Siyabonga ngokuvakashela i-Nature.com.Inguqulo yesiphequluli oyisebenzisayo inokusekelwa okulinganiselwe kwe-CSS.Ukuze uthole ulwazi olungcono kakhulu, sincoma ukuthi usebenzise isiphequluli esibuyekeziwe (noma uvale imodi yokuhambisana ku-Internet Explorer).Okwamanje, ukuze siqinisekise ukwesekwa okuqhubekayo, sizobonisa isayithi ngaphandle kwezitayela ne-JavaScript.
I-Microbial corrosion (MIC) iyinkinga enkulu ezimbonini eziningi njengoba ingabangela ukulahlekelwa okukhulu kwezomnotho.I-2707 super duplex stainless steel (2707 HDSS) isetshenziswe ezindaweni zasolwandle ngenxa yokumelana kwayo namakhemikhali okuhle kakhulu.Kodwa-ke, ukumelana kwayo ne-MIC akukaze kuboniswe ngokuhlolwa.Kulolu cwaningo, ukuziphatha kwe-MIC kwe-2707 i-aerobics ye-2707 HDSS ibangelwa i-bacterissumdougaerug ye-bacterissum i-aerobics ye-2707 HDSS. .Ukuhlaziywa kwe-electrochemical kwabonisa ukuthi phambi kwe-Pseudomonas aeruginosa biofilm ku-2216E medium, kube noshintsho oluhle emandleni okugqwala kanye nokwanda kokugqwala kwamanje kokugqwala.Ukuhlaziywa kwe-X-ray photoelectron spectroscopy (XPS) kubonise ukuncipha kokuqukethwe kwe-Cr ebusweni besifanekiso esingaphansi kwe-biofilm ekhiqiza i-biofilm ekhiqiza i-biofilm ephezulu. ka-0.69 μm phakathi nezinsuku eziyi-14 zokufukamela. Nakuba lokhu kukuncane, kubonisa ukuthi i-2707 HDSS ayivikelekile ngokugcwele ku-MIC ye-P. aeruginosa biofilms.
I-Duplex stainless steels (DSS) isetshenziswa kabanzi ezimbonini ezihlukahlukene ngokuhlanganiswa kwayo okuhle kwezakhiwo ezinhle kakhulu zemishini kanye nokumelana nokugqwala1,2.Nokho, umgodi wendawo usaqhubeka usenzeka futhi uthinta ubuqotho bale steel3,4.DSS ayimelani nokugqwala kwe-microbial (MIC)5,6.Naphezu kobubanzi obubanzi bokusetshenziswa kwemvelo ye-DSS eyanele lapho kusenezinhlelo zokusebenza zokumelana ne-DSS isikhathi eside lapho i-DSS isetshenziswa khona isikhathi eside. .Lokhu kusho ukuthi kudingeka izinto ezibiza kakhulu ezinokumelana nokugqwala okuphezulu.U-Jeon et al7 bathole ukuthi ngisho nezinsimbi ezingenasici ze-duplex (SDSS) zinemikhawulo ethile mayelana nokumelana nokugqwala.Ngakho-ke, ama-super duplex stainless steels (HDSS) anokumelana nokugqwala okuphakeme kuyadingeka kwezinye izinhlelo zokusebenza.Lokhu kuholele ekuthuthukisweni kwe-HDSS enengxubevange ephezulu.
Ukumelana nokugqwala kwe-DSS kuncike esilinganisweni sezigaba ze-alpha ne-gamma kanye ne-Cr, Mo kanye ne-W izifunda eziphelile 8, 9, 10 eziseduze nesigaba sesibili.I-HDSS iqukethe okuqukethwe okuphezulu kwe-Cr, Mo ne-N11, ngakho-ke inokumelana nokugqwala okuhle kakhulu kanye nenani eliphezulu (45-50) I-Pitting Resistance Equit (PREN. I-0.5 wt% W) + 16 wt% N12.Ukumelana kwayo okuhle kakhulu nokugqwala kuncike ekubunjweni okulinganiselayo okuqukethe cishe izigaba ze-50% ze-ferrite (α) kanye ne-50% austenite (γ), i-HDSS inezakhiwo ezingcono zemishini nokumelana okuphezulu kune-DSS13 evamile.Izakhiwo ze-Chloride corrosion.Ukumelana nokugqwala okuthuthukisiwe kwandisa ukusetshenziswa kwe-HDSS ezindaweni ezigqwalile ze-chloride, njengendawo yasolwandle.
Ama-MIC ayinkinga enkulu ezimbonini eziningi ezifana nezinsiza zikawoyela negesi nezamanzi14.I-MIC yenza u-20% wawo wonke umonakalo wokugqwala15.MIC ukugqwala kwe-bioelectrochemical okungabonwa ezindaweni eziningi.Amafilimu e-biofilm akha ezindaweni zensimbi ashintsha izimo ze-electrochemical, ngaleyo ndlela athinte inqubo yokugqwala okukholelwa ukuthi i-MICE ibangelwa ukugqwala kwe-microorganism. s i-corrode metals ukuze ithole amandla asekelayo ukuze uphile17.Ucwaningo lwakamuva lwe-MIC lubonise ukuthi i-EET (ukudluliselwa kwe-electron engaphandle) iyisici sokunciphisa isilinganiso ku-MIC esibangelwa ama-electrogenic microorganisms.Zhang et al.I-18 ibonise ukuthi abaxhumanisi be-electron basheshisa ukudluliswa kwe-electron phakathi kwamaseli e-Desulfovibrio sessificans kanye ne-304 yensimbi engagqwali, okuholela ekuhlaselweni okunzima kakhulu kwe-MIC.Enning et al.19 kanye noVenzlaff et al.20 ibonise ukuthi amabhaktheriya e-corrosive sulfate-reducing (SRB) biofilms angamunca ngokuqondile ama-electron asuka kuma-substrates ensimbi, okuholela ekugqwaleni okukhulu kwemigodi.
I-DSS yaziwa ngokungenwa kalula yi-MIC ezindaweni eziqukethe i-SRB, amagciwane e-iron-reducing (IRB), njll. 21 .Lawa magciwane abangela umgodi wendawo endaweni ye-DSS ngaphansi kwe-biofilms22,23.Ngokungafani ne-DSS, i-MIC ye-HDSS24 ayaziwa kahle.
I-Pseudomonas aeruginosa iyi-bacterium emise okwe-gram-negative motile esakazwa kabanzi emvelweni25.I-Pseudomonas aeruginosa nayo iyiqembu elikhulu le-microbial endaweni yasolwandle, okwenza i-MIC ibe yinsimbi.I-Pseudomonas ihileleke kakhulu ezinqubweni zokugqwala futhi ibonakala njengephayona le-almafilmt e-biomafilm.28 kanye noYuan et al.29 ibonise ukuthi i-Pseudomonas aeruginosa inomkhuba wokwandisa izinga lokugqwala kwensimbi ethambile nama-alloys ezindaweni ezinamanzi.
Inhloso eyinhloko yalo msebenzi bekuwukuphenya izakhiwo ze-MIC ze-2707 HDSS ezibangelwa i-marine aerobic bacterium i-Pseudomonas aeruginosa isebenzisa izindlela ze-electrochemical, amasu okuhlaziya umphezulu kanye nokuhlaziywa komkhiqizo wokugqwala. okwenziwe ukutadisha ukuziphatha kwe-MIC kwe-2707 HDSS.Ukuhlaziywa kwe-Energy dispersive spectrometer (EDS) kwenziwa ukuze kutholwe izakhi zamakhemikhali endaweni egqwalile.Ngaphezu kwalokho, ukuhlaziywa kwe-X-ray photoelectron spectroscopy (XPS) kwasetshenziswa ukuze kutholwe ukuzinza kwefilimu ye-oxide passivation ngaphansi kwethonya lendawo yasolwandle equkethe i-Pseudomonas pieruginosa ukujula kwe-laser ye-SMl i-scanning ye-laser ye-scan.
Ithebula 1 libala ukwakheka kwamakhemikhali kwe-2707 HDSS.Table 2 libonisa ukuthi ama-2707 HDS anezakhiwo ezinhle kakhulu ze-HDS.Elongaded of auesture eziphathwayo nge-microscucture equkethe cishe ama-50%
Umfanekiso 2a ubonisa amandla okujikeleza avulekile (Eocp) ngokumelene nedatha yesikhathi sokuchayeka ye-2707 HDSS ku-abiotic 2216E medium kanye ne-P. aeruginosa umhluzi izinsuku ezingu-14 ku-37 °C.Kubonisa ukuthi ushintsho olukhulu nolubalulekile ku-Eocp lwenzeka phakathi namahora angu-24 okuqala. bese yehla ngokucijile, yafinyelela -477 mV (vs. SCE) kanye -236 mV (vs. SCE) yesampula ye-abiotic kanye no-P, ngokulandelanayo ).I-Pseudomonas aeruginosa amakhuphoni, ngokulandelanayo.Ngemva kwamahora angu-24, inani le-Eocp elingu-2707 HDSS le-P. aeruginosa lalizinzile ngokuqhathaniswa kokuthi -228 mV (vs. SCE), kuyilapho inani elihambisanayo lamasampuli angewona awebhayoloji lalicishe libe ngu- -442 mV (vs. I-SCE esikhundleni sokuba khona kwe-Porugino ephansi).
Ukuhlolwa kwe-Electrochemical kwezibonelo ze-2707 HDSS ku-abiotic medium kanye nomhluzi we-Pseudomonas aeruginosa ku-37 °C:
(a) I-Eocp njengomsebenzi wesikhathi sokuchayeka, (b) ijika le-polarization ngosuku 14, (c) Rp njengomsebenzi wesikhathi sokuchayeka kanye (d) ne-icorr njengomsebenzi wesikhathi sokuchayeka.
Ithebula lesi-3 libala amanani wepharamitha ye-electrochemical corrosion of 2707 HDSS amasampuli avezwe ku-abiotic medium kanye ne-Pseudomonas aeruginosa inoculated medium izinsuku ezingu-14. Ama-tangents we-anodic kanye nama-cathodic curves akhishwe ukuze afike ezimpambanweni eziveza ukugqwala kwe-corrosion current kanye ne-corrrosion yamanje ye-corrrosion (i-corrrosion yamanje) βc) ngokwezindlela ezijwayelekile30,31.
Njengoba kuboniswe kuMfanekiso 2b, ukushintshwa okuya phezulu kwejika le-P. aeruginosa kubangele ukwanda kwe-Ecorr uma kuqhathaniswa nejika le-abiotic.Inani le-icorr, elilingana nezinga lokugqwala, lenyuke laya ku-0.328 μA cm-2 ku-Pseudomonas aeruginosa isampula, μ Aeruginosa izikhathi ezine ze-μA-7 izikhathi ezine ze-biological).
I-LPR iyindlela yakudala ye-electrochemical engabhubhisi yokuhlaziya ukugqwala okusheshayo.Yaphinde yasetshenziselwa ukutadisha i-MIC32.Umfanekiso 2c ubonisa ukumelana ne-polarization (Rp) njengomsebenzi wesikhathi sokuchayeka.Ivelu ephezulu ye-Rp isho ukugqwala okuncane. Phakathi namahora okuqala angu-24, i-Rp engu-2707 HDSS ifinyelele inani eliphakeme elingu-5 kbiotic 9 cm 9Ω1 cm2 kanye ne-5 kbiotic cm29 cm ephezulu kumasampula e-Pseudomonas aeruginosa.Umfanekiso 2c uphinda ubonise ukuthi inani le-Rp lehle ngokushesha ngemva kosuku olulodwa futhi lahlala lingashintshile kangako ezinsukwini eziyi-13 ezilandelayo. Inani le-Rp lesampula le-Pseudomonas aeruginosa licishe libe ngu-40 kΩ cm2, eliphansi kakhulu kunesampula engu-450 kΩ-cm2 yesampula ye-nonbiological.
Inani le-icorr lilingana nezinga lokugqwala elifanayo.Inani layo lingabalwa kusukela kuzibalo ezilandelayo ze-Stern-Geary,
Ukulandela uZou et al.33, inani elijwayelekile le-Tafel slope B kulo msebenzi licatshangwe ukuthi lingu-26 mV/dec. Umfanekiso 2d ubonisa ukuthi i-icorr yesampula engeyona eyebhayoloji engu-2707 ihlale izinzile, kuyilapho isampula ye-P. aeruginosa iguquguquka kakhulu ngemva kwamahora angu-24 okuqala. izilawuli zesayensi.Lo mkhuba uhambisana nemiphumela yokumelana ne-polarization.
I-EIS ingenye indlela engonakali esetshenziselwa ukuveza ukusabela kwe-electrochemical ezindaweni ezigqwalile.I-Impedance spectra kanye namanani okubalwa amandla ezibonelo ezivezwe kumidiya ye-abiotic kanye nesixazululo se-Pseudomonas aeruginosa, ukumelana ne-Rb kwefilimu/ifilimu ye-biofilm okwakhiwa phezu kwesifanekiso, ukumelana nogesi we-Rct chargence, i-Cdl Electron CPE) amapharamitha.Le mingcele yabuye yahlaziywa ngokufaka idatha kusetshenziswa imodeli yesekethe elinganayo (EEC).
Umfanekiso wesi-3 ubonisa iziza ze-Nyquist ezijwayelekile (a no-b) kanye neziza ze-Bode (a' kanye no-b') zamasampula e-HDSS angu-2707 ku-abiotic medium kanye nomhluzi we-P. aeruginosa ngezikhathi ezahlukene zokufukamela. isikhathi sokuphumula esingaguquki singanikezwa yi-phase maxima.Umfanekiso 4 ubonisa i-monolayer (a) kanye ne-bilayer (b) izakhiwo ezisekelwe ngokomzimba kanye nama-EEC azo ahambisanayo.CPE yethulwa kumodeli we-EEC.Ukuvuma nokuvinjelwa kwayo kuvezwa kanje:
Amamodeli amabili angokomzimba namasekhethi ahambisanayo afanayo wokufaka i-spectrum ye-impedance yesifanekiso se-2707 HDSS:
lapho i-Y0 iwubukhulu be-CPE, j inombolo ecatshangelwayo noma (-1) 1/2, ω imvamisa ye-angular, futhi n inkomba yamandla e-CPE engaphansi kobunye35.I-inverse of the charge transfer resistance (okungukuthi 1/Rct) ihambisana nezinga lokugqwala.I-Rct encane isho ukuthi i-corrosion rate ye-Pmona yezinsuku ezingu-27 isho ukugqwala okusheshayo kwezinsuku ezingu-27. amasampula e-eruginosa afinyelele ku-32 kΩ cm2, amancane kakhulu kuno-489 kΩ cm2 wamasampuli angewona awebhayoloji (Ithebula 4).
Izithombe ze-CLSM nezithombe ze-SEM kumfanekiso wesi-5 zibonisa ngokusobala ukuthi ukumbozwa kwe-biofilm ebusweni besampula engu-2707 HDSS ngemva kwezinsuku ezingu-7 kuminyene. Nokho, ngemva kwezinsuku eziyi-14, ukumbozwa kwe-biofilm bekumbalwa futhi kwavela amaseli afile. kusukela ku-23.4 μm ngemva kwezinsuku ezingu-7 kuya ku-18.9 μm ngemva kwezinsuku ezingu-14. Ubukhulu obujwayelekile be-biofilm buphinde buqinisekisa lo mkhuba.Yehla ukusuka ku-22.2 ± 0.7 μm ngemva kwezinsuku ezingu-7 kuya ku-17.8 ± 1.0 μm ngemva kwezinsuku ezingu-14.
(a) Isithombe se-3-D CLSM ngemva kwezinsuku ezingu-7, (b) isithombe se-3-D CLSM ngemva kwezinsuku eziyi-14, (c) Isithombe se-SEM ngemva kwezinsuku ezingu-7 kanye (d) nesithombe se-SEM ngemva kwezinsuku eziyi-14.
I-EDS yembule izakhi zamakhemikhali kuma-biofilms kanye nemikhiqizo yokugqwala kumasampuli adalulwe ku-P. aeruginosa izinsuku eziyi-14. Umfanekiso 6 ubonisa ukuthi okuqukethwe kwe-C, N, O, no-P ku-biofilms nemikhiqizo yokugqwala kuphakeme kakhulu kunalokho okusezinsimbi ezingenalutho, ngoba lezi zakhi zihlotshaniswa nama-biofilms kanye nama-metabolites awo.Ama-Microbes we-C, ne-Feromilli ye-iron adinga inani eliphakeme le-iron kanye ne-Feromilli ye-iron idinga kuphela inani le-iron kanye ne-Feromilli ephezulu imikhiqizo ye-rosion ebusweni bezibonelo ibonisa ukuthi i-matrix yensimbi ilahlekelwe izakhi ngenxa yokugqwala.
Ngemva kwezinsuku ezingu-14, umgodi onama-P. aeruginosa nangaphandle kwawo wawubonwa ku-2216E medium. Ngaphambi kokufukamela, indawo yesampula yayibushelelezi futhi ingenasici (Fig. 7a) .Ngemva kokufukamela nokususwa kwemikhiqizo ye-biofilm ne-corrosion, imigodi ejulile ebusweni bezibonelo yahlolwa njengoba kuboniswe ngaphansi kwe-7 ye-figure ye-ClNo. -amasampula okulawula izinto eziphilayo (ubukhulu bomgodi ukujula 0.02 μm).Ukujula komgodi okukhulu okubangelwa i-Pseudomonas aeruginosa kwaba ngu-0.52 μm ngemva kwezinsuku ezingu-7 kanye no-0.69 μm ngemva kwezinsuku ezingu-14, ngokusekelwe ekujuleni komgodi okulinganiselwe kwamasampula angu-3 (amasampula aphezulu angu-10 wokujula komgodi) afinyelelwe ku-2 μ± 20 amasampuli angu-2 ± 20 ± 20.4 ± 20 ngayinye. 0.15 μm, ngokulandelanayo (Ithebula 5).Lawa manani wokujula komgodi mancane kodwa abalulekile.
(a) Ngaphambi kokuchayeka, (b) izinsuku eziyi-14 ku-abiotic medium kanye (c) nezinsuku eziyi-14 kumhluzi we-Pseudomonas aeruginosa.
Umfanekiso 8 ubonisa i-spectra ye-XPS yezindawo ezihlukene zesampula, futhi ukwakheka kwamakhemikhali okuhlaziywe kwendawo ngayinye kufinyezwa kuThebula 6.Kuthebula lesi-6, amaphesenti e-athomu ka-Fe ne-Cr ebukhoneni be-P. aeruginosa (amasampula A no-B) abephansi kakhulu kunalawo amasampuli okulawula okungewona awebhayoloji (amasampuli e-Drugel-Cr kanye ne-Druginovel Cr). ijika le-spectral lifakwe ezingxenyeni ezine eziphezulu ezinamandla abophezelayo (BE) amanani angu-574.4, 576.6, 578.3 kanye no-586.8 eV, okungamaniswa ku-Cr, Cr2O3, CrO3 kanye ne-Cr(OH)3, ngokulandelanayo (Fig. 9a i-spectrum-spectrum, i-spectrum ye-bhloologica kanye ne-browser ye-cr. iziqongo ezimbili eziyinhloko ze-Cr (573.80 eV ye-BE) kanye ne-Cr2O3 (575.90 eV ye-BE) ku-Fig. 9c kanye no-d, ngokulandelana.Umehluko omangalisa kakhulu phakathi kwamasampula e-abiotic kanye ne-P. aeruginosa ubukhona be-Cr6+ kanye nengxenye ehlobene engaphezulu ye-Cr(OH)8 ye-efilm beneathm8 ye-beathm.
I-spectra ebanzi ye-XPS yobuso besampula ye-2707 HDSS kumidiya emibili yizinsuku eziyi-7 nezinsuku eziyi-14, ngokulandelana.
(a) Izinsuku eziyi-7 zokuchayeka ku-P. aeruginosa, (b) izinsuku eziyi-14 zokuchayeka ku-P. aeruginosa, (c) izinsuku eziyi-7 ku-abiotic medium kanye (d) nezinsuku eziyi-14 endaweni ye-abiotic.
I-HDSS ibonisa amazinga aphezulu okumelana nokugqwala ezindaweni eziningi.Kim et al.2 ibike ukuthi i-UNS S32707 HDSS ichazwe njenge-DSS enengxubevange ephezulu ene-PREN engaphezu kuka-45. Inani le-PREN lesampula le-2707 HDSS kulo msebenzi lalingu-49. Lokhu kungenxa yokuqukethwe kwayo okuphezulu kwe-chromium kanye namazinga aphezulu e-molybdenum kanye ne-Ni, okunenzuzo endaweni ene-acidic kanye ne-microdefect-free-chloride ewusizo ukuzinza kwesakhiwo nokumelana nokugqwala.Nokho, naphezu kokumelana kwayo okuhle kakhulu namakhemikhali, idatha yokuhlola kulo msebenzi iphakamisa ukuthi i-2707 HDSS ayivikelekile ngokuphelele ku-MIC ye-P. aeruginosa biofilms.
Imiphumela ye-electrochemical ibonise ukuthi izinga lokugqwala le-2707 HDSS ku-P. aeruginosa umhluzi lenyuke kakhulu ngemva kwezinsuku ezingu-14 uma kuqhathaniswa ne-non-biological medium. Emfanekisweni 2a, ukuncipha kwe-Eocp kwabonwa kokubili okuphakathi kwe-abiotic kanye nomhluzi we-P. aeruginosa phakathi namahora angu-24 okuqala. 6.Nokho, izinga le-Eocp yezinto eziphilayo laliphezulu kakhulu kunele-Eocp engeyona eyebhayoloji.Kunesizathu sokukholelwa ukuthi lo mehluko ubangelwa ukwakheka kwe-biofilm ye-P. aeruginosa.Kumfanekiso we-2d, phambi kwe-P. aeruginosa, inani le-icorr le-2707 HDSS lafinyelela ku-0.620 oda lokuphakama kwe-μA ngaphezu kwe-magnia yokulawula okungu-0. I-63 μA cm-2), eyayihambisana nenani le-Rct elilinganiswa yi-EIS. Phakathi nezinsuku ezimbalwa zokuqala, amanani e-impedance ku-P. aeruginosa umhluzi akhuphuka ngenxa yokunamathiselwe kwamaseli e-P. aeruginosa nokwakhiwa kwama-biofilms. Ngakho-ke, ukumelana nokugqwala kwehla ngokuhamba kwesikhathi, futhi okunamathiselwe kwe-P. aeruginosa kubangele ukugqwala kwendawo.Amathrendi emithonjeni yezindaba ye-abiotic ayehlukile.Ukumelana nokugqwala kokulawula okungekona okwebhayoloji kwakuphakeme kakhulu kunenani elihambisanayo lamasampuli adalulwe kumhluzi we-P. aeruginosa.Ngaphezu kwalokho, ngamasampula e-abiotic, inani le-Abiotic ΩΩ Ω 2707 SS lifinyelele ku-2709 cm ngosuku lwe-RctΩ2707 ye-HDΩ efinyelela ku-2748 kSS ngosuku lwe-RctΩ2727 ye-HD. yayiphindwe izikhathi ezingu-15 inani le-Rct (32 kΩ cm2) ebukhoneni be-P. aeruginosa.Ngakho-ke, i-2707 HDSS inokumelana nokugqwala okuhle kakhulu endaweni eyinyumba, kodwa ayimelani nokuhlaselwa kwe-MIC yi-P. aeruginosa biofilms.
Le miphumela ingabuye ibonwe kusukela kuma-polarization curves ku-Fig. 2b.I-anodic branching kwathiwa i-Pseudomonas aeruginosa biofilm formation kanye nokusabela kwe-oxidation yensimbi.Ngaso leso sikhathi ukusabela kwe-cathodic ukuncishiswa kwe-oxygen.Ukuba khona kwe-P. aeruginosa kwandisa kakhulu ukugqwala kwe-corrosion order ephakeme kunomthamo omkhulu. I-ruginosa biofilm inyusa ukugqwala kwendawo okungu-2707 HDSS.Yuan et al29 bathole ukuthi ukugqwala kwamanje kwe-70/30 Cu-Ni alloy kwenyuke ngaphansi kwenselelo ye-P. aeruginosa biofilm.Lokhu kungase kube ngenxa yokuhlaziywa kwe-biocatalysis yokunciphisa umoya-mpilo nge-Pseudomonas aeruginos c ama-biofilms angase abe nomoya-mpilo omncane ngaphansi kwawo.Ngakho-ke, ukwehluleka ukuphinda kudlule indawo yensimbi nge-oxygen kungase kube isici esinomthelela ku-MIC kulo msebenzi.
Dickinson et al.I-38 iphakamise ukuthi amazinga okuphendula kwamakhemikhali kanye ne-electrochemical angathinteka ngokuqondile umsebenzi we-metabolic we-bacterial sessile ebusweni besampula kanye nemvelo yemikhiqizo yokugqwala.Njengoba kuboniswe kuMfanekiso 5 kanye neThebula 5, kokubili inombolo yeseli kanye nokuqina kwe-biofilm kwehle ngemva kwezinsuku ze-14. i-2216E medium noma ukukhishwa kwama-ion ensimbi anobuthi kusukela ku-matrix ye-HDSS engu-2707. Lona umkhawulo wokuhlolwa kwenqwaba.
Kulo msebenzi, i-P. aeruginosa biofilm ikhuthaze ukuncipha kwendawo kwe-Cr ne-Fe ngaphansi kwe-biofilm endaweni engu-2707 HDSS (I-Fig. 6).Kuthebula lesi-6, ukuncishiswa kwe-Fe ne-Cr kusampula D uma kuqhathaniswa nesampula C, okubonisa ukuthi i-Fe ne-Cr encibilikisiwe ebangelwa i-P. aeruginosa imvelo esetshenziswe ngale kwe-6 yezinsuku ze-27 ze-biofilm yokuqala. .Iqukethe i-17700 ppm Cl-, eqhathaniswa naleyo etholakala emanzini olwandle emvelo.Ukuba khona kwe-17700 ppm Cl- kwakuyisizathu esiyinhloko sokwehliswa kwe-Cr kumasampula e-abiotic ezinsuku ezingu-7 nezingu-14 ahlaziywa yi-XPS.Uma kuqhathaniswa ne-P. aeruginosabition yesampula yamasampuli aqinile we-dissor− isampula ye-discorinosabiotic eqinile ngenxa yesampula ye-dissor− ye-dissor 2707 HDSS ezindaweni eziphilayo.Umfanekiso 9 ubonisa ukuba khona kwe-Cr6+ kufilimu ye-passivation.Ingase ibandakanyeke ekukhishweni kwe-Cr endaweni yensimbi yi-P. aeruginosa biofilms, njengoba kuphakanyiswe u-Chen no-Clayton.
Ngenxa yokukhula kwebhaktheriya, amanani e-pH aphakathi ngaphambi nangemva kokutshala ayengu-7.4 no-8.2, ngokulandelana.Ngakho-ke, ngaphansi kwe-P. aeruginosa biofilm, ukugqwala kwe-organic acid mancane amathuba okuba kube nomthelela kulo msebenzi ngenxa ye-pH ephezulu kakhulu endaweni eyinqwaba.I-pH yendawo engeyona eyebhayoloji ayizange ishintshe kakhulu ngesikhathi sokulawula okungeyona eyebhayoloji engu-71. Isikhathi sokuhlola sezinsuku ezingu-4. Ukwanda kwe-pH endaweni yokugoma ngemva kokufukamela kwakungenxa yomsebenzi we-metabolic we-P. aeruginosa futhi kwatholakala ukuthi kunomphumela ofanayo ku-pH uma kungekho imichilo yokuhlola.
Njengoba kuboniswe kumfanekiso wesi-7, ukujula komgodi okuphakeme okubangelwa i-P. aeruginosa biofilm kwakungu-0.69 μm, okwakukukhulu kakhulu kunaleyo ye-abiotic medium (0.02 μm).Lokhu kuhambisana nedatha ye-electrochemical echazwe ngenhla.Ukujula komgodi okungu-0.69 μm kuncane izikhathi eziyishumi kune-μ2m inani elifanayo le-DSS elibikiwe ngaphansi kwezimo ezingu-92525. I-707 HDSS ibonisa ukumelana ne-MIC okungcono kakhulu uma kuqhathaniswa ne-2205 DSS. Lokhu akufanele kusimangaze, njengoba i-2707 HDSS inokuqukethwe kwe-chromium ephakeme, ehlinzeka ngokudlula okuhlala isikhathi eside, ngenxa yesakhiwo sesigaba esinokulinganisela ngaphandle kwe-precipitates yesibili eyingozi, okwenza kube nzima ku-P. aeruginosa ukuthi inqamule futhi iqale ukufiphala kwamaphuzu.
Ekuphetheni, umgodi we-MIC watholakala ebusweni be-2707 HDSS ku-P. aeruginosa umhluzi uma kuqhathaniswa nokubhoboza okungenangqondo emithonjeni ye-abiotic.Lo msebenzi ubonisa ukuthi i-2707 HDSS inokumelana okungcono kwe-MIC kune-2205 DSS, kodwa ayivikelekile ngokugcwele ku-MIC ngenxa ye-P. aeruginosa biofilm.
Ikhuphoni le-2707 HDSS linikezwa iSikole Se-Metallurgy sase-Northeastern University (NEU) e-Shenyang, e-China.Ukwakheka okuyisisekelo kwe-2707 HDSS kuboniswa kuThebula 1, elahlaziywa Umnyango Wokuhlaziywa Kwezinto Zokusebenza kanye Nokuhlola we-NEU.Wonke amasampuli aphathwe ku-1180 °C nge-top-exposed SS ye-1-corroped ye-SS engu-20hroped ihora le-SS elivezwe ngehora elingu-7. indawo engu-1 cm2 yapholishwa yaba igridi engu-2000 ngephepha le-silicon carbide yaphinde yapholishwa ngokumiswa kwempushana engu-0.05 μm Al2O3. Izinhlangothi nangaphansi kuvikelwe ngopende ongenayo. Ngemva kokoma, izibonelo zagezwa ngamanzi angcolile ahlanjululwe futhi zafakwa inzalo ngo-75% we-ultraviolet.0v. V) ukukhanya amahora angu-0.5 ngaphambi kokusetshenziswa.
I-Marine Pseudomonas aeruginosa I-MCCC 1A00099 strain yathengwa e-Xiamen Marine Culture Collection Centre (MCCC), e-China.I-Pseudomonas aeruginosa ikhuliswe ngendlela ye-aerobic ngo-37°C kuma-flasks angu-250 ml kanye no-500 ml wengilazi yamaseli e-electrochemical kusetshenziswa i-Marine 2216E yase-China ye-Biotechingda liquid (QMedium. I-Sidium (g/L): 19.45 NaCl, 5.98 MgCl2, 3.24 Na2SO4, 1.8 CaCl2, 0.55 KCl, 0.16 Na2CO3, 0.08 KBr, 0.034 SrCl2, 0.08 3000 2, 2 SrO4, 2 H00, 2 H 6 NH3, 0016 NH3, 0016 NaH2PO4, 5.0 peptone, 1.0 yeast extract kanye ne-0.1 ferric citrate.Autoclave ku-121 ° C imizuzu engu-20 ngaphambi kwe-inoculation.Bala amaseli e-sessile kanye ne-planktonic usebenzisa i-hemocytometer ngaphansi kwe-4000mktometer ye-microscope ekhanyayo ye-microscope ye-X i-microscope yokukhanya kwe-X i-microscope yokukhanya kwe-microscope yokukhanya inosa ngokushesha ngemva kokujova cishe 106 cells/ml.
Ukuhlolwa kwe-electrochemical kwenziwa kuseli yengilazi yakudala ene-electrode emithathu enevolumu ephakathi engu-500 ml. Ishidi leplatinamu kanye ne-calomel electrode egcwele (SCE) kuxhunywe ku-reactor ngama-Luggin capillaries agcwele amabhuloho kasawoti, asebenza njengama-counter and reference electrode, ngokulandelana. -indawo esemaceleni ye-electrode esebenzayo.Ngesikhathi sokulinganisa i-electrochemical, amasampula abekwe ku-2216E medium futhi agcinwe ekushiseni okungaguquki kwe-incubation (37 ° C) endaweni yokugezela yamanzi.OCP, LPR, EIS kanye nedatha ye-polarization engase ibe namandla alinganiswa kusetshenziswa i-Autolab potentiostat (Reference 600TM, I-Gam.1 yokuhlola i-Incubation Instruments ye-USA). I-s-1 ebangeni le--5 ne-5 mV nge-Eocp kanye nemvamisa yesampula ye-1 Hz.EIS yenziwa nge-sine wave ebangeni lemvamisa engu-0.01 kuya ku-10,000 Hz kusetshenziswa i-voltage engu-5 mV esetshenziswayo endaweni engaguquki Eocp. 2 kuya ku-1.5 V vs. EoCP ngesilinganiso sokuskena esingu-0.166 mV/s.Ukuhlolwa ngakunye kwaphindwa izikhathi ezi-3 nge-P. aeruginosa nangaphandle kwayo.
Izibonelo zokuhlaziywa kwe-metallographic zapholishwa ngomshini ngephepha le-SiC elimanzi elingu-2000 bese zipholishwa ngokuqhubekayo ngempushana engu-0.05 μm Al2O3 yokumiswa okuyimpushana ukuze ibonwe.
Ngemuva kokufukamela, amasampula ahlanzwa izikhathi ezi-3 ngesisombululo se-phosphate-buffered saline (PBS) (pH 7.4 ± 0.2) abese ehlanganiswa ne-2.5% (v/v) glutaraldehyde amahora angu-10 ukulungisa ama-biofilms. Ngemva kwalokho yaphelelwa amanzi ngochungechunge lwezigaba (50%, 8, 9, 70%, 70%, 50%, 9%, 70%, 70%, 70%, 50%, 70%, 70%, 70%, 70%, 70%, 9%, 70%, 50%, 9%, 70%, 70%, 70%, 70%, 70%, 70%, 9%, 9%, 9%, 70%, 9%, 9%, 70%, 9. I-00% v/v) ye-ethanol ngaphambi kokoma komoya.Ekugcineni, ingaphezulu lesampula lifafazwa ngefilimu yegolide ukuze kuhlinzekwe ukuqhutshwa kokubhekwa kwe-SEM.Izithombe ze-SEM bezigxile ezindaweni ezinamaseli e-P. aeruginosa anyakazayo kakhulu endaweni yesifanekiso ngasinye.Yenza ukuhlaziya kwe-EDS ukuze uthole izakhi zamakhemikhali.ALSSMMS I-Scanning ye-SMCS1 Germany yasetshenziswa ukukala ukujula komgodi.Ukuze kubonwe imigodi yokugqwala ngaphansi kwe-biofilm, ucezu lokuhlola lwaqale lwahlanzwa ngokuvumelana ne-Chinese National Standard (CNS) GB/T4334.4-2000 ukuze kukhishwe imikhiqizo yokugqwala kanye ne-biofilm ebusweni besiqephu sokuhlola.
I-X-ray photoelectron spectroscopy (i-XPS, i-ESCALAB250 uhlelo lokuhlaziya indawo, i-Thermo VG, e-USA) ukuhlaziywa kwenziwa kusetshenziswa umthombo we-X-ray we-monochromatic (umugqa we-aluminium Kα ku-1500 eV amandla kanye namandla angu-150 W) phezu kwebanga elibanzi lamandla abophayo 0 ngaphansi kwezimo ezijwayelekile -1350 eV.High-resolution berekhoda i-eV yesinyathelo se-20 ye-eV.
Ama-specimens afakiwe asusiwe futhi ahlanjululwa kahle nge-PBS (pH 7.4 ± 0.2) ye-15 s45. Ukuze kubhekwe ukusebenza kwebhaktheriya kwama-biofilms kumasampuli, ama-biofilms angcoliswa kusetshenziswa i-LIVE/DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, Eugene fluorescent, USA) Udayi we-SYTO-9 kanye nodayi we-fluorescent we-propidium iodide (PI) obomvu.Ngaphansi kwe-CLSM, amachashazi anombala oluhlaza okotshani kanye nobomvu amelela amaseli aphilayo nafile, ngokulandelana.Ngokokufaka amabala, ingxube engu-1 ml equkethe u-3 μl SYTO-9 kanye ne-3 μl PI ifakwe i-incubated imizuzu engu-20 oC emazingeni okushisa angama-23 ama-stainer amnyama abonwa ngama-stainer angama-23 ekamelweni. (488 nm yamaseli aphilayo kanye no-559 nm wamaseli afile) kusetshenziswa umshini we-Nikon CLSM (C2 Plus, Nikon, Japan).Ukujiya kwe-Biofilm kukalwe ngemodi yokuskena engu-3-D.
Indlela yokucaphuna lesi sihloko: Li, H. et al.Microbial corrosion of 2707 super duplex stainless steel by marine Pseudomonas aeruginosa biofilm.science.Rep.6, 20190;doi: 10.1038/srep20190 (2016).
I-Zanotto, F., Grassi, V., Balbo, A., Monticelli, C. & Zucchi, F. Stress corrosion cracking ye-LDX 2101 duplex stainless steel in chloride solution phambi kwe-thiosulfate.coros.science.80, 205–212 (2014).
UKim, ST, Jang, SH, Lee, IS & Park, YS Umphumela wokwelashwa kokushisa kwesixazululo kanye ne-nitrogen ekuvikelweni kwegesi ekuvikelekeni kokugqwala kwe-pitting ye-super duplex stainless steel welds.coros.science.53, 1939-1947 (2011).
Shi, X., Avci, R., Geiser, M. & Lewandowski, Z. A Comparative Chemical Study of Microbial and Electrochemically Induced Pitting Corrosion in 316L Stainless Steel.coros.science.45, 2577–2595 (2003).
Luo, H., Dong, CF, Li, XG & Xiao, K. Electrochemical behaviour of 2205 duplex stainless steel in alkaline solutions of different pH in the presence of chloride.Electrochim.Journal.64, 211–220 (2012).
Little, BJ, Lee, JS & Ray, RI Umphumela we-marine biofilms ekugqwaleni: ukubuyekezwa okufushane.Electrochim.Journal.54, 2-7 (2008).