What is the difference between cationic adsorbate and anionic polyacrylamide?

The first one—anionic polyacrylamide (AN PAM) contained 30% of the ionizable carboxyl groups whereas the cationic polyacrylamide (CT PAM)—35% of the quaternary amine groups. The average molecular weight of the adsorbate was equal to 13,000 and 7000 kDa, respectively.

How does pH affect adsorption of cationic polyacrylamide?

The adsorbed amounts of cationic PAM increase with the pH decrease (higher adsorption of CT PAM is observed at pH 7 than 5). The pK b value for the cationic polyacrylamide is 9.3. At pH 5 and 7 the degree of quaternary amine groups dissociation in the polymer chains varies in the range of 99.4–99.9%.

How does adsorption of anionic polyacrylamide occur?

Under such electrostatic conditions adsorption of anionic polyacrylamide on the montmorillonite surface proceeds mainly through hydrogen bonds which are formed between the solid hydroxyl groups and the polymer functional groups (occurring both in the undissociated and dissociated forms).

How does pH 5 affect adsorption of anionic polyacrylamide chains?

At pH 5 there is the point of zero charge of montmorillonite and adsorption of anionic polyacrylamide chains (whose carboxyl groups are totally dissociated, Table 1) can lead to electrosteric interactions between the solid particles covered with the AN PAM layers.

What is ionic polyacrylamide (PAM)?

These substances, also called soil flocculants, are macromolecular compounds which contribute to the reinforcement of soil structure as a result of its adsorption on the mineral surface. The soil conditioners commonly used in agriculture is ionic polyacrylamide (PAM)—both anionic and cationic.

Which polyacrylamide adsorbate contains ionizable carboxyl groups?

Two types of polyacrylamide ( Korona) differing in the ionic group contents were applied as the adsorbate in the study. The first one—anionic polyacrylamide (AN PAM) contained 30% of the ionizable carboxyl groups whereas the cationic polyacrylamide (CT PAM)—35% of the quaternary amine groups.