Mesoscale evolution of non-graphitizing pyrolytic carbon in aligned carbon nanotube carbon matrix nanocomposites

Abstract

Polymer-derived pyrolytic carbons (PyCs) are highly desirable building blocks for high strength low density ceramic meta-materials, and reinforcement with nanofibers is of interest to address brittleness and tailor multi-functional properties. The properties of carbon nanotubes (CNTs) make them leading candidates for nanocomposite reinforcement, but how CNT confinement influences the structural evolution of the PyC matrix is unknown. Here, the influence of aligned CNT proximity interactions on nano-and meso-scale structural evolution of phenol-formaldehyde derived PyCs is established as a function of pyrolysis temperature (T p) using x-ray diffraction, Raman spectroscopy, and

Process-morphology scaling relations quantify self-organization in capillary densified nanofiber arrays

“…Aligned CNT arrays were grown in a 22 mm internal diameter quartz tube furnace at atmospheric pressure via a previously described thermal catalytic chemical vapor deposition process with ethylene as the carbon source and 600 ppm of water vapor added to the inert gas. [40][41][42] The CNTs were grown on 1 cm  1 cm Si substrates via a base-growth mechanism on a catalytic layer composed of 1 nm Fe on 10 nm Al 2 O 3 deposited via electron beam physical vapor deposition. [43][44][45] The CNTs self-assemble into aligned arrays that were B10-300 mm tall, and were composed of multiwalled CNTs with an average outer diameter of B8 nm (3-7 walls with B5 nm inner diameter and intrinsic CNT density of E1.6 g cm À3 ), 42,[45][46][47] inter-CNT spacing of B60-80 nm, [48][49][50] and V f of B1% CNTs.…”

Morphology control of aligned carbon nanotube pins formed via patterned capillary densification

“…Following substrate patterning, vertically-aligned CNT arrays were grown by a base-growth mechanism in a 22 mm internal diameter quartz tube furnace at atmospheric pressure via a previously-described thermal catalytic chemical vapor deposition process, which uses ethylene as the carbon source and 600 ppm of water vapor added to the inert gas, allowing cm-scale CNT arrays to be grown [71][72][73]. In each pattern, the growing CNTs self-assemble into aligned arrays of height (h) ∼ 10−50 μm, controlled by growth time and measured via optical microscopy.…”

Fabrication and Characterization of Graphene Microcrystal Prepared from Lignin Refined from Sugarcane Bagasse

“…Glassy carbon is not amorphous matter, but has a glass-like microcrystal structure, consisting of microcrystals of fullerene, carbon nanotube, and/or graphene [ 1 , 2 , 3 ]. In the microstructure of glassy carbon materials, the sp 2 carbon atoms are chemically bonded by sp 3 carbon atoms, forming a 3D structural network [ 4 , 5 , 6 , 7 , 8 , 9 ]. The possession of such a unique structure grants glassy carbon a great variety of physical and chemical properties [ 10 , 11 , 12 , 13 , 14 ].…”

“…Theoretical study on the structure of glassy carbon has also steadily progressed since its discovery. In recent years, the newly invented fullerene, carbon nanotube, and graphene helped researchers to restudy and re-evaluate the microstructures of glassy carbon [ 7 , 8 , 22 , 23 ]. Graphene, particularly, has obtained extended uses in drug delivery, membrane, biomedical and adsorption applications, in addition to use in sensors [ 24 , 25 , 26 , 27 , 28 ].…”

“…In a recent study, it was found that by adding a small fraction of carbon nanotubes to a phenol-formaldehyde polymer, similar glassy carbon could be achieved at 800 °C, 200 °C lower than the previous temperature [ 7 ]. Another study reported that compression of glassy carbon at high pressure and certain temperatures induced the local buckling of graphene sheets through sp 3 nodes to form interpenetrating graphene networks with a long-range disorder and short-range order on a nanometer scale [ 10 ].…”