서강대학교

초록

This thesis presents the investigation of the water transport phenomena of carbonaceous materials and thermal transport of biomembrane systems. Accordingly, the main part of this thesis can be divided into two parts: (1) water transport study and (2) thermal transport study. The study of water transport through nanotubes such as carbon nanotube (CNT) and boron nitride nanotube (BNNT) under deformed state is first presented in the first part of the thesis. In this part of the study, non-equilibrium molecular dynamics (NEMD) is used to study how the transport of water is affected when the CNTs and BNNTs are deformed. The results were then compared with that of the Pristine nanotubes. The main aim of this study is to get a better insight into the effect of deformation on water transport through these nanotubes rather than directly comparing the CNTs and BNNTs to one another. The deformations such as screw distortion, XY – distortion, and Z – distortion are investigated in this work. XY - distortion of value 2 shows a change from single-file water transport to near-Fickian diffusion. The XY – distortions of higher value show a notable negative effect on water transport when their distortion values get larger. These suggest that the degree of deformation plays a crucial role in water transport through deformed nanotubes. The Z – distortion of 2 showed discontinuous single-file chain formation inside the nanotubes. Similar phenomena are observed in both types of nanotubes but with the change in the magnitude of their effects. In the subsequent study, the effect of deformation induced by different defects along the length of carbon nanotube (CNT) on water transport is studied. The defects considered in this study are Stone-Wales defect, one atom vacancy or mono-vacancy, three types of two-atom vacancy or bi-vacancy, and four types of three atom vacancy or tri-vacancy. The deformation induced by the defects near the entrance and exit of the nanotubes has a preeminent effect on the water molecule’s movement through the nanotube due to significant deformation. This work is followed by our investigation on water and ion transport through the interstitial channel formed in-between the Carbon nanotubes, when they are arranged in a square array. The water transport through the interstitial channel of (8,8) CNT formed by heavily stacking them is studied in this part of the work. This work is carried out to study the water and ion transport through the interstitial channel with the minimum distance between the CNTs less than the equilibrium distance of the CNT. This study of the imaginary interstitial channel helps us to understand the dynamics of the water and ion transport through the interstitial channels that exist in the nanotube forest. In the final part of the thesis, a brief introduction to the molecular dynamics works carried out on the Stratum corneum and the thermal conductivity of bilayer simulations are given. This is followed by our simulation details and the discussion about the initial work towards the determination of the thermal conductivity of the human skin along with the shortcomings that are being faced and possible solutions are discussed.