Surfactant-mediated dispersions of carbon nano-onions in aqueous solution

Abstract

In this work, we investigate the ability of different surfactants to form homogeneous and stable dispersions of carbon nano-onions (CNOs) in water via non-covalent interactions. For our purposes, we select three ionic surfactants, namely the cationic hexadecyltrimethylammonium bromide (CTAB) and the two anionic deoxycholic acid sodium salt (DCAS) and sodium dodecylbenzenesulfonate (SDBS). We examine the dispersing efficacy at dispersing CNOs and long-term stability by UV-vis absorption spectroscopy, dynamic light scattering and zeta-potential. Among the three surfactants, the anionic surfactants show the best ability to create stable CNO dispersions, with SDBS exhibiting superior efficacy. Our non-covalent strategy provides a valuable approach to enhance the solubility features while preserving the unique properties of CNOs.

Hyaluronic Acid-Conjugated Carbon Nanomaterials for Enhanced Tumour Targeting Ability

“…Covalent strategies have the advantage to introduce onto the CNM surface polar groups such as carboxylic acid groups, leading to a water soluble and stable derivatives [ 41 ]. However, this strategy leads to the disruption of the regular sp 2 -hybridized network, thus potentially affecting the intrinsic properties of the materials [ 42 , 43 ]. Therefore, in order to preserve the pristine surface of CNMs and thus their native physicochemical properties, non-covalent approaches are typically preferred [ 44 , 45 ].…”

Electrochemical Properties of Screen-Printed Carbon Nano-Onion Electrodes

“…Similar to other CNMs, pristine CNOs are highly hydrophobic and tend not to disperse well in organic and aqueous solvents due to aggregation, which can limit practical applications [ 24 , 31 ].…”

Biocompatible Dispersants for Carbon Nanomaterials

“…These dispersions were mainly used as a comparison to cellulose-based dispersions, which were found to be more effective. ACSs are capable of dispersing CNOs, as demonstrated by our group using hexadecyltrimethylammonium bromide (CTAB) and SDBS [48] (Table 4 (1)). This study also found that ACSs with negatively charged head groups are more effective at dispersing CNOs than their cationic counterparts.…”

“…The aqueous dispersion was found to be stable for six weeks, with a CNO: SDC mass ratio of 2:1 found to be ideal for surfactant efficiency. This CNO functionalisation was driven by hydrophobic interactions [48].…”

“…The Unlike cellulose-based surfactants, BAS has been tested with 0D CNMs. In 2020, Camisasca and Giordani non-covalently functionalised CNOs with sodium deoxycholate (SDC) [48] (Table 3 (1)). The dispersion was produced through a simple process involving sonication and mixing.…”