【摘要】 通过将水溶性聚二甲基硅氧烷(PDMS)和聚乙二醇(PEG)引入到酸催化的TEOS溶胶体系,制备多孔二氧化硅膜,并实现了孔隙率的可靠性。水溶性PDMS的加入可有效防止二氧化硅膜的开裂,同时单层膜的厚度可达到700 nm,但当PDMS的量过高时,膜的开裂现象则会发生。实验发现,通过改变PDMS的量可实现膜的孔隙率在30%~48%可控,当引入PEG后膜的孔隙率则会进一步增加。通过采用纯氧环境替代空气环境退火,制备的二氧化硅膜孔隙率可达到80%。进一步研究了PDMS和PEG的含量对二氧化硅膜孔隙率的影响规律,并详细探讨其形成机制。更多还原

【Abstract】 SiO₂ films with controllable porosity were prepared using an acid-catalyzed sol-gel process from tetraethylorthosilicate（TEOS）-based solution in the presence of water-soluble polydimethylsiloxane（PDMS） and polyethylene glycol（PEG）.The incorporation of PDMS greatly inhibited the films from cracking,resulting in crack-free SiO₂ films with single-coating thickness of above 700 nm.However,it was found that the crack would happen in the films if the content of PDMS beyond a certain range.At the same time,the porosity of SiO₂ films changed in the range of 30%⁴8%as PDMS content varied.By introducing PEG to the hybrid system as a template agent,SiO₂ thick films showed a relatively higher porosity.In addition,when annealed under oxygen atmosphere instead of air condition,the porosity of SiO₂ films could be further increased to 80%.This paper investigated porosity of SiO₂ films dependence on the content of PDMS and PEG as well as processing conditions.Furthermore,the relative reasons were also discussed in detail.更多还原