Polyglycerol‐Derived Amphiphiles for the Solubilization of Single‐Walled Carbon Nanotubes in Water: A Structure–Property Study

Abstract

A series of nonionic amphiphiles derived from polyglycerol dendrons were studied for their ability to solubilize and isolate single-walled carbon nanotubes. The amphiphiles possessed differently sized polar head groups, hydrophobic tail units, and various aromatic and non-aromatic groups between the head and tail groups. Absorbance analysis revealed that amphiphiles with anchor groups derived from pyrene were far inferior to those that possessed simple linear aliphatic tail groups. Absorbance and near-infrared fluorescence analyses revealed a weak dependence on the dendron size of the head group, but a strong positive trend in suspended nanotube density and fluorescence intensity for amphiphiles with longer tail units. Variations in the moieties linking the head and tail groups led to a range of effects on the suspensions, with linkers imparting flexibility and a bent shape that gave improved performance overall. This was illustrated most dramatically by a pair of benzamide-containing amphiphiles, the para isomer of which showed evidence in the fluorescence data of increased nanotube aggregate formation when compared with the meta isomer. In addition, statistical AFM was used to illustrate more directly the microscopic differences between amphiphiles that were effective at nanotube bundle disruption and those that were not.

Chiral selectivity of polyglycerol-based amphiphiles incorporating different aromatic cores

“…The surfactant comprised a tail made of an alkyl chain, effective in debundling the tubes, and a polyglycerol head, to ensure water solubility. Modifying the head and tail morphology as well as including different aromatic fragments between head and tail, the amphiphiles displayed different properties, such as critical micellar concentration, nanotubes dispersing ability, long‐term stability, and so on . Small aromatic moieties, for example, pyrene, perylene, porphirine, can replace alkyl chain to bring tubes in solution but the higher adsorption energy makes the surfactant efficiently stick on the nanotubes and more difficult to be desorbed and removed.…”

Amphiphile replacement on carbon nanotube surfaces: Effect of aromatic groups on the interaction strength

“…A C 3 concentration 5 mmol/L almost , respectively. The image shows the PLE peaks of the (7,5) and (7,6) tube. After addition of C 3 the (7,5) peak is much stronger than the (7,6) peak.…”

“…2 Experimental setup and sample preparation 2.1 Compounds Figure 1 depicts the amphiphiles used in this work [6]. Similar to established surfactants like sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS) [1,3,4], the amphiphiles consist of an alkyl chain to adsorb onto the CNT surface.…”

Platinum on Nanodiamond: A Promising Prodrug Conjugated with Stealth Polyglycerol, Targeting Peptide and Acid‐Responsive Antitumor Drug

“…[ 19 ] In this context, it is proposed that polyglycerol (PG) [ 20 ] is a better alternative to PEG for biomedical applications of nanoparticle [ 21 ] in terms of biocompatibility, solubility and stability in physiological environment, and extensibility for further chemical derivatization. [ 19,29,30 ] To take advantage of the above characteristics of PG, PG-coating has been extensively applied quite recently to nanoparticles such as superparamagnetic iron oxide nanoparticle, [ 25,31,32 ] silica-encapsulated iron oxide nanoparticle, [ 33 ] nanodiamond (ND), [ 24,[34][35][36] zinc oxide nanoparticle, [ 26 ] carbon nanotubes, [37][38][39][40] quantum dots, [ 41 ] Fe@ Au nanoparticles [ 42 ] and mesoporous silica nanoparticles, [ 43 ] and even stem cell. [ 19,29,30 ] To take advantage of the above characteristics of PG, PG-coating has been extensively applied quite recently to nanoparticles such as superparamagnetic iron oxide nanoparticle, [ 25,31,32 ] silica-encapsulated iron oxide nanoparticle, [ 33 ] nanodiamond (ND), [ 24,[34][35][36] zinc oxide nanoparticle, [ 26 ] carbon nanotubes, [37][38][39][40] quantum dots, [ 41 ] Fe@ Au nanoparticles [ 42 ] and mesoporous silica nanoparticles, …”