Preparation of chitosan/bentonite composites by impingement flow-hydraulic cavitation and its application

Abstract

Objective: In order to solve the problem that the preparation of chitosan/montmorillonite composites by traditional mechanical stirring was time-consuming and not conducive to scale-up production. Methods: Chitosan/montmorillonite composites were prepared by impinging stream hydrodynamic cavitation, the effects of four factors, namely chitosan dosage, chitosan molecular weight, reaction time and reaction temperature on the organic ignition loss were investigated, and then the optimum method of preparation was optimized by using the L9（34） orthogonal test. The structure of the composite was characterized by scanning electron microscopy, infrared spectroscopy, X-ray diffraction and Specific surface analyzer. Results: The optimal solution for the preparation of chitosan/montmorillonite composites was: chitosan dosage 25 g, chitosan relative molecular weight 1 500 000. Hydrodynamic cavitation time 20 min and hydrodynamic cavitation reaction temperature 80 ℃. The composites prepared under these conditions had a organic ignition loss rate of 37.42%. The characterization results demonstrate that chitosan has been successfully loaded onto montmorillonite and the composite still has the porous structure of montmorillonite. Conclusion: Comparing the impinging stream hydrodynamic cavitation method to the composites prepared by the conventional mechanical mixing method, the structure of the composite is looser, and the specific surface area is larger, the organic ignition loss rate and decolorization rate of sugar cane juice is higher, and the hydrodynamic cavitation preparation method is timesaving.

Keywords

• chitosan
• montmorillonite
• impinging stream
• hydrodynamic cavitation
• organic ignition loss rate
• sugar cane juice clarification