目的 开发和评估一种基于聚乳酸(PLA)和纳米纤维素(NFC)的微纳复合膜包装材料，以提高果蔬保鲜效果，并减小对环境的影响。方法 使用聚对苯二甲酸乙二醇酯(PET)薄膜替代果蔬进行定量化测试，通过改变NFC(质量分数为0.5%)与不同浓度、粒径PLA微粒的混合液喷涂次数，研究它对PET薄膜氧气透过率、水蒸气透过率和辐射散热效果的影响。结果 NFC(质量分数为0.5%)喷涂5次时，复合膜的氧气和水蒸气透过率最低;纤维素中加入适中浓度和粒径(如30 μm)的PLA微粒能够增强氧气阻隔性能，降低PET薄膜的水蒸气透过率;5次喷涂为平衡点，过多喷涂，其阻湿性能反而下降;NFC和PLA微粒的添加使得PET薄膜具有一定的辐射散热效果。结论 适当的NFC和PLA微粒浓度、粒径，以及喷涂次数可显著提高复合膜的性能，该微纳复合膜通过提升纤维素膜均匀性增强阻氧、阻湿性能，具有潜在的辐射降温作用，为果蔬保鲜微包装材料的开发提供了策略。

The work aims to develop and evaluate a micro-nano composite film packaging material based on polylactic acid (PLA) and nanofibrillated cellulose (NFC) to enhance the preservation effect of fruits and vegetables and reduce the environmental impact. Polyethylene terephthalate (PET) films were used to replace fruits and vegetables for quantitative testing. The effects of the spraying times of a mixture of 0.5% NFC and PLA micro-particles of different concentrations and particle sizes on the oxygen permeability, water vapor permeability and radiation heat dissipation effect of PET films were studied. The results showed at 5 times of spraying of 0.5% NFC, the oxygen and water vapor permeability of the composite film were the lowest. Adding PLA micro-particles of moderate concentration and particle size (such as 30 μm) to cellulose could enhance the oxygen barrier performance and reduce the water vapor permeability of PET films. Five times of spraying were the balance point, and excessive spraying would instead reduce the moisture resistance. The addition of NFC and PLA micro-particles gave PET films a certain radiation heat dissipation effect. In conclusion, NFC and PLA micro-particles of appropriate concentrations, particle sizes and spray times can significantly improve the performance of the composite film. This micro-nano composite film enhances the oxygen and moisture barrier performance by improving the uniformity of the cellulose film and has a potential radiation cooling effect, providing a strategy for the development of micro-packaging materials for fruit and vegetable preservation.