Comparative studies on dispersing of multi-wall carbon nanotubes (CNTs) using two anionic surfactants (sodium dodecyl sulphate, SDS, and sodium dodecyl benzenosulfonate, SDBS) are presented. The studies were conducted on the surfactant concentrations that were close to the critical micelle concentration (CMC). The stability of CNTs suspensions obtained for surfactant solutions at concentrations lower than the CMC was investigated. It was also found that the surfactant structure has an influence on the diameter distribution of dispersed CNTs. (c) 2010 Elsevier Inc. All rights reserved.