Surface Coverage and Competitive Adsorption on Carbon Nanotubes

• Type: Article in International Scientific Journal
• Date: 2015

Authors

Ricardo M F Fernandes (Author) FCUP; Matat Buzaglo (Author) Other; Oren Regev (Author) Other; Eduardo F Marques (Author) FCUP; Istvan Furo (Author) Other

Journal

Title: Journal of Physical Chemistry C

Vol. 119

Pages: 22190-22197

ISSN: 1932-7447

Publisher: American Chemical Society

Indexing

ISI Web of Knowledge - 20 Citations

Scopus - 20 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-00G-P6R

DOI: 10.1021/acs.jpcc.5b06685

Abstract (EN): The binding strength of dispersants to the surface of carbon nanotubes is of crucial importance for the efficiency of the dispersion process and for potential applications, yet data are scarce on this subject. Here we present the results of diffusion NMR experiments in dispersions of single-walled carbon nanotubes (SWNTs) prepared by either the polymer Pluronics F127 or the protein bovine serum albumin (BSA). The experiments detect the amount of F127 molecules adsorbed onto the SWNT surface. This quantity is recorded (i) in F127-SWNT dispersions to which BSA molecules are added and (ii) in BSA-SWNT dispersions to which F127 molecules are added. The data clearly show that F127 replaces BSA adsorbed at the SWNT surface, while BSA leaves the adsorbed F127 coverage intact. Consequently, F127 binds to the nanotube surface more strongly than BSA. Hence, we provide a way to categorize dispersants by adsorption strength. We also provide evidence showing that the nanotubes dispersed by BSA form loose aggregates where a large part of the surface is not in direct contact with the surrounding liquid. The results are discussed in relation to previous findings in the literature.

Language: English

Type (Professor's evaluation): Scientific