Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln , Lincoln, Nebraska 68588-0643, United States.
ACS Appl Mater Interfaces. 2013 Oct 23;5(20):9949-56. doi: 10.1021/am401864j. Epub 2013 Oct 1.
Fabrication of a percolating conductive device exhibiting "necklace-like morphology" is being reported utilizing a new route. This device was fabricated by exploiting the electrostatic self-assembly of citrate capped negatively charged Au nanoparticles (NPs) (60 nm diameter) over positively charged poly(allylamine hydrochloride) (PAH) fibrous scaffold and followed by synthesis of small Au NPs (∼10 nm) on the PAH surface. These 10 nm Au NPs were selectively synthesized over the PAH fiber surface using the surface catalyzed reduction of Au precursor (HAuCl4), leading to a continuous conducting network. This conducting device demonstrated a room temperature (RT) Coulomb-blockade characteristic, which is indicative of "single electron device". The deposition of Au NPs was directed by the diameter of PAH fibers and UV-irradiation exposure time used during the synthesis process. The average diameter of the fibers was in the ∼100-150 nm range, and the polyelectrolyte (PAH) was fabricated using the electrospinning technique. The size of these fibers was controlled by tuning the physical properties of PAH solution. Exposure of UV-irradiation for 25 min was sufficiently enough to deposit Au NPs in close proximity to each other. Longer exposure time (∼60 min) resulted in a device which showed linear Ohmic current-voltage (I-V) behavior. The present process is reproducible, efficient, and resulted in a structurally stable and robust device.
正在报道一种新方法来制造具有“项链状形态”的渗透导电装置。该装置是通过利用带负电荷的柠檬酸封端的金纳米粒子（NPs）（60nm 直径）在带正电荷的聚烯丙基盐酸盐（PAH）纤维支架上的静电自组装，然后在 PAH 表面合成小的 Au NPs（10nm）来制造的。这些 10nm Au NPs 是在 PAH 纤维表面上使用 Au 前体（HAuCl4）的表面催化还原选择性合成的，从而形成连续的导电网络。这种导电装置表现出室温（RT）库仑阻塞特性，表明为“单电子器件”。Au NPs 的沉积由 PAH 纤维的直径和合成过程中使用的 UV 照射暴露时间指导。纤维的平均直径在100-150nm 范围内，并且使用静电纺丝技术制造了聚电解质（PAH）。通过调整 PAH 溶液的物理性质来控制这些纤维的尺寸。暴露于 UV 辐射 25 分钟足以使 Au NPs 彼此紧密沉积。更长的暴露时间（~60 分钟）导致呈现线性欧姆电流-电压（I-V）行为的装置。本工艺具有重现性、高效性，并且得到了结构稳定且坚固的装置。
