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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, ukuchasana kwayo ne-MIC akuzange kubonakaliswe ngokomfuniselo.Kulu phononongo, ukuziphatha kwe-MIC ye-2707 ye-aerobicsa ye-2707 i-substrate aerobics ye-marigasse ye-marineerobes ibangelwa yi-2707 HDSS. .Uhlalutyo lwe-Electrochemical lubonise ukuba phambi kwe-Pseudomonas aeruginosa biofilm kwi-2216E medium, bekukho utshintsho oluhle kwi-corrosion potential and ukwanda kwe-corrosion current density.Uhlalutyo lwe-X-ray photoelectron spectroscopy (XPS) lubonise ukuncipha komxholo we-Cr kumphezulu we-specimen engaphantsi kwe-biofilm ebonisa ubunzulu be-biofilm eveliswa yi-biofilm. ye-0.69 μm ngeentsuku ze-14 zokufukamela. 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.Noko kunjalo, i-pitting yendawo isenzeka kwaye ichaphazela ingqibelelo yale steel3,4.DSS ayixhathisi kwi-corrosion ye-microbial (MIC) 5,6.Nangona uluhlu olubanzi lokusingqongileyo lwe-DSS lusenexesha elide lokumelana ne-DSS apho usetyenziso lwe-DSS lusekho ukuxhathisa okwaneleyo kwe-DSS. .Oku kuthetha ukuba izinto ezibiza kakhulu kunye nokumelana ne-corrosion ephezulu ziyafuneka.I-Jeon et al7 ifumene ukuba i-super duplex stainless steels (SDSS) inemida ethile ngokubhekiselele kwi-corrosion resistance.Ngoko ke, i-super duplex stainless steels (HDSS) enokumelana nokunyuka okuphezulu kuyafuneka kwezinye izicelo.Oku kwakhokelela ekuphuhlisweni kwe-HDSS exutywe kakhulu.
Ukuxhatshazwa kwe-corrosion ye-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 ekufutshane nesigaba sesibini.I-HDSS iqulethe umxholo ophezulu we-Cr, Mo kunye ne-N11, ngoko inokumelana nokugqwesa okugqwesileyo kunye nexabiso eliphezulu (45-50) I-Pitting Resistance Equistance (3% i-Movalent + 3%), inqunywe ngeNombolo yokumelana ne-3%. I-0.5 wt% W) + 16 wt% N12.Ukumelana 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.
I-MICs yingxaki enkulu kumashishini amaninzi afana ne-oyile kunye negesi kunye nezinto eziluncedo zamanzi14.MIC i-akhawunti ye-20% yawo wonke umonakalo we-corrosion15.MIC yi-bioelectrochemical corrosion enokuthi ibonwe kwiindawo ezininzi.I-Biofilms eyenza kwiindawo zetsimbi ziguqula iimeko ze-electrochemical, ngaloo ndlela zichaphazela inkqubo ye-corrosion ikholelwa ukuba i-Miccorogenic ikholelwa ukuba i-Miccorogen ikholelwa ukuba yi-microcorrosion process. s i-corrode metals ukufumana amandla okugcina amandla ukuze uphile17.Uphando lwangoku lwe-MIC luye lwabonisa 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.Pseudomonas aeruginosa ikwayiqela elikhulu le-microbial kwindawo yolwandle, ebangela ukuba i-MIC ibe yintsimbi.I-Pseudomonas ibandakanyeka ngokusondeleyo kwiinkqubo ze-corrosion kwaye ibonwa njengobuvulindlela be-bioMafilmt e-colonizer.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 yi-marine aerobic bacterium i-Pseudomonas aeruginosa isebenzisa iindlela ze-electrochemical, ubuchule bokuhlalutya umphezulu kunye nohlalutyo lwemveliso yokubola.Izifundo ze-Electrochemical ezibandakanya i-Open Circuit Potential (OCP), i-Linear Polarization Resistance (LPR), i-Linear Polarization Resistance (i-PompedaEIS) eyenziwa ukufunda ukuziphatha kwe-MIC ye-2707 HDSS.Uhlalutyo lwe-Energy dispersive spectrometer (EDS) lwenziwa ukufumana izinto zekhemikhali kwi-corrod surface.Ukongezelela, uhlalutyo lwe-X-ray photoelectron spectroscopy (XPS) lusetyenziselwa ukufumanisa ukuzinza kwefilimu ye-oxide passivation phantsi kwempembelelo yendalo yaselwandle equkethe i-Pseudomonas pieruginosa ye-laser ilinganiswe phantsi kwe-laser aeruginosa ye-laser.
Itheyibhile 1 idwelisa ubume bemichiza angama-2707 i-HDSSS.ICOCT 2 ibonisa ukuba i-2707 i-HDSS ineempawu ezinamaqhinga angama-2750.
Umzobo 2a ubonisa amandla esekethe evulekileyo (Eocp) versus data ixesha sesichengeni 2707 HDSS in abiotic 2216E medium kunye P. aeruginosa umhluzi iintsuku ezili-14 nge-37 °C.Ibonisa ukuba utshintsho olukhulu kunye olubalulekileyo lwenzeka kwi-Eocp kwiiyure zokuqala ezingama-24. I-Eocp yamaxabiso aphantsi kwe-1 5aCE kunye ne-1 S. 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 ye-3 idwelisa i-electrochemical corrosion parameter values ​​​​ye-2707 HDSS iisampulu ezivezwe kwi-abiotic medium kunye ne-Pseudomonas aeruginosa inoculated medium kwiintsuku ze-14. I-tangents ye-anodic kunye ne-cathodic curves ikhutshwe ukuba ifike kwiindlela zokungena ezinikezela ukubola kwe-corrosion kunye ne-corrosion yangoku ye-corrosion (i-corrrosion yangoku) kunye ne-corrosion yangoku 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 i-corrosion.Ikwasetyenziselwa ukufunda i-MIC32.Umfanekiso we-2c ubonisa ukuxhathisa kwe-polarization (Rp) njengomsebenzi wexesha lokuvezwa.Ixabiso eliphezulu le-Rp lithetha ukubola okuncinci.Kwiiyure ezingama-24 zokuqala, i-Rp ye-2707 HDΩs ifikelele kwisampulu ye-2707 HDΩ2 ephezulu ye-5 kbiotic 9 cm29 cm kunye ne-5 kbiotic ye-9 cm29. kwiisampuli ze-Pseudomonas aeruginosa.Umfanekiso we-2c ubonisa ukuba ixabiso le-Rp lehla ngokukhawuleza emva kosuku olunye kwaye lahlala lingatshintshi kwiintsuku ezizayo ze-13. Ixabiso le-Rp yesampuli ye-Pseudomonas aeruginosa malunga ne-40 kΩ cm2, ephantsi kakhulu kune-450 kΩ-cm2 yesampuli ye-nonbiological.
Ixabiso le-icorr lilingana nexabiso lokutya okufanayo.
Ukulandela uZou et al.33, ixabiso eqhelekileyo Tafel ithambeka B kulo msebenzi kucingelwa ukuba 26 mV/dec.Figure 2d ibonisa ukuba icorr yesampula non-biological 2707 wahlala uzinzile noko, ngelixa P. aeruginosa isampulu eguquguqukayo kakhulu emva kweeyure zokuqala ezingama-24. ulawulo lwenzululwazi.Lo mkhwa uhambelana neziphumo zokuchasa i-polarization.
I-EIS yenye indlela engonakalisiyo esetyenziselwa ukubonakalisa ukusabela kwe-electrochemical kwi-interfaces ezigqwesileyo.Impedance spectra kunye nexabiso le-capacitance elibalwayo leesampuli ezivezwe kwi-abiotic media kunye nesisombululo se-Pseudomonas aeruginosa, ukuxhathisa kwe-Rb yefilimu / i-biofilm eyenziwe kumphezulu we-specimen, i-Rct i-chargency transfer resistance, i-Cdl capecitant ye-Cdl (i-Cdl castal) CPE) iiparamitha.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. ixesha lokuphumla lingaguquguquki linokubonelelwa nge-phase maxima.Umfanekiso we-4 ubonisa i-monolayer (a) kunye ne-bilayer (b) esekelwe kwizakhiwo zomzimba kunye nee-EEC ezihambelanayo.CPE ifakwe kwimodeli ye-EEC.Ukwamkelwa kwayo kunye nokuphazamiseka kuchazwe 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 (oko kukuthi i-1 / Rct) ihambelana nezinga lokubola.I-Rct encinci ithetha ngokukhawuleza i-corrosion rate ye-Pmona yeentsuku ze-27. iisampulu ze-eruginosa zifikelele kwi-32 kΩ cm2, incinci kakhulu kune-489 kΩ cm2 yeesampuli ezingekho zebhayoloji (Itheyibhile 4).
Imifanekiso ye-CLSM kunye nemifanekiso ye-SEM kwi-Figure 5 ibonisa ngokucacileyo ukuba i-biofilm coverage phezu komfanekiso we-2707 HDSS emva kweentsuku ze-7 zixinene.Nangona kunjalo, emva kweentsuku ze-14, i-biofilm coverage yayincinci kwaye ezinye iiseli ezifileyo zabonakala. ukusuka kwi-23.4 μm emva kweentsuku ezi-7 ukuya kwi-18.9 μm emva kweentsuku ezili-14. Ubuninzi be-biofilm obuqhelekileyo buqinisekisile lo mkhwa.Yehla ukusuka kwi-22.2 ± 0.7 μm emva kweentsuku ezi-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 ibonise 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 zidibene ne-biofilms kunye ne-metabolites yazo. iimveliso ze-rosion kumphezulu weesampuli zibonisa 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 yayibushelelezi kwaye ingenasiphako (Fig. 7a) .Emva kokufakwa kunye nokususwa kwe-biofilm kunye nemveliso ye-corrosion, imigodi enzulu kakhulu kumphezulu we-specimens yavavanywa njengoko iboniswe phantsi kwe-cl-figure ye-cl-figure engabonakaliyo, iboniswe phantsi kwe-cl-figure. -iisampulu zolawulo lwebhayoloji (ubukhulu bomngxuma ubunzulu 0.02 μm). Ubunzulu bomngxuma obuninzi obubangelwa yi-Pseudomonas aeruginosa yaba yi-0.52 μm emva kweentsuku ezisi-7 kunye ne-0.69 μm emva kweentsuku ezili-14, ngokusekwe kumndilili wobunzulu obuphezulu beesampulu ezi-3 (i-10 ubuninzi bomngxuma ubunzulu amaxabiso afikelelekayo μ ± 20 μm 2 ± 20 ± 20 ± 20 ± 20. ± 20 ± 20. ± 20. ± 20. ± 20. ± 20. ± 20. ± 20. 0.15 μm, ngokulandelelanayo (Itheyibhile 5) .La maxabiso obunzulu 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 nokwakhiwa kweekhemikhali ezihlalutyelwe kwindawo nganye zishwankathelwa kwiThebhile 6.KwiThebhile 6, iipesenti ze-athomu ze-Fe kunye ne-Cr phambi kwe-P. aeruginosa (iisampulu A kunye ne-B) ziphantsi kakhulu kunezo zesampuli ze-non-biological control (isampuli ze-samples ze-Crinovel kunye ne-Druginovel Cr). Ijika le-spectral lifakelwe kumacandelo amane encopho anamandla okubopha (BE) amaxabiso e-574.4, 576.6, 578.3 kunye ne-586.8 eV, enokuthi ifakwe kwi-Cr, i-Cr2O3, i-CrO3 kunye ne-Cr (OH) 3, ngokulandelanayo (Umfanekiso we-non-spectrum2, i-spectrum ye-non-biological kunye ne-cr. 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 kweesampulu ze-abiotic kunye ne-P. aeruginosa kwakukho ubukho be-Cr6 + kunye ne-fraction ye-Cr (OH) 5)8 ye-beathm ye-beathm ye-3.
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 yayiyi-49.Oku kubangelwa umxholo wayo we-chromium ephezulu kunye namanqanaba aphezulu e-molybdenum kunye ne-Ni, enenzuzo kwimeko ye-acidic kunye ne-defective ye-microdefect-i-microdefect-i-microdefect-free, i-microdefect kunye ne-microdefect. Uzinzo lwesakhiwo 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 kwi-abiotic medium kunye ne-P. aeruginosa umhluzi ngexesha leeyure ze-24. 6.Nangona kunjalo, inqanaba le-biological Eocp laliphezulu kakhulu kune-non-biological Eocp.Kukho isizathu sokukholelwa ukuba lo mahluko ubangelwa yi-P. aeruginosa biofilm formation.Kumfanekiso we-2d, phambi kweP. I-63 μA cm-2), eyayihambelana nexabiso le-Rct elilinganiswe yi-EIS.Ngexesha leentsuku ezimbalwa zokuqala, ixabiso le-impedance kwi-P. aeruginosa umhluzi liye lanyuka ngenxa yokuqhotyoshelweyo kweeseli ze-P. aeruginosa kunye nokwakhiwa kwe-biofilms.Nangona kunjalo, xa i-biofilm igubungela ngokupheleleyo umphezulu we-specimen, i-impedance ye-impedance layers ye-biofilm yohlaselo iyancipha. Ngoko ke, ukuxhathisa kwe-corrosion yehla ngokuhamba kwexesha, kwaye ukuncamathiselwa kwe-P. aeruginosa kubangele ukubola kwendawo.Iintsingiselo kwimidiya ye-abiotic yahlukile.Ukumelana nokugqwala kokulawulwa kwe-non-biological kwakuphezulu kakhulu kunexabiso elihambelanayo leisampulu ezivezwe kwi-P. aeruginosa broth.Ngaphezu koko, iisampulu ze-abiotic ezifikelele kwi-2708 ye-HD, kwixabiso le-2708 le-Rct14 ye-HD, i-Rct 1429 ngosuku lwafikelela kwi-2708 ye-hdg ye-2707 SS kwixabiso le-2707 SS. kwaba ngamaxesha e-15 ixabiso 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. aeruginosa biofilms.
Ezi ziphumo zingaphinda zibonwe kwi-polarization curves kwi-Fig. 2b.I-anodic branching ibangelwa i-Pseudomonas aeruginosa i-biofilm formation kunye ne-metal oxidation reactions.Ngexesha elifanayo ukusabela kwe-cathodic kukunciphisa i-oxygen.Ubukho be-P. aeruginosa kwandisa kakhulu i-corrosion order i-corrosion order i-high density of a density. i-ruginosa biofilm inyusa i-corrosion yendawo ye-2707 HDSS.Yuan et al29 yafumanisa ukuba i-corrosion density yangoku ye-70/30 Cu-Ni alloy yanda phantsi komngeni weP. I-c biofilms 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 icebise ukuba iireyithi zeekhemikhali kunye neempendulo ze-electrochemical zinokuchaphazeleka ngokuthe ngqo ngumsebenzi we-metabolic we-bacterial sessile phezu komfanekiso kunye nohlobo lwemveliso ye-corrosion.Njengoko kubonisiwe kwi-Figure 5 kunye neThebhile 5, zombini inombolo yeseli kunye nobukhulu be-biofilm buyancipha emva kweentsuku ze-14. Oku kunokuchazwa ngokufanelekileyo ukuba emva kweentsuku ze-14 ze-sesent ze-270 ze-HD ze-14 ze-setriple ze-70 ze-HD ze-70 ze-70 ze-14 ze-setriple ze-270 ze-HD ezifayo i-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 nesampuli C, ebonisa ukuba i-Dissolved Fe kunye ne-Cr ebangelwa yi-P. .Iqulethe i-17700 ppm Cl-, ethelekiseka naleyo ifumaneka kumanzi olwandle endalo. Ubukho be-17700 ppm Cl- yayisesona sizathu siphambili sokunciphisa i-Cr kwi-7- kunye ne-14 yeentsuku ze-abiotic iisampuli ezihlalutywe yi-XPS.Xa kuthelekiswa ne-P. I-2707 HDSS kwiindawo ze-abiotic.Umfanekiso we-9 ubonisa ubukho be-Cr6 + kwifilimu ye-passivation.Inokuthi ibandakanyeke 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, ngokulandelanayo. Ngoko ke, ngaphantsi kwe-P. aeruginosa biofilm, ukubola kwe-asidi ye-organic akunakwenzeka ukuba kube negalelo kulo msebenzi ngenxa ye-pH ephezulu kwi-bulk medium. Ixesha lovavanyo lweentsuku ze-4. 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 kwemichilo yokuvavanya.
Njengoko kubonisiwe kwi-Figure 7, ubunzulu bomgodi obuphezulu obubangelwa yi-P. aeruginosa biofilm yayiyi-0.69 μm, eyayinkulu kakhulu kune-abiotic medium (0.02 μm) I-707 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. aeruginosa ikhuphe kwaye iqalise amaphuzu.
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 yiSikolo seMetallurgy yeYunivesithi yaseNortheastern (NEU) e-Shenyang, e-China.I-elemental composition ye-2707 HDSS iboniswe kwiThebhile 1, eyahlalutywa yi-NEU yokuHlalutywa kwezinto kunye neSebe loVavanyo.Zonke iisampuli zaphathwa nge-1180 ° C kwi-1180 ° C, i-top-expensive ye-HDSS ye-1 corroped iyure ye-1000000000000000000000000 kwi-100 yovavanyo lwe-SS. indawo ye-1 cm2 yagudiswa yaya ku-2000 grit nge-silicon carbide paper kwaye yaphuculwa ngakumbi nge-0.05 μm Al2O3 powder suspension.Amacala kunye nezantsi zikhuselwe ngepeyinti engasebenziyo.Emva kokumiswa, imizekelo yahlanjululwa ngamanzi ahlambulukileyo ahlambulukileyo kwaye yahlanjululwa nge-ultraviolet ..5 driv. V) ukukhanya kwiiyure ze-0.5 ngaphambi kokusetyenziswa.
I-Marine Pseudomonas Aeruginosa McCC 1A00099s ithengwe kwiZiko leNkqutyana yeXiamen (i-MCCEC) i-Aersuugin ye-Amerrochedomass i-Aersuginoy Co., i-Qingdao, Chingseo, Chinga ) .Memerium (g / l): 19.45 I-NACCL2, 3.24 h3, 0,55 NH3, 00 NH3, 00,36 NH26 NH26 NH26 Nah26 NH25 NH26 Nah26 nant I-5.0 ye-Peptone, i-1.0 ye-Yeasts kunye ne-0.1 fric tictractrave nge-121 ° C kangangeeseli ze-pitktonic pseududunosa ngokukhawuleza emva kokuba i-Inoculation imalunga ne-106 yeeseli / 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) idityaniswe kwi-reactor nge-Luggin capillaries egcwele iibhulorho zetyuwa, esebenza njenge-counter kunye ne-reference electrodes, ngokulandelanayo.Ukwenza i-electrodes esebenzayo, i-rubber specimen ifakwe kwi-1 cm efakwe kwi-copper evulekileyo kunye ne-1 cm efakwe kwi-copper evulekileyo, i-rubber ifakwe kwi-copper efihliweyo kunye ne-1 cm. -indawo esecaleni yendawo ye-electrode esebenzayo. Ngexesha lokulinganisa i-electrochemical, iisampuli zafakwa kwi-2216E medium kwaye zigcinwe kwiqondo lokushisa elihlala lihlala (37 ° C) kwindawo yokuhlambela amanzi.OCP, LPR, EIS kunye nedatha ye-polarization enokubakho ilinganiswa ngokusebenzisa i-Autolab potentiostat (Ireferensi 600TM, i-Gamry 1 irekhodi ye-Instrument ye-USA). I-s-1 phezu koluhlu lwe-5 kunye ne-5 mV kunye ne-Eocp kunye ne-sampling frequency ye-1 Hz.EIS yenziwe nge-sine wave kwi-frequency range 0.01 ukuya kwi-10,000 Hz usebenzisa i-5 mV esetyenzisiweyo i-voltage kwi-Eocp. I-2 ukuya ku-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) kwaye emva koko zilungiswe nge-2.5% (v/v) glutaraldehyde ngeeyure ezili-10 ukulungisa i-biofilms.Kwathi emva koko kwaphelelwa ngamanzi ngoluhlu lwenqanaba (50%, 8%, 90%, 70%, 9%, 9%, 70%, 70%, 50%, 90%, 70%, 90%, 90%, 90%, 70% kunye ne-70% I-00% v / v) ye-ethanol ngaphambi kokumisa umoya.Ekugqibeleni, umphezulu wesampuli uhlanjululwe ngefilimu yegolide ukubonelela nge-conductivity ye-SEM observation.Imifanekiso ye-SEM yayigxininise kwiindawo ezinobuninzi beeseli ze-sessile ze-P. aeruginosa kumphezulu we-specimen nganye.Yenza uhlalutyo lwe-EDS ukuze ufumane izinto zekhemikhali.Askoscoic Zescopic (SMCL) I-Scanning ye-Chemical elements. yayisetyenziselwa ukulinganisa ubunzulu bomgodi.Ukuze kugcinwe imigodi yokugqwala phantsi kwe-biofilm, isiqwenga sovavanyo saqala sacocwa ngokwe-Chinese National Standard (CNS) GB/T4334.4-2000 ukususa iimveliso ze-corrosion kunye ne-biofilm kumphezulu wesiqwenga sovavanyo.
I-X-ray photoelectron spectroscopy (i-XPS, i-ESCALAB250 inkqubo yohlalutyo lomphezulu, i-Thermo VG, e-USA) uhlalutyo lwenziwa kusetyenziswa umthombo we-X-reyi we-monochromatic (umgca we-aluminium Kα ku-1500 eV amandla kunye ne-150 W amandla) phezu koluhlu olubanzi lwamandla olubophayo 0 phantsi kweemeko eziqhelekileyo -1350 eV. High-resolution eV.
Iisampuli ezifakwe kwi-incubated zaye zasuswa kwaye zahlanjululwa ngobumnene nge-PBS (pH 7.4 ± 0.2) kwi-15 s45. Ukuqwalasela ukusebenza kwebhaktheriya ye-biofilms kwiisampuli, i-biofilms yachithwa ngokusebenzisa i-LIVE / DEAD BacLight Bacterial Viability Kit (Invitrogen, i-Eugene fluorescent, i-Eugene ye-fluorescent, i-USA) Idayi ye-SYTO-9 kunye nedayi ebomvu ye-fluorescent propidium iodide (PI) Ngaphantsi kwe-CLSM, amachaphaza ane-fluorescent eluhlaza kunye nobomvu amele iiseli eziphilayo kunye nezifileyo, ngokulandelanayo.Ukucoca, umxube we-1 ml oqulethe i-3 μl SYTO-9 kunye ne-3 μl isisombululo se-PI yafukanyelwa kwimizuzu engama-20 e-oC kwiqondo lokushisa elimnyama kwi-23 ye-waward ye-staining kwi-23 yeqondo lokushisa kwi-23 yegumbi. (i-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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