The behavior of liquids confined in carbon nanotubes has attracted considerable attention in recent years because of the interest in understanding the motion of highly confined liquids and the technological promise of using nanotubes for building novel nanofluidic devices. This presentation will give an overview of experimental studies of behavior of aqueous liquids inside carbon nanotubes. Open CNTs can be filled with simple liquids and colloidal solutions and used in devices transporting particulate fluids. Gold nanoparticles can be attached to inner tube surfaces to facilitate in situ surface enhanced Raman spectroscopy studies of the liquid composition and chemical interactions inside nanotubes. We have investigated the liquid/vapor distribution in nanotubes, the interaction of aqueous fluids with the tube walls, and the effect of hydrothermal treatment and annealing on the surface chemistry of carbon nanotubes. We observed a gradual reduction of the contact angle (hydrophobic-to-hydrophilic transition) with the increased coverage of a carbon wall by functional group. This effect may partially be attributed to the surface dipole moment that changes the orientation of the interfacial water. It has also been shown that the nature of the surface moieties is important, with hydrogen or hydroxyl inducing the formation of an extended hydrogen bond network between the water molecules and the doping sites on the nanotube walls, leading to enhanced wetting. Our results show that it is possible to tailor the wetting behavior of carbon nanotubes by controlling their surface structure and surface chemistry. Nanotube devices developed for fluidic studies can be used for in situ chemical studies using Raman spectroscopy or TEM. We have shown the possibility of in situ chemical experiments in closed hydrothermal nanotubes. The experimental observations of liquids inside nanotubes will be critically compared with theoretical predictions