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Forecasting continuous carbon nanotube production in the floating catalyst environment

Accepted version
Peer-reviewed

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Article

Change log

Authors

Bulmer, JS 
Gspann, T 
Mizen, J 
Ryley, J 

Abstract

We pre­sent val­i­dated sta­tis­ti­cal mod­els and uni­vari­ate cor­re­la­tions of car­bon nan­otube (CNT) tex­tile prop­er­ties (spe­cific elec­tri­cal con­duc­tiv­ity, Ra­man G:D ra­tio and mass yield rate) ex­tracted con­tin­u­ously from float­ing cat­a­lyst chem­i­cal vapour de­po­si­tion (FC-CVD) re­ac­tors over a uniquely wide mul­ti­vari­ate ex­per­i­men­tal space. This in­cludes di­rectly con­trolled re­ac­tor set­tings (e.g. pre­cur­sor con­cen­tra­tions, gas flow rates, fur­nace tem­per­a­tures and wind­ing speeds), in­di­rect pa­ra­me­ters (e.g. am­bi­ent tem­per­a­ture and pres­sure), and time-de­pen­dent re­ac­tor in­flu­ences such as re­ac­tor tube age. Two ver­ti­cal FC-CVD re­ac­tors, with dif­fer­ent pre­cur­sor de­liv­ery ar­chi­tec­tures, were con­sid­ered: 1) in which pre­cur­sors were pre-mixed to­gether as a liq­uid so­lu­tion that was di­rectly in­jected into re­ac­tor; 2) in which va­por­ised pre­cur­sors were in­de­pen­dently in­jected in the gas phase us­ing Cori­o­lis-based mi­croflu­idic mass flow con­trollers with con­cen­tra­tions mon­i­tored in-line us­ing FTIR spec­troscopy. Fac­tors favour­ing high­est elec­tri­cal con­duc­tiv­ity fi­bres in­clude: lower hy­dro­gen flows, lean fuel-to-gas mix­tures, higher wind­ing rates, higher ar­gon flows, with many thio­phene con­cen­tra­tion in­ter­ac­tions with other pa­ra­me­ters; for high­est Ra­man G:D ra­tios: leaner fuel-to-gas mix­tures, lower thio­phene con­cen­tra­tions, higher hy­dro­gen flows, and greater ex­ter­nal lab­o­ra­tory pres­sure; but for yield rate, sys­tem­atic trends were harder to dis­cern. This study demon­strates the de­gree of pre­dictabil­ity in FC-CVD re­ac­tors, quan­ti­ta­tively ranks im­pact of FC-CVD pa­ra­me­ters, and iden­ti­fies re­gions of fi­bre “spinnabil­ity” which cor­re­spond well with a re­cent meta-analy­sis of ex­per­i­men­tal re­sults in the lit­er­a­ture.

Description

Keywords

Carbon nanotube fibers, Floating catalyst, Design of experiments

Journal Title

Chemical Engineering Journal

Conference Name

Journal ISSN

1385-8947
1873-3212

Volume Title

390

Publisher

Elsevier BV
Sponsorship
Engineering and Physical Sciences Research Council (EP/M02086X/1)
Engineering and Physical Sciences Research Council (EP/M015211/1)