LBL法在柔性基材表面制备单壁碳纳米管复合导电薄膜研究

Preparation of the Conductive Films of SWCNs on the Flexible Substrate through Layer-by-Layer Self-assembly Technique

本研究提出了采用层层自组装(LBL)法制备单壁碳纳米管(SWNTs)有机导电薄膜。首先采用过硫酸铵(APS)水溶液改善SWNTs的水分散性,使其表面含有大量的羟基(O-H)、羰基(C=O)和少量的羧基(COOH)基团。然后采用APS水溶液和受限光催化氧化法在BOPP薄膜和PET薄膜表面引入带有负电荷的硫酸根。以BOPP和PET为基材,以聚烯丙基胺盐(PAH)或聚二甲基二烯丙基氯化胺(PDDA)为聚阳离子,以APS氧化改性后的SWNTs为聚阴离子,依靠聚阴离子与聚阳离子间的静电吸引作用和氢键作用进行LBL组装,从而在PET和BOPP基材表面获得SWNTs的透明导电薄膜。同时,详细分析了影响SWNTs吸附量以及薄膜导电性的诸多因素,包括高分子种类(PAH和PDDA)和SWNTs改性程度。紫外可见光谱和方块电阻测试结果表明,将经10%APS水溶液70℃氧化处理4h的SWNTs配制成0.05mg/ml的水溶液,与0.5mmol/ml的PDDA水溶液进行LBL组装时,能获得最佳组装效果;LBL组装层数为20双层时,所得的SWNTs导电薄膜的电导率分别为4.57S/cm(PET基材表面)和2.12S/cm(BOPP基材表面)。

In this paper, The conductive films of single walled carbon nanotubes （SWNTs） on the flexible substrate through layerbylayer self-assembly（LBL） technique were investigated. First, SWNTs were modified with ammonium persulphate （APS） aqueous solution. A large number of hydroxyl （O=H）, carbonyl （C = O） and carboxyl （COOH） groups were introduced to the sidewall of modified SWNTs to improve the water dispersion. Then, APS aqueous solution and the method named confined photocatalytic oxidation were used for the introduction of negatively charged SO24 to the surface of biaxially oriented polypropylene film （BOPP） and polyethylene terephthalate film （PET）. Taking BOPP or PET as substrates, poly allylamine hydrochloride （PAIl） or poly dimethyldiallyl ammonium chloride （PDDA） as polycations, oxidized SWNTs by APS as polyanions, via the electrostatic attraction and hydrogen bonding between polyanions and polycations, the conductive films of SWNTs on PET or BOPP substrate surface could be formed by layer - by - layer self - assembly method.Meanwhile, the factors which influenced the adsorption of SWNTs and conductivity cluding polymer species （PAH and PDDA） and the modification extent of SWNTs of the UV LBL films were investigated, in vis spectra and sheet resistance were utilized to monitor the LBL process The LBL assemblies were realized with a stable 0.05mg/ml dispersion of SWNTs oxidized by 10% APS treatment at 70°C for 4h as component no. 1 and 0.5mmol/ml PDDA no. 2. After 20 bilayers deposition, the electrical conductivity of SWNTs thin films reached 4 2. 12S/cm on BOPP substrate aqueous 57S/cm solution as component on PET substrate and