Conductive, Monodisperse Polyaniline Nanofibers of Controlled Length Using Well‐Defined Cylindrical Block Copolymer Micelles as Templates

Abstract

Stable colloidal dispersions of polyaniline (PAni) nanofibers with controlled lengths from about 200 nm-1.1 μm and narrow length distributions (Lw/Ln < 1.04; Lw = weight average micelle length, Ln = number average micelle length) were prepared through the template-directed synthesis of PAni using monodisperse, solution-self-assembled, cylindrical, block copolymer micelles as nanoscale templates. These micelles were prepared through a crystallization-driven living self-assembly method from a poly(ferrocenyldimethylsilane)-b-poly(2-vinylpyridine) block copolymer (PFS25 -b-P2VP425). This material was initially self-assembled in iPrOH to form cylindrical micelles with a crystalline PFS core and a P2VP corona and lengths of up to several micrometers. Sonication of this sample then yielded short cylinders with average lengths of 90 nm and a broad length distribution (Lw/Ln = 1.32). Cylindrical micelles of PFS25 -b-P2VP425 with controlled lengths and narrow length distributions (Lw/Ln < 1.04) were subsequently prepared using thermal treatment at specific temperatures between 83.5 and 92.0 °C using a 1D self-seeding process. These samples were then employed in the template-directed synthesis of PAni nanofibers through a two-step procedure, where the micellar template was initially stabilised by deposition of an oligoaniline coating followed by addition of a polymeric acid dopant, resulting in PAni nanofibers in the emeraldine salt (ES) state. The ES-PAni nanofibers were shown to be conductive by scanning conductance microscopy, whereas the precursor PFS25-b-P2VP425 micelle templates were found to be dielectric in character.

50th Anniversary Perspective: Functional Nanoparticles from the Solution Self-Assembly of Block Copolymers

“…178 PFDMS cylindrical BCPs have also been used as templates for solgel deposition to create coated nanowires (see section 6.3). 179,180 As previously discussed, living CDSA provides a route to forming spatially segregated amphiphilic multi-block comicelles. Amphiphilic block comicelles consisting of a hydrophobic PFDMS-b-PDMS central segment with PFDMS-b-P2VP termini have been used to produce supermicelles through controlled aggregation.…”

Controlling the Size of Two-Dimensional Polymer Platelets for Water-in-Water Emulsifiers

“… 29 However, these approaches do not offer the ability to readily modulate the chemistry, size, or shape of the construct to explore its effectiveness as a stabilizer. Indeed, despite the recent extensive interest in such ultrathin 2D materials, such as graphene, boron nitride, and clay platelets, for applications in optical devices, 30 catalyst arrays, 31 organic electronics 32 and as templates, 33 investigations into the combination of controlled particle shape and size are much less explored owing to the inability to control this further dimension in inorganic materials. Hence, we propose utilizing the precision and complexity offered by organic polymer assembly methods to create a series of nanoparticle stabilizers of tunable chemistry with controlled size and shape.…”

Construction and electronic properties of carbon nanotube hybrids with conjugated cubic silsesquioxane

“…As can be seen in Fig. 43,44 From the HR-TEM images, as shown in Fig. For SWNT-COOH, we only notice that the smoothness and length have remained the same, which suggests the overall configuration of SWNT remains structurally intact under the Friedel-Crafts conditions.…”