Molecular Dynamics Simulation And Experimental Study Of Nanochannel Conductivity

Nanostructures have a wide range of research prospects in many fields such as nanoscale separation,biochemical sensing,energy conversion,etc.due to their special characteristics different from macrostructures.When the size of the structure is reduced to the order of nanometers,the transmission characteristics of the substance will change,resulting in new physical phenomena different from the macro.The research and application of these new physical phenomena will expand the application field of nanofluidics,which is also in line with To meet the needs of the development of flow control technology.In this paper,molecular dynamics simulations and experiments are combined to study the electrical conductivity of single-wall carbon nanotubes,boron nitride nanotubes,and silicon nanochannels,and to explore the influencing factors of electrical conductivity in single-wall carbon nanotubes.The specific research contents are as follows:(1)The Nanotube Modeler was used to establish single-wall carbon nanotubes,boron nitride nanotubes and silicon nanochannel models,and the molecular dynamics simulation method was used to comparatively study the single-wall carbon nanotubes,boron nitride nanotubes and silicon nanochannels.Of conductivity.Simulation results show that single-walled carbon nanotubes have smaller wall adhesion resistance than boron nitride nanotubes and silicon nanochannels,and particles have higher electrical mobility in single-walled carbon nanotubes,so single-walled carbon nanotubes have More excellent electrical conductivity.(2)A further simulation study was conducted on the influencing factors of single-wall carbon nanotube conductivity.The simulation results show that when electrically neutral small-diameter single-walled carbon nanotubes(SWCNTs)enter the single-walled carbon nanotubes,the volume effect of SWCNT itself will block the movement of ions in the pipeline,resulting in the weakening of the ion current in the pipeline,but with the With the enhancement of the charged amount of SWCNT,more and more counter ions are attracted to the single-walled carbon nanotubes,which leads to the enhancement of the ionic current;by increasing the charge density of the wall surface of the pipeline and the electric field strength,it is found that the ionic current in the pipeline is nonlinear Change trend.In summary,the volume of SWCNT,the amount of charge,the charge density of the wall surface of the pipe,and the strength of the applied electric field affect the conductivity of the single-wall carbon nanotube.(3)Designed and built a four-probe test stand,studied the relationship between the conductivity of the nanochannel immersed in the sodium chloride solution and the concentration of the solution,and verified the diameter of the nanochannel.The experimental results show that at low solution concentrations,the conductance in the nanochannel increases linearly with the increase of the solution concentration.When the solution concentration reaches a certain value,the conductance in the nanochannel will increase due to the increasing Viscous resistance tends to be stable.