三维有序多孔图案化SiC陶瓷的制备

结合毛细管微模塑技术、模板技术和先驱体转化技术, 以图案化聚二甲基硅氧烷(PDMS)弹性体为模具,以氧化硅凝胶小球为模板, 以液态聚碳硅烷(PCS)为先驱体, 经过氧化硅凝胶小球图案化模板的形成, 先驱体的渗入, 模板中先驱体的交联, 弹性模具的去除, 图案化先驱体的无机化和模板的去除, 制备了图案化多孔SiC 陶瓷.研究结果表明：所制备的图案化多孔陶瓷中, 图案的尺寸受图案化PDMS 弹性模具的控制, 球形孔的孔径可由氧化硅凝胶小球来调节. 图案化陶瓷中球形孔不仅三维有序排列, 而且由于模板中小球的相互接触形成的“窗 口”使球形孔三维贯通.

Preparation of Three-dimensionally Ordered Macroporous SiC Patterns

Three-dimensionally ordered macroporous(3DOM) SiC patterns were fabricated successfully on silicon substrate using polydimethylsiloxane (PDMS) elastometric stamp as mold, silica spheres as template, polycarbosilane (PCS) as preceramic polymer. The preparing process included the formation of patterned silica template, precursor infiltration into the template, curing of the precursor, demolding of PDMS mold, pyrolysis of the cured preceramic polymer pattern and etching of the silica template. The results show that the dimension of SiC pattern can be controlled by using PDMS molds with different dimensions and the pore diameter in the patterned porous ceramic can be tailored by using different sizes of silica sphere template. The pores pack together to be a three-dimensionally ordered structure and the small windows originated from the contacting points of the silica spheres endow the porous patterns with a three-dimensionally penetrated structure. The prepared macroporous ceramic patterns will be potentially applied in chemical harsh conditions due to the advanced properties of the SiC ceramic.