Carbon Nanotube Immobilized Composite Hollow Fiber Membranes for Extraction of Volatile Organics from Air

Abstract

This paper reports the development of novel carbon nanotube immobilized composite membranes (CNIMs) for the extraction of volatile organics from air. The nanotubes were immobilized onto the selective layer of a composite membrane where they served as sorption sites and provided additional pathways for enhanced solute transport. Depending upon the process conditions, the presence of carbon nanotubes led to the organic removal with flux as high as 37.7 × 10 −5 , 72.9 × 10 −5 , and 8.22 × 10 −5 gm mol/m 2 min and an increase in mass-transfer coefficient of about 92.2%, 22.7%, and 44.3% for toluene, dichloromethane, and ethanol, respectively. The CNIMs demonstrated several advantages, including enhanced recovery at low concentrations and low temperature.

Single-Walled Carbon Nanotubes (SWCNTs), as a Novel Sorbent for Determination of Mercury in Air

“…In last ten years, a large number (80+) of articles regarding aqueous phase adsorption of a variety of synthetic organic compound (SOC) by CNTs were published in peer-reviewed journals ( Apul & Karanfil, 2015 ) but articles about extraction and separation of occupational pollutant from gaseous ambient aided by CNTs is rare but attractive issue ( Saeedi et al, 2014 ; Ragunath, & Mitra, 2015 ).…”

“…The adsorption-related applications of CNTs to solve environmental pollution problems have received considerable attention in recent years ( Agnihotri, Rood, & Rostam-Abadi, 2005 ). In some studies, this sorbents have been used successfully for metalcations such as cadmium and copper ( Vellaichamy & Palanivelu, 2011 ; Moradi, Zare, & Yari, 2011 ) lead ( Moradi et al, 2011 ), chromium ( Jung et al, 2013 ) mercury ( Pitoniak, 2003 ), nickel ( Adolph, Xavier, Kriveshini, & Rui 2012 ), zinc ( Vellaichamy et al, 2011 ; Tajik & Mohammadi, 2011 ), drugs ( Fazelirad, Ranjbar, Taher, & Sargazi, 2015 ; Wang Sun, Pan, & Xu, 2015 ) endocrine-disrupting compounds ( Jung et al, 2013 ) and organic contaminants ( Yu et al, 2014 ) in the aquatic environment as well as benzene ( Saeedi, Javid, Ghorannevis, Moattar, & Mashinchian, 2014 ) toluene, dichloromethane and ethanol ( Ragunath & Mitra, 2015 ) in gaseous ambient.…”

Adsorptive Removal of Dichloromethane Vapor on FAU and MFI Zeolites: Si/Al Ratio Effect and Mechanism

“…The annual world production of DCM is more than 500 000 tons, of which about 77% is emitted into the atmosphere . Due to its high toxicity and carcinogenic character, combined with its contribution to global warming, depletion of the ozone layer, and the formation of photochemical smog, the removal of DCM is a major environmental concern. − …”

A physical entrapment method for the preparation of carbon nanotube reinforced macroporous adsorption resin with enhanced selective extraction performance

“…2,3 Over the last two decades, CNTs have aroused extensive attention from researchers in a number of fields due to their excellent sorption, electronic, thermal, mechanical and field emission properties, which have made them the most promising carbon-based nanomaterial over other materials. [5][6][7][8][9][10][11][12] In the field of analytical chemistry, CNTs have potential roles in improving the analytical process and have been demonstrated to play an important part in analytical techniques such as solid-phase extraction (SPE), [13][14][15][16][17][18][19] solid-phase microextraction (SPME), [20][21][22][23][24] stationary or pseudostationary phases for chromatographic separation (LC, GC, CE), [25][26][27] membrane extraction, [28][29][30] sensors, 1,31,32 microelectrodes 33,34 and microfluidic chips. 35 Among the fascinating properties, a wide range of surface areas (110-407 m 2 g −1 ) 17 and the ability to establish π-π electrostatic interactions endow CNTs with favorable adsorption properties, which have fostered their use as an excellent sorbent material for aromatic compounds, 18 e.g., phenols, 36 polybrominated diphenyl ethers, 37 and organochlorine pesticides 38 in a host of analytical processes.…”

“…Recently, CNTs have been incorporated into various support materials to facilitate the adsorption of analytes in a selective and reproducible manner. These support materials are mainly polymer monoliths, 39 glass macroparticles, 2 steel capillaries, 2 silica capillaries, 27 filter paper, 32 membranes, [28][29][30] fibers, 20,21,24 magnetic nanoparticles 40 and chromatography columns. [25][26][27] Once CNTs are incorporated into the support materials, the interactions between CNTs will be suppressed and the immobilized CNTs will exhibit an increased adsorption capacity and extraction efficiency for analytes.…”