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I-Microbial corrosion (MIC) yingxaki enkulu kumashishini amaninzi njengoko ingabangela ilahleko enkulu yezoqoqosho.I-2707 i-super duplex stainless steel (2707 HDSS) isetyenziswe kwiindawo zaselwandle ngenxa yokumelana kwayo neekhemikhali ezigqwesileyo.Nangona kunjalo, ukuxhathisa kwayo kwi-MIC akuzange kubonakaliswe ngokomfuniselo.Kolu phononongo, ukuziphatha kwe-MIC kwe-2707 ye-aerobics ye-2707 HDSS ye-aerobics ye-Aerobics ye-HDSS I-aeruginosa iphandwa.Uhlalutyo lwe-Electrochemical lubonise ukuba phambi kwe-Pseudomonas aeruginosa biofilm kwi-2216E medium, kukho utshintsho oluhle kwi-corrosion potential and ukwanda kwe-corrosion current density.Uhlalutyo lwe-X-ray photoelectron spectroscopy (XPS) lubonise ukuncipha kwi-Cr content on the surface of the surface of the specm. I-aeruginosa biofilm ivelise ubunzulu bomgodi obuyi-0.69 μm ngeentsuku ezili-14 zokufukanyelwa. Nangona oku kuncinci, kubonisa ukuba i-2707 HDSS ayikhuselekanga ngokupheleleyo kwi-MIC ye-P. aeruginosa biofilms.
Duplex steels stainless (DSS) zisetyenziswa ngokubanzi kumashishini ahlukeneyo kwindibaniselwano yazo efanelekileyo yeempawu ezigqwesileyo zoomatshini kunye nokumelana nomhlwa1,2.Nangona kunjalo, i-pitting yendawo isenzeka kwaye ichaphazela ingqibelelo yale steel3,4.DSS ayixhathisi kwi-microbial corrosion (MIC) 5,6.Nangona uluhlu olubanzi lokusingqongileyo lwe-DSS lusekhona ukuchasana kwe-DSS apho kukho ukuxhathisa okwaneleyo kwe-DSS. ukusetyenziswa ixesha elide.Oku kuthetha ukuba izinto ezibiza kakhulu kunye nokumelana nomhlwa okuphezulu kuyafuneka.I-Jeon et al7 ifumene ukuba i-super duplex stainless steels (SDSS) inemida ethile malunga nokumelana nokubola.Ngoko ke, i-super duplex stainless steels (HDSS) kunye nokumelana okuphezulu kwe-corrosion kuyafuneka kwezinye izicelo.Oku kwakhokelela ekuphuhlisweni kwe-HDSS ephezulu.
Ukumelana nokubola kwe-DSS kuxhomekeke kumlinganiselo wezigaba ze-alpha kunye ne-gamma kunye ne-Cr, i-Mo kunye ne-W iyancipha imimandla ye-8, i-9, i-10 ecaleni kwesigaba sesibini.I-HDSS iqulethe umxholo ophezulu we-Cr, i-Mo kunye ne-N11, ngoko inokumelana nokugqwesa okugqwesileyo kunye nexabiso eliphezulu (45-50) I-Pitting Resistance Equistance (3% ye-PREN) enqunywe yi-Cr + 3% ye-Equivalent. (wt.% Mo + 0.5 wt% W) + 16 wt% N12. Ukuxhatshazwa kwayo okugqwesileyo kwe-corrosion kuxhomekeke ekubunjweni okulinganayo okuqukethe malunga ne-50% ye-ferrite (α) kunye ne-50% ye-austenite (γ) izigaba, i-HDSS inezixhobo ezingcono zomatshini kunye nokuchasana okuphezulu kune-DSS13 eqhelekileyo. Iimpawu ze-Chloride corrosion.I-corrosion resistance resistance yandisa ukusetyenziswa kwe-HDSS kwiindawo ezinobungozi zekloride, ezifana neendawo zaselwandle.
Ii-MIC ziyingxaki enkulu kumashishini amaninzi afana ne-oyile kunye negesi kunye nezinto eziluncedo zamanzi14.I-MIC i-akhawunti ye-20% yawo wonke umonakalo we-corrosion15.MIC yi-bioelectrochemical corrosion enokubonwa kwiindawo ezininzi.I-Biofilms ezenza kwiindawo zetsimbi ziguqula iimeko ze-electrochemical, ngaloo ndlela zichaphazela inkqubo ye-corrosion ekholelwa ukuba i-MIC ikholelwa ngokubanzi ukuba i-corrosion process. I-biofilms.Ii-microorganisms ze-Electrogenic zigrulisa isinyithi ukuze zifumane amandla okugcina amandla ukuze ziphile17.Uphando lwakutsha nje lwe-MIC lubonise ukuba i-EET (i-extracellular electron transfer) yinto yokunciphisa izinga kwi-MIC eyenziwa yi-electrogenic microorganisms.Zhang et al. I-18 ibonise ukuba abalamli be-electron bakhawuleza ukudluliselwa kwe-electron phakathi kweeseli ze-Desulfovibrio sessificans kunye ne-304 yensimbi engenasici, ekhokelela ekuhlaselweni kwe-MIC. 19 kunye noVenzlaff et al. 20 ibonise ukuba i-corrosive sulfate-reducing bacteria (SRB) biofilms inokufunxa ngokuthe ngqo ii-electron ezisuka kwi-substrates zetsimbi, okukhokelela kwi-corrosion enzulu yepitting.
I-DSS iyaziwa ukuba ichaphazeleka kwi-MIC kwiindawo eziqulethe i-SRB, iibhaktheriya zokunciphisa isinyithi (IRB), njl.
I-Pseudomonas aeruginosa yi-gram-negative-motile-shaped rod-shaped bacterium esasazwa ngokubanzi kwindalo25.I-Pseudomonas aeruginosa nayo liqela elikhulu le-microbial kwindawo yolwandle, ebangela ukuba i-MIC ibe yintsimbi.I-Pseudomonas ibandakanyeka ngokusondeleyo kwiinkqubo ze-corrosion kwaye ibonwa njengobuvulindlela be-almafilmt e-biomafilmt. 28 kunye Yuan et al. I-29 ibonise ukuba i-Pseudomonas aeruginosa inomkhwa wokunyusa izinga lokubola kwentsimbi epholileyo kunye ne-alloys kwiindawo ezinamanzi.
Injongo ephambili yalo msebenzi yayikukuphanda iipropati ze-MIC ze-2707 HDSS ezibangelwa ibhaktheriya ye-aerobic yolwandle i-Pseudomonas aeruginosa isebenzisa iindlela ze-electrochemical, ubuchule bokuhlalutya umphezulu kunye nohlalutyo lwemveliso ye-corrosion.Izifundo ze-Electrochemical ezibandakanya i-Open Circuit Potential (OCP), i-Linear Polarization Resistance (LPR), i-Linear Polarization Resistance (LPR), i-Electoscopy I-Dynamic Polarization yenziwa ukufundisisa ukuziphatha kwe-MIC ye-2707 HDSS.Uhlalutyo lwe-Energy dispersive spectrometer (EDS) lwenziwa ukufumana izinto zekhemikhali kwi-corrod surface.Ukongezelela, uhlalutyo lwe-X-ray ye-photoelectron spectroscopy (XPS) yasetyenziselwa ukufumanisa ukuzinza kwefilimu ye-oxide passivation phantsi kwempembelelo yendalo yolwandle elinganisiweyo equkethe i-pietruginosa ye-laser ye-pietruginosa ye-laser. imicroscope (CLSM).
Itheyibhile 1 idwelisa ukubunjwa kweekhemikhali ze-2707 HDSS.Itheyibhile 2 ibonisa ukuba i-2707 HDSS ineepropati ezintle kakhulu zomatshini ezinamandla okuvelisa i-650 MPa. Umzobo we-1 ubonisa i-microstructure ye-optical yesisombululo sobushushu esiphathwe nge-2707 HDSS.Iibhendi ezongeziweyo ze-austenite kunye ne-ferrite izigaba ngaphandle kwe-microstructure ye-5 kunye ne-500% ye-austenite equkethe i-microstructure yesibini izigaba ze-ferrite.
Umzobo 2a ubonisa amandla esekethe evulekileyo (Eocp) versus data exposure time for 2707 HDSS in abiotic 2216E medium and P. aeruginosa broth for 14 days at 37 °C.Ibonisa ukuba utshintsho olukhulu nolubalulekileyo kwi-Eocp lwenzeka phakathi kweeyure ezingama-24 zokuqala. I-Eocp.5a values ​​peked at both SVES (1) amaxabiso e-Eocp. I-16 h kwaye emva koko yehla ngokukhawuleza, ifikelela -477 mV (vs. SCE) kunye -236 mV (vs. SCE) yesampuli ye-abiotic kunye ne-P, ngokulandelanayo). I-Pseudomonas aeruginosa amakhuphoni, ngokulandelanayo.Emva kweeyure ze-24, ixabiso le-Eocp le-2707 HDSS ye-P. aeruginosa yayizinzile kwi--228 mV (vs. SCE), ngelixa ixabiso elihambelanayo leesampuli ezingezona zebhayoloji lalimalunga ne -442 mV (vs. SCE i-SCE ephantsi).
Uvavanyo lwe-Electrochemical ye-2707 HDSS imizekelo kwi-abiotic medium kunye ne-Pseudomonas aeruginosa broth kwi-37 °C:
(a) I-Eocp njengomsebenzi wexesha lokuvezwa, (b) iigophe zepolarization ngosuku lwe-14, (c) Rp njengomsebenzi wexesha lokuvezwa kunye (d) ne-icorr njengomsebenzi wexesha lokuvezwa.
Itheyibhile 3 idwelisa ixabiso lepharamitha ye-electrochemical corrosion ye-2707 HDSS iisampulu ezivezwe kwi-abiotic medium kunye ne-Pseudomonas aeruginosa medium inoculated iintsuku ezili-14. I-tangents ye-anodic kunye ne-cathodic curves yakhutshwa ukuze ifike kwi-intersections ivelisa ukubola kwe-corrosion current) kunye ne-corrosion yangoku ye-corrosion amathambeka (βα kunye ne-βc) ngokweendlela eziqhelekileyo30,31.
Njengoko kubonisiwe kwi-Figure 2b, ukutshintshwa okuphezulu kwe-P. aeruginosa curve kubangele ukwanda kwe-Ecorr xa kuthelekiswa ne-abiotic curve.Ixabiso le-icorr, elihambelana nezinga lokubola, linyuke laya kwi-0.328 μA cm-2 kwi-Pseudomonas aeruginosa isampuli0-08 isampuli ye-cm.
I-LPR iyindlela ye-electrochemical engonakaliyo yokuhlalutya ngokukhawuleza ukugqwala.Kwaye kwasetyenziselwa ukufunda i-MIC32.Umfanekiso we-2c ubonisa ukuxhathisa kwe-polarization (Rp) njengomsebenzi wexesha lokuvezwa.Ixabiso eliphezulu le-Rp lithetha ukubola okuncinci.Kwiiyure zokuqala ze-24, i-Rp ye-2707 HDSS ifikelele kwi-5 ye-5 kbiotic ye-9 cm29 kunye nexabiso eliphezulu le-kbiotic 9 cm kunye ne-9 kbiotic 9 cm. I-kΩ cm2 yeesampuli ze-Pseudomonas aeruginosa.Umfanekiso 2c ubonisa ukuba ixabiso le-Rp lehla ngokukhawuleza emva kosuku olunye kwaye lahlala lingatshintshiyo kwiintsuku ezizayo ze-13. Ixabiso le-Rp yesampuli ye-Pseudomonas aeruginosa imalunga ne-40 kΩ cm2, ephantsi kakhulu kunexabiso le-non-non-cm2 ye-cm250 k.
Ixabiso le-icorr lilingana nexabiso lokutya okufanayo.
Ukulandela uZou et al. 33, ixabiso eliqhelekileyo lethambeka le-Tafel B kulo msebenzi kwakucingelwa ukuba yi-26 mV/dec.Umfanekiso 2d ubonisa ukuba icorr yesampulu ye-non-biological 2707 yahlala izinzile, ngelixa isampuli ye-P. aeruginosa iguquguquka kakhulu emva kweeyure ezingama-24 zokuqala. kunolawulo olungelulo lwebhayoloji.Lo mkhwa uhambelana neziphumo zokuxhathisa i-polarization.
I-EIS yenye indlela engonakalisiyo esetyenziselwa ukubonakalisa ukusabela kwe-electrochemical kwi-interfaces ezigqwesileyo.Impedance spectra kunye nexabiso lokubala le-capacitance ye-specimens evezwe kwi-abiotic media kunye nesisombululo se-Pseudomonas aeruginosa, ukuxhathisa kwe-Rb yefilimu / ifilimu ye-biofilm eyenziwe kumphezulu we-specimen, ukuxhathisa i-Rct yentlawulo yombane kunye ne-Cdlpatant ye-Cdlpatant yokudlulisa umbane Iiparamitha zeSigaba seSigaba (CPE). Ezi parameters zahlaziywa ngakumbi ngokufaka idatha usebenzisa imodeli yesekethe elinganayo (EEC).
Umfanekiso wesi-3 ubonisa iindawo eziqhelekileyo zeNyquist (a kunye ne-b) kunye neeploti zeBode (a' kunye ne-b') zeesampuli ze-2707 ze-HDSS kwi-abiotic medium kunye ne-P. aeruginosa umhluzi wamaxesha ahlukeneyo okufukamela. I-impedance.Ulwazi malunga nexesha lokuphumla rhoqo linganikezelwa yi-phase maxima.Umfanekiso we-4 ubonisa i-monolayer (a) kunye ne-bilayer (b) esekelwe kwizakhiwo zomzimba kunye nee-EEC zabo ezihambelanayo.CPE ifakwe kwimodeli ye-EEC.Ukwamkelwa kwayo kunye nokuphazamiseka kubonakaliswa ngolu hlobo lulandelayo:
Iimodeli ezimbini zomzimba kunye neesekethe ezilinganayo zokulinganisa i-impedance spectrum ye-2707 HDSS specimen:
apho i-Y0 ubukhulu be-CPE, j yinombolo ecingelwayo okanye (-1) 1 / 2, ω yi-frequency ye-angular, kwaye n isalathisi samandla e-CPE esingaphantsi kobunye35.I-inverse yokuchasana kokudluliselwa kwentlawulo (okt 1 / Rct) ihambelana nezinga lokubola.I-Rct encinci ithetha ngokukhawuleza i-corrosion rate ye-14 ye-Rct 27. Iisampulu ze-Pseudomonas aeruginosa zifikelele kwi-32 kΩ cm2, incinci kakhulu kune-489 kΩ cm2 yeesampuli ezingezizo zebhayoloji (Itheyibhile 4).
Imifanekiso ye-CLSM kunye nemifanekiso ye-SEM kwi-Figure 5 ibonisa ngokucacileyo ukuba i-biofilm coverage ebusweni be-2707 HDSS isampuli emva kweentsuku ze-7 zixinene.Nangona kunjalo, emva kweentsuku ze-14, ukukhutshwa kwe-biofilm kwakuncinci kwaye ezinye iiseli ezifileyo zabonakala. Ubunzima be-biofilm butshintshile ukusuka kwi-23.4 μm emva kweentsuku ezisi-7 ukuya kwi-18.9 μm emva kweentsuku ezili-14. Umyinge wobunzima be-biofilm nawo waqinisekisa lo mkhwa.Yehla ukusuka kwi-22.2 ± 0.7 μm emva kweentsuku ezisi-7 ukuya kwi-17.8 ± 1.0 μm emva kweentsuku ezili-14.
(a) Umfanekiso we-3-D CLSM emva kweentsuku ezisi-7, (b) umfanekiso we-3-D CLSM emva kweentsuku ezili-14, (c) umfanekiso we-SEM emva kweentsuku ezisi-7 kunye (d) nomfanekiso we-SEM emva kweentsuku ezili-14.
I-EDS ibonakalise izinto zekhemikhali kwii-biofilms kunye neemveliso zokubola kwiisampuli ezivezwe kwi-P. aeruginosa iintsuku ze-14. Umzobo 6 ubonisa ukuba umxholo we-C, N, O, kunye ne-P kwi-biofilms kunye neemveliso ze-corrosion ziphezulu kakhulu kunezinyithi ezingenanto, kuba ezi zinto zihambelana ne-biofilms kunye ne-metabolites yazo. I-biofilm kunye nemveliso ye-corrosion ebusweni bemizekelo ibonisa ukuba i-matrix yensimbi ilahlekelwe izinto ngenxa yokubola.
Emva kweentsuku ze-14, i-pitting kunye nangaphandle kwe-P. aeruginosa yabonwa kwi-2216E medium.Ngaphambi kokufakwa kwe-incubation, i-specimen surface yayihamba kakuhle kwaye ingenasiphako (Fig. 7a) .Emva kokufakwa kunye nokususwa kwemveliso ye-biofilm kunye ne-corrosion, imigodi enzulu kakhulu kwi-specimens ye-specimens ihlolwe phantsi kwe-cl-figure ye-7, efunyenwe phantsi kwe-CLSM ecacileyo, umphezulu iisampulu ulawulo non-zebhayoloji (ubuninzi emhadini ubunzulu 0.02 μm). Ubunzulu emhadini ubuninzi obangelwa Pseudomonas aeruginosa kwaba 0.52 μm emva kweentsuku ezisi-7 kunye 0.69 μm emva kweentsuku ezili-14, ngokusekwe kumndilili ubunzulu umngxuma 3 iisampulu (10 emhadini ubuninzi ezikhethiweyo iisampulu ± 2 ubunzulu ezikhethiweyo 2 nganye. μm kunye ne-0.52 ± 0.15 μm, ngokulandelelanayo (Itheyibhile 5) .La maxabiso ubunzulu bomgodi mancinci kodwa abalulekile.
(a) Phambi kokuba sesichengeni, (b) iintsuku ezili-14 kwi-abiotic medium kunye (c) neentsuku ezili-14 kwi-Pseudomonas aeruginosa broth.
Umzobo we-8 ubonisa i-XPS spectra yeendawo ezahlukeneyo zesampulu, kunye nokwakheka kweekhemikhali ezihlalutyelwe kwindawo nganye zishwankathelwa kwiThebhile 6.KwiThebhile 6, iipesenti ze-athomu ze-Fe kunye ne-Cr phambi kwe-P. aeruginosa (iisampulu ze-A kunye ne-B) zaziphantsi kakhulu kunezo zesampuli zokulawula ezingezo-zebhayoloji (isampuli ze-P, isampuli ze-C, i-Druginop kunye ne-Druginop2. core-level spectral curve yafakelwe amacandelo amane encopho ngamandla okubopha amandla (BE) amaxabiso 574.4, 576.6, 578.3 kunye 586.8 eV, ezinokuthi zibalelwe Cr, Cr2O3, CrO3 kunye Cr (OH) 3, ngokulandelelana non-biological spec. I-spectrum ye-core-level ye-2p iqulethe iincopho ezimbini eziphambili ze-Cr (573.80 eV ye-BE) kunye ne-Cr2O3 (575.90 eV ye-BE) kwi-Fig. 9c kunye ne-d, ngokulandelanayo.Owona mahluko ubalaseleyo phakathi kwe-abiotic kunye ne-P. aeruginosa iisampulu yayibubukho be-Cr6 + 88 ye-Cr6 + kunye ne-68BE ephezulu ye-H. eV) ngaphantsi kwebhayofilm.
I-spectra ye-XPS ebanzi yobuso be-2707 HDSS i-specimen kwimidiya emibini yientsuku ze-7 kunye neentsuku ze-14, ngokulandelanayo.
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I-HDSS ibonisa amanqanaba aphezulu okuxhathisa i-corrosion kwiindawo ezininzi.Kim et al. I-2 ibike ukuba i-UNS S32707 HDSS ichazwe njenge-DSS ene-alloyed kakhulu kunye ne-PREN engaphezulu kwe-45.Ixabiso le-PREN ye-2707 HDSS i-specimen kulo msebenzi yayingu-49.Oku kubangelwa umxholo wayo we-chromium ephezulu kunye namanqanaba aphezulu e-molybdenum kunye ne-Ni, enenzuzo kwi-acidic i-acidic kunye ne-high-defect-free-chloride. i-microstructure iluncedo ekuzinzeni kwesakhiwo kunye nokumelana nokubola.Nangona kunjalo, nangona i-chemical resistance resistance, idatha yovavanyo kulo msebenzi ibonisa ukuba i-2707 HDSS ayikhuselekanga ngokupheleleyo kwi-MIC ye-P. aeruginosa biofilms.
Iziphumo ze-Electrochemical zibonise ukuba izinga lokubola kwe-2707 HDSS kwi-P. aeruginosa broth yanda kakhulu emva kweentsuku ze-14 xa kuthelekiswa ne-non-biological medium.Kumfanekiso we-2a, ukunciphisa i-Eocp kwabonwa kuzo zombini i-abiotic medium kunye ne-P. aeruginosa umhluzi kwiiyure zokuqala ze-24. Emva kokugqiba i-spetocmen ye-surface ye-specmen kunye ne-surface ye-biological uzinzile ngokwentelekiso36.Nangona kunjalo, umgangatho we-biological Eocp wawuphezulu kakhulu kune-non-biological Eocp.Kukho isizathu sokukholelwa ukuba lo mahluko ubangelwa yi-P. aeruginosa biofilm formation.Kumfanekiso we-2d, phambi kwe-P. aeruginosa, ixabiso le-icorr le-2707 le-2707 ye-HDSS ephezulu, efikelela kwi-μA ye-HDSS ephezulu ye-0.6 cm22 ukuya kwi-0. leyo yolawulo abiotic (0.063 μA cm-2), nto leyo engqinelana nexabiso Rct kulinganiswa EIS.Ngexesha leentsuku ezimbalwa zokuqala, amaxabiso impedance kwi P. aeruginosa umhluzi anda ngenxa uncamathiselo iiseli P. aeruginosa kunye nokusekwa biofilms.Nangona kunjalo, xa biofilm igubungele ngokupheleleyo uhlaselo umaleko uhlaselo umphezulu wokhuselo lwe-impedance yokuqala. ukubunjwa kwe-biofilms kunye ne-metabolites ye-biofilm.Ngoko ke, ukunyanzeliswa kwe-corrosion kuye kwancipha ngokuhamba kwexesha, kwaye i-attachment ye-P. aeruginosa ibangele i-corrosion yendawo.Iendlela ezihamba ngayo kwimidiya ye-abiotic zahluke.Ukuxhatshazwa kwe-corrosion ye-non-biological control yayiphezulu kakhulu kunexabiso elihambelanayo leesampuli ezivezwe kwi-P. aeruginosa isampuli, i-R. I-2707 HDSS ifikelele kwi-489 kΩ cm2 ngosuku lwe-14, eyayiyi-15 amaxesha exabiso le-Rct (32 kΩ cm2) phambi kwe-P. aeruginosa.Ngoko ke, i-2707 HDSS inokumelana nokugqwesa okugqwesileyo kwindawo eyinyumba, kodwa ayichasananga nokuhlaselwa kwe-MIC yi-P. aeruginosafil
Ezi ziphumo zingaphinda zibonwe kwi-polarization curves kwi-Fig. ukuba i-P. aeruginosa biofilm yonyusa i-corrosion yendawo ye-2707 HDSS.Yuan et al29 yafumanisa ukuba ubuninzi be-corrosion yangoku ye-70/30 Cu-Ni ingxubevange yenyuka phantsi komngeni we-P. I-2707 HDSS kulo msebenzi.I-biofilms ye-Aerobic nayo ingaba ne-oksijini encinci phantsi kwayo.Ngoko ke, ukungaphumeleli ukuphinda kudlule i-metal surface nge-oksijini kunokuba negalelo kwi-MIC kulo msebenzi.
UDickinson et al. I-38 iphakamise ukuba iireyithi zeekhemikhali kunye neempendulo ze-electrochemical zinokuchaphazeleka ngokuthe ngqo ngumsebenzi we-metabolic we-sessile ibhaktheriya phezu komfanekiso kunye nohlobo lwemveliso ye-corrosion.Njengoko kubonisiwe kwi-Figure 5 kunye neThebhile 5, zombini inombolo yeseli kunye nobukhulu be-biofilm bunciphe emva kweentsuku ze-14. Oku kunokuchazwa ngokufanelekileyo ukuba emva kweentsuku ze-14 ze-SS, ininzi ye-270 ye-HD yafa, ininzi yeeseli ze-HD ze-7 ukuncipha kwezondlo kwi-2216E medium okanye ukukhutshwa kwee-ion zetsimbi ezinetyhefu ukusuka kwi-matrix ye-HDSS ye-2707. Oku kukunciphisa imifuniselo yebhetshi.
Kulo msebenzi, i-P. aeruginosa biofilm ikhuthaze ukuchithwa kwendawo ye-Cr kunye ne-Fe phantsi kwe-biofilm kwindawo ye-2707 HDSS (umzobo 6) .KwiThebhile 6, ukunciphisa i-Fe kunye ne-Cr kwisampuli D xa kuthelekiswa nesampula C, ebonisa ukuba i-Fe kunye ne-Cr echithiweyo ebangelwa yi-P. linganisa iindawo zaselwandle.Iqulethe i-17700 ppm Cl-, ethelekiseka naleyo ifumaneka kumanzi olwandle endalo.Ubukho be-17700 ppm Cl- yayisesona sizathu siphambili sokuncitshiswa kwe-Cr kwi-7- kunye ne-14 yeentsuku ze-abiotic iisampulu ezihlalutywe yi-XPS.Xa kuthelekiswa ne-P. kwi-Cl-resistance eyomeleleyo ye-2707 HDSS kwiindawo ze-abiotic.Umfanekiso we-9 ubonisa ubukho be-Cr6 + kwifilimu ye-passivation.Inokubandakanyeka ekususweni kwe-Cr kwiindawo zensimbi nge-P. aeruginosa biofilms, njengoko kucetyiswe nguChen noClayton.
Ngenxa yokukhula kwebhaktheriya, ixabiso le-pH eliphakathi phambi nasemva kokulima laliyi-7.4 kunye ne-8.2, ngokulandelelanayo. Ngoko ke, ngaphantsi kwe-P. aeruginosa biofilm, ukubola kwe-asidi ye-organic akunakwenzeka ukuba kube negalelo kulo msebenzi ngenxa ye-pH ephezulu kwi-medium bulk. 7.5) ngexesha lovavanyo lweentsuku ze-14. Ukunyuka kwe-pH kwi-inoculation medium emva kokufakwa kwe-incubation ngenxa yomsebenzi we-metabolic we-P. aeruginosa kwaye kwafunyaniswa ukuba nefuthe elifanayo kwi-pH ngokungabikho kwemicu yokuvavanya.
Njengoko kuboniswe kwi-Figure 7, ubunzulu bomgodi obuninzi obangelwa yi-P. aeruginosa biofilm yi-0.69 μm, eyayinkulu kakhulu kune-abiotic medium (0.02 μm) .Oku kuhambelana nedatha ye-electrochemical echazwe ngasentla.I-0.69 μm yomgodi we-pit ingaphezu kwamaxesha alishumi amancinci kune-μ2m205 yexabiso elifanayo le-DSS echazwe phantsi kwe-9. idatha ibonisa ukuba i-2707 HDSS ibonisa ukuxhathisa okungcono kwe-MIC xa kuthelekiswa ne-2205 DSS. Oku akufanele kusimangalise, njengoko i-2707 HDSS inomxholo ophezulu we-chromium, inika i-passivation ehlala ixesha elide, ngenxa yesakhiwo sesigaba esilungeleleneyo ngaphandle kwe-precipitates yesibini eyingozi, okwenza kube nzima ukuba i-P.
Ukuqukumbela, i-MIC pitting ifunyenwe kumphezulu we-2707 HDSS kwi-P. aeruginosa umhluzi xa kuthelekiswa nomgodi ongenanto kwi-abiotic media.Lo msebenzi ubonisa ukuba i-2707 HDSS inokumelana ne-MIC engcono kune-2205 DSS, kodwa ayikhuselekanga ngokupheleleyo kwi-MIC ngenxa yeP.
Ikhuphoni ye-2707 HDSS inikezelwa yiSikole seMetallurgy yeYunivesithi yaseNortheastern (NEU) e-Shenyang, eChina.I-elemental composition ye-2707 HDSS iboniswe kwiThebhile 1, eyahlalutywa yi-NEU yokuHlalutywa kwezinto kunye neSebe loVavanyo.Zonke iisampuli zaphathwa kwi-1180 ° C kwi-1 corroped ye-HDSS kwi-1 corroped yeyure ye-2000. kunye nommandla ophezulu oveziweyo we-1 cm2 wagudiswa ukuya kwi-2000 grit nge-silicon carbide paper kwaye uphuculwe ngakumbi nge-0.05 μm Al2O3 powder suspension.Amacala kunye nezantsi zikhuselwe ngepeyinti engasebenzi. emva koko yomiswe emoyeni phantsi kwe-ultraviolet (UV) ukukhanya kweeyure ze-0.5 ngaphambi kokusetyenziswa.
I-Marine Pseudomonas aeruginosa MCCC 1A00099 strain yathengwa kwi-Xiamen Marine Culture Collection Centre (MCCC), eChina.I-Pseudomonas aeruginosa yayikhuliswe nge-aerobically nge-37°C kwi-250 ml yeeflaski kunye ne-500 ml yeeseli zeglasi ze-electrochemical zisebenzisa i-Marine 2216E ye-Biotechingda ulwelo lwe-Hope. Qingdao, China).Phakathi (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 SrCl30, 0.034 SrCl2, 0.2 H2, 0.0. 0.004 NaSiO3, 0016 NH3, 0016 NH3, 0016 NaH2PO4, 5.0 peptone, i-1.0 yeast extract kunye ne-0.1 ferric citrate.I-Autoclave kwi-121 ° C kwimizuzu ye-20 ngaphambi kwe-inoculation.Bala i-sessile engaphantsi kwe-autonomic kunye ne-hemocytomic cell400meter ye-planktonic ye-planktonic ye-planktonic. ukukhuliswa.Ukuxinwa kweeseli zokuqala zeplanktonic Pseudomonas aeruginosa ngokukhawuleza emva kokugonywa kwakumalunga neeseli ze-106 / ml.
Iimvavanyo ze-electrochemical zenziwa kwi-classic yeglasi ye-electrode yeglasi kunye nomthamo ophakathi kwe-500 ml. Iphepha leplatinum kunye ne-calomel electrode egcweleyo (SCE) idibaniswe ne-reactor nge-Luggin capillaries ezaliswe ngamabhuloho etyuwa, esebenza njenge-counter kunye ne-reference electrodes, ngokulandelanayo.Ukwenza i-electrodes esebenzayo, i-rubber-coated ifakwe kwi-copper, i-rubber-coated ifakwe kwi-exypo efakwe kwi-copper nganye. I-cm2 yendawo eveziweyo yecala elilodwa lommandla we-electrode esebenzayo.Ngexesha lokulinganiswa kwe-electrochemical, iisampuli zafakwa kwi-2216E medium kwaye zigcinwe kwiqondo lokushisa elingaguqukiyo (37 ° C) kwindawo yokuhlambela amanzi.OCP, LPR, EIS kunye neenkcukacha ezinokubakho ze-polarization zilinganiswe ngokusebenzisa i-Autolab potentiostat (Ireferensi ye-600, i-Instrument scan, i-USA, i-ILPm yovavanyo lwe-U.S. izinga le-0.125 mV s-1 phezu koluhlu lwe-5 kunye ne-5 mV kunye ne-Eocp kunye ne-sampling frequency ye-1 Hz.EIS yenziwa nge-sine wave kuluhlu lwamaza obuninzi be-0.01 ukuya kwi-10,000 Hz usebenzisa i-5 mV esetyenziswayo yombane kwindawo ezinzileyo ye-Eocp. ifikeleleke.Ii-polarization curves zaye zaqhutywa ukusuka kwi-0.2 ukuya kwi-1.5 V vs. Eocp ngesantya sokuskena se-0.166 mV / s. Uvavanyo ngalunye luphindwe ngamaxesha e-3 kunye nangaphandle kwe-P. aeruginosa.
Imizekelo yohlalutyo lwe-metallographic yagudiswa ngomatshini nge-2000 grit emanzi yephepha le-SiC kwaye yaphinda yakhazimliswa nge-0.05 μm Al2O3 yomgubo wokunqunyanyiswa kwe-optical observion.
Emva kokufukanyelwa, iisampulu zahlanjwa amaxesha e-3 ngesisombululo se-phosphate-buffered saline (PBS) (pH 7.4 ± 0.2) zaza zalungiswa nge-2.5% (v/v) glutaraldehyde iiyure ezili-10 ukulungisa i-biofilms. I-95% kunye ne-100% v / v) ye-ethanol ngaphambi kokumisa komoya. Ekugqibeleni, umphezulu wesampuli uhlanjululwe ngefilimu yegolide ukubonelela nge-conductivity ye-SEM observation.Imifanekiso ye-SEM yayigxininise kwiindawo ezinobuninzi beeseli zeP. (LSM 710, Zeiss, eJamani) yayisetyenziselwa ukulinganisa ubunzulu bomgodi.Ukuze kugcinwe imigodi yokubola phantsi kwe-biofilm, isiqwenga sovavanyo saqala sahlanjululwa ngokwe-Chinese National Standard (CNS) GB / T4334.4-2000 ukususa iimveliso ze-corrosion kunye ne-biofilm phezu kwendawo yokuvavanya.
I-X-ray photoelectron spectroscopy (i-XPS, i-ESCALAB250 inkqubo yohlalutyo lomphezulu, i-Thermo VG, e-USA) uhlalutyo lwenziwa kusetyenziswa umthombo we-X-ray we-monochromatic (umgca we-aluminium Kα ku-1500 eV amandla kunye ne-150 W amandla) phezu koluhlu olubanzi lwamandla abophezelayo 0 phantsi kweemeko eziqhelekileyo -1350 eV.High-resolution eV. ubukhulu.
Iisampuli ezifakwe kwi-incubated zisuswe kwaye zihlanjululwe ngobumnene nge-PBS (pH 7.4 ± 0.2) kwi-15 s45. Ukuqwalasela ukusebenza kwebhaktheriya ye-biofilms kwiisampuli, i-biofilms yahlanjululwa ngokusebenzisa i-LIVE / DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, i-Eugene, i-Eugene, i-fluorescent eluhlaza, i-USA, i-Eugene ye-fluorescent) Idayi ye-fluorescent SYTO-9 kunye nedayi ye-fluorescent yepropidium iodide (PI) ebomvu.Ngaphantsi kwe-CLSM, amachaphaza ane-fluorescent eluhlaza kunye nobomvu amele iiseli eziphilayo nezifileyo, ngokulandelanayo.Ukwenzela ukungcolisa, umxube we-1 ml oqulethe i-3 μl SYTO-9 kunye ne-3 μl isisombululo se-PI sifakwe kwi-20 yemizuzu ye-20. iisampulu zabonwa kumaza amabini (488 nm yeeseli eziphilayo kunye ne-559 nm yeeseli ezifileyo) usebenzisa umatshini we-Nikon CLSM (C2 Plus, Nikon, Japan) .Ubukhulu be-Biofilm bulinganiswa kwimodi yokuskena ye-3-D.
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