中文摘要：

采用高效分散剂和超声波分散技术将不同掺杂比的纳米TiO2引入小麦蛋白成膜液中,用流延法制得分散均匀的纳米复合膜。研究了纳米TiO2用量对小麦蛋白纳米复合膜的力学性能、透湿性、透氧性的影响规律,通过红外光谱（IR）、扫描电镜（SEM）、原子力显微镜（AFM）和透射电镜（TEM）表征其结构。结果表明：随着纳米TiO2用量的增加,复合膜的抗拉强度和断裂伸长率先增大后减小,透湿性和透氧性则按先减小后增大的趋势变化。当纳米TiO2用量为1：200时,复合膜的断裂伸长率最大,比小麦蛋白膜提高了64%,而透湿率和透氧系数则最低,分别比小麦蛋白膜降低了26.6%和59%;IR分析表明纳米TiO2在复合膜中并非简单的物理固定,而是与小麦蛋白分子之间产生一定的相互作用,纳米粒较均匀地镶嵌在连续的蛋白质基体中,破坏了蛋白质分子原有的纹理结构。TEM观察表明适量纳米TiO2粒子掺入到蛋白质基体中能达到初级粒径分散状态,且颗粒分散均匀。

英文摘要：

Nano-titania（TiO2）were dispersed into wheat gluten solution in different mass ratios by efficient dispersant and ultrasonic treatment to achieve an evenly distributed nano-composite films through casting technique.The effect of TiO2 dosage on the mechanical property,water vapour permeability and oxygen permeability of composite films were studied.Composite films were characterized by infrared spectroscopy（IR）,scanning electron microscopy（SEM）,atomic force microscopy（AFM） and transmission electron microscopy（TEM）,respertively.The results indicate that,with the increasing of TiO2 dosage the tensile strength and breaking extension ratio increase firstly and then decrease,the water vapour permeability and oxygen permeability decline firstly and rise later.When the mass ratio of TiO2 and wheat gluten is 1：200,the breaking extension ratio achieves its maximal value,which shows a 64% increase compared with wheat gluten film,whereas the water vapour permeability and oxygen permeability are at their minimum values,which decrease by 26.6% and 59% respectively compared with wheat gluten film.There exists interaction between titanium dioxide nanoparticles and wheat gluten moleculae according to infrared spectrum analysis.Nano-TiO2 particles are embedded evenly in the continuous phase,and the texture of protein moleculae is damaged.TEM observation shows that nanoparticles according to their primary particle size are uniformly dispersed in the protein matrix when approprate amount of nano-TiO2 was added.