反胶束刻蚀法制备具有多孔结构的高导电聚(3,4-二氧乙烯噻吩)纳米薄膜

Fabrication of Porous and Conductive Poly(3,4-ethylenedioxythiophene)Nanofilm Through Reverse Micellar Etching Method

图案化导电薄膜在传感器领域有着非常广泛的应用。本文中在亲水处理的二氧化硅晶片基板上涂覆氯化铁/PEG-PPG-PEG嵌段共聚物/正丁醇的混合溶液,形成含有反胶束纳米球的氧化剂薄膜;以3,4-二氧乙烯噻吩单体分子为气相,通过气相沉积的方式得到具有纳米孔图案的多孔性聚(3,4-二氧乙烯噻吩)(PEDOT)薄膜。利用偏光显微镜、扫描电镜研究PEDOT薄膜纳米多孔结构的形成机制,并采用四点探针测试图案化薄膜的电性能。结果表明,PEG-PPG-PEG嵌段共聚物浓度和环境湿度的增加都有助于孔的生成。在PEG-PPG-PEG质量分数0.2%和处理基片的环境湿度为60%的条件下,制备的导电图案化薄膜的电导率可达到83.68S/cm,其平均孔径可达到248nm。通过反胶束刻蚀法对导电薄膜进行图案化处理,相对于其他图案化方法操作简单、成本较低,在生物传感器、气体传感器等领域有巨大的应用潜力。

Patterned conductive thin films have been widely used in the field of sensors.In this study,patterned poly(3,4-ethylenedioxythiophene)(PEDOT)nanofilm with nanoporous is achieved by reverse micellar etching.Firstly,the surface of silicon dioxide wafer substrate was hydrophilized,and a quite mount of water molecules were absorbed on the surface of the substrate at a certain humidity.Then,the mixed solution of ferric chloride/PEG-PPG-PEG block copolymer/n-butanol was coated on the surface of the substrate to form an oxidant film containing reverse micellar nanospheres.Porous PEDOT films were obtained through vapor phase polymerization method(VPP).Optical microscope and scanning electron microscope were used to verify the formation mechanism of nanopore pattern,and four-point probe was used to test the electrical properties of patterned thin films.A series of conditions affecting the pattern formation,such as the concentration of PEG-PPG-PEG block copolymer and ambient humidity of silica wafer processing,were studied.The results of this study show that the increase of PEG-PPG-PEG block copolymer concentration and ambient humidity contribute to pore formation.The highest conductivity of the conductive patterned film can reach 83.68 S/cm,while its hole aperture is around 248 nm.Reverse micelle etching method can greatly increase the specific surface area of PEDOT film.Compared with other patterning methods,the method is simple in operation and low in cost,and has great application potential in biosensor,gas sensor and other fields.