Potentiometric Study of Carbon Nanotube/Surfactant Interactions by Ion-Selective Electrodes. Driving Forces in the Adsorption and Dispersion Processes

Abstract

The interaction (adsorption process) of commercial ionic surfactants with non-functionalized and functionalized carbon nanotubes (CNTs) has been studied by potentiometric measurements based on the use of ion-selective electrodes. The goal of this work was to investigate the role of the CNTs’ charge and structure in the CNT/surfactant interactions. Non-functionalized single- (SWCNT) and multi-walled carbon nanotubes (MWCNT), and amine functionalized SWCNT were used. The influence of the surfactant architecture on the CNT/surfactant interactions was also studied. Surfactants with different charge and hydrophobic tail length (sodium dodecyl sulfate (SDS), octyltrimethyl ammonium bromide (OTAB), dodecyltrimethyl ammonium bromide (DoTAB) and hexadecyltrimethyl ammonium bromide (CTAB)) were studied. According to the results, the adsorption process shows a cooperative character, with the hydrophobic interaction contribution playing a key role. This is made evident by the correlation between the free surfactant concentration (at a fixed [CNT]) and the critical micellar concentration, cmc, found for all the CNTs and surfactants investigated. The electrostatic interactions mainly determine the CNT dispersion, although hydrophobic interactions also contribute to this process.

Environmental risks and toxicity of surfactants: overview of analysis, assessment, and remediation techniques

“…Recent advances in the ion-selective potentiometric analysis are based on modification with carbon nanotubes and nanomaterials. Special review articles have been devoted to these developments in the last 2 decades (Dimeski et al 2010;Jozanović et al 2019;Menger et al 2021;Ostos et al 2021).…”

Effects of sodium dodecyl benzene sulfonate on the combined toxicity of multi-walled carbon nanotubes and cadmium to Escherichia coli

“…S4 and S6). The hydrophobic interaction and electrostatic attraction resulted in the adsorption of surfactants on MWCNTs (Zhong et al, 2013;Lopez-Lopez et al, 2016;Ostos et al, 2021). The hydrophobic interaction between S-MWCNTs and SDBS was the strongest, which resulted in the highest adsorption capacity of SDBS on S-MWCNTs.…”

The Physical Chemistry and Chemical Physics (PCCP) Section of the International Journal of Molecular Sciences in Its Publications: The First 300 Thematic Articles in the First 3 Years

“…Articles [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ] can be attributed to the first of the thematic areas indicated in the PCCP Section, and the distribution of these articles into the above categories is presented in Table 2 . As it can be seen, of the four types of articles established by the magazine’s standards ( Reviews , Originals, Communications , Editorials ), only the first two are presented here.…”

“…These particles are also reviewed in [ 21 ], which provides the latest information on mesoporous silica nanoparticles (MSN), functionalized to target subcellular compartments, with an emphasis on the cytoplasm, mitochondria, and nucleus, which are now widely used as drug carriers due to their unique physical–chemical characteristics. To some extent, this also includes the other two review articles from this thematic area, namely [ 9 , 22 ], the first of which addresses the problem of the existence of the so-called exclusion zones (EZ), namely, a layer of water in which plastic microspheres are repelled from hydrophilic surfaces, the second of which explores the systematization of processes known in the literature for obtaining microparticles of insoluble β-glucans from spent brewer’s yeast and gives an idea of how a by-product of brewing can be converted into potential food items. To the specifics of intermolecular interactions in systems containing surfactants, publications [ 4 , 12 , 18 ] were devoted; intermolecular interactions, in which the formation of hydrogen bonds plays a key role, are discussed to varying degrees in [ 5 , 23 , 25 ].…”