Ultrasonic Deposition of High-Selectivity Nanoporous Carbon Membranes

Abstract

Ultrasonic deposition creates a thin film of polymer on a tubular, macroporous, stainless steel support. Using polyfurfuryl alcohol as the nanoporous carbon precursor and a pyrolysis temperature of 723 kelvin, a membrane was prepared with the following permeances, measured in moles per square meter per Pascal per second: nitrogen, 1.8 x 10(-12); oxygen, 5.6 x 10(-11); helium, 3.3 x 10(-10); and hydrogen, 6.1 x 10(-10). The ideal separation factors as compared to that for nitrogen are 30:1, 178:1, and 331:1 for oxygen, helium, and hydrogen, respectively.

High capacitance carbon-based xerogel film produced without critical drying

“…[1][2][3][4][5][6][7] Although numerous methods such as chemical vapor deposition, hydrothermal decomposition of carbide compounds, and polymer coating and pyrolysis have been developed for the fabrication of carbon film, [8][9][10] easily scalable self-supported nanoporous carbon films have not yet been obtained with any of them. The following promising methods for fabricating the pore structure of carbon film have recently been reported: colloidal silica imprinting, microbead patterning, and presynthesized mesoporous silica scaffolding.…”

Fine ultra-micropore control using the intrinsic viscosity of precursors for high performance carbon molecular sieve membranes

“…Single gas permeability of the CMS membranes was tested by a dead-end set up using a time-lag method [19]. A setting for testing is shown in Fig.2.…”

“…Therefore, the characteristics of polymer precursor and carbonisation process affect the structure and performance of CMS membranes. There is an array of polymers that have been employed for the preparation of CMS membranes including phenolic resin [1][2][3][4][5][6][7], polyimide (PI) [8][9][10][11][12][13][14][15][16][17], polyfurfuryl alcohol [18,19], poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) [20] and poly (phthalazinone ether sulfone ketone) (PPESK) [21]. In addition, carbon templates such as triblock copolymers [22] and surfactant hexyltriethylammonium bromide (C6) [23] have been embedded and carbonised in silica films as molecular sieve structures for desalination and gas separation.…”

Magnetic field guided formation of long carbon filaments (sausages)

“…However, CNTs are usually long and tangled which limits their applications. To obtain short CNTs, many methods have been developed, such as chemical etching [1], ultrasonic treatment [2] and scanning tunneling microscope (STM) voltage [3]. These techniques have a limited yield and often create structural damage.…”

“…Carbon scientists throughout the world have been attracted to the study of the structure, texture and diversity of various carbon materials due to their wide range of application in nanodevices [1], energy storage [2], separation technologies [3] and lubricants. By very different processes, carbon nanotubes, spheres, beads, onions, glassy carbon, and pyrolytic carbon have been synthesized.…”