Tshuaj oxidation txoj kev yog ib txwm siv rau kev npaj expandable graphite. Nyob rau hauv txoj kev no, ntuj flake graphite yog tov nrog tsim nyog oxidant thiab intercalating tus neeg saib xyuas, tswj ntawm ib tug tej yam kub, tsis tu ncua stirred, thiab ntxuav, lim thiab qhuav kom tau expandable graphite. Cov txheej txheem oxidation tshuaj tau dhau los ua txoj kev paub tab hauv kev lag luam nrog qhov zoo ntawm cov khoom siv yooj yim, kev ua haujlwm yooj yim thiab tus nqi qis.
Cov txheej txheem txheej txheem ntawm cov tshuaj oxidation muaj xws li oxidation thiab intercalation.Qhov oxidation ntawm graphite yog qhov yooj yim mob rau kev tsim ntawm expandable graphite, vim hais tias seb lub intercalation cov tshuaj tiv thaiv yuav ua tau smoothly nyob ntawm seb lub degree ntawm qhib ntawm lub graphite txheej.Thiab ntuj graphite ntawm chav tsev. Qhov kub thiab txias muaj kev ruaj ntseg zoo heev thiab cov kua qaub thiab alkali tsis kam, yog li nws tsis hnov mob nrog cov kua qaub thiab alkali, yog li ntawd, qhov sib ntxiv ntawm oxidant tau dhau los ua ib qho tseem ceeb ntawm cov tshuaj oxidation.
Muaj ntau ntau hom oxidants, feem ntau siv oxidants yog cov khoom oxidants (xws li poov tshuaj permanganate, potassium dichromate, chromium trioxide, potassium chlorate, thiab lwm yam), kuj tuaj yeem ua tau qee cov kua oxidizing (xws li hydrogen peroxide, nitric acid, thiab lwm yam. ). Nws tau pom nyob rau hauv xyoo tas los no uas poov tshuaj permanganate yog lub ntsiab oxidant siv los npaj nthuav graphite.
Nyob rau hauv qhov kev txiav txim ntawm oxidizer, graphite yog oxidized thiab nruab nrab network macromolecules nyob rau hauv graphite txheej ua planar macromolecules nrog zoo nqi. Vim yog qhov ua tsis zoo ntawm qhov zoo tib yam, qhov kev ncua deb ntawm cov txheej graphite nce, uas muab cov channel thiab qhov chaw rau lub intercalator nkag mus rau graphite txheej smoothly. Nyob rau hauv cov txheej txheem ntawm expandable graphite, tus neeg sawv cev intercalating yog cov kua qaub. Nyob rau hauv xyoo tas los no, cov kws tshawb fawb feem ntau siv sulfuric acid, nitric acid, phosphoric acid, perchloric acid, mix acid thiab glacial acetic acid.
Electrochemical txoj kev yog nyob rau hauv ib tug tas li tam sim no, nrog rau cov aqueous tov ntawm lub insert raws li cov electrolyte, graphite thiab hlau cov ntaub ntawv (stainless steel khoom, platinum phaj, txhuas phaj, titanium phaj, thiab lwm yam) ua ib tug composite anode, hlau ntaub ntawv tso rau hauv lub electrolyte li cathode, tsim ib lub voj kaw; Los yog cov graphite raug tshem tawm hauv cov electrolyte, nyob rau hauv cov electrolyte tib lub sij hawm tso rau hauv qhov tsis zoo thiab zoo phaj, los ntawm ob lub electrodes yog energized txoj kev, anodic oxidation. Qhov saum npoo ntawm graphite yog oxidized rau carbocation. Nyob rau tib lub sijhawm, nyob rau hauv kev sib koom ua ke ntawm electrostatic attraction thiab concentration sib txawv diffusion, acid ions los yog lwm yam polar intercalant ions yog embedded ntawm graphite txheej los tsim graphite expandable.
Piv nrog rau cov tshuaj oxidation txoj kev, cov txheej txheem electrochemical rau kev npaj ntawm expansable graphite nyob rau hauv tag nrho cov txheej txheem tsis siv cov oxidant, qhov kev kho mob yog loj, cov seem ntawm cov tshuaj corrosive yog me me, cov electrolyte tuaj yeem rov ua dua tom qab cov tshuaj tiv thaiv, Tus nqi ntawm cov kua qaub yog txo, tus nqi tau txais kev cawmdim, kev ua qias tuaj ib puag ncig raug txo, kev puas tsuaj rau cov khoom siv tsawg, thiab kev pabcuam lub neej txuas ntxiv.Nyob rau hauv xyoo tas los no, electrochemical txoj kev tau maj mam dhau los ua txoj kev nyiam rau kev npaj graphite expandable los ntawm ntau lub lag luam nrog ntau qhov zoo.
Gas-theem diffusion txoj kev yog los tsim cov graphite expandable los ntawm kev hu rau lub intercalator nrog graphite nyob rau hauv gaseous daim ntawv thiab intercalating cov tshuaj tiv thaiv. Feem ntau, cov graphite thiab cov ntxig yog muab tso rau ntawm ob qho tag nrho ntawm cov iav kub-resistant iav reactor, thiab lub tshuab nqus tsev yog pumped thiab kaw, yog li nws tseem hu ua ob-chamber method.Qhov no feem ntau yog siv los ua ke halide -EG thiab alkali hlau -EG hauv kev lag luam.
Qhov zoo: cov qauv thiab kev txiav txim ntawm lub reactor tuaj yeem tswj tau, thiab cov reactants thiab cov khoom tuaj yeem sib cais tau yooj yim.
Qhov tsis zoo: cov khoom siv tshuaj tiv thaiv yog qhov nyuaj dua, kev ua haujlwm nyuaj dua, yog li cov khoom tsim tawm raug txwv, thiab cov tshuaj tiv thaiv yuav tsum tau ua nyob rau hauv qhov kub thiab txias, lub sij hawm ntev dua, thiab cov tshuaj tiv thaiv kab mob siab heev, kev npaj ib puag ncig yuav tsum. yog lub tshuab nqus tsev, yog li tus nqi tsim khoom yog qhov siab, tsis haum rau cov ntawv loj loj.
Txoj kev sib xyaw ua kua theem yog ncaj qha sib xyaw cov khoom siv nrog graphite, nyob rau hauv kev tiv thaiv ntawm kev txav ntawm cov roj inert lossis sealing system rau cov tshuaj tiv thaiv cua sov los npaj cov graphite nthuav dav. Nws yog feem ntau siv rau kev sib txuas ntawm alkali hlau-graphite interlaminar compounds (GICs).
Qhov zoo: Cov txheej txheem tshuaj tiv thaiv yog qhov yooj yim, cov tshuaj tiv thaiv ceev ceev, los ntawm kev hloov pauv ntawm graphite raw cov ntaub ntawv thiab inserts tuaj yeem ncav cuag ib qho qauv thiab muaj pes tsawg leeg ntawm expandable graphite, haum rau ntau lawm.
Qhov tsis zoo: Cov khoom tsim tsis ruaj khov, nws yog ib qho nyuaj rau kev cuam tshuam nrog cov khoom siv dawb uas txuas rau saum npoo ntawm GICs, thiab nws yog ib qho nyuaj los xyuas kom meej qhov sib xws ntawm graphite interlamellar tebchaw thaum muaj coob tus synthesis.
Txoj kev melting yog sib tov graphite nrog intercalating khoom thiab cua sov los npaj expandable graphite.Raws li qhov tseeb hais tias eutectic Cheebtsam yuav txo tau lub melting point ntawm lub system (hauv qab lub melting point ntawm txhua yam), nws yog ib txoj kev rau kev npaj ntawm ternary los yog multicomponent GICs los ntawm inserting ob los yog ntau yam tshuaj (uas yuav tsum muaj peev xwm tsim ib tug molten ntsev system) ntawm graphite khaubncaws sab nraud povtseg ib txhij. Feem ntau siv nyob rau hauv kev npaj ntawm hlau chlorides - GICs.
Qhov zoo: Cov khoom siv hluavtaws muaj kev ruaj ntseg zoo, yooj yim los ntxuav, yooj yim tshuaj tiv thaiv ntaus ntawv, tsis tshua muaj tshuaj tiv thaiv kub, lub sij hawm luv luv, haum rau loj-scale ntau lawm.
Disadvantages: nws yog ib qho nyuaj rau tswj cov qauv kev txiav txim thiab muaj pes tsawg leeg ntawm cov khoom nyob rau hauv cov tshuaj tiv thaiv txheej txheem, thiab nws yog ib qhov nyuaj los xyuas kom meej qhov sib xws ntawm cov qauv kev txiav txim thiab muaj pes tsawg leeg ntawm cov khoom nyob rau hauv loj synthesis.
Cov txheej txheem siab yog sib xyaw graphite matrix nrog alkaline ntiaj teb hlau thiab cov hmoov hlau tsis tshua muaj hauv ntiaj teb thiab hnov mob los tsim M-GICS nyob rau hauv cov xwm txheej hnyav.
Qhov tsis zoo: Tsuas yog thaum lub vapor siab ntawm cov hlau dhau ntawm qhov chaw pib, qhov kev tso tawm tuaj yeem ua tiav; Txawm li cas los xij, qhov kub thiab txias yog siab dhau, yooj yim ua rau hlau thiab graphite tsim carbides, tsis zoo cov tshuaj tiv thaiv, yog li cov tshuaj tiv thaiv kub yuav tsum tau tswj nyob rau hauv ib tug tej yam ntau yam.Lub insertion kub ntawm lub ntiaj teb tsis tshua muaj hlau yog siab heev, yog li yuav tsum tau siv rau lub siab. txo cov tshuaj tiv thaiv kub.Qhov no yog qhov tsim nyog rau kev npaj cov hlau-GICS uas tsis tshua muaj melting point, tab sis cov cuab yeej nyuaj thiab cov kev ua haujlwm yuav tsum nruj, yog li nws tsis tshua siv tam sim no.
Txoj kev tawg feem ntau yog siv graphite thiab nthuav tus neeg sawv cev xws li KClO4, Mg (ClO4) 2·nH2O, Zn (NO3) 2·nH2O pyropyros los yog cov khoom sib tov npaj, thaum nws yog rhuab, graphite yuav ib txhij oxidation thiab intercalation cov tshuaj tiv thaiv cambium compound, uas yog ces. nthuav dav hauv txoj kev "explosive", yog li tau nthuav dav graphite.Thaum hlau ntsev siv los ua tus neeg sawv cev nthuav dav, cov khoom lag luam yog ntau txoj hauv kev, uas tsis tsuas yog nthuav graphite, tab sis kuj yog hlau.
