Research on process optimization, mechanism of nanocellulose preparation and exploration of multifunctional applications by ball milling

This paper conducts in-depth research on the process optimization, mechanism and multifunctional application of preparation by ball milling nanocellulose . The impact of key parameters such as ball milling time, ball material ratio and rotation speed on nanocellulose performance was systematically explored, and the preparation process was optimized. Various characterization methods were used to analyze the structural evolution law of cellulose during ball milling, and the mechanism of nanocellulose preparation by ball milling was revealed. Based on the optimized preparation process, the large-scale production of nanocellulose has been successfully achieved, and its multifunctional applications in the fields of composite material enhancement, biomedical and energy environment have been explored. This study provides theoretical basis and technical support for the industrial application of nanocellulose preparation by ball milling.

As a new nanomaterial, nanocellulose has attracted much attention due to its unique structure and excellent properties. Among many preparation methods, ball milling has become a research hotspot because of its advantages such as simple operation, low cost and easy to scale. This paper aims to systematically study the process parameter optimization of nanocellulose preparation by ball milling, deeply analyze its preparation mechanism, and explore its multifunctional application in multiple fields, providing a reference for the industrialization of nanocellulose.

1. Process optimization of nanocellulose preparation by ball milling

The key process parameters for the preparation of by ball milling nanocellulose include ball milling time, ball material ratio and rotation speed. This study systematically optimized the effect of these parameters on nanocellulose performance through single-factor experiments and orthogonal experiments.

Ball milling time is a key factor affecting the size and morphology of nanocellulose. As the ball milling time extends, the cellulose fibers gradually become refined, but excessive ball milling time may lead to excessive fracture of the fibers, affecting the aspect ratio of the nanocellulose. The experimental results show that the optimal ball milling time is 6-8 hours.

The ball-material ratio (mass ratio of grinding media to cellulose raw materials) affects the ball-milling efficiency and product performance. Higher ball ratios can improve grinding efficiency, but excessive ball ratios can lead to increased energy consumption and product contamination. Studies have shown that the optimal ball-feed ratio is 20:1.

The rotation speed directly affects the mechanical energy input during the ball milling process. Higher speeds can improve grinding efficiency, but excessive speeds can lead to temperature increase and cellulose degradation. Experiments found that the optimal speed is 400-500 rpm.

By optimizing the above parameters, high-quality nanocellulose with a diameter of 10-50 nm and a length of 1-2 μm were successfully prepared, with a yield of more than 85%.

2. Research on the mechanism of preparation of nanocellulose by ball milling

In order to deeply understand the mechanism of nanocellulose preparation by ball milling, this study used X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to systematically analyze the structural evolution of cellulose during ball milling.

XRD analysis showed that as the ball milling time was longer, the crystallinity of cellulose gradually decreased. This is mainly due to the damage to the cellulose crystal structure due to the mechanical force. However, typical diffraction peaks of cellulose can still be observed even after long ball milling, indicating that the ball milling method mainly affects the amorphous region of cellulose while retaining part of the crystalline structure.

FTIR analysis showed that the chemical structure of cellulose remained basically unchanged during the ball milling process, but the strength of the hydroxyl peak increased. This suggests that the ball milling process may increase the surfactivity of the cellulose, which is conducive to subsequent functional modification.

SEM observations found that cracks and peeling occurred on the surface of cellulose fibers in the early stage of the ball milling, and then gradually dissociated into nanofibers. This process is closely related to ball milling time, ball material ratio and rotation speed. By optimizing these parameters, precise regulation of nanocellulose morphology and size can be achieved.

3. Large-scale production of nanocellulose preparation by ball milling

In order to realize the large-scale production of nanocellulose preparation by ball milling method, this study designed and built a pilot-scale continuous ball milling system. The system uses multi-stage tandem ball mill tanks, each equipped with an independent temperature control and cooling system to ensure the stability and controllability of the production process.

The pilot results show that the continuous ball milling system can stably produce nanocellulose with a diameter of 20-100 nm and a length of 0.5-5 μm, with a production capacity of 10 kg/h. Compared with traditional batch ball milling, the energy consumption of continuous ball milling systems is reduced by 30% and the production efficiency is improved by 50%.

In addition, this study also develops a process parameter optimization system based on machine learning. The system automatically adjusts the ball mill parameters by collecting and analyzing production data in real time to ensure the stability of product quality. Practical application shows that the system can increase the product pass rate to more than 95%.

4. Exploration of multifunctional application of nanocellulose preparation by ball milling

Based on the optimized preparation process, this study further explores the multifunctional application potential of nanocellulose prepared by ball milling in different fields. In the field of composite materials, nanocomposites are prepared by adding nanocellulose to polylactic acid (PLA) matrix. The results show that the addition of 3 wt% nanocellulose can increase the tensile strength of PLA by 45%, and the thermal deformation temperature will be increased by 15°C, which significantly improves the mechanical properties and thermal stability of the material.

In the field of biomedical science, porous scaffold materials are prepared by nanocellulose prepared by ball milling. The material has good biocompatibility and cellular affinity and can be used in tissue engineering and wound dressings. In vitro experiments showed that the scaffold material can effectively promote the proliferation and migration of fibroblasts.

In the field of energy environment, nanocellulose and carbon nanotubes are combined to prepare flexible supercapacitor electrode materials. The material exhibits excellent electrochemical properties, with a specific capacitance of 320 F/g and good cycle stability. In addition, the application of nanocellulose-based aerogels in water treatment also showed good pollutant adsorption performance, with a removal rate of heavy metal ions exceeding 90%.

V. Conclusion

This study systematically optimizes the process parameters of nanocellulose preparation by ball milling , deeply analyzes its preparation mechanism, and successfully achieves large-scale production. The optimal process conditions are: ball milling time is 6-8 hours, ball material ratio is 20:1, and speed is 400-500 rpm. The prepared nanocellulose has broad application prospects in the fields of composite material reinforcement, biomedical and energy environment. Future research should focus on the reduction of energy consumption by ball milling, functional modification of nanocellulose, and exploration of new application fields to further expand its application scope and commercial value.