Rau cov kws tshaj lij ua haujlwm ntawm CNT conductive muab tshuaj txhuam, yuav luag txhua tus tau ntsib qhov teeb meem no: Cov tshuaj txhuam tau npaj ib hnub muaj qhov dej zoo, nrog rau kev tsim nyog viscosity thiab fineness. Tom qab khaws cia ib hmos, txawm li cas los xij, nws hloov mus rau hauv cov khoom zoo li jelly uas tsis tuaj yeem nchuav rau tag kis.
Tsuas yog cov neeg sab hauv tuaj yeem nkag siab qhov kev ntxhov siab. Dab tsi ua rau viscosity rebound thiab jelly-zoo li gelation hauv CNT conductive paste? Niaj hnub no peb piav qhia txog cov txheej txheem thiab cov kev daws teeb meem.
1. Phenomenon txhais: "Viscosity Rebound" yog dab tsi?
"Jelly-zoo li" yog ib lub ntsiab lus siv raugelation. Tej yam tsos mob:
Freshly npaj CNT conductive paste qhia tau zoo fluidity thiab tswj viscosity.
Tom qab so rau ob peb teev mus rau ib lossis ob hnub, viscosity nce siab, fluidity ploj, thiab muab tshuaj txhuam los ua ib nrab ntawm cov gel lossis txawm tias tag nrho solidified.
Qhov teeb meem no tshwj xeeb tshaj yog nyob rau hauvAqueous CNT conductive pastes; roj-raws li (NMP) systems kuj qhia gelation nyob rau hauv tej yam kev mob. Nws feem ntau tshwm sim poob nthav: tsim nyog hauv cov qauv kev sim tab sis ua tsis tiav hauv kev tsim khoom loj; ruaj khov nyob rau hauv nplawm tso tsheb hlau luam tab sis gelling tom qab hloov mus rau qhov chaw so.
Ib tus neeg siv kev lag luam tau qhia tias: "Kuv CNT muab tshuaj txhuam tau ntws zoo rau hnub ib tab sis gelled hnub tom qab. Kuv siv SMA-grafted, phosphate amine ntsev, thiab carboxylic acid amine ntsev dispersants, nrog homogenizer dispersion thiab milling, thiab particle loj raws li cov kev cai -tab sis nws tseem tig mus rau jelly." Qhov kev tsis meej pem no tau qhia los ntawm cov kws tshaj lij suav tsis txheeb.
2. Peb Qhov Tseem Ceeb Uas Ua Rau Jelly-Like gelation
Yuav kom daws tau gelation, peb yuav tsum xub to taub nws keeb kwm, uas nyob rau hauv CNT zog thiab dispersion stability.
1) Tsis muaj zog khi ntawm Dispersant thiab CNTs
CNTs muaj thaj tsam loj heev (ib-walled: 800-1300 m² / g; multi-walled: 180-210 m² / g) thiab muaj zog inter-tube van der Waals, ua rau lawv yooj yim rau agglomeration. Stable dispersion yuav tsum tau dispersants adsorbed rau CNT qhov chaw los muab steric hindrance los yog electrostatic repulsion.
Txawm li cas los xij, cov pa dispersants xws liCMC (sodium carboxymethyl cellulose)thiabPVP (polyvinylpyrrolidone)tsis yog tsim rau CNTs. Lawv txoj kev khi rau CNTs tsis muaj zog thiab nws yooj yim raudesorptionthaum so. Thaum dispersants desorb, CNTs rov entangle thiab tsim 3D network, ua rau gelation.
Ib tug kws tshawb fawb tau sau tseg: "Nrog 4.3% CNT cov ntsiab lus thiab 30% dispersant (los ntawm hmoov loj), tshem tawm PVP thiab hloov cov dispersants tshem tawm gelation." Qhov no lees paubdispersant mismatch yog qhov ua rau sab saum toj.
2) Thixotropic Trap: Thickening ntawm So
CNT conductive paste yog ib yamnon-Newtonian thixotropic kua:
Sheared (stirred): qauv tawg, fluidity txhim kho.
Thaum so: kev hloov kho cov qauv, fluidity zuj zus.
Submicroscopically, dispersants thiab CNTs tsim linear lossis network qauv. Stirring lov cov qauv no; so tso cai rau lawv rov tsim kho. Kev tsim kho ntau dhau ua rau gelation.
Cov kab ke nrog cov khoom siv me me (piv txwv li, LiFePO₄) yuav tsum muaj cov khoom sib txuas thiab cov khoom siv hluav taws xob ntau dua, tsim cov tes hauj lwm yooj yim dua thaum so thiab qhia cov dej tsis zoo. Qhov no piav qhia tias vim li cas qee cov qauv tsim muaj gelation heev.
3) System Instability: pH Imbalance los yog dej noo ntau dhau
Aqueous systems: pH yog ib qho tseem ceeb rau dispersion stability. Feem ntau cov dispersants (piv txwv li, hloov SMA copolymers) ua haujlwm zoo tshaj plaws ntawmpH 9-13. Sab nraum qhov no, kev hloov pauv ntawm molecular hloov, steric hindrance tsis muaj zog, thiab CNTs rov ua dua.
Roj-based NMP systems: noo noo yog qhov kev hem thawj zais. NMP yog cov polar thiab hygroscopic heev. Cov dej noo ntau dhau ua rau cov txheej txheem adsorption dispersant thiab tej zaum yuav hnov mob nrog binders (piv txwv li, PVDF), ua rau gelation. Cov txheej txheem kev lag luam yognoo noo tsawg dua los yog sib npaug rau 1500 ppmrau CNT conductive paste.
Lwm yam kev tshwm sim: qhov loj ntawm qhov kub thiab txias swings, tsis txaus dispersion (tsis txaus milling, tsis zoo linear ceev).
3. Kev daws teeb meem: Los ntawm Kev Kho Kom Zoo Rau Qhov Chaw Tswj
Kev kho tam sim rau Gelled Paste
Rov ua duakom huv si. Thixotropic kua shear-nyias; muaj zog nplawm tuaj yeem tawg cov qauv gel thiab rov ua kom muaj dej. Cov tshuaj gelation hnyav los yog tsis tuaj yeem ua rau cov khoom seem.
Kev Tiv Thaiv Kev Tiv Thaiv (Industry-Proven)
Kev daws 1: Siv CNT-Specific Hyper-Dispersants
Pa CMC / PVP khi tsis muaj zog thiab desorb yooj yim. Niaj hnubCNT-tailored hyper-dispersion systemsmuab ntau zog adsorption raws li thawj txoj cai tsom xam ntawm 1D vs . 0D cov ntaub ntawv dispersion.
Peb tus tswv FB-series hyper-dispersants xa:
40% txo qis viscosity nyob rau hauv tib yam
Single‑walled CNT paste solid content >1%
50% txo viscosity rebound nyob rau hauv high-silicon systems
Tsis muaj gelation thoob plaws hauv lub neej ua haujlwm
Siv: 20-100% (ntau-walled CNTs); 100-200% (ib-walled CNTs). Nws txo cov viscosity, txhim kho cov dej ntws, thiab txo qhov teeb meem.
Kev daws 2: nruj me ntsis tswj pH thiab noo noo
Aqueous systems: Khaws pH hauv qhov pom kev zoo (feem ntau 9–13); calibrate pH meters tsis tu ncua; siv pH adjusters yog tias xav tau.
Roj-raws li systems: NMP noo noo tuaj<500 ppm; workshop relative humidity <30%; vacuum‑dry CNTs at 80–100 °C for 4–8 hours before use.
Txoj Kev 3: Tswj Kev Ncaj Ncees Ncaj Ncees
Yog tias tsis siv tshuaj txhuam tam sim rau txheej, thovqeeb nruam stirringntawm ib tug linear ceev ntawm2–4 m/s. Ceev heev qhia npuas; qeeb dhau tsis suppress gelation.
Tsis txhob hloov txoj kev uas tso cai rau so ntev (piv txwv li, tipping chim). Txo lub sijhawm so lossis ua kom qis qis qis thaum lub sijhawm cia.
4. Shandong Tanfeng Qhov zoo: Tsis txhob gelation los ntawm qhov chaw
Rau cov neeg siv qis qis, kev koom tes nrog cov chaw tsim khoom muaj txiaj ntsig zoo dua li rov sim dua thiab ua yuam kev. Peb lub zog tseem ceeb:
Optimized dispersant systemPeb tau tso tseg qhov dav dav CMC/PVP thiab tau txais tus kheej-tsim dispersion qauv nrog CNT ruaj khov, tshem tawm gelation txaus ntshai ntawm qhov chaw.
Mature txheej txheem tswjTag nrho-txheej txheem kev soj ntsuam nruj: kev kuaj cov khoom siv raw (nqus, pH); dispersion tsis (milling lub sij hawm, linear ceev, kub); Kev tshuaj xyuas cov khoom tiav (viscosity, fineness, T₂ so lub sij hawm). Txhua batch hla7-hnub so kev ruaj ntseg pov thawjkom tsis muaj gelation.
Kev daws teeb meem, tsis yog cov khoom lag luam xwbPeb muab cov lus qhia tshwj xeeb raws li koj cov qauv, txheej txheem, thiab ib puag ncig: kev hloov pauv pH, cia kub, nplawm qhov xav tau, thiab lwm yam. Cov ntsiab lus no txiav txim siab ua tiav lossis tsis ua tiav.
Peb tsim CNTs ntawm cov tshuaj vapor deposition (CVD), tswj lub raj txoj kab uas hla, nam piv, thiab defect ceev los txhawb kev ruaj khov dispersion. Nruab nrog cov cuab yeej ntsuas ua tiav, peb nruj me ntsis tshuaj xyuas viscosity, fineness, thiab hlau impurities ib batch. Peb cov khoom siv dav siv nyob rau hauv lub zog tshiab tsheb, polymer composites, elastomers, aerospace, thiab lwm yam.
5. Cov lus pom zoo rau cov neeg siv
Txhawm rau zam qhov teeb meem gelation nrog CNT conductive paste:
Nyiam pre-dispersed paste tshaj hmoov: Hmoov muaj qhov nyuaj dispersion siab thiab ntau yam hloov pauv; pre-dispersed paste simplifies kev ua thiab txhim kho stability.
Paub meej tias qhov system dispersion thiab cov txheej txheem khaws cia: Nug cov neeg muag khoom, "Koj puas yuav muab tshuaj gel thaum so?" thiab "Dab tsi yog qhov yuav tsum tau khaws cia?"-tsis yog tsom rau tus nqi xwb.
Siv tam sim tom qab xa khoom; do thaum khaws cia: Khaws qis-ceev nplawm hauv lub tank cia yog tias tsis siv tam sim ntawd.
Rov ua dua me ntsis gelation: High-speed stirring rau 10-20 feeb feem ntau restores fluidity rau me ntsis gelation.
Gelation ntawm CNT conductive muab tshuaj yog qhov teeb meem kev lag luam ntev ntev -tab sisdaws tau. Feem ntau cov teeb meem tuaj yeem tiv thaiv tau los ntawm kev xaiv qhov zoo dispersant, tswj cov txheej txheem tsis, thiab tswj kom zoo stirring.
Yog tias koj tab tom nrhiav CNT conductive paste lossis xav tau kev pab daws teeb meem gelation, thov hu rau peb. Raws li cov kws tshaj lij kev tsim khoom, peb pab tig cov khoom siv ua haujlwm siab no rau hauv kev ruaj khov, txhim khu kev qha tsim khoom rau koj cov kab ntau lawm.