Research On The Structure And Diffusion Of Water Molecules In Different Carbon Nanotubes(CNT)

Computer simulation technology is akind of new science and technology involving a greatmany subjects, which has been developed into the third largest scientific research technologywhile the other two are the theoretical research and experimental discovery. Moleculardynamics simulation is formed just based on the rapid development of computer simulationtechnology. It can provide a large number of reliable data forexperimental and theoretical studyand makes up the deficiency of the experiment and theory to make scientific research personnelmastertheworld’sadvancedresearchtechniques.Onbaseofthemoleculardynamicssimulationtechnology and the characteristic of carbon nanotube, mainly, this paper studied the structureand diffusion of water molecules in different carbon nanotubes at different temperatures, suchas150K,300K and450K. Through changing the diameter and temperature, we have simulatedthe structure of water molecules in carbon nanotubes with different diameters at differenttemperatures and calculated its related diffusion coefficient. In this article, we have adopted thearmchair carbon nanotube and the rigid SPC potential energy model of water molecular. In oursimulation, we found that the water molecules in (8,8) carbon nanotubes will form regularquadrangles at the temperature of300K. When the temperature is150K, water molecules arenot regularly structured and the arrayed order is lower. However, at the temperature of150Kand300K, the structures of water molecules in (9,9),(10,10),(11,11) carbon nanotubes arenot regular, and with the increase of temperature, their arrayed order will also reduce. With theincrease of carbon nanotubes diameter, corresponding peak value of radial distribution functionincreases gradually, but its position of wave peak is almost same. Therefore, when the diameterof carbon nanotubes increases, the distribution location of the water molecules will be morerandom, that is to say, the limited effect of water molecules will abate, and at this time most ofthe water molecules will distribute near the wall of carbon nanotubes.At the same temperature,the diffusion coefficient of water molecules will increase with the enlargement of theirdiameters, while, in the carbon nanotubes with same diameter, the diffusion coefficient of watermolecules also increased gradually with the increase of temperature.