Wang Zhonglin, academician team of Beijing Institute of nano energy and system, Chinese Academy of Sciences: oil water solid interface contact electrification and its application in double signal chemical sensor

Since the advent of the friction Nanogenerator (Teng), researchers have developed a variety of friction nanogenerators Not only the friction electrification between solids can be used, but also the contact separation between liquids and solids can be used to build Teng In recent years, many different types of liquid-solid Teng have been developed for energy collection and biochemical sensing However, at present, only the contact electrification of liquid-solid Teng in a single liquid system has been studied, while the contact electrification process of Teng in "oil / water" multiphase system has not been studied The problem of "oil / water" interface is an important problem in the fields of chemistry, biology and engineering The existing research shows that the "oil / water" interface is often spontaneously charged, so how does the "oil / water" interface charge affect the contact electrification process of Teng? Recently, a single electrode mode of liquid-solid Teng has been developed by Wang Zhonglin of Georgia Institute of technology and Beijing Institute of nano energy and system of Chinese Academy of Sciences The process of contact electrification of oil-water-solid interface has been studied systematically, and its application prospect in self driving DOPA double signal detection has been shown (adv mater 2019, 1902793) Dr Jiang Peng and graduate student Zhang Lei are the co first authors of this paper, and the corresponding author is Academician Wang Zhonglin Introduction to Academician Wang Zhonglin, Academician Wang Zhonglin, director and chief scientist of Beijing Institute of nano energy and system, Chinese Academy of Sciences, Professor of director chair of life school of Georgia Institute of technology, Professor of life chair of Hightower Professor Wang is the winner of the Albert Einstein World Award of Science in 2019, Eni award the "Nobel Prize" for energy in 2018, Thomson Reuters citation laureate award in 2015, James C McGrady new material award in 2014 and Mrs medal in 2011 He is a foreign academician of the Chinese Academy of Sciences, the European Academy of Sciences and the Canadian Academy of engineering He is the founding editor and current editor of nano energy (latest if: 15.548), a famous international journal in the field of nano energy Jiang Peng, associate professor, School of pharmacy, Wuhan University In 2013, he received a doctor's degree from Wuhan University; in 2013-2015, he worked in the school of pharmacy of Wuhan University, and then remained in the school till now; in 2017-2019, he worked in the research group of Professor Wang Zhonglin of Georgia Institute of technology, and he was engaged in the research of visiting scholars The research direction is controllable preparation and application of fluorescent nanomaterials, and development of self driving drug delivery system and wearable health monitoring system based on friction Nanogenerator As the first author, he has published many papers in adv mater., chem Mater., biomaterials, nanoscale and other journals He presided over the programs of NSFC youth fund and China Postdoctoral Science Fund, and participated in the national science and technology major special project of "prevention and control of major infectious diseases such as AIDS and viral hepatitis" Cutting edge research achievements: oil water solid interface contact electrification and its application in double signal chemical sensing In recent years, many different types of liquid-solid Teng have been developed for energy collection, biochemical sensing and other fields However, at present, only the contact electrification of liquid-solid Teng in a single liquid system has been studied, while the contact electrification process of Teng in "oil / water" multiphase system has not been studied In order to study the contact electrification process of Teng in "oil / water" multiphase system, especially the influence of "oil / water" interface charge on Teng signal output, Academician Wang Zhonglin's research team developed a single electrode mode liquid-solid Teng based on polytetrafluoroethylene (PTFE), copper electrode and glass substrate Their research results show that when the liquid-solid Teng is inserted into the "oil / water" multiphase, two unique signals can be generated, one is from the contact electrification and electrostatic induction between the liquid (water or oil) and the PTFE film of Teng (V Teng and I Teng); the other is from the electrostatic induction of the copper electrode to the "oil / water" interface charge (Δ V interface and I interface ）, which only occurs when Teng passes through the "oil / water" interface Interestingly, when the polydopamine layer was modified on the PTFE and glass surface of Teng, the two signals showed the opposite trend, i.e the V Teng and I Teng signals decreased, while the "oil / water" interface signals Δ V interface and I interface increased Moreover, there is a good linear relationship between the values of iteng and I interface and the natural logarithm of dopamine concentration, which shows the application prospect of this Teng in self driving dopamine double signal detection First of all, the author made a single electrode mode liquid-solid Teng based on PTFE, copper electrode and glass substrate, and studied the electrical signal output of the Teng in a single oil phase and water phase respectively The results show that the electrical signal output is consistent with the generation mechanism of Teng (Figure 1) Figure 1 Electrical output of liquid-solid Teng in single-phase solution system (source: adv mater.) when liquid-solid Teng is inserted into the "oil / water" solution, in addition to generating electrical signals similar to that of single-phase solution system, a unique interface signal will be generated when Teng passes through the "oil / water" interface As shown in Figure 2, when the bottom of Teng passes through the "oil / water" interface, an obvious voltage drop will appear in the open circuit voltage curve, corresponding to which an obvious pulse peak will appear in the short circuit current signal By adjusting the pH value of aqueous solution and the concentration of electrolyte to change the interface potential, and measuring the change of interface signal, the results show that the change of interface signal is consistent with the change trend of interface potential The author speculates that the interface signal is from the electrostatic induction of copper electrode to the "oil / water" interface charge Fig 2 Electrical output of liquid-solid Teng in "oil / water" multiphase system (source: adv mater.) when the polydopamine layer is modified on the PTFE and glass surfaces of Teng, the two unique signals produced show the opposite trend of change, that is, the V Teng and I Teng signals decrease, while the interface signals Δ V interface and I interface Add (Figure 3) The increase of hydrophilicity on the surface of Teng caused by the polydopamine modified layer is considered to be the main reason for the change of interface signal In order to confirm this conjecture, the author treated the glass surface of Teng with plasma to increase the hydrophilicity of the surface of Teng The results show that the "oil / water" interface signal produced by the plasma treated Teng is obviously enhanced, which is consistent with the change trend of the modification of poly dopamine Fig 3 Effect of polydopamine modification on electrical output of liquid-solid Teng in "oil / water" multiphase system (source: adv mater.), after modified with 0-500 μ m dopamine, liquid-solid Teng in "oil / water" The two signals generated in the system show opposite change trends with the increase of dopamine concentration, and both of them are linear with the natural logarithm of dopamine concentration, showing the application prospect of Teng in dopamine double signal detection (Figure 4) Figure 4 Diagram of the relationship between short circuit current and dopamine concentration of liquid-solid Teng in "oil / water" system (source: adv mater.) in this work, the contact electrification process of liquid-solid Teng in "oil / water" multiphase system was studied for the first time, and the influence of "oil / water" interface charge on Teng electrical signal output was discussed Two kinds of unique signals generated by liquid-solid Teng in the "oil / water" system have developed a dual signal sensing platform for dopamine detection The author believes that this concept will contribute to the development of Teng in the field of "oil / water" interface research and chemical sensing Nowadays, people and scientific research have been paid more and more attention in the economic life China has ushered in the "node of science and technology explosion" Behind the progress of science and technology is the work of countless scientists In the field of chemistry, in the context of the pursuit of innovation driven, international cooperation has been strengthened, the influence of Returned Scholars in the field of R & D has become increasingly prominent, and many excellent research groups have emerged in China For this reason, CBG information adopts the 1 + X reporting mechanism CBG information website, chembeangoapp, chembeango official micro blog, CBG information wechat subscription number and other platforms jointly launch the column of "people and scientific research", approach the representative research groups in China, pay attention to their research, listen to their stories, record their demeanor, and explore their scientific research spirit.