Preparation and antimicrobial property of chitosan oligosaccharide derivative/rectorite nanocomposite

► QCMCO/REC (QCOR) nanocomposite was achieved under microwave irradiation in 70 min. ► It was much faster than conventional heating method of 48 h. ► There were hydrogen bonding and electrostatic interaction between QCMC and REC. ► Compared to QCMC, QCOR nanocomposites had higher thermal stability. ► Compared to QCMC, QCOR nanocomposites showed stronger antimicrobial activity.