Peng C Q, Thio Y S, Gerhardt R A
School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA 30332, USA. School of Polymer Textile and Fiber Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA 30332, USA.
Nanotechnology. 2008 Dec 17;19(50):505603. doi: 10.1088/0957-4484/19/50/505603. Epub 2008 Nov 25.
A new salt-free approach was developed for fabricating conductive paper by layer-by-layer (LBL) assembly of conductive indium tin oxide (ITO) nanoparticles and polyelectrolytes onto wood fibers. Subsequent to the coating procedure, the fibers were manufactured into conductive paper using traditional paper making methods. The wood fibers were first coated with polyethyleneimine (PEI) and then LBL assembled with poly(sodium 4-styrenesulfonate) (PSS) and ITO for several bilayers. The surface charge intensity of both the ITO nanoparticles and the coated wood fibers were evaluated by measuring the zeta-potential of the nanoparticles and short fibers, respectively. The ITO nanoparticles were found to preferentially aggregate on defects on the fiber surfaces and formed interconnected paths, which led to the formation of conductive percolation paths throughout the whole paper. With ten bilayer coatings, the as-made paper was made DC conductive, and its sigma(dc) was measured to be 5.2 x 10(-6) S cm(-1) in the in-plane (IP) direction, while the conductivity was 1.9 x 10(-8) S cm(-1) in the through-the-thickness (TT) direction. The percolation phenomena in these LBL-assembled ITO-coated paper fibers was evaluated using scanning electron microscopy (SEM), current atomic force microscopy (I-AFM), and impedance measurements. The AC electrical properties are reported for frequencies ranging from 0.01 Hz to 1 MHz. A clear transition from insulating to conducting behavior is observed in the AC conductivity.
通过将导电氧化铟锡(ITO)纳米颗粒和聚电解质逐层(LBL)组装到木纤维上,开发了一种制备导电纸的无盐新方法。在涂覆过程之后,使用传统造纸方法将纤维制成导电纸。首先用聚乙烯亚胺(PEI)涂覆木纤维,然后与聚(4-苯乙烯磺酸钠)(PSS)和ITO进行LBL组装若干双层。分别通过测量纳米颗粒和短纤维的zeta电位来评估ITO纳米颗粒和涂覆木纤维的表面电荷强度。发现ITO纳米颗粒优先聚集在纤维表面的缺陷上并形成相互连接的路径,这导致在整个纸张中形成导电渗流路径。经过十次双层涂覆后,制成的纸张具有直流电导率,其面内(IP)方向的σ(dc)测量值为5.2×10^(-6) S cm^(-1),而在厚度方向(TT)的电导率为1.9×10^(-8) S cm^(-1)。使用扫描电子显微镜(SEM)、电流原子力显微镜(I-AFM)和阻抗测量来评估这些LBL组装的ITO涂层纸纤维中的渗流现象。报告了0.01 Hz至1 MHz频率范围内的交流电性能。在交流电导率中观察到从绝缘行为到导电行为的明显转变。