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MECHANISM OF PLASTICITY FROM COLLOID STANDPOINT 1
Author(s) -
Bole G. A.
Publication year - 1922
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1922.tb17431.x
Subject(s) - polarity (international relations) , colloid , plasticity , electrolyte , materials science , chemical physics , polarity reversal , particle (ecology) , polarity symbols , surface charge , nanotechnology , ion , chemistry , chemical engineering , composite material , physics , geology , electrode , biochemistry , oceanography , breakdown voltage , organic chemistry , quantum mechanics , voltage , engineering , cell
ABSTSRACT Introduction .—Brief statement of present conceptions of the colloid chemists. Theory .—Plasticity is caused by the, enveloping film of colloidal material which surrounds the clay grains, this film being of opposite polarity to the grain proper. Addition of electrolyte acting as deflocculant causes outer layer of film to be attracted to ion of same polarity as clay particle, thus reducing effective diameter and increasing polarity of plasticity inducing particles. Particles which were held by surface forces of “particles in contact” are no longer in contact and are actually repelling each other due to like and increased polarity. A flocculating ion drives action in opposite direction causing an increase in depth of colloid film thereby increasing surface in actual contact and decreasing repulsive force of plasticity inducing particles. Transport numbers as well as polarity are governing factors in ions of electrolytes. Measurements .—Touch method is proven to be unreliable. Desirability of a unit of measurement. Plea for a unit of colloidality and standard method for measurement.