Journal ArticleDOI
Aqueous Dispersions of Single-wall and Multiwall Carbon Nanotubes with Designed Amphiphilic Polycations
Vladimir A. Sinani,Muhammed K. Gheith,Alexander A. Yaroslavov,A. A. Rakhnyanskaya,Kai Sun,Arif A. Mamedov,James P. Wicksted,Nicholas A. Kotov +7 more
Reads0
Chats0
TLDR
It is suggested that the efficiency of macromolecular dispersion agents for NT solubilization correlates with the topological and electronic similarity of polymer-NT and NT-NT interactions in the nanotube bundles.Abstract:
Poor solubility of single-walled and multiwalled carbon nanotubes (NTs) in water and organic solvents presents a considerable challenge for their purification and applications. Macromolecules can be convenient solubilizing agents for NTs and a structural element of composite materials for them. Several block copolymers with different chemical functionalities of the side groups were tested for the preparation of aqueous NT dispersions. Poly(N-cetyl-4-vinylpyridinium bromide-co-N-ethyl-4-vinylpyridinium bromide-co-4-vinylpyridine) was found to form exceptionally stable NT dispersions. It is suggested that the efficiency of macromolecular dispersion agents for NT solubilization correlates with the topological and electronic similarity of polymer-NT and NT-NT interactions in the nanotube bundles. Raman spectroscopy and atomic force and transmission electron microcopies data indicate that the polycations are wrapped around NTs forming a uniform coating 1.0-1.5 nm thick. The ability to wind around the NT originates in the hydrophobic attraction of the polymer backbone to the graphene surface and topological matching. Tetraalkylammonium functional groups in the side chains of the macromolecule create a cloud of positive charge around NTs, which makes them hydrophilic. The prepared dispersions could facilitate the processing of the nanotubes into composites with high nanotube loading for electronic materials and sensing. Positive charge on their surface is particularly important for biological and biomedical applications because it strengthens interactions with negatively charged cell membranes. A high degree of spontaneous bundle separation afforded by the polymer coating can also be beneficial for NT sorting.read more
Citations
More filters
Journal ArticleDOI
Chemistry of Carbon Nanotubes
TL;DR: Department of Materials Science, University of Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Triesteadays.
Journal ArticleDOI
Comparative study of carbon nanotube dispersion using surfactants.
Richa Rastogi,Rahul Kaushal,S. K. Tripathi,Amit L. Sharma,Inderpreet Kaur,Lalit M. Bharadwaj +5 more
TL;DR: TEM analysis of a high-surfactant-concentration sample enables us to construct a plausible mechanism for decrease in CNT dispersion at high surfactant concentration, consistent with the UV-vis observations.
Journal ArticleDOI
Surface modifications for the effective dispersion of carbon nanotubes in solvents and polymers
Sangwon Kim,Taehoon Kim,Yern Seung Kim,Hongsoo Choi,Hyeong Jun Lim,Seung Jae Yang,Chong Rae Park +6 more
TL;DR: In this paper, a review of the state of the art in surface modifications and the resultant dispersibility of CNTs is provided, with particular emphasis on the quantitative characterization of surface modification and dispersions.
Journal ArticleDOI
Functionalized carbon nanotubes as emerging nanovectors for the delivery of therapeutics
TL;DR: The potential of f-CNT to deliver different types of therapeutic molecules is described and stable covalent bonds or supramolecular assemblies based on noncovalent interactions are described.
Journal ArticleDOI
PEG Branched Polymer for Functionalization of Nanomaterials with Ultralong Blood Circulation
Giuseppe Prencipe,Scott M. Tabakman,Kevin Welsher,Zhuang Liu,Andrew P. Goodwin,Li Zhang,Joy Henry,Hongjie Dai +7 more
TL;DR: In this paper, the synthesis of poly(ethylene glycol) grafted branched polymers for functionalization of various nanomaterials including carbon nanotubes, gold nanoparticles (NPs), and gold nanorods (NRs), affording high aqueous solubility and stability for these materials.