Shin Keun-Young, Kim Minkyu, Lee James S, Jang Jyongsik
World Class University program of Chemical Convergence for Energy &Environment, School of Chemical and Biological Engineering, Seoul National University, 151-742, Korea.
A Photo-Electronic Hybrids Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Korea.
Sci Rep. 2015 Sep 4;5:13615. doi: 10.1038/srep13615.
Highly omnidirectional and frequency controllable carbon/polyaniline (C/PANI)-based, two- (2D) and three-dimensional (3D) monopole antennas were fabricated using screen-printing and a one-step, dimensionally confined hydrothermal strategy, respectively. Solvated C/PANI was synthesized by low-temperature interfacial polymerization, during which strong π-π interactions between graphene and the quinoid rings of PANI resulted in an expanded PANI conformation with enhanced crystallinity and improved mechanical and electrical properties. Compared to antennas composed of pristine carbon or PANI-based 2D monopole structures, 2D monopole antennas composed of this enhanced hybrid material were highly efficient and amenable to high-frequency, omnidirectional electromagnetic waves. The mean frequency of C/PANI fiber-based 3D monopole antennas could be controlled by simply cutting and stretching the antenna. These antennas attained high peak gain (3.60 dBi), high directivity (3.91 dBi) and radiation efficiency (92.12%) relative to 2D monopole antenna. These improvements were attributed the high packing density and aspect ratios of C/PANI fibers and the removal of the flexible substrate. This approach offers a valuable and promising tool for producing highly omnidirectional and frequency-controllable, carbon-based monopole antennas for use in wireless networking communications on industrial, scientific, and medical (ISM) bands.
分别采用丝网印刷和一步法、尺寸受限水热策略制备了基于碳/聚苯胺（C/PANI）的高度全向且频率可控的二维（2D）和三维（3D）单极天线。通过低温界面聚合合成了溶剂化的C/PANI，在此过程中，石墨烯与PANI的醌环之间强烈的π-π相互作用导致PANI构象扩展，结晶度提高，机械性能和电学性能得到改善。与由原始碳或基于PANI的二维单极结构组成的天线相比，由这种增强型混合材料组成的二维单极天线对高频全向电磁波具有高效性和适应性。基于C/PANI纤维的三维单极天线的平均频率可以通过简单地切割和拉伸天线来控制。相对于二维单极天线，这些天线具有较高的峰值增益（3.60 dBi）、较高的方向性（3.91 dBi）和辐射效率（92.12%）。这些改进归因于C/PANI纤维的高堆积密度和长径比以及柔性基板的去除。这种方法为生产用于工业、科学和医疗（ISM）频段无线网络通信的高度全向且频率可控的碳基单极天线提供了一种有价值且有前景的工具。
