玉米淀粉/TiO2纳米复合薄膜制备与性能

以玉米淀粉为基质，结合纳米Ti O₂，通过超声分散采用流延法制备了可生物降解的淀粉/Ti O₂纳米复合薄膜，研究了纳米Ti O₂对薄膜拉伸性能、阻隔性能及抗菌活性的影响，采用扫描电子显微镜(SEM)、红外光谱仪(FTIR)和X射线衍射仪(XRD)对复合膜的微观形貌和结构进行了表征。结果表明，淀粉/Ti O₂纳米复合膜中Ti O₂与淀粉分子间存在缔合作用，含适量Ti O₂的复合膜组分之间有良好的相容性，与淀粉膜相比，纳米复合膜的拉伸性能和水蒸气阻隔性能得到有效改善，含0.8%Ti O₂(质量分数，下同)的纳米复合膜拉伸强度为7.54 MPa，比淀粉膜提高了53.9%，水蒸气透过系数为5.50×10^-5 g/(mm·d)，较淀粉膜降低了23.5%，该复合膜同时表现出较好的紫外线隔离性能及抗菌活性。

Preparation and performance of corn starch/TiO2 nanocomposite films

TiO₂ nanoparticles were incorporated into corn starch to prepare a series of biodegradable starch/TiO₂ nanocomposite films for food packaging through ultrasonic dispersion and solution casting. The effect of TiO₂ nanoparticles on the mechanical properties， water vapor resistance properties and antibacterial activities of the nanocomposite films were investigated. Scanning electron microscope， infrared spectrometer and X?ray diffractometer were used to characterize the morphology and microstructure of the films. The results indicated that the compatibility of corn starch with TiO₂ nanoparticles was enhanced at a proper addition amount of TiO₂ nanoparticles due to the formation of molecular association. Compared to pure starch film， the nanocomposite films achieved an effective improvement in mechanical performance and vapor barrier property. The nanocomposite film containing 0.8 wt% TiO₂ nanoparticles presented tensile strength of 7.54 MPa and water vapor permeability of 5.50×10^-5 g/（mm·d）， which were 53.9 % higher and 23.5 % lower than those of pure starch film， respectively. The nanocomposite films exhibited a good antimicrobial capability and reduced transmittance of UV light.