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利用溶胶-凝胶法制备出纳米SiO2空心球结构材料,并采用煅烧或萃取的方法除去表面活性剂,对各种样品的表面形貌、结构特征以及表面硅羟基总数等进行了研究。结果表明:原始样品分散均匀,具有统一的尺寸大小以及丰富的表面硅羟基。此外,煅烧能更有效的除去表面活性剂,而萃取能更多的保留硅墙壁上的Si-CH3。煅烧虽然会导致部分微孔的塌陷,但是会更大的提高样品的比表面积。同时,由于共生羟基向孤立羟基的转化以及Si-CH3在高温下的氧化反应而拥有了较之萃取样品更多的表面硅羟基。
The hollow nanostructured hollow spheres were prepared by sol-gel method. The surface active agents were removed by calcination or extraction. The surface morphology, structural characteristics and the total number of silanol groups of the samples were studied. The results showed that the original samples were uniformly dispersed, with uniform size and abundant surface silanols. In addition, calcination removes the surfactant more efficiently, and the extraction retains more Si-CH3 on the silicon walls. Although calcining can lead to the collapse of some micropores, it will greatly increase the specific surface area of the sample. At the same time, it possesses more surface silanol groups than the extracted samples due to the conversion of symbiotic hydroxyl groups to isolated hydroxyl groups and the oxidation of Si-CH3 at high temperatures.