Molecular Dynamics Simulations Of Carbon Nanotube Functionalization

The functionlization of carbon nanotube(CNT) has become the study hotspot recently.The CNT distribution in the nanocomposites or some solution environment has beenimproved by the functionlization, and provide the favorable condition for CNT to separateor purify.The study of functionlization of the CNT has gradually developed the method toprepare the specified functional CNT and composite. The functional CNT not only keepthe original special nature, but aslo put up the adorn radical activity in the reaction, andprovide the possibility for CNT to disperse, assemble and surface reaction, and thereforeto arouse the enormous interest of the scientists, and made the CNT more active in thestage of the nanophase materials.The article studied the sub atomic structure, interface action and heat function of chiralmolecular nonfunctionlization of the CNT by the molecular simulation, the main contentcontains the three section:1. The simulated chiral dendrimers (G0,G1 and G2) were binaphthyl cored-basedchiral phenylene dendrimers and single wall carbon nanotube(SWNT), the the modelswere constructed and optimized. The interaction between the chiral dendrimers andSWNT were studied, the conclusion was obtained by the energy analysis, temperatureeffect and RDF analysis: strong nonbond energy was exist, which related to the differentphenylene rings of G0-G2, the interaction made the binding energy of SWNT anddendrimers increased, but the interaction of SWNT and G1 and G2 strongly decreased asthe temperature increase. By the analysis the RDF of the three composite, we know thatSWNT can effectively jion with G0-G2 by nonbond interaction. Theoreticallydemonstrated the possibility of nocovalent functionalization of SWNT with chiraldendrimers, which can be used to produce nanocomposites such as highly sensitive aswell as enantioselective fluorescent sensors.2. Molecular dynamic simulation was used to the noncovalent functionlization ofSWNT with the tryptophan, study their interaction, theoretically demonstrated thepossibility of nocovalent functionalization of SWNT. Calculate the two's interaction in200ps with molecular dynamics, and find that the whole simulation process was that theenergy gradually decreased and finally got the stable stucture,aslo demonstrated thatSWNT and tryptophan in the composite could combined with interaction, and the interaction was mainly theπ–πinteraction, beside the vdw and electrostatic, and thecomposite has the lowest interaction at 498K, the conposite absolutely stable.3. Select the tyrosine to nonfunctionlize SWNT, calculate the two componets'interaction with the molecular dynamics, the results was that the composites'energygradually decreased to get the stable structure in the process, aslo demonstrated they couldinteract with each other. By the analysis of the energy evolution from 298K to 598K in thecomposite, find that the interaction were all negative at different temperature,denmonstrated that the two have the stronginteraction, which was mainly theπ–πinteraction, the vdw and electrostatic, the composite has absolutely stable structure at373K. And finally, by the comparation of the simulated results, we find that the compositeof SWNT and the tryptophan has lower interaction to gain more stable structure, and theinteraction mainly caused by the vdw and electrostatic. We respected to use the chiralfunction of tryptophan and tyrosine join with SWNT's special function, may be used in thesepration, recognization and mesurement of the chiral substance, which was important todevelop SWNT in the seperation study.