High-Quality Single-Walled Carbon Nanotubes with Small Diameter, Controlled Density, and Ordered Locations Using a Polyferrocenylsilane Block Copolymer Catalyst Precursor

Abstract

Carbon nanotubes (CNTs), with their exceptional electrical properties, chemical stability, and mechanical strength, have attracted a great deal of attention. This makes the material attractive for a wide range of applications, including composite materials, 1 battery electrode materials, 2 nanoelectronics, 3,4 and nanoscale sensors. 5 However, the properties of CNTs are highly dependent on their structure and size. Such sensitivity to size and structure imposes a potential barrier to the realization of the novel properties of CNTs in many applications. In the growth of CNTs by chemical vapor deposition (CVD), the diameters of CNTs are determined by the sizes of catalysts. 6 One way to obtain CNTs with fewer chiral arrangements is to use smaller catalyst particles. Thus, CNTs with smaller diameters, for example less than 2 nm, are most likely to be single-walled with fewer geometrical arrangements. This should limit the band gap range and allow the possibility of having all metallic or all semiconducting CNTs from a given growth. Moreover, such small-diameter nanotubes have larger band gaps, which minimize off-state leakage, thereby increasing the transistor on/off current ratio in transistor applications. 7 Significant progress has been made in driving catalyst size, and thus nanotube diameters, down

Synthesis and Solution Self‐Assembly of Polyisoprene‐block‐poly(ferrocenylmethylsilane): A Diblock Copolymer with an Atactic but Semicrystalline Core‐Forming Metalloblock

“…Figure 26a shows a SEM image of a SWCNT array prepared by CVD onto a PS-b-PFEMS film. 293 The ability of PFS BCP to generate catalytically-active Fe nanoparticles for the formation of SWCNTs is significantly greater than that shown by PFS homopolymers. This appears to be a consequence of the formation of smaller, higher surface area particles from confined PFS nanodomains.…”

“…[291][292][293][294] PS-b-PFEMS thin films were self-assembled and treated with UV-ozone to remove volatile organics and convert non-volatile inorganics into SiO2 and Fe2O3. After pyrolysis, the films were used for chemical vapour deposition (CVD) growth of SWCNTs, which were subsequently characterised by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.…”

“…Shell-crosslinked micelles have also been aligned and patterned on silicon substrates by microfluidic techniques, which may have interesting applications as magnetic memory materials or catalysts after pyrolysis. [291][292][293] PFS shell-crosslinked nanotubes have been shown allowing potential for encapsulation of guest particles or compounds within the hollow of the nanotube via in-situ redox reaction using PFS as a reductant. 344,346,366 Silver nanoparticles were prepared within the nanotubes through reaction with Ag[PF6].…”

Versatile and controlled functionalization of polyferrocenylsilane‐b‐polyvinylsiloxane block copolymers using a N‐hydroxysuccinimidyl ester strategy

“…14,15 Polyferrocenylsilane block copolymers have attracted widespread attention with respect to their self-assembly in the solid state to form metal-rich nanodomains. [16][17][18][19][20][21][22][23] In addition, solution self-assembly of BCPs containing a solvophobic poly(ferrocenyldimethylsilane) (PFS) block have also been well-studied and have been found to favour the formation of morphologies with low interfacial curvature such as cylinders and platelets due to core crystallization. [24][25][26] Significantly, the core termini of the micelles remain active to further growth on addition of further molecularly dissolved BCP.…”

Patterning strategies in nanofabrication : from periodic patterns to functional nanostructures

“…2.15a), [91] nanoparticles, [92] nanowires ( Fig. 2.15b), [93] nanotubes, [94] nanopillars, [95] nanoporous materials [85,96] and in particular photonic crystals. [97] As shown in Figs.…”