this paper discusses different important gas permeation models such as “maxwell”, “bruggeman”, “lewis-neilson”, and “pal” models to predict “mixed matrix membranes” (mmms) performance. the main parameter considered and discussed is the permeability of hydrogen on carbon nanotubes (cnts)-mmm. for evaluation of the theoretical models, experimental data of permeability for h2 were compared to the ...

The discovery of lower dimensional forms of Carbon with unique mechanical and electronic properties has generated new possibilities in many areas of technology especially in nanotechnology. Recent emergence of some nanoscale device applications show how this potential is turning into a reality. Over the years, we have employed various levels of theory to study the structure and properties of ca...

The axial coefficients of thermal expansion (CTE) of various carbon nanotubes (CNTs), i.e., single-wall carbon nanotubes (SWCNTs), and some multi-wall carbon nanotubes (MWCNTs), were predicted using molecular dynamics (MDs) simulations. The effects of two parameters, i.e., temperature and the CNT diameter, on CTE were investigated extensively. For all SWCNTs and MWCNTs, the obtained results cle...

First-principles calculations based on density functional theory are carried out to investigate the Li storage capability of graphitic carbon nitride nanotubes. The porous nanotubes provide unprecedented opportunity for energy storage due to their uniform size of pores in the wall and doubly bonded nitrogen at the edges of the pore. The calculations predict that the Li atoms can easily access t...

Magnetic force microscope ( MFM ) is a powerful technique for mapping the magnetic force gradient above the sample surface. Herein, single-wall carbon nanotubes (SWCNT) were used to fabricate MFM probe by dielectrophoresis method which is a reproducible and cost-effective technique. The effect of induced voltage on the deposition manner of carbon nanotubes (CNT) on the atomic force microscope (...

Unusual physical properties of single-wall carbon nanotubes have started a search for similar tubular structures of other elements. In this paper, we present a theoretical analysis of single-wall nanotubes of silicon and group-III-V compounds. Starting from precursor graphenelike structures we investigated the stability, energetics, and electronic structure of zigzag and armchair tubes using th...

Single walled carbon nanotubes represent the future of structural aerospace vehicle systems due to their unparalleled strength characteristics and demonstrated multifunctionality. This multifunctionality rises from the CNT’s unique capabilities for both metallic and semiconducting electron transport, electron spin polarizability, and band gap modulation under strain. By incorporating the use of...

Internal functionalization of single-walled nanotubes is an attractive, yet difficult challenge in nanotube materials chemistry. Here we report single-walled metal oxide nanotubes with covalently bonded primary amine moieties on their inner wall, synthesized through a one-step approach. Conclusive molecular-level structural information on the amine-functionalized nanotubes is obtained through m...

Today’s business environment is causing utilities to examine methods to cut costs and to maximize revenues. Development of a comprehensive program for marketing and utilization* of coal combustion by-products (CCBPs) by a utility can generate additional revenue streams; reduce operating costs at plants; and defer capital costs of developing new waste disposal capacity. These factors can be opti...