Nanofluidics in carbon nanotubes: Review
Authors: Aleksandr Noya, Hyung Gyu Parka,b, Francesco Fornasieroa, Jason K. Holta, Costas P. Grgoropoulosb, Olgica Bakajina,*
aMolecular biophysics and Functional Nanostructures Group, Chemistry, Materials and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA 94550, USA
bDepartment of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720-1740, USA
Summary
Carbon nanotubes (CNT) can be used in water treatment technology if used as membranes in seawater desalination technology. These can be used in limits of continuum hydrodynamics to study at nanofluidics scales. Navier stoke’s equation that describe the dynamic behavior of water on the macroscopic scale can be utilized. The properties and structure of CNT are unique. It is actually a rolled sheet of graphene in the form of a cylinder. It is shown in figure 1.
Figure 1. Rolling of graphene to form CNT
Water can flow inside the cylinder hole and ions will be blocked based on size. Molecular dynamics studies of gas transport in CNT showed that gas can flow three orders of magnitude smoothly in CNT pores with equal size to those of other currently used membranes. CNT membranes are available in polymeric CNT membranes as multi walled nanotubes consisting of many layers of graphenes wrapped over one another. Silicon nitride CNT membranes are also available with additional feature of withstanding high pressure and can be utilized in seawater desalination technologies.
Water flux is four to five orders of magnitude higher in these membranes. The simulations predict a flux of twelve water molecules per nm2 per ns. Nanofiltration, ion exclusion, and transport properties for CNT membranes favor the research of molecular dynamics using these CNT membranes.
Reviewer: Aamir Alaud-din
aamiralauddin@gist.ac.kr