Noncovalent Nonspecific Functionalization and Solubilization of Multi‐Walled Carbon Nanotubes at High Concentrations with a Hyperbranched Polyethylene

Abstract

A hyperbranched polyethylene (HBPE) is employed herein for noncovalent nonspecific functionalization and solubilization of multi‐walled carbon nanotubes (MWCNTs) in organic solvents. Though constructed solely from ethylene without any specific functionality, this unique hyperbranched polymer has been found to effectively solubilize MWCNTs at surprisingly high concentrations (up to 1 235 mg · L−1) in organic solvents such as chloroform and THF. These solubilities are comparable to and even better than the reported best values obtained through noncovalent specific functionalization with conjugated polymers capable of forming specific π‐π interaction with nanotubes in organic solvents. TEM and XRD results confirm that the nanotubes are completely exfoliated and debundled/de‐entangled upon functionalization with HBPE.

A novel ferrocene-containing polymer based dispersant for noncovalent dispersion of multi-walled carbon nanotubes in chloroform

“…The concentration of the MWCNTs in CHCl 3 was determined by TGA method [22]. Typically, 0. with specially designed polymers such as pyrene capped polystyrene (0.25 mg/mL) [23], foldamer oligo(mphenylene ethynylene)s (0.1 mg/mL) [24] and linear conjugated poly(arylene ethynylene)s (0.94 mg/mL) [25].…”

“…-sonication at 20 o C for 60 min and then left undisturbed overnight. The stableMWCNTs/PFcEMA dispersion was obtained after filtration through glass wool (0.1 g) by using 5.0 mL syringe[22]. The stable dispersion was used for lateral analysis after proper dilution.…”

Synthesis of Heterobifunctional Hyperbranched Polyethylenes Tethered with Dual Acryloyl and 2‐Bromoisobutyryl Functionalities via One‐Pot Chain‐Walking Terpolymerization

“…[8] We have recently studied the potential applications of these hyperbranched polyethylenes as viscosity modifiers in lubricant formulation, [9] as processing aids in polymer extrusion processing, [10] and as a unique functionalization agent for solubilization of carbon nanotubes in organic solvents. [11] Some unique properties and outstanding performances have been discovered in these specialty applications. [9][10][11][12] To broaden the application scope of hyperbranched polyethylenes as functional materials, various functionalities have also been introduced onto the hyperbranched polymer architecture by chain walking copolymerization of ethylene with functional monomers, primarily acrylates and 1-alkenes containing special functional groups.…”

“…[11] Some unique properties and outstanding performances have been discovered in these specialty applications. [9][10][11][12] To broaden the application scope of hyperbranched polyethylenes as functional materials, various functionalities have also been introduced onto the hyperbranched polymer architecture by chain walking copolymerization of ethylene with functional monomers, primarily acrylates and 1-alkenes containing special functional groups. [12][13][14][15] The remarkable low oxophilicity of Pd-diimine catalysts and their outstanding capability of incorporating acrylate comonomers have facilitated the success of such copolymerizations and polymer functionalization.…”

Impact of size control of graphene oxide nanosheets for enhancing electrical and mechanical properties of carbon nanotube–polymer composites

“…[14][15][16][17] In this regard, a great deal of research has been devoted to preventing CNT agglomeration and improving the dispersion quality of CNTs. [18][19][20][21] Although several methods using chemical functionalization or organic surfactants have been suggested for exfoliating CNTs in solvent, such methods oen suffer from degradation of electrical and mechanical properties of CNTs due to the formation of defects on the surfaces of the CNTs or the insulating nature of the surfactants. Recently, graphene oxide (GO) has received much attention as a platform for many applications in aqueous media, such as pH, thermal, and optical sensors, due to its amphiphilic structure, which consists of a hydrophobic, p-conjugated 2D carbon sheet that contains various hydrophilic oxygen functional groups.…”