Cellulose ether pane morphology yepakutanga ettringite

Mhedzisiro yehydroxyethyl methyl cellulose ether uye methyl cellulose ether pane morphology ye ettringite mukutanga simende slurry yakadzidzwa ne scanning electron microscopy (SEM). Mhedzisiro yacho inoratidza kuti kureba-dhayamita reshiyo ye ettringite makristasi mu hydroxyethyl methyl cellulose ether yakagadziridzwa slurry idiki pane iyo yakajairwa slurry, uye morphology ye ettringite makristasi ipfupi tsvimbo-yakafanana. Hurefu-dhayamita reshiyo ye ettringite makristasi mumethyl cellulose ether yakagadziridzwa slurry yakakura kupfuura iyo yakajairwa slurry, uye morphology ye ettringite makristasi ndeye tsono-tsvimbo. Iwo ettringite makristasi mune akajairwa simende slurries ane aspect ratio pane imwe nzvimbo pakati. Kuburikidza nechidzidzo chekuedza chiri pamusoro, zvinoramba zvakajeka kuti mutsauko wehuremu hwema molecular emhando mbiri dze cellulose ether ndiyo inonyanya kukosha inokanganisa morphology ye ettringite.

Mazwi akakosha:ettringite; Kureba-dhayamita reshiyo; Methyl cellulose ether; Hydroxyethyl methyl cellulose ether; morphology

Ettringite, seyakawedzeredzwa zvishoma hydration chigadzirwa, ine mhedzisiro yakakosha pakuita kwekongiri yesimende, uye yagara iri iyo hotspot yekutsvagisa yesimende-yakavakirwa zvinhu. Ettringite imhando ye trisulfide type calcium aluminate hydrate, chimiro chayo chemakemikari ndeye [Ca3Al (OH) 6 · 12H2O]2 · (SO4)3 · 2H2O, kana inogona kunyorwa se 3CaO · Al2O3 · 3CaSO4 · 32H2O, inowanzopfupikiswa seAFt. . MuPortland simende system, ettringite inonyanya kuumbwa nekuita kwegypsum ine aluminate kana ferric aluminate zvicherwa, izvo zvinotora basa rekunonoka hydration uye kutanga simba resimende. Kuumbwa uye morphology ye ettringite inobatwa nezvinhu zvakawanda senge tembiricha, pH kukosha uye ion concentration. Pakare muna 1976, Metha et al. yakashandisa scanning electron microscopy kuti idzidze morphological maitiro eAFt, uye yakaona kuti morphology yezvigadzirwa zve hydration zvakawedzerwa zvishoma zvakasiyana zvishoma apo nzvimbo yekukura yakanga yakakura zvakakwana uye apo nzvimbo yakanga iri shoma. Yekutanga yaive spherules mutete-mudonzvo-mudonzvo, nepo ekupedzisira ainyanya kunge ari mapfupi-akaita shamhu prism. Tsvagiridzo yaYang Wenyan yakawana kuti mafomu eAFt aive akasiyana nenzvimbo dzakasiyana dzekurapa. Nzvimbo dzakanyorova dzinononoka chizvarwa cheAFt mukuwedzera-doped kongiri uye kuwedzera mukana wekuzvimba kwekongiri uye kutsemuka. Nzvimbo dzakasiyana dzinokanganisa kwete chete kuumbwa uye microstructure yeAFt, asiwo vhoriyamu kugadzikana. Chen Huxing et al. akawana kuti kugadzikana kwenguva refu kweAFt kwakaderera nekuwedzera kweC3A zvinyorwa. Clark naMonteiro et al. akawana kuti nekuwedzera kwekumanikidzwa kwezvakatipoteredza, AFt crystal chimiro chakashanduka kubva pakurongeka kuenda kune kusagadzikana. Balonis naGlasser vakaongorora shanduko yedensity yeAFm neAFt. Renaudin et al. akadzidza shanduko yezvimiro zveAFt isati yanyudzwa uye mushure mekunyudzwa mune mhinduro uye zvimiro zvimiro zveAFt muRaman spectrum. Kunther et al. akadzidza mhedzisiro yekudyidzana pakati peCSH gel calcium-silicon ratio uye sulfate ion paAFt crystallization pressure neNMR. Panguva imwecheteyo, zvichibva pakushandiswa kweAFt mune sement-based materials, Wenk et al. akadzidza AFt crystal orientation yekongiri chikamu kuburikidza neyakaoma synchrotron mwaranzi X-ray diffraction yekupedzisa tekinoroji. Kuumbwa kweAFt mune yakasanganiswa simende uye hotspot yekutsvagisa ye ettringite yakaongororwa. Zvichienderana nekunonoka kwe ettringite kuita, dzimwe nyanzvi dzakaita tsvakiridzo yakawanda pamusoro pechikonzero cheAFt chikamu.

Kuwedzera kwevhoriyamu kunokonzerwa nekuumbwa kwe ettringite dzimwe nguva kwakanaka, uye inogona kuita se "kuwedzera" yakafanana neiyo magnesium oxide yekuwedzera agent kuchengetedza vhoriyamu kugadzikana kwesimende-yakavakirwa zvinhu. Kuwedzerwa kwepolymer emulsion uye redispersible emulsion powder inoshandura macroscopic maitiro e-cement-based materials nekuda kwekuita kwavo kwakakosha pane microstructure ye-cement-based materials. Zvisinei, kusiyana neredispersible emulsion powder iyo inonyanya kuwedzera chisungo chekubatanidza chedhaka yakaomeswa, mvura-inonyunguduka polymer cellulose ether (CE) inopa ichangobva kusanganiswa dhaka kuchengetedza kwemvura kwakanaka uye kukora simba, nokudaro kuvandudza kushanda kwekushanda. Non-ionic CE inowanzoshandiswa, kusanganisira methyl cellulose (MC), hydroxyethyl cellulose (HEC), hydroxypropyl methyl cellulose (HPMC),hydroxyethyl methyl cellulose (HEMC), nezvimwewo, uye CE inobata basa mumatope achangobva kusanganiswa asi inokanganisawo hydration process ye simenti slurry. Zvidzidzo zvakaratidza kuti HEMC inoshandura huwandu hweAFt inogadzirwa sechigadzirwa che hydration. Zvisinei, hapana zvidzidzo zvakaenzanisa zvakarongeka mhedzisiro yeEC pane microscopic morphology yeAFt, saka bepa rino rinoongorora mutsauko wemhedzisiro yeHEMC neMC pane microscopic morphology ye ettringham mukutanga (1-zuva) simende slurry kuburikidza nekuongorora kwemifananidzo uye. kuenzanisa.

1. Kuedza

1.1 Raw Materials

P · II 52.5R Portland simende inogadzirwa neAnhui Conch Cement Co., LTD yakasarudzwa sesimende mukuyedza. Iwo maviri cellulose ethers hydroxyethyl methylcellulose (HEMC) uye methylcellulose (methylcellulose, Shanghai Sinopath Group) zvichiteerana. MC); Mvura inosanganiswa imvura yepombi.

1.2 Nzira dzekuedza

Chiyero chemvura-samende ye samende paste sampuli yaiva 0.4 (chiyero chemvura kune simenti), uye zvinyorwa zve cellulose ether yaiva 1% yehuwandu hwesamende. Kugadzirira kwemuenzaniso kwakaitwa maererano neGB1346-2011 "Nzira yekuedza yeKushandisa Mvura, Kuisa Nguva uye Kugadzikana kweCement Standard Consistency". Mushure mekugadzira mufananidzo, firimu repurasitiki rakavharirwa pamusoro pechiumbwa kudzivirira kubuda kwemvura uye carbonization, uye mufananidzo wacho wakaiswa muimba yekurapisa ine tembiricha ye (20±2)℃ uye hunyoro hwe (60±5). ) %. Mushure mezuva re1, mold yakabviswa, uye muenzaniso wacho wakaputsika, ipapo sampuli duku yakatorwa kubva pakati uye yakanyoroveswa muanhydrous ethanol kuti ipedze hydration, uye sampuli yakatorwa uye yakaomeswa isati yaedzwa. Sample dzakaomeswa dzakanamirwa patafura yekuenzanisira ine conductive yakapetwa-mativi anonamira, uye musara wefirimu regoridhe rakapfapfaidzwa pamusoro neCressington 108auto otomatiki ion sputtering chiridzwa. The sputtering current yaive 20 mA uye nguva yekupuruzira yaive 60 s. FEI QUANTAFEG 650 zvakatipoteredza Scanning electron Microscope (ESEM) yakashandiswa kuona morphological maitiro eAFt pachikamu chemuenzaniso. Iyo yakakwira vacuum yechipiri electron mode yakashandiswa kuona iyo AFT. Iyo yekumhanyisa voltage yaive 15 kV, dhayamita dhayamita yaive 3.0 nm, uye kureba kwekushanda kwakadzorwa kunosvika gumi mm.

2. Migumisiro uye nhaurirano

SEM mifananidzo ye ettringite muakaomeswa HEMC-yakagadziridzwa simende slurry yakaratidza kuti kutaridzika kukura kweakaturikidzana Ca (OH) 2 (CH) kwaive pachena, uye AFt yakaratidza kuunganidza kusingaite kwekapfupi tsvimbo-yakafanana AFt, uye imwe pfupi tsvimbo-yakafanana AFT yakavharwa. ine HEMC membrane chimiro. Zhang Dongfang et al. yakawanawo tsvimbo pfupi-yakafanana neAFt pakuona shanduko ye microstructure yeHEMC yakagadziridzwa simende slurry kuburikidza neESEM. Vaitenda kuti zvakajairwa simende slurry yakakurumidza kuita mushure mekusangana nemvura, saka AFt crystal yaive yakatetepa, uye kuwedzera kwezera re hydration kwakatungamira kukuwedzera kwehurefu-dhayamita reshiyo. Zvisinei, HEMC yakawedzera viscosity yemhinduro, yakaderedza kusungirirwa kweioni mukugadzirisa uye kunonoka kusvika kwemvura pamusoro pezvikamu zveclinker, saka kureba-diameter ratio yeAFt yakawedzera muhutano husina simba uye maitiro ayo e-morphological akaratidza. pfupi tsvimbo-yakafanana chimiro. Kuenzaniswa neAFt mune yakajairwa simende slurry yezera rimwe chete, iyi dzidziso yakave yakasimbiswa zvishoma, asi haishande kutsanangura morphological shanduko yeAFt muMC yakagadziridzwa simende slurry. SEM mifananidzo ye ettridite mu 1-zuva yakaomeswa MC yakagadziridzwa simende slurry yakaratidzawo yakanangwa kukura kwe layered Ca (OH) 2, mamwe maAFt akafukidzwa nefirimu chimiro cheMC, uye AFt yakaratidza morphological maitiro ekukura kwesumbu. Nekudaro, nekuenzanisa, AFt crystal muMC yakagadziridzwa simende slurry ine yakakura kureba-dhayamita reshiyo uye yakawanda slender morphology, ichiratidza yakajairika acicular morphology.

Zvose HEMC uye MC zvakanonoka kutanga hydration process ye simenti uye yakawedzera viscosity yemhinduro, asi kusiyana kweAFt morphological maitiro akakonzerwa navo akanga achiri kukosha. Chiitiko chiri pamusoro apa chinogona kutsanangurwa zvakare kubva pakuona kwemamorekuru chimiro che cellulose ether uye AFt crystal chimiro. Renaudin et al. yakanyorovesa AFt yakasanganiswa mumushonga wealkali wakagadzirwa kuti uwane "kunyorova AFt", ndokuibvisa zvishoma ndokuiomesa pamusoro peiyo yakanyungudutswa yeCaCl2 solution (35% hunyoro hunoenderana) kuti iwane "kuoma AFt". Mushure mekuvandudzwa kwechimiro chekudzidza neRaman spectroscopy uye X-ray poda diffraction, zvakaonekwa kuti pakanga pasina mutsauko pakati pezvivakwa zviviri, chete kutungamira kwekristaro kuumbwa kwemasero kwakashandurwa mukuomesa, ndiko kuti, mukuita kwezvakatipoteredza. kuchinja kubva pa "kunyorova" kuenda "kuoma", AFt makristasi akagadzira masero pamwe neyakajairwa nzira yekuwedzera zvishoma nezvishoma. Iyo AFt makristasi pamwe ne c yakajairika nzira yakava shoma uye shoma. Iyo inonyanya kukosha chikamu chetatu-dimensional nzvimbo inoumbwa neyakajairwa mutsara, b yakajairika mutsara uye c yakajairwa mutsara iyo inotenderera kune imwe neimwe. Muchiitiko chekuti b zvakajairwa zvakagadziriswa, AFt makristasi akaungana pamwe neyakajairwa, zvichikonzera kuwedzera sero muchinjiko chikamu mundege yeab normals. Nokudaro, kana HEMC "ichichengeta" mvura yakawanda kupfuura MC, nzvimbo "yakaoma" inogona kuitika munzvimbo yakagara, ichikurudzira lateral aggregation uye kukura kweAft crystals. Patural et al. vakawana kuti CE pachayo, iyo yakakwira dhigirii yepolymerization (kana iyo yakakura huremu hwemamorekuru), iyo yakakura viscosity yeEC uye zvirinani kuchengetedza kwemvura kuita. Iyo molecular structure yeHEMCs neMCS inotsigira pfungwa iyi, neboka rehydroxyethyl rine huremu hwakakura zvikuru kupfuura boka rehydrogen.

Kazhinji, makristasi eAFt anoumba uye anonaya chete kana maion akakodzera asvika pane imwe saturation mugadziriro yekugadzirisa. Naizvozvo, zvinhu zvakaita senge ion concentration, tembiricha, pH kukosha uye nzvimbo yekugadzira mumhinduro mhinduro inogona kukanganisa zvakanyanya morphology yeAFt makristasi, uye shanduko mumamiriro ekugadzira ekugadzira anogona kushandura morphology yeAFt makristasi. Naizvozvo, chiyero che AFt makristasi mune yakajairwa simende slurry pakati pezviviri izvi inogona kukonzerwa nechinhu chimwe chete chekushandiswa kwemvura mukutanga hydration ye simenti. Zvisinei, mutsauko muAFt crystal morphology inokonzerwa neHEMC uye MC inofanira kunyanya kukonzerwa nehutano hwavo hwekuchengetedza mvura. Hemcs neMCS vanogadzira “kuvharwa” kwezvifambiso zvemvura mukati memicrozone yematope matsva esimende, zvichiita kuti pave ne“nguva pfupi” umo mvura “iri nyore kupinda uye yakaoma kubuda.” Nekudaro, panguva ino, iyo yemvura chikamu nharaunda mukati uye padyo neiyo microzone inoshandurwa zvakare. Zvinhu zvakadai seiyo ion concentration, pH, nezvimwewo, Shanduko yenzvimbo yekukura inotaridzwazve mune morphological maitiro eAFt makristasi. Iyi "loop yakavharwa" yekutakura kwemvura yakafanana neyo nzira yekuita inotsanangurwa naPourchez et al. HPMC ichiita basa mukuchengetedza mvura.

3. Mhedziso

(1) Kuwedzerwa kwehydroxyethyl methyl cellulose ether (HEMC) uye methyl cellulose ether (MC) inogona kuchinja zvakanyanya morphology ye ettringite mukutanga (1 zuva) yakajairika simende slurry.

(2) Kureba uye dhayamita ye ettringite crystal muHEMC yakagadziridzwa simende slurry idiki uye pfupi tsvimbo chimiro; Hurefu uye dhayamita reshiyo ye ettringite makristasi muMC yakagadziridzwa simende slurry yakakura, inova yetsono-tsvimbo chimiro. Iwo ettringite makristasi mune akajairwa simende slurries ane aspect ratio pakati pezviviri izvi.

(3) Mhedzisiro yakasiyana yeviri cellulose ethers pane morphology ye ettringite inonyanya kukonzerwa nekusiyana kwehuremu hwema molecular.