Polymer nanocomposites from self-assembled polystyrene-grafted carbon nanotubes

Abstract

Supramolecular self-assembly and anisotropic patchiness generate long-range networks in polymer-grafted carbon nanotubes, opening new possibilities using industrially attractive processes.

Grafting Multiwalled Carbon Nanotubes with Polystyrene to Enable Self-Assembly and Anisotropic Patchiness

“…TGA drops in mass are used to calculate the stepwise yields of chemical modification of the nanotubes. 22,23,25,26 FT-IR is used to confirm the presence of reactive functional groups introduced to the nanotubes. TEM is used to confirm anisotropic self-assembly of polymer-grafted nanotubes against pristine counterparts.…”

“…Here we will show how a series of straightforward chemical modification steps 22,23 can be applied to insert PS chains on the sidewalls of MWCNTs in order to modify their surface patchiness and to promote their anisotropic self-assembly 23 at the nanoscale. During the modification route, a first step allows for the selective hydroxylation of pristine MWCNTs at the sidewalls by following a biphasic catalytically mediated oxidation reaction to yield the hydroxylated counterparts namely, MWCNT-OH.…”

Control of pH-Responsiveness in Graphene Oxide Grafted with Poly-DEAEMA via Tailored Functionalization

“…Grafting through of GO-g-AEMA to yield GO-g-poly[DEAEMA] was done via radical polymerization following a protocol adapted from the literature as mentioned ahead [16,29]. In a standard experiment, 60 mg of freshly synthesized and dry GO-g-AEMA were dispersed in a 5-fold weight excess of DEAEMA monomer (325 µL, 300 mg) and purged with N 2 for 2 min.…”

“…These properties are mainly originated by their low-dimensionality (1D, 2D) and high surface-to-volume ratio as well as their π-conjugated surface [8], which have propelled their incorporation into a wide range of functional systems where they usually play a central role. The usage of these nanostructures commonly takes advantage of one or more of the Nanomaterials 2020, 10, 614 2 of 13 different properties they possess, for instance, as nanometric supports for heterogeneous catalysts [9][10][11], optical or electrochemical transducers in sensors and biosensors [12][13][14][15], mechanical reinforcement or electrical percolation modulation in polymer nanocomposites [16][17][18][19][20], nanoscale-enhanced radiosensitization and drug delivery in cancer therapy and tumor bioimaging [21][22][23], among others. However, in order to provide them with the additional features required for a particular purpose (catalytic activity, ion recognition, stimuli responsiveness, etc.…”

“…In this way, the range of useful reactive groups that can be introduced to the carbon nanomaterial surface, for example, for further polymer grafting, is as large as the polymerization chemistries available in the literature, which rely on three approaches [33]: (i) grafting through, that consists of polymer chains incorporated into the superficial reactive groups through the propagation reaction; (ii) grafting from, i.e., propagation of the polymer chains from surface-attached initiators; and (iii) grafting to, or attachment of, previously synthesized polymer chains to the reactive groups. For instance, vinylic or acrylic moieties can be superficially incorporated to the nanocarbons for further grafting through radical polymerization [16,34,35], alkyl halides or alkyl trithiocarbonates can be, respectively, used in grafting from for successive atom transfer radical polymerization (ATRP) [36] or reversible addition-fragmentation chain-transfer (RAFT) [37] polymerization and azido-terminated polymers can be otherwise exploited in grafting to using click chemistry [38,39].…”