Structure of Carbon Nanotube-dendrimer composite

TL;DR

This study uses all-atom molecular dynamics simulations to explore how different dendrimers, especially PAMAM, interact with carbon nanotubes, revealing their wrapping behavior, binding strength, and potential to improve nanotube solubility.

Contribution

It provides detailed microscopic insights into dendrimer-nanotube interactions, highlighting differences between PAMAM and PETIM dendrimers and their potential for dispersion applications.

Findings

PAMAM dendrimers wrap compactly around nanotubes.

Non-protonated dendrimers exhibit more wrapping than protonated ones.

PAMAM shows stronger interaction with nanotubes compared to PETIM.

Abstract

Using all atomistic molecular dynamics (MD) simulations we report the microscopic picture of the nanotube-dendrimer complex for PAMAM dendrimer of generation 2 to 4 and carbon nanotube of chirality (6,5). We find compact wrapping conformations of dendrimer onto the nanotube surface for all the three generations of PAMAM dendrimer. The degree of wrapping is more for non-protonated dendrimer compared to the protonated dendrimer. For comparison we also study the interaction of another dendrimer, poly(propyl ether imine) (PETIM), with nanotube and show that PAMAM dendrimer interacts strongly as compared to PETIM dendrimer as is evident from the distance of closest approach as well as the number of close contacts between the nanotube and dendrimer. We also calculate the binding energy between the nanotube and the dendrimer using MM/PBSA methods and attribute the strong binding to the charge transfer between them. Dendrimer wrapping on CNT will make it soluble and can act as an efficient dispersing agent for nanotube.