Gold nanoparticles were selectively attached to chemically functionalized surface sites on nitrogen-doped carbon (CN x ) nanotubes. A cationic polyelectrolyte was adsorbed on the surface of the nanotubes by electrostatic interaction between carboxyl groups on the chemically oxidized nanotube surface and polyelectrolyte chains. Negatively charged 10 nm gold nanoparticles from a gold colloid suspension were subsequently anchored to the surface of the nanotubes through the electrostatic interaction between the polyelectrolyte and the nanoparticles. This approach provides an efficient method to attach other nanostructures to carbon nanotubes and can be used as an illustrative detection of the functional groups on carbon nanotube surfaces.

The ability to modify the surface of carbon nanotubes is of crucial importance for their utilization in different applications. In the present paper we report on the chemical modification of multiwalled carbon nanotubes (MWNT) by means of epoxide-based functional groups. MWNT were first carboxylated along their walls. This was followed by further reactions to attach di-glycidyl ether of bisphenol-A-based epoxide resin. The behavior of the modified nanotubes in various solvents was altered due to the chemical changes, and analytical techniques were utilized to detect the chemical attachments. The implications of the surface modification achieved are discussed primarily in terms of nanotube−polymer composite applications.

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Battery safety is critical for many applications including portable electronics, hybrid and electric vehicles, and grid storage. For lithium ion batteries, the conventional polymer based separator is unstable at 120 °C and above. In this research, we have developed a pure aluminum oxide nanowire based separator; this separator does not contain any polymer additives or binders; additionally, it is a bendable ceramic. The physical and electrochemical properties of the separator are investigated. The separator has a pore size of about 100 nm, and it shows excellent electrochemical properties under both room and high temperatures. At room temperature, the ceramic separator shows a higher rate capability compared to the conventional Celgard 2500 separator and life cycle performance does not show any degradation. At 120 °C, the cell with the ceramic separator showed a much better cycle performance than the conventional Celgard 2500 separator. Therefore, we believe that this research is really an exciting scientific breakthrough for ceramic separators and lithium ion batteries and could be potentially used in the next generation lithium ion batteries requiring high safety and reliability.