Synthesis and Microphase Separation of Poly(styrene-<i>b</i>-acrylonitrile) Prepared by Sequential Anionic and ATRP Techniques

Amorphous carbon nanotubes have been prepared by casting thin films of polyacrylonitrile (PAN) and polystyrene‐block‐polyacrylonitrile (PS‐b‐PAN) within a porous anodic aluminum oxide (AAO) membrane followed by pyrolysis. Raman and wide‐ angle X‐ray diffraction (WAXD) measurements indicate that the carbon nanotubes are of low crystallinity. The thickness of the carbon nanotube walls is controlled by either changing the concentration of the precursor solution or by using multiple casting and pyrolysis steps. When diblock copolymers of PS‐b‐PAN are used, it is found that nanopores are created within the nanotube walls after pyrolysis. The carbon nanotubes can be used to create carbon coated nanorods of polystyrene‐block‐polybutadiene (PS‐b‐PBD).

show abstract

“…Thin-film studies of PS-b-PAN from TEM suggest a cylindrical morphology, which was retained after pyrolysis. [26] Figure 2a …”

Section: Resultsmentioning

confidence: 99%

“…PS-b-PAN, with a volume fraction of PAN ca. 60 %, was prepared by sequential anionic and atom transfer radical polymerization techniques [26] and had a total M w of 5.3 kg mol -1 as characterized by NMR spectroscopy, and M w /M n = 1.26, as characterized using DMF gel-permeation chromatography (GPC) versus PS standards. Polystyrene-b-poly- …”

Section: Methodsmentioning

confidence: 99%

Amorphous Carbon Nanotubes with Tunable Properties via Template Wetting

Chen¹,

Shin

Leiston-Belanger

et al. 2006

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…Template-based strategies provide a promising way to achieve this goal; however, the design of efficient templates remains challenging. [12][13][14][15][16] Recently, it has been demonstrated that pyrolysis of soft templates assembled from block copolymers provides a versatile approach to well-defined discrete nanostructured carbon materials. [17,18] Carbon nanoparticles were obtained by pyrolysis of block copolymer micelles with either a cross-linked shell [19,20] or a cross-linked core.…”

Section: Introductionmentioning

confidence: 99%

A Novel Route for the Preparation of Discrete Nanostructured Carbons from Block Copolymers with Polystyrene Segments

Huang

Tang

Lee

et al. 2007

Macro Chemistry & Physics

View full text Add to dashboard Cite

Well‐defined nanostructured carbon was prepared by pyrolysis of core cross‐linked micelles formed from block copolymers containing polystyrene segments. These micelles were obtained by self‐assembly of poly(ethylene oxide)‐block‐polystyrene (PEO113‐b‐PS52) diblock copolymer or brush macromolecules containing polymethacrylate backbone and side chains with PS and poly(acrylic acid) block segments (PBPEM330‐g‐PS40‐b‐PAA111) in selective solvents. UV irradiation was used to induce cross‐linking of the PS core in the micelles. After pyrolysis, the cross‐linked PS cores were converted to a partially graphitic carbon, while the shells were sacrificed, resulting in the formation of discrete carbon nano‐objects. The formation of carbon material was confirmed by Raman scattering spectroscopy while the morphology of the precursor and the resulting pyrolyzed product was studied by atomic force microscope (AFM).magnified image

show abstract

“…A series of PANbased copolymers, such as poly(acrylonitrile-b-butyl acrylate), were prepared and expanded the possibility of copolymer self-assembly. At the same time, the derived carbon materials present varied morphologies and structures [21][22][23]. On the other hand, the general preparation of PAN-derived carbon/metal nanocomposites involves multiple steps: i) PAN carbonization into carbon nanofiber (CNF); ii) functionalization of CNF; iii) subsequent dispersion of metal nanoparticles (NPs) [24].…”

Section: Introductionmentioning

confidence: 99%