| With the development of science and technology,the detection of the interface related parameters,such as the Interface charge and polarity and zeta potential,playing an important role in ships,machinery,biology,chemistry,and many other fields such as environmental pollutants detection.At present,there are many different methods of detection technology,but in order to adapt the different environment,developing a new and more convenient detection technology is still of great significance.This paper presents a kind of interface charge detection method on the basis of the charge transfer,analyzes its working principle and sets up the test system,realizes the measurement of the polarity and surface charge of the suspended droplet in the air.Specifically,the research contents of this paper mainly include:(1)Based on the principle of charge transfer,a method for detecting the surface charge of the suspended droplet is established and the influence factors are studied.Research results show that the measured current signal values only depend on the air-liquid interface charge of the suspended droplet in the air,and have no connection with the contacted electrolyte solution such as its volume,and type and the type of electrode.At the same time,the charge on the air-liquid interface of the drop increases with the increase of its surface area and air-liquid interface zeta potential.(2)The charge polarity of the air-liquid interface of different kinds of suspended droplets in the air is measured by using the surface charge measurement technique based on the charge transfer.Research results show that the air-liquid interface of water,CTAB and SDS solution is negatively charged.(3)The critical micelle concentration(CMC)of different surfactants in aqueous solution is detected.This paper uses different concentrations of surfactant suspended droplet to contact with the air-liquid interface of the electrolyte solution,and fits the two types of voltage pulse signal data respectively before and after the CMC.The CMC value is determined according to the intersection point of two fitting curves.The results show that CMC value of CTAB in aqueous solution is about 0.93mmol/L,and the CMC value of SDS in aqueous solution is about 7.81mmol/L,which is consistent with relevant parameters in the reports.A new interface charge detection technology of the suspended droplet in the air is presented in this paper.With the advantages of simple construction and quick detection,this method can be used to develop a novel and portable interface charge detection device. |
