Sciences of contact-electrification and its impact to chemistry
主讲人：WANG Zhong Lin
Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, China.
时间：2023年12月20日 15：00-17：00
地点：东区会议中心学术报告厅
项目摘要
Although contact electrification (triboelecrification) (CE) has been documented since 2600 years ago, its scientific understanding remains inconclusive, unclear and un-unified. This paper reviews the updated progress for studying the fundamental mechanism of CE using Kelvin probe force microscopy for solid-solid cases. Our conclusion is that electron transfer is the dominant mechanism for CE between solid-solid pairs. Electron transfer occurs only when the interatomic distance between the two materials is shorter than the normal bonding length (typically ~0.2 nm) in the region of repulsive forces. A strong electron cloud overlap (or wave function overlap) between the two atoms/molecules in the repulsive region leads to electron transition between the atoms/molecules, owing to the reduced interatomic potential barrier. The role played by contact/friction force is to induce strong overlap between the electron clouds (or wave function in physics, bonding in chemistry). The electrostatic charges on the surfaces can be released from the surface by electron thermionic emission and/or photon excitation, so these electrostatic charges may not remain on the surface if sample temperature is higher than ~300-400 0C.
The electron transfer model could be extended to liquid-solid, liquid-gas and even liquid-liquid cases. As for the liquid-solid case, molecules in the liquid would have electron cloud overlap with the atoms on the solid surface at the very first contact with a virginal solid surface, and electron transfer is required in order to create the first layer of electrostatic charges on the solid surface. This step only occurs for the very first contact of the liquid with the solid. Then, ion transfer is the second step and is the dominant process thereafter, which is a redistribution of the ions in solution considering electrostatic interactions with the charged solid surface. This is proposed as a two-step formation process of the electric double layer (EDL) at the liquid-solid interface.
主讲人简介
王中林院士，中国科学院北京纳米能源与系统研究所所长，中国科学院大学讲席教授。王教授是2023年全球能源奖(Global Energy Prize)， 2019年爱因斯坦世界科学奖(Albert Einstein World Award of Science)、2018年埃尼奖 (ENI award – The “Nobel prize”for Energy，能源界最高奖)、与2015年汤森路透引文桂冠奖等四大国际大奖获得者。他是美国物理学会James C. McGroddy新材料奖、2013年中华人民共和国国际科技合作奖，和2011年美国材料学会奖章(MRS Medal)等国际奖得主。他是中科院外籍院士、美国国家发明家科学院院士，欧洲科学院院士、欧洲工程院院士、加拿大工程院国际院士，韩国科学与技术院外籍院士、国际纳米能源领域著名刊物 Nano Energy的创刊主编和现任主编。
王院士是纳米能源研究领域的奠基人。他发展了基于纳米能源的高熵能源与新时代能源体系；开创了基于纳米发电机的自驱动系统及蓝色能源宏大领域，与基于压电电子学与压电光电子学效应的第三代半导体的崭新领域；建立了压电电子学、压电光电子学与摩擦电子学学科；发现了六个新物理效应：压电电子学效应、压电光电子学效应、压电光子学效应、摩擦伏特效应、热释光电子效应和交流光伏效应。他是全球全科顶尖科学家终身影响力排名前二，2019-2022单年影响力连续排名第一，材料与工程终身排名第一，在Nature，Science及其子刊上发表了110篇文章，文章总引用超43万次，h指数超310。他拥有二百多项发明专利，并亲自发起和创建了八家公司。