Borodinov Nikolay, Ievlev Anton V, Carrillo Jan Michael, Collins Liam, Calamari Andrea, Mamak Marc, Mulcahy Patrick John, Sumpter Bobby G, Ovchinnikova Olga, Maksymovych Petro
The Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, UNITED STATES.
Oak Ridge National Laboratory, Oak Ridge, Tennessee, UNITED STATES.
Nanotechnology. 2018 Nov 1. doi: 10.1088/1361-6528/aaed54.
Triboelectric charging strongly affects the operation cycle and handling of materials and can be used to harvest mechanical energy through triboelectric nanogenerator set-up. Despite ubiquity of triboelectric effects, a lot of mechanisms surrounding the relevant phenomena remain to be understood. Continued progress will rely on the development of rapid and reliable methods to probe accumulation and dynamics of static charges. Here, we demonstrate in-situ quantification of tribological charging with nanoscale resolution, that is applicable to a wide range of dielectric systems. We apply this method to differentiate between strongly and weakly charging compositions of industrial grade polymers. The method highlights the complex phenomena of electrostatic discharge upon contact formation to pre-charged surfaces, and directly reveals the mobility of surface charges. Systematic characterization of commercial polyethylene terephthalate samples revealed the compositions with the best antistatic properties and provided an estimate of characteristic charge density up to 5×10<sup>-5</sup> C/m<sup>2</sup>. Large-scale molecular dynamics simulations were used to resolve atomistic level structural and dynamical details revealing enrichment of oxygen containing groups near the air-interface where electrostatic charges are likely to accumulate.
摩擦起电强烈影响材料的操作周期和处理过程，并可用于通过摩擦纳米发电机装置收集机械能。尽管摩擦电效应无处不在，但围绕相关现象的许多机制仍有待了解。持续的进展将依赖于开发快速可靠的方法来探测静电荷的积累和动态。在这里，我们展示了具有纳米级分辨率的摩擦起电的原位量化，该方法适用于广泛的介电系统。我们应用此方法区分工业级聚合物的强充电和弱充电成分。该方法突出了与预充电表面接触形成时静电放电的复杂现象，并直接揭示了表面电荷的迁移率。对商用聚对苯二甲酸乙二酯样品的系统表征揭示了具有最佳抗静电性能的成分，并提供了高达5×10⁻⁵ C/m² 的特征电荷密度估计值。大规模分子动力学模拟用于解析原子级别的结构和动力学细节，揭示了空气界面附近可能积累静电荷的含氧基团的富集情况。
