cles. The aim of this work is to study the adsorption of The behavior of small inorganic particles at the fiber/water in-CaCO 3 particles on a series of cationic grafted copolymers. terface has been analyzed from the kinetics and isotherms of ad-Indeed, cationic polymers are usually added to retain CaCO 3 sorption of CaCO 3 particles onto cationic fibers. The introduction particles during paper pulp treatment to enhance some paper of cationic moieties onto cellulosic fibers leads to a copolymer that properties such as gloss and stability. In a previous paper can easily adsorb negatively charged particles. At equilibrium, the (9), we reported the effects of chemical parameters on the adsorption ratio of CaCO 3 particles on a cationic copolymer of adsorption of CaCO 3 particles by cellulose poly(acryloxyecellulose and poly(2-acryloxyethyltrimethylammonium chloride) thyltrimethylammonium chloride) (PAEAC)-grafted cois related closely to the particle size, the temperature, the agitation, polymers. In the present work, we analyze the effects of and the ionic strength of the suspension. Kinetic models have shown that the weakly charged copolymers present a high-affinity-physical parameters on this adsorption (stirring speed, partitype kinetics when the CaCO 3 particle average diameter is small cle size of the adsorbate, temperature, and ionic strength).
(20 to 30 mm). For an average particle diameter equal to 72 mm, The adsorption kinetics and isotherms have been established the kinetics corresponds to an adsorption with a lower affinity. and the interactions between the grafted polymeric chains
The rate constants are 6.6 1 10 012 , 2.9 1 10 012 , and 1.2 1 10 012 and the CaCO 3 particles are examined. Kinetic models were m 3 /s for particles with average diameters of 20, 30, and 72 mm, used to characterize the different types of adsorption.
respectively. We have also noted that the adsorption increases with agitation and reaches a plateau after 5 min. The ionic strength EXPERIMENTAL influences the electrostatic interactions between the positive sites of the graft and the anion of the adsorbate. Indeed a decreasing adsorption is observed when the ionic strength increases. α§ 1996 Cellulosic Materials and Grafting Procedure