How to separate SWCNTs nanotubes through covalent methods and wall functionalization (PhD in nano-microelectronics) 

Researcher  and author: Dr.   (   Afshin Rashid)



Note: Separation of SWCNTs by covalent methods of  functionalizing the wall of carbon nanotubes has a cylindrical structure with SP2. And the hybridization of their carbon atoms is related to the inactivity  of the carbon nanotube exactly to  the orbital adaptation of π due to curvature. 

More activity of carbon nanotubes with smaller diameters than incremental reactions can be related to the intensification of spatial pressure. In addition, electrophilic selectivity reactions on SWCNTs are much easier to perform on metal nanotubes  because they have higher HOMO levels  Selectivity in wall functionalization reactions  Based on the knowledge of electron levels (DOS), it can be understood that this reaction plays an important role in the functionalization of the wall of carbon nanotubes.  Unlike semiconductor SWCNTs, metal nanotubes  have DOS electrons on  the Fermi surface, and the Fermi surface is the chemical potential of the  electrons. At zero temperature, this  surface contains electrons, but in semiconductors,  electrons are placed in the energy gap, in which  there are no permissible energy levels. Therefore, electrons are present to stabilize the charge transfer complex  formed by increasing the reactant to the  surface of the nanotube. Metal SWCNTs  can better stabilize the transducer and therefore  increase the reaction speed. This  may be due to the activity of metal SWCNTs  in electrophilic additive reactions  such as increasing dichlorocarbon and reactive carbon  (ondiazonium) and increasing hydrosilytation  Reactions of SWCNTs with diazonium ions  or salts have been performed so far  , and for the first time water-soluble aryl diazonium reactants  selectively work well with metal SWCNTs  .

Diazonium  salts  convert metal SWCNTs into semiconductors by forming an aryl covalent bond  on nanotubes  After  heat treatment, nanotubes with azonium groups,  metal nanotubes are recovered and aryl groups  are separated from the nanotube walls. The presence of the diazonium functional  group deactivates the  metal nanotubes in electrical equipment  because the covalent activation of the diazonium significantly disturbs  the optical and electrical properties of  metal SWCNTs. To optimize this reaction, more benzene salts are being  investigated  



Conclusion: 

Selective covalent functionalization of the walls of  semiconductor SWCNTs due to the dipole reaction of  increasing the cyclic azomethineylides  obtained from trialkylamine-N oxides with  polycyclic aromatics, causes the  amount of metal nanotubes in the bottom of the container to  increase. Theoretical studies show that  the bipolar ring increase is sensitive to the diameter and  chirality of nanotubes.

Researcher  and author: Dr.   (   Afshin Rashid)

PhD in Nano-Microelectronics