Flows in one-dimensional and two-dimensional carbon nanochannels: Fast and curious
- PDF / 583,991 Bytes
- 5 Pages / 580.752 x 783 pts Page_size
- 41 Downloads / 167 Views
Introduction Carbon is a “go-to” material for applications in the fields of molecular separations via adsorption, as electrode materials in batteries, and for strong composite materials. From a fundamental point of view, carbon can form different types of hybridized bonds (sp, sp2, and sp3), which underpin the formation of a wide variety of allotropes, including diamond, graphite, fullerenes, and nanotubes. Graphene, an individual carbon layer of monoatomic thickness, has also been isolated and its properties evaluated. While wide-ranging experimental and theoretical work has been undertaken on the electronic, electrochemical, and mechanical properties of carbon allotropes, understanding and exploiting the molecular- and fluid-transport properties within the confines of the nanoscale afforded by the one-dimensional (1D) structure of carbon nanotubes (CNTs) and the twodimensional (2D) planar structure of graphene is a new frontier. Carbon is special from the fluidic perspective, and the discovery of new nanofluidic behavior associated with graphitic materials has triggered explosive growth in this field. Much, however, remains to be discovered and understood. There is potential in these discoveries to lead to disruptive new technologies for water purification, desalination, and energy generation and storage. In this article, we focus primarily on experimental
studies of carbon nanostructures. Other articles in this issue review the theoretical studies undertaken in this field.
One-dimensional carbon channels Molecular simulations have played a key role in the development of this field. In 2001, Hummer et al. investigated the water-conduction properties of single-walled CNTs and reported extraordinary water speeds in CNTs of around 90 cm s–1 under moderate pressure drops, comparable to aquaporin protein channels, an extremely performing biological water filter.1 Around the same time, Johnson et al., using molecular dynamics (MD) simulations, reported orders of magnitude larger transport diffusivities of gases inside the smooth interiors of CNTs, compared to what was expected by classical hydrodynamics.2 It was interesting to observe that two different states of matter—liquids and gases—with different molecular densities, showed similar behavior during flow through CNTs. Several years later, experimental studies were undertaken when methods were developed to fabricate membranes composed of a large ensemble of vertically aligned CNTs. Carbon nanotubes were grown in a vertical array and the space between these tubes were filled with a polymer3 or ceramic.4 This consolidated film was released from the substrate to
Mainak Majumder, Monash University, Australia; [email protected] Alessandro Siria, Laboratoire de Physique Statistique de l’Ecole Normale Supérieure, France; [email protected] Lydéric Bocquet, École Normale Supérieure, France; [email protected] doi:10.1557/mrs.2017.62
278
• VOLUME 42 • APRIL 2017 • www.mrs.org/bulletin © 2017 Downloaded MRS fromBULLETIN https:/www.cambridge.org/core. Kainan Unive
Data Loading...
