当前位置：
X-MOL 学术
›
J. Phys. Chem. B
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Imaging Channel Connectivity in Nafion Using Electrostatic Force Microscopy
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2018-01-11 00:00:00 , DOI: 10.1021/acs.jpcb.7b08230 Austin M. Barnes 1 , Steven K. Buratto 1
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2018-01-11 00:00:00 , DOI: 10.1021/acs.jpcb.7b08230 Austin M. Barnes 1 , Steven K. Buratto 1
Affiliation
|
Channel connectivity is an important material property that is considered in making higher-performance proton-exchange membranes. Our group has previously demonstrated that nearly 50% of the aqueous surface domains in Nafion films do not have a connected path to the opposite side of the membrane. These so-called “dead-end” channels lead to a loss in the conductance efficiency of the membrane. Understanding the structure of these dead-end channels is an important step in improving the conductance of the membrane. Although conductive atomic force microscopy is able to provide insight into the connected channels, it does directly report on the dead-end channels. To address this, we use electrostatic force microscopy (EFM) to probe channel connectivity in a Nafion thin film (100–300 nm) under ambient conditions. EFM provided an image of the capacitive phase shift, which is influenced by surface charge, dielectric permittivity, and tip-sample geometry. We studied several individual channels and measured the quadratic dependence of the EFM signal with the bias voltage. Applying a simple parallel plate model allowed us to assign differences in the EFM signal to particular channel shapes: connected cylindrical channels, dead-end cylinder channels, and bottleneck channels.
中文翻译：
使用静电力显微镜在Nafion中成像通道连通性
通道连通性是制造高性能质子交换膜时要考虑的重要材料属性。我们的小组以前已经证明，Nafion膜中近50％的水表面域没有与膜相反侧的连接路径。这些所谓的“死角”通道导致膜的电导效率损失。了解这些死角通道的结构是改善膜电导的重要步骤。尽管导电原子力显微镜能够洞悉连接的通道，但它确实可以直接报告死端通道。为了解决这个问题，我们使用静电力显微镜（EFM）在环境条件下探测Nafion薄膜（100–300 nm）中的通道连通性。EFM提供了电容性相移的图像，该图像受表面电荷，介电常数和针尖样品几何形状的影响。我们研究了几个单独的通道，并测量了带有偏置电压的EFM信号的二次相关性。应用简单的平行板模型可以使EFM信号中的差异分配给特定的通道形状：连接的圆柱通道，死角圆柱通道和瓶颈通道。
更新日期：2018-01-11
中文翻译：
使用静电力显微镜在Nafion中成像通道连通性
通道连通性是制造高性能质子交换膜时要考虑的重要材料属性。我们的小组以前已经证明，Nafion膜中近50％的水表面域没有与膜相反侧的连接路径。这些所谓的“死角”通道导致膜的电导效率损失。了解这些死角通道的结构是改善膜电导的重要步骤。尽管导电原子力显微镜能够洞悉连接的通道，但它确实可以直接报告死端通道。为了解决这个问题，我们使用静电力显微镜（EFM）在环境条件下探测Nafion薄膜（100–300 nm）中的通道连通性。EFM提供了电容性相移的图像，该图像受表面电荷，介电常数和针尖样品几何形状的影响。我们研究了几个单独的通道，并测量了带有偏置电压的EFM信号的二次相关性。应用简单的平行板模型可以使EFM信号中的差异分配给特定的通道形状：连接的圆柱通道，死角圆柱通道和瓶颈通道。
京公网安备 11010802027423号