This paper presents a detailed study that maps the surface charges and dopant distribution on the electropolymerized thin film of polyaniline–poly(styrenesulfonate) (PANI/PSS). The focus is on two distinct states of PANI/PSS: the fully doped emeraldine salt (ES/PSS) and the dedoped emeraldine base (EB/PSS). This investigation utilizes advanced frequency modulation electrostatic force microscopy (FM-EFM) and atomic force microscopy (AFM). The polymer film comprises polymer grains, and FM-EFM data suggest a non-uniform distribution of dopants on the grain surface, with a higher doped periphery than the core. Quantifying the charge at the periphery and core of ES/PSS and EB/PSS grains provides unique insight into the charge distribution within the polymer film. The charge density is estimated to be 10 times higher in the periphery region (∼120 μC/cm²) than in the core region (∼11 μC/cm²) and 100 times higher than EB/PSS (∼0.8 μC/cm²). We have directly observed the morphological changes of PANI/PSS from the ES/PSS state to the EB/PSS state using the AFM topographic profile. These findings provide a better understanding of the behavior of the charge/dopant distribution on the surface of the polymer films and pave the way for further research and development of PANI/PSS-based electronic devices.

中文翻译：

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使用先进的调频静电力显微镜对 PANI/PSS 薄膜中的电荷/掺杂剂分布进行直接成像


本文提出了一项详细的研究，绘制了聚苯胺-聚（苯乙烯磺酸）（PANI/PSS）电聚合薄膜上的表面电荷和掺杂剂分布。重点是 PANI/PSS 的两种不同状态：完全掺杂的翠绿亚胺盐 (ES/PSS) 和去掺杂的翠绿亚胺碱 (EB/PSS)。这项研究利用了先进的调频静电力显微镜 (FM-EFM) 和原子力显微镜 (AFM)。聚合物薄膜包含聚合物颗粒，FM-EFM 数据表明颗粒表面上的掺杂剂分布不均匀，外围的掺杂量高于核心。量化 ES/PSS 和 EB/PSS 颗粒外围和核心的电荷可以提供对聚合物薄膜内电荷分布的独特见解。外围区域的电荷密度 (∼120 μC/cm ² ) 估计比核心区域 (∼11 μC/cm ² ) 高 10 倍，比 EB/PSS (∼0.8 μC/cm ^{2 )}高 100 倍）。我们利用 AFM 形貌剖面直接观察到 PANI/PSS 从 ES/PSS 状态到 EB/PSS 状态的形态变化。这些发现提供了对聚合物薄膜表面电荷/掺杂剂分布行为的更好理解，并为进一步研究和开发基于PANI/PSS的电子器件铺平了道路。