Hierarchical Hybrids of Carbon Nanotubes in Amphiphilic Poly(ethylene oxide)-block-polyaniline through a Facile Method: From Smooth to Thorny

Abstract

A facile approach was developed to synthesize conjugated block copolymer (BCP) poly(ethylene oxide)-b-polyaniline (PEO-PANI). Aldehyde group-terminated PEO was prepared by an esterification reaction of p-formylbenzoic acid and PEO and then reacted with PANI from chemical oxidative polymerization. FT-IR, (1)H NMR, and GPC results indicated that BCPs with different PEO block lengths were successfully synthesized. Moreover, the BCPs were employed to noncovalently modify multiwalled carbon nanotubes (MWNTs) through either the direct or indirect method. In the former method, transmission electron microscopy images showed that a core-shell MWNT@BCP hybrid with a shell thickness of gyration diameter of PEO block (2Rg,PEO) was obtained in 1-methyl-2-pyrrolidone (NMP). These hybrids can be well dispersed in many common solvents and poly(vinyl alcohol) matrix. With the increase of PEO block length, the stability of the MWNT dispersion would be highly improved. Interestingly, in the indirect method where deionized water was added to the NMP solution of BCP/MWNT mixture, the surface of the hybrid micelles encapsulated with MWNTs changed from smooth into hierarchically thorny with the increase of BCP/MWNT weight ratio. In this case, the water contact angle had a minimum value of ~70° at the ratio of 1/8, indicating that the hierarchical thorns followed a Cassie-Baxter regime rather than a Wenzel one. A possible formation mechanism of the unique structure was also proposed.

Thermally Sensitive N‐Type Thermoelectric Aniline Oligomer‐Block‐Polyethylene Glycol‐Block‐Aniline Oligomer ABA Triblock Copolymers

“…However, PANI has its limitation, such as a slow solubility in organic solvents and poor processibility, which constrains practical application. To overcome the defects of PANI, aniline oligomers and PANI based copolymers have been used instead of PANI in some fields due to good solubility in many common solvents . Yang et al reported a kind of PEO‐PANI block copolymer and its composites with multiwalled carbon nanotubes (CNTs), which exhibit excellent dispersion properties in many common solvents and unique self‐assembly structures .…”

“…To overcome the defects of PANI, aniline oligomers and PANI based copolymers have been used instead of PANI in some fields due to good solubility in many common solvents . Yang et al reported a kind of PEO‐PANI block copolymer and its composites with multiwalled carbon nanotubes (CNTs), which exhibit excellent dispersion properties in many common solvents and unique self‐assembly structures . Noticeably, aniline oligomers exhibit similar electrochemical activity as PANI, and own well‐defined structures and end groups .…”

Noncovalent functionalization of carbon nanotube using poly(vinylcarbazole)‐based compatibilizer for reinforcement and conductivity improvement in epoxy composite

“…Small molecules or polymer dispersants have been extensively utilized to noncovalently functionalize CNTs utilizing the multiple weak interactions such as van der Waals interactions, π‐π interactions, electrostatic interactions, and so on . Among various noncovalent methods, the strategy based on π‐π stacking interaction between polycyclic aromatic hydrocarbon and CNTs has attracted great attention . For example, Zou et al .…”

AB2 Y-shaped miktoarm star conductive polyaniline-modified poly(ethylene glycol) and its electrospun nanofiber blend with poly(ε-caprolactone)

“…[17][18][19][20] In order to overcome these major deciencies, well established techniques are: (1) doping of PANI with functionalized protonic organic acids (e.g., dodecylbenzene sulfonic acid, and camphorsulfonic acid); 21 (2) preparation of PANI composites with thermoplastic polymers; 22 (3) monomer modication (e.g., rings and N-substituted anilines); 23 and (4) incorporation of polar functional groups, polymeric chains or long and exible alkyl chains in the PANI backbone. 26 In this respect, poly(ethylene oxide) (PEO), 27 poly(ethylene glycol) (PEG), 28 chitosan, 29 gelatin, 30 and poly(3-caprolactone) (PCL) 31 can be used for enhanced biocompatibility of the PANI. 25 PANI in puried form exhibits relatively good biocompatibility, which is further enhanced by blending with other polymers.…”