Interaction between chitosan-based clay nanocomposites and cellulose in a chemical pulp suspension

• QCS/OMMT nanocomposite was achieved under microwave irradiation.
• QCS entered into OMMT interlayer and clay layers distributed uniformly in QCS.
• QCS/OMMT showed good retention and drainage-aid effect in lower dosage.
• The main interaction between QCS/OMMT and cellulose was the effect of charge patch.
• QCS/OMMT showed strong adsorption effect with CaCO3 substrates.

Quaternized chitosan/organic montmorillonite (QCS/OMMT) nanocomposites were synthesized under microwave irradiation. XRD and TEM analyses confirmed that QCS intercalated into the interlayer of OMMT and clay layers distributed uniformly in QCS matrix. QCS/OMMT nanocomposites were used as retention and drainage-aid agents in pulp suspension, during which the interface behavior of positively charged QCS/OMMT nanocomposites on negatively charged cellulosic substrate and CaCO3 substrate was investigated. With the addition of QCS/OMMT nanocomposites, the particle size of cellulosic substrate increased, while the beating degree and the total residual carbohydrate concentration decreased. The results indicated that QCS/OMMT nanocomposite made a difference in paper making process through the charge patch interaction. Moreover, QCS/OMMT nanocomposites had a strong interaction with CaCO3, which was significant in fiber fines retention and paper production. When the mass ratio of QCS to OMMT was 8:1, the QCS/OMMT nanocomposite demonstrated the strongest retention and drainage-aid effect.