氨基改性边缘氧化的石墨烯复合PEDOT∶PSS透明热电薄膜的制备与性能研究

Preparation and properties of amino modified edge oxidized graphene composite PEDOT∶PSS transparent thermoelectric film

通过高锰酸钾和浓硫酸氧化石墨边缘,加入双氧水与氨水混合溶液进行剥层,得到边缘氧化石墨烯(EGO)。使用乙二胺对EGO进行氨基化改性,得到氨基改性的边缘氧化石墨烯(NEGO)。将NEGO与聚3,4-二氧乙烯噻吩∶聚苯乙烯磺酸(PEDOT∶PSS)水分散液混合,在聚对苯二甲酸乙二醇酯(PET)基膜上涂膜,制备NEGO/PEDOT∶PSS透明热电薄膜。通过傅里叶变换红外光谱仪、显微拉曼成像光谱仪、X射线衍射仪,自制塞贝克系数测试装置、四探针测试仪等对样品进行表征。结果表明制备的NEGO能在PEDOT∶PSS酸性分散液中稳定分散,与PEDOT∶PSS有着强烈的π-π共轭作用,NEGO掺杂量为3%(质量分数)时,热电薄膜的热电效率最高,功率因子达到0.99μW/(m·K^(2)),薄膜透光度大于80%。

The graphite edges were oxidized by potassium permanganate and concentrated sulfuric acid,and then exfoliated by adding a mixed solution of hydrogen peroxide and ammonia to prepare edge graphene oxide(EGO).Next,EGO was modified by ethylenediamine to obtain amino-modified marginal graphene oxide(NEGO).After that,NEGO was mixed with poly 3,4-dioxyethylene thiophene:polystyrene sulfonic acid(PEDOT∶PSS)aqueous dispersion,and coated on a polyethylene terephthalate(PET)base film to prepare NEGO/PEDOT∶PSS composite thermoelectric film.The samples were characterized by Fourier transform infrared spectrometer,Raman spectrometer,X-ray diffractometer,self-made Seebeck coefficient tester and four-probe tester etc.The results showed that the prepared NEGO could be stably dispersed in the PEDOT∶PSS acid dispersion and had a strongπ-πconjugation effect with PEDOT∶PSS.When the NEGO doping amount was 3wt%,the obtained film had the highest thermoelectric efficiency,its power factor reached 0.99μW/(m·K^(2)),and the transmittance of the film was higher than 80%.