Self‐Suspended Polyaniline Doped with a Protonic Acid Containing a Polyethylene Glycol Segment

Abstract

Self-suspended nanoparticles (NPs) are flowable at or near room temperature without the presence of any solvent. The zero vapor pressure of self-suspended NPs eliminates the environmental concerns associated with using various solvents, and has attracted extensive research interests recently. Various hybrid self-suspended NPs have been synthesized from surface modification of the nanostructures, for example, SiO 2 , g-Fe 2 O 3 , [1,2] TiO 2 , [3] ZnO, [4] quantum dots, [5] gold, platinum, palladium, [6] CaCO 3 , [7] and carbon nanotubes. [8][9][10] The intrinsic electronic, magnetic, and luminescent properties of various nanostructures have made the self-suspended NPs a promising alternative to conducting lubricants, heat-transfer fluids, batteries, and printing electronics. [2,4,11] Aside from the above mentioned self-suspended NPs and their corresponding liquid-like [1,2] behavior, herein we report a self-suspended polyaniline (PANI) that exhibits a unique thermoreversible gel-like rheological response. Owing to the intrinsic electrical properties of PANI, the self-suspended PANI might exhibit high electroconductivity, excellent electroluminescence, unique electrochromism, and outstanding processability, which could have widespread application in electrochromic devices, medical diagnostic transducers, lightweight batteries, electroluminescent devices, fuel cells, sensors, and actuators. [12][13][14][15][16][17][18] We anticipate that the technique reported here is also applicable to other polymers for exhibiting this unique structure and properties.The self-suspended PANI was prepared using a long-chain protonic acid containing a polyethylene glycol segment (CH 3 H) (NPES) as the dopant during the polymerization of the aniline monomers, and then removed the excess of NPES in the polymer solution through extensive dialysis. A dialysis experiment was carried out to investigate the removal of NPES, and the result indicates that all the unreacted NPES molecules can be extracted out of the dialysis bag (see the Supporting Information, Figure S1), which resulted in a solvent-free system. The doped PANI derivatives can self-assemble into nanofibrils. [19] By controlling the average doping ratio of the PANI molecule chain within a system, the PANI nanofibrils can further organize into micelles and exhibit unique thermoreversible gel-like rheology behavior. [20][21][22][23][24] Although such thermoreversible rheology behavior resembles those of previously reported thermoreversible gels, [25][26][27][28] the two categories are essentially different in that a real thermoreversible gel possesses a fibrillar network morphology. [27] The micelle morphology may originate from the nature of NPES which is quite different from those used in previously reported work involving sulfonic acid doped PANI; [25][26][27][28] for example, NPES contains a long flexible chain segment of polyethylene glycol. These NPES molecules with high flexibility significantly alter the assembly behavior of doped PANI and thus results in PANI derivative...

Self-suspended polyaniline containing self-dissolved lyotropic liquid crystal with electrical conductivity

“…Also, the temperature‐dependent viscosity are less than 50 Pa·s over the whole test temperature range, showing again that PANI‐GAE flows just like a “real liquid.” This is further confirmed by the photograph as shown in the inset of Figure (b). It should be pointed out that PANI‐GAE reported here is essentially solvent‐free without any unreacted molecules, as proved in our previous work . Accordingly, such new self‐suspended PANI with a typical liquid‐like behavior can be processed with conventional solution‐processing technique, and can be potentially applied to antistatic and anticorrosion coatings.…”

“…In the past few years, self‐suspended particle fluid has emerged as a new technique to address the processing issue of nanomaterials . Apart from the self‐suspended NPs and their associated liquid‐like behavior, a self‐suspended PANI that exhibits unique thermoreversible gel‐like rheological response has been reported in our previous work . This self‐suspended PANI was synthetized by doping PANI with a protonic acid containing a polyethylene glycol segment.…”

Electrical stimuli improve osteogenic differentiation mediated by aniline pentamer and PLGA nanocomposites

“…Preparation and characterization of AP/PLGA nanocomposites. Preparations of aniline pentamer (AP) and its chemical structures have been previously described (12,13). AP and PLGA were dissolved in chloroform to form a 0.06 g̸ml solution.…”

“…First they were mixed together and then stirred and sonicated. Solid nanocomposites were obtained by precipitation in anhydrous alcohol and were dried in vacuum for 48 h. The nanocomposites were characterized as previously described (12,13).…”

“…Several conducting polymers have been used to create biosensors, neural probes, drug release regulators, initiators and auto-oxidants (8)(9)(10). Conducting polymers are also preferred for biomedical applications, due to their beneficial bone-healing properties (11)(12)(13). Wong et al (11) confirmed that conducting polymers effectively control the shape and growth of mammalian cells.…”