Adsorption of hydrolysable cations at the aquacoat/water interface. An electrokinetic study

✍ Scribed by P. Vera; A.Ben Taleb; J. Salcedo; V. Gallardo

• Book ID: 103966980
• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 388 KB
• Volume: 92
• Category: Article
• ISSN: 0927-7757
• DOI: 10.1016/0927-7757(94)02856-7

✦ Synopsis

Some surface electrical properties of Aquacoat, a polymer latex of great interest in pharmaceutical technology, are characterised by means of electrophoretic mobility measurements. The effect of pH in the presence of CaCl,, BaCl,, MgSO, and LaCI, solutions of different concentrations is investigated. The two latter solutions can be considered as activating electrolytes for the polymer particles: two charge-reversal pH values are found associated with the surface precipitation of the corresponding hydroxide and with its isoelectric point respectively. The first charge reversal occurs at the same pH (lanthanum solutions) or at an even slightly higher pH (magnesium solutions) than that of bulk precipitation. This fact suggests that the charge reversal mechanisms proposed previously for inorganic colloids could be specific to the polymer/solution interface.