Adsorption of Hybrid Polyacrylamides on Anisotropic Kaolinite Surfaces: Effect of Polymer Characteristics and Solution Properties


Adsorption kinetics of organic-inorganic (hybrid) Al(OH)3-polyacrylamide (Al-PAM) with different molecular weights (for organic characteristics) and contents of aluminum hydroxide nanoparticles (for inorganic characteristics) on kaolinite basal planes was studied using a versatile quartz crystal microbalance with dissipation (QCM-D). The flocculation dynamics of kaolinite by Al-PAMs was assessed by measuring the initial settling rate of flocculated kaolinite particles and the turbidity of the supernatant after settling of flocculated solids. The areal mass (mg/m2) of Al-PAMs adsorbed on tetrahedral silica and octahedral alumina basal planes of kaolinite increased with increasing molecular weight of the polymer. Increasing the content of Aluminum hydroxide nanoparticle in Al-PAM has resulted in an increase of the amount of the polymer adsorbed on silica basal planes while opposite trend was found on alumina basal planes. Results obtained from the adsorption kinetics study of Al-PAM6R (Mw = 2.2 million Dalton, 0.11 wt% Aluminum) on silica basal planes revealed that the early stage of adsorption is diffusion-controlled. Thus, initially the adsorption rate increased with increasing temperature while the maximum coverage decreased. Moreover, the adsorption of Al-PAMs on silica basal planes was shown to decrease significantly in plant recycle (process) water compared to deionized water. Al-PAMs of higher molecular weight and/or high content of inorganic Al (OH)3 nanoparticles were found to be more effective in flocculating kaolinite as indicated by the faster settling rates and clearer supernatant.


Mining Engineering


Authors would like to thank the NSERC (Natural Science and Engineering Research Council of Canada) and Missouri University of Science and Technology for the financial support.

Keywords and Phrases

Adsorption; Alumina; Deionized water; Diffusion; Flocculation; Kaolinite; Molecular weight; Nanoparticles; Organic polymers; Polyacrylates; Polymers; Quartz crystal microbalances; Silica; Adsorption kinetics; Diffusion controlled; Increasing temperatures; Organic-inorganic hybrid polymer; Polymer characteristics; Quartz crystal microbalance with dissipation; Solid liquid separation; Solution property; Aluminum; Aluminum hydroxide; Aluminum silicate; Deionized water; Nanoparticle; Polyacrylamide; Polymer; Adsorption kinetics; Article; Flocculation; Mass; Molecular dynamics; Molecular weight; Priority journal; Quartz crystal microbalance; Supernatant; Surface property; Suspension; Temperature; Diffusion coefficient; QCM-D; Solid-liquid separation

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Article - Journal

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© 2016 Elsevier, All rights reserved.

Publication Date

01 Jun 2016