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分别采用三种不同方法对硼酸铝晶须(AlBw)进行表面改性。方法一:将AlBw与商品纳米二氧化硅(SiO2)在一定工艺下直接高温熔附;方法二:将正硅酸乙酯(TEOS)用溶胶-凝胶法水解形成Si-O网络结构的膜,同时包裹于AlBw表面,进一步与商品纳米SiO2高温熔附;方法三:用溶胶-凝胶法在一定工艺条件下使TEOS水解得到纳米SiO2,同时沉积于AlBw表面,然后高温熔附。透射电镜(TEM)和扫描电镜(SEM)观察不同方法改性AlBw后其表面形态的变化。按一定质量比加入树脂基质中,测试树脂弯曲性能,SEM观察断口形貌。结果表明:晶须改性后可以提高复合树脂的弯曲性能,不同改性方法作用不同;商品SiO2纳米颗粒直接熔附于AlBw进行表面改性,复合树脂的弯曲强度达(95.28±4.53)MPa,但AlBw、纳米SiO2间团聚明显;采用TEOS溶胶-凝胶法对AlBw进行表面处理后与商品SiO2纳米颗粒混合,团聚有改善,但分布不均匀;采用TEOS溶胶-凝胶法直接生成纳米SiO2改性AlBw,是一种理想的改性方法,经此法改性的AlBw-SiO2复合体可以显著提高复合树脂的弯曲性能,复合树脂的弯曲强度达(130.29±8.38)MPa,SiO2粒径分布均匀,AlBw表面有分布较均匀的、分散的SiO2纳米颗粒熔附,团聚程度降低。
Three different methods were used to modify AlBw whiskers. Method one: AlBw and commercial nanosilica (SiO2) were directly melted under a certain process. Method two: TEOS was hydrolyzed by the sol-gel method to form a film of Si-O network structure , While wrapped in AlBw surface, and further with the commercial high temperature nano-SiO2 melt; Method three: sol-gel method under certain conditions TEOS hydrolyzed to obtain nano-SiO2, while deposited on the AlBw surface, and then high temperature melting. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to observe the morphological changes of AlBw modified by different methods. The resin matrix was added at a certain mass ratio to test the flexural properties of the resin. The fracture morphology was observed by SEM. The results showed that the whisker modification could improve the bending properties of composite resin, and the effect of different modification methods was different. The commercial SiO2 nanoparticles were directly melted on AlBw for surface modification. The flexural strength of composite resin reached 95.28 ± 4.53 MPa, However, the agglomeration between AlBw and nano-SiO2 was obvious. After the surface treatment of AlBw by TEOS sol-gel method, it was mixed with commercial SiO2 nano-particles and the agglomeration was improved but the distribution was not uniform. The nano-SiO2 was directly formed by TEOS sol-gel method AlBw is an ideal modification method. The AlBw-SiO2 composite modified by this method can significantly improve the bending properties of the composite resin. The flexural strength of the composite resin reaches (130.29 ± 8.38) MPa and the distribution of the SiO2 particle size is even , AlBw surface is more evenly distributed, dispersed SiO2 nanoparticles melt, reduce the degree of agglomeration.