抗菌性无定型纳米二氧化钛/聚乳酸膜的制备及表征

溶胶-凝胶法水解异丙醇钛制备纳米二氧化钛（TiO2）溶液，进行粒径优化及表征。紫外光谱、红外光谱、X射线衍射、粒径测试结果表明制备的纳米TiO2为较高可见光利用率的无定型纳米粒子。采用溶液共混法制备聚乳酸/纳米二氧化钛（polylactic acid/nano-TiO2，PLA/nano-TiO2）复合膜，研究不同纳米TiO2质量分数对PLA/nano-TiO2复合膜的性质影响。结果表明，PLA/nano-TiO2复合膜中纳米TiO2质量分数为0.6%时拉伸强度达到最大值，为63.3 MPa，此时断裂伸长率最小，为2.3%。PLA/nano-TiO2复合膜接触角均低于纯PLA膜，从78.40°减小到72.83°；PLA/nano-TiO2复合膜的吸水率显著高于纯PLA膜，从0.56%提高为1.48%；PLA/nano-TiO2复合膜水蒸气透过率比纯PLA膜高，从3.46×10－8（g·m）/（m2·h·Pa）提高到4.66×10－8（g·m）/（m2·h·Pa）。由PLA/nano-TiO2复合膜的抑菌性实验可知，添加纳米TiO2的复合膜在紫外光照下有明显的抑菌效果。

Preparation and Properties of Antibacterial Amorphous Titanium Dioxide-Polylactic Acid Composite Films

Nano-titanium dioxide (TiO2) solution was prepared from titanium tetraisopropoxide (TTIP) using the solgel method. The molar ratio between TTIP and water was optimized for smaller particle size. The nano-titanium dioxide was amorphous nanoparticles with high visible light utilization as characterized by Fourier transform infrared (FTIR) spectroscopy, UV spectroscopy, X-ray diffraction and particle size analysis. Furthermore polylactic acid/titanium dioxide (PLA/nano-TiO2) composite film was prepared by solution blending method, and the properties of composite films with different titanium dioxide contents were studied. The PLA/0.6% nano-TiO2 composite film had the maximum tensile strength of 63.3 MPa and the minimum elongation at break of 2.3%. The water resistance test indicated that the contact angle of the PLA/nano-composite film was lower than that of pure PLA film (72.83° versus 78.40°). In addition, the water absorption rate of was significantly higher than that of pure PLA film (1.48% versus 0.56%) and there was also an increase in water vapor permeability as compared to pure PLA film (4.66 × 10-8 (g·m)/(m2·h·Pa) versus 3.46 × 10-8 (g·m)/(m2·h·Pa)). Meanwhile, the composite film had a significant antibacterial effect under ultraviolet light.