained from experiments on the adhesion of glass or quartz particles to a flat glass substrate (centrifugal method) or to the wall of a glass capillary through which an aqueous electrolyte solution was passed. Coagulation experiments carried out in 10−2 mole/1 MgCl2 showed the action of hydration layers on hydrophilic surfaces, whereas surface methylation is associated with adhesion in the inner potential minimum. In addition essential ageing effects interpreted as interparticle gelation were observed, especially on the interaction of alkali glass surfaces. Adhesive strength in the case of flocculation with hydrolysed polyacrylamide and a cationic Praestol mainly depends on the polymer concentration and on the preadsorption conditions before the particle-substrate attachment. A significant strengthening of adhesion due to reconformation of the bridging agents was not observed for a contact time greater than 3 min. The effect of steric stabilization with polymer overdosing could be proved by a special preparation technique.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01419891
Permalink
