Tinokutendai nekushanyira Nature.com. Shanduro yebrowser yauri kushandisa ine rutsigiro rushoma rweCSS. Kuti uwane ruzivo rwakanaka, tinokurudzira kuti ushandise browser yakagadziridzwa (kana kudzima compatibility mode muInternet Explorer). Panguva ino, kuti tive nechokwadi chekuti rutsigiro runoramba ruchienderera mberi, ticharatidza saiti iyi isina masitayera uye JavaScript.
Kuora kwemicrobial corrosion (MIC) idambudziko guru mumaindasitiri mazhinji sezvo kunogona kukonzera kurasikirwa kukuru kwehupfumi.2707 super duplex stainless steel (2707 HDSS) yakashandiswa munzvimbo dzegungwa nekuda kwekusagona kwayo makemikari. Zvisinei, kusagona kwayo kuuraya MIC hakuna kuratidzwa nekuyedza. Muchidzidzo ichi, maitiro eMIC e2707 HDSS anokonzerwa nebhakitiriya rePseudomonas aeruginosa remugungwa akaongororwa.Kuongororwa kweElectrochemical kwakaratidza kuti pamberi pePseudomonas aeruginosa biofilm mu2216E medium, pakanga paine shanduko yakanaka mukugona kuuraya uye kuwedzera kwehuwandu hwe corrosion current.Kuongororwa kweX-ray photoelectron spectroscopy (XPS) kwakaratidza kudzikira kweCr content pamusoro pesampuli iri pasi pebiofilm.Kuongororwa kwemifananidzo yemapits kwakaratidza kuti P. aeruginosa biofilm yakagadzira kudzika kwakanyanya kwegomba re0.69 μm mukati memazuva gumi nemana ekuiswa mukati memvura.Kunyangwe izvi zviri zvidiki, zvinoratidza kuti 2707 HDSS haina kudzivirirwa zvizere ku MIC yeP. aeruginosa biofilms.
Simbi dzisina ngura mbiri (DSS) dzinoshandiswa zvakanyanya mumaindasitiri akasiyana-siyana nekuda kwekusanganiswa kwadzo kwakanaka kwehunhu hwemakanika uye kuramba ngura1,2. Zvisinei, kupinza kwenzvimbo kuchiri kuitika uye kunokanganisa kusimba kwesimbi iyi3,4.DSS haidziviriri ngura yehutachiona (MIC)5,6. Pasinei nekusiyana-siyana kwekushandiswa kweDSS, kuchine nzvimbo uko kuramba ngura kweDSS kusina kukwana kushandiswa kwenguva refu. Izvi zvinoreva kuti zvinhu zvinodhura zvakanyanya zvine kuramba ngura kwakanyanya zvinodiwa.Jeon et al7 vakaona kuti kunyangwe simbi dzisina ngura mbiri (SDSS) dzine zvimwe zvisingakwanisike maererano nekuramba ngura.Naizvozvo, simbi dzisina ngura mbiri (HDSS) dzine kuramba ngura kwakawanda dzinodiwa mune zvimwe zvinoshandiswa.Izvi zvakaita kuti pave neHDSS yakabatana zvakanyanya.
Kuramba kweDSS kunokonzerwa nechikamu chealpha negamma uye nzvimbo dzakaderera dzeCr, Mo neW 8, 9, 10 dziri pedyo nechikamu chechipiri. HDSS ine huwandu hwakawanda hweCr, Mo neN11, saka ine hunhu hwakanaka hwekudzivirira ngura uye ine nhamba yakaenzana (45-50) Pitting Resistance Equivalent Number (PREN), inosarudzwa ne wt.% Cr + 3.3 (wt.% Mo + 0.5 wt% W) + 16 wt% N12. Kuramba kwayo ngura kwakanaka kunoenderana nechikamu chakaenzana chine zvikamu zvinosvika 50% ferrite (α) uye 50% austenite (γ), HDSS ine hunhu huri nani hwemakanika uye hunhu hwakanyanya kupfuura DSS13. Hunhu hweChloride ngura. Kuramba kuri nani kwekudzivirira ngura kunowedzera kushandiswa kweHDSS munzvimbo dzine chloride crusting, dzakadai senzvimbo dzegungwa.
MaMIC idambudziko guru mumaindasitiri akawanda akadai semafuta negesi nemvura.14. MIC inoumba 20% yekukuvara kwese kwengura15. MIC ingura ye bioelectrochemical inogona kuonekwa munzvimbo dzakawanda. Ma biofilms anoumbwa pamusoro pesimbi anochinja mamiriro e electrochemical, nokudaro achikanganisa maitiro ekuora. Zvinotendwa zvakanyanya kuti MIC corrosion inokonzerwa ne biofilms. Ma electrogen microorganisms anoora simbi kuti awane simba rinochengetedza kuti ararame.17. Zvidzidzo zveMIC zvazvino zvakaratidza kuti EET (extracellular electron transfer) ndiyo inoderedza mwero muMIC inokonzerwa ne electrogen microorganisms.Zhang et al. 18 vakaratidza kuti ma electron mediators anokurumidza kutamisa ma electron pakati pema Desulfovibrio sessificans cells ne 304 stainless steel, zvichikonzera kurwiswa kwakanyanya kweMIC.Enning et al. 19 naVenzlaff et al. 20 vakaratidza kuti corrosive sulfate-reducing bacteria (SRB) biofilms inogona kutora ma electron zvakananga kubva ku simbi substrates, zvichikonzera corrosion yakanyanya.
DSS inozivikanwa kuti inogona kubatwa neMIC munzvimbo dzine SRB, mabhakitiriya anoderedza iron (IRB), nezvimwewo. 21. Mabhakitiriya aya anokonzera nzvimbo dzakaita semakomba panzvimbo dzeDSS pasi pebiofilms22,23. Kusiyana neDSS, MIC yeHDSS24 haizivikanwe zvakanyanya.
Pseudomonas aeruginosa ibhakitiriya rinofamba rakaita setsvimbo rine giramu-negative iro rakapararira zvakanyanya muzvisikwa25. Pseudomonas aeruginosa iboka guru remabhakitiriya munzvimbo dzegungwa, zvichiita kuti MIC ive simbi. Pseudomonas inobatanidzwa zvakanyanya mukuita kwengura uye inozivikanwa semupi wekutanga panguva yekuumbwa kwebiofilm. Mahat et al. 28 naYuan et al. 29 vakaratidza kuti Pseudomonas aeruginosa ine katsika kekuwedzera mwero wengura wesimbi isina kusimba uye alloys munzvimbo dzine mvura.
Chinangwa chikuru chebasa iri kwaive kuongorora hunhu hweMIC ye2707 HDSS hwakakonzerwa nebhakitiriya rePseudomonas aeruginosa remugungwa vachishandisa nzira dzemagetsi, matekiniki ekuongorora pamusoro uye kuongorora chigadzirwa chekuora. Zvidzidzo zvemagetsi zvinosanganisira Open Circuit Potential (OCP), Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS), uye Potential Dynamic Polarization zvakaitwa kuti zvidzidze maitiro eMIC e2707 HDSS. Kuongororwa kweEnergy dispersive spectrometer (EDS) kwakaitwa kuti kuonekwe zvinhu zvemakemikari pamusoro pengura. Pamusoro pezvo, X-ray photoelectron spectroscopy (XPS) analysis yakashandiswa kuona kugadzikana kweoxide film passivation pasi pesimba renzvimbo yegungwa ine Pseudomonas aeruginosa. Kudzika kwegomba kwakayerwa pasi pe confocal laser scanning microscope (CLSM).
Tafura 1 inoratidza kuumbwa kwemakemikari e2707 HDSS. Tafura 2 inoratidza kuti 2707 HDSS ine hunhu hwakanaka hwemakanika ine simba rekubudisa re650 MPa. Mufananidzo 1 unoratidza chimiro cheoptical microstructure chemhinduro yakapiswa nekupisa ye2707 HDSS. Mabhendi akareba ezvikamu zve austenite neferrite asina zvikamu zvechipiri anogona kuonekwa muchimiro che microstructure chine zvikamu zve austenite ne50% zve ferrite.
Mufananidzo 2a unoratidza mukana wekushanda kwesero (Eocp) zvichienzaniswa nenguva yekubuda kwe2707 HDSS mu abiotic 2216E medium uye P. aeruginosa broth kwemazuva gumi nemana pa37 °C. Unoratidza kuti shanduko huru uye yakakosha muEocp inoitika mukati memaawa makumi maviri nemana ekutanga. Makoshero eEocp muzviitiko zvese zviri zviviri akasvika pa -145 mV (vs. SCE) maawa angangoita gumi nematanhatu uye akazodzikira zvakanyanya, achisvika -477 mV (vs. SCE) uye -236 mV (vs. SCE) yesample ye abiotic neP, zvichiteerana). Makuponi ePseudomonas aeruginosa, zvichiteerana. Mushure memaawa makumi maviri nemana, kukosha kweEocp kwe2707 HDSS yeP. aeruginosa kwakanga kwakadzikama pa -228 mV (vs. SCE), nepo kukosha kwakafanana kwemasampuru asiri ebhayoloji kwaive kuri -442 mV (vs. SCE). Eocp pamberi peP. aeruginosa yakanga yakaderera.
Kuongororwa kwemakemikari kwe2707 HDSS sampuli mu abiotic medium nemuto wePseudomonas aeruginosa pa37 °C:
(a) Eocp sebasa renguva yekuratidzwa, (b) makomba epolarization pazuva rechi14, (c) Rp sebasa renguva yekuratidzwa uye (d) icorr sebasa renguva yekuratidzwa.
Tafura 3 inoratidza electrochemical corrosion parameter values ​​​​ye2707 HDSS samples dzakaiswa mu abiotic medium nePseudomonas aeruginosa inoculated medium kwemazuva gumi nemana. Ma tangents ema anodic ne cathodic curves akatorwa kuti asvike panzvimbo dzinosangana corrosion current density (icorr), corrosion potential (Ecorr) neTafel slopes (βα neβc) zvichienderana nenzira dzakajairwa30,31.
Sezvakaratidzwa muMufananidzo 2b, kukwira kweP. aeruginosa curve kwakaita kuti Ecorr iwedzere zvichienzaniswa neabiotic curve. Iko kukosha kweicorr, iyo inoenderana ne corrosion rate, yakawedzera kusvika pa 0.328 μA cm-2 muPseudomonas aeruginosa sample, kakapetwa kana kupfuura yemuenzaniso usiri we biological (0.087 μA cm-2).
LPR inzira yekare isingaparadze yekuongorora ngura nekukurumidza. Yakashandiswawo kudzidza MIC32. Mufananidzo 2c unoratidza polarization resistance (Rp) senzira yekuona nguva yekubuda. Kukosha kweRp kwakakwira kunoreva ngura shoma. Mukati memaawa makumi maviri nemana ekutanga, Rp ye2707 HDSS yakasvika pa1955 kΩ cm2 yemasampuli asina biotic uye 1429 kΩ cm2 yemasampuli ePseudomonas aeruginosa. Mufananidzo 2c unoratidzawo kuti kukosha kweRp kwakaderera nekukurumidza mushure mezuva rimwe chete uye kwakaramba kusina kuchinja kwemazuva gumi nematatu anotevera. Kukosha kweRp kwemuenzaniso wePseudomonas aeruginosa kunenge 40 kΩ cm2, iyo yakaderera zvikuru pane kukosha kwe450 kΩ cm2 kwemuenzaniso usiri webiological.
Kukosha kweiyo icorr kunoenderana nechiyero chengura chakaenzana. Kukosha kwayo kunogona kuverengerwa kubva muequation inotevera yeStern-Geary,
Zvichitevera Zou et al. 33, kukosha kwakajairika kweTafel slope B mubasa iri kwaifungidzirwa kuva 26 mV/dec. Mufananidzo 2d unoratidza kuti icorr yemuenzaniso we2707 usiri webiological yakaramba yakagadzikana, nepo muenzaniso weP. aeruginosa wakachinja-chinja zvakanyanya mushure memaawa makumi maviri nemana ekutanga. Makoshero eicorr emuenzaniso weP. aeruginosa aive akakwira zvakanyanya kupfuura zvinodzora zvisiri zvebiological. Maitiro aya anoenderana nemigumisiro yekudzivirira polarization.
EIS imwe nzira isingaparadze inoshandiswa kuratidza mashandiro emagetsi panzvimbo dzakaora. Impedance spectra uye capacitance values ​​​​yakaverengerwa yesampuli dzakaratidzwa kune abiotic media uye Pseudomonas aeruginosa solution, Rb resistance ye passive film/biofilm yakagadzirwa pamusoro pemuenzaniso, Rct charge transfer resistance, Cdl electric double layer capacitance (EDL) uye QCPE Constant Phase Element (CPE) parameters. Aya ma parameter akaongororwa zvakare nekuisa data uchishandisa equivalent circuit (EEC) model.
Mufananidzo 3 unoratidza maNyquist plots (a na b) uye maBode plots (a' na b') e2707 HDSS samples mu abiotic medium uye P. aeruginosa broth panguva dzakasiyana dzekufukidzwa. Dhayamita yeNyquist ring inoderera kana paine Pseudomonas aeruginosa. Iyo Bode plot (Mufananidzo 3b') inoratidza kuwedzera kwehukuru hwe impedance yese. Ruzivo pamusoro penguva yekurelaxation constant runogona kupihwa ne phase maxima. Mufananidzo 4 unoratidza monolayer (a) uye bilayer (b) based physical structures uye maEECs anoenderana nawo.CPE inounzwa muEEC model. Kupinda kwayo uye impedance zvinoratidzwa seizvi:
Mamodheru maviri epanyama uye maseketi akaenzana anoenderana ekugadzirisa impedance spectrum ye2707 HDSS sampuli:
apo Y0 ndiyo hukuru hweCPE, j ndiyo nhamba yekufungidzira kana (-1)1/2, ω ndiyo angular frequency, uye n ndiyo CPE power index iri pasi pe unity35. Inverse yechaji transfer resistance (kureva 1/Rct) inoenderana ne corrosion rate. Diki Rct zvinoreva corrosion rate inokurumidza 27. Mushure memazuva gumi nemana ekuiswa mukati, Rct yemasampuli ePseudomonas aeruginosa yakasvika 32 kΩ cm2, diki zvikuru pane 489 kΩ cm2 yemasampuli asiri ebhayoloji (Tafura 4).
Mifananidzo yeCLSM nemifananidzo yeSEM ​​iri muMufananidzo 5 zvinoratidza pachena kuti kufukidza kwebiofilm pamusoro pe2707 HDSS sampuli mushure memazuva manomwe kwakaoma. Zvisinei, mushure memazuva gumi nemana, kufukidza kwebiofilm kwakanga kushoma uye mamwe masero akafa akaonekwa. Tafura 5 inoratidza ukobvu hwebiofilm pa2707 HDSS sampuli mushure mekusangana neP. aeruginosa kwemazuva manomwe negumi nemana. Ukobvu hwepamusoro hwebiofilm hwakachinja kubva pa23.4 μm mushure memazuva manomwe kusvika pa18.9 μm mushure memazuva gumi nemana. Avhareji yeukobvu hwebiofilm yakasimbisawo maitiro aya. Yakaderera kubva pa22.2 ± 0.7 μm mushure memazuva manomwe kusvika pa17.8 ± 1.0 μm mushure memazuva gumi nemana.
(a) Mufananidzo we3-D CLSM mushure memazuva manomwe, (b) Mufananidzo we3-D CLSM mushure memazuva gumi nemana, (c) Mufananidzo weSEM mushure memazuva manomwe uye (d) Mufananidzo weSEM mushure memazuva gumi nemana.
EDS yakaratidza zvinhu zvemakemikari mu biofilms uye zvigadzirwa zvengura pasampuli dzakaratidzwa kuP. aeruginosa kwemazuva gumi nemana. Mufananidzo 6 unoratidza kuti huwandu hweC, N, O, uye P mu biofilms uye zvigadzirwa zvengura hwakakwira zvakanyanya kupfuura huri musimbi dzisina chinhu, nekuti zvinhu izvi zvine chekuita ne biofilms uye metabolites dzadzo. Ma microbes anongoda huwandu hushoma hwe chromium nesimbi. Huwandu hwakawanda hweCr neFe mu biofilm uye zvigadzirwa zvengura pamusoro pesampuli zvinoratidza kuti matrix yesimbi yarasikirwa nezvinhu nekuda kwengura.
Mushure memazuva gumi nemana, makomba ane uye asina P. aeruginosa akaonekwa mune 2216E medium. Musati makomba aiswa, pamusoro pemuenzaniso pakanga pakanyatsonaka uye pasina chikanganiso (Mufananidzo 7a). Mushure mekukanda nekubvisa biofilm uye zvigadzirwa zvengura, makomba akadzika pamusoro pemuenzaniso akaongororwa pasi peCLSM, sezvakaratidzwa muMufananidzo 7b uye c. Hapana makomba akajeka akawanikwa pamusoro pemuenzaniso wekusadzora wezvinhu zvipenyu (kudzika kwegomba kwakanyanya 0.02 μm). Kudzika kwegomba kwakanyanya kwakakonzerwa nePseudomonas aeruginosa kwaive 0.52 μm mushure memazuva manomwe uye 0.69 μm mushure memazuva gumi nemana, zvichibva paavhareji yekudzika kwegomba kwemasampuli matatu (10 magogo egomba akasarudzwa pamuenzaniso wega wega) akasvika 0.42 ± 0.12 μm uye 0.52 ± 0.15 μm, zvichiteerana (Tafura 5). Aya makomba egomba madiki asi akakosha.
(a) Usati wasangana nechirwere ichi, (b) mazuva gumi nemana uri muchimiro chemvura isina utachiona uye (c) mazuva gumi nemana uri muPseudomonas aeruginosa broth.
Mufananidzo 8 unoratidza maXPS spectra enzvimbo dzakasiyana dzesample, uye machemical compositions akaongororwa panzvimbo imwe neimwe akapfupikiswa muTafura 6. MuTafura 6, maatomu percentages eFe neCr aripo neP. aeruginosa (samples A naB) aive akaderera zvakanyanya pane evasinga-biological control samples (samples C naD). Kune sample yeP. aeruginosa, Cr 2p core-level spectral curve yakaiswa kune zvikamu zvina zvepeak zvine simba rekubatanidza (BE) re574.4, 576.6, 578.3 uye 586.8 eV, izvo zvinogona kuverengerwa kuCr, Cr2O3, CrO3 uye Cr(OH)3, zvichiteerana (Mufananidzo 9a na b). Kune vasiri-biological sampuli, Cr 2p core-level spectrum ine main peaks maviri eCr (573.80 eV yeBE) uye Cr2O3 (575.90 eV yeBE) muMufananidzo 9c nad, zvichiteerana. Inonyanya kushamisa Musiyano uripo pakati pemasampuli e-abiotic neP. aeruginosa waivapo kweCr6+ uye chikamu chakakwirira cheCr(OH)3 (BE ye586.8 eV) pasi pebiofilm.
Magirazi eXPS akafara pamusoro pemuenzaniso we2707 HDSS ari muzvikamu zviviri izvi ane mazuva manomwe nemazuva gumi nemana, zvichiteerana.
(a) Mazuva manomwe ekubatwa neP. aeruginosa, (b) Mazuva gumi nemana ekubatwa neP. aeruginosa, (c) Mazuva manomwe mu abiotic medium uye (d) Mazuva gumi nemana mu abiotic medium.
HDSS inoratidza mazinga akakwirira ekudzivirira ngura munzvimbo zhinji.Kim et al. 2 vakataura kuti UNS S32707 HDSS yakatsanangurwa seDSS yakabatanidzwa zvakanyanya ine PREN inopfuura 45. PREN kukosha kwe2707 HDSS sampuli mubasa iri kwaive 49. Izvi zvinokonzerwa nehuwandu hwayo hwe chromium yakawanda uye huwandu hwakawanda hwe molybdenum neNi, izvo zvinobatsira munzvimbo dzine acidic uye chloride yakawanda. Pamusoro pezvo, chimiro chakaenzana zvakanaka uye microstructure isina kukanganisa zvinobatsira pakugadzikana kwechimiro uye kudzivirira ngura. Zvisinei, pasinei nekudzivirira kwayo kwakanaka kwemakemikari, data rekuyedza mubasa iri rinoratidza kuti 2707 HDSS haina kudzivirirwa zvachose kuMIC yeP. aeruginosa biofilms.
Mhedzisiro yemakemikari emagetsi yakaratidza kuti mwero wekuora kwe2707 HDSS mumuto weP. aeruginosa wakawedzera zvakanyanya mushure memazuva gumi nemana zvichienzaniswa nemuto weP. aeruginosa. MuMufananidzo 2a, kudzikira kweEocp kwakaonekwa mune zvese zviri zviviri abiotic medium nemuto weP. aeruginosa mumaawa makumi maviri nemana ekutanga. Mushure mezvo, biofilm yapedza kufukidza pamusoro pemuenzaniso uye Eocp inova yakadzikama36. Zvisinei, mwero weEocp yebhayoloji waive wakakwira zvakanyanya pane weEocp yebhayoloji isiri biological. Pane chikonzero chekutenda kuti mutsauko uyu unokonzerwa nekuumbwa kweP. aeruginosa biofilm. MuMufananidzo 2d, pamberi peP. aeruginosa, kukosha kweicorr kwe2707 HDSS kwakasvika 0.627 μA cm-2, iyo yaive yakakura kupfuura iyo yeabiotic control (0.063 μA cm-2), iyo yaienderana neRct value yakayerwa neEIS. Mumazuva mashoma ekutanga, impedance values Mumuto weP. aeruginosa wakawedzera nekuda kwekunamirwa kwemasero eP. aeruginosa uye kuumbwa kwebiofilms. Zvisinei, kana biofilm yakafukidza pamusoro pemuenzaniso, impedance inoderera. Rutivi rwekudzivirira runorwiswa kutanga nekuda kwekuumbwa kwebiofilms uye biofilm metabolites. Nokudaro, kuramba kwekuora kwakadzikira nekufamba kwenguva, uye kunamatira kweP. aeruginosa kwakakonzera ngura munzvimbo. Mafambiro e abiotic media akanga akasiyana. Kuramba kwekuora kwekutonga kusiri kwebiological kwaive kwakanyanya kupfuura kukosha kwakaenzana kwemasampuli akaoneswa kumuto weP. aeruginosa. Uyezve, kune masampuli e abiotic, kukosha kweRct kwe2707 HDSS kwakasvika 489 kΩ cm2 pazuva rechi14, iyo yaive ka15 kukosha kweRct (32 kΩ cm2) pamberi peP. aeruginosa. Nokudaro, 2707 HDSS ine kuramba kwekuora kwakanaka munzvimbo isina tsvina, asi haidziviriri kurwiswa neMIC neP. aeruginosa biofilms.
Mhedzisiro iyi inogonawo kuonekwa kubva pamakomba epolarization ari muMufananidzo 2b. Kubatana kweanodic kwakakonzerwa nekuumbwa kwePseudomonas aeruginosa biofilm uye metal oxidation reactions. Panguva imwe chete cathodic reaction kudzikira kweoxygen. Kuvapo kweP. aeruginosa kwakawedzera zvakanyanya corrosion current density, inenge yakakura kupfuura abiotic control. Izvi zvinoratidza kuti P. aeruginosa biofilm inowedzera localized corrosion ye2707 HDSS. Yuan et al29 vakaona kuti corrosion current density ye70/30 Cu-Ni alloy yakawedzera pasi pekupikiswa kweP. aeruginosa biofilm. Izvi zvinogona kunge zvichikonzerwa ne biocatalysis yekuderedzwa kweoxygen nePseudomonas aeruginosa biofilms. Kuongororwa uku kunogonawo kutsanangura MIC ye2707 HDSS mubasa iri. Aerobic biofilms inogonawo kuva neoxygen shoma pasi payo. Nokudaro, kukundikana kudzorerazve pamusoro pesimbi neoxygen kunogona kuva chinhu chinokonzera MIC mubasa iri.
Dickinson nevamwe vake 38 vakataura kuti mwero wemakemikari nemakemikari anogona kukanganiswa zvakananga nekushanda kwemasero ebhakitiriya anoputika pamusoro pemuenzaniso uye hunhu hwezvigadzirwa zvengura. Sezvinoratidzwa muMufananidzo 5 neTafura 5, nhamba yesero uye ukobvu hwebiofilm zvakaderera mushure memazuva gumi nemana. Izvi zvinogona kutsanangurwa zvine musoro kuti mushure memazuva gumi nemana, mazhinji emasero anoputika pamusoro pe2707 HDSS akafa nekuda kwekushomeka kwezvinovaka muviri mu2216E medium kana kuburitswa kwemaion esimbi ane chepfu kubva mu2707 HDSS matrix. Uku kuganhurirwa kwekuyedza kwebatch.
Mubasa iri, P. aeruginosa biofilm yakakurudzira kudzikira kweCr neFe pasi pebiofilm pamusoro pe2707 HDSS (Mufananidzo 6). MuTafura 6, kudzikira kweFe neCr mumuenzaniso D zvichienzaniswa nemuenzaniso C, zvichiratidza kuti Fe yakanyungudutswa neCr yakakonzerwa neP. aeruginosa biofilm yakaramba iripo kupfuura mazuva manomwe ekutanga. Iyo 2216E medium inoshandiswa kutevedzera nharaunda dzegungwa. Ine 17700 ppm Cl-, inofananidzwa neinowanikwa mumvura yegungwa yechisikigo. Kuvapo kwe17700 ppm Cl- ndiko kwaive chikonzero chikuru chekudzikira kweCr musampuli dzeabiotic dzemazuva manomwe negumi nemana dzakaongororwa neXPS. Zvichienzaniswa nesampuli dzeP. aeruginosa, kudzikira kweCr musampuli dzeabiotic kwaive kushoma nekuda kwekusasimba kweCl− kwe2707 HDSS munzvimbo dzeabiotic. Mufananidzo 9 unoratidza kuvapo kweCr6+ mufirimu repassivation. Inogona kunge iine chekuita nekubviswa kweCr kubva pamusoro pesimbi neP. aeruginosa biofilms, sezvakakurudzirwa naChen naClayton.
Nekuda kwekukura kwebhakitiriya, pH yenzvimbo iyi isati yakura uye mushure mekurima yaive 7.4 uye 8.2, zvichiteerana. Saka, pasi peP. aeruginosa biofilm, organic acid corrosion haigone kuve chinhu chinobatsira pabasa iri nekuda kwepH yakakwira munzvimbo yakawanda. PH yenzvimbo isiri yebiological control haina kuchinja zvakanyanya (kubva pa7.4 yekutanga kusvika pa7.5 yekupedzisira) mukati menguva yekuedza kwemazuva gumi nemana. Kuwedzera kwepH munzvimbo inopinza mushure mekudya kwakakonzerwa nebasa reP. aeruginosa uye kwakawanikwa kune mhedzisiro imwechete papH pasina test strips.
Sezvakaratidzwa muMufananidzo 7, kudzika kwegomba kwakanyanya kwakakonzerwa neP. aeruginosa biofilm kwaive 0.69 μm, iyo yaive yakakura kupfuura iyo yeabiotic medium (0.02 μm). Izvi zvinoenderana nedata re electrochemical rakatsanangurwa pamusoro apa. Kudzika kwegomba re 0.69 μm kwakaderera kanopfuura kagumi pane kukosha kwe 9.5 μm kwakataurwa kwe2205 DSS pasi pemamiriro akafanana. Aya data anoratidza kuti 2707 HDSS inoratidza kuramba kweMIC kuri nani zvichienzaniswa ne2205 DSS. Izvi hazvifanirwe kushamisa, sezvo 2707 HDSS ine huwandu hwakawanda hwe chromium, inopa passivation inogara kwenguva refu, nekuda kwechimiro chechikamu chakaringana chisina precipitates inokuvadza, zvichiita kuti zviomere P. aeruginosa kubvisa passivate uye kutanga mapoinzi eclipse.
Mukupedzisa, MIC pitting yakawanikwa pamusoro pe2707 HDSS mumuto weP. aeruginosa zvichienzaniswa nepitting isingakoshi mu abiotic media. Basa iri rinoratidza kuti 2707 HDSS ine MIC resistance iri nani pane 2205 DSS, asi haina kudzivirirwa zvizere kuMIC nekuda kweP. aeruginosa biofilm. Izvi zvakawanikwa zvinobatsira mukusarudza simbi dzisina ngura dzakakodzera uye humbowo hwenguva yebasa renzvimbo yegungwa.
Kuponi ye2707 HDSS inopihwa neChikoro cheMetallurgy cheNortheastern University (NEU) muShenyang, China. Kuumbwa kwe2707 HDSS kunoratidzwa muTafura 1, iyo yakaongororwa neNEU Materials Analysis and Testing Department. Mienzaniso yese yakagadziriswa pa1180 °C kweawa imwe chete. Pamberi pekuyedzwa kwekuora, 2707 HDSS yakaita semari ine nzvimbo yepamusoro ye1 cm2 yakakweshwa kusvika pa2000 grit nepepa resilicon carbide ndokukweshwazve ne 0.05 μm Al2O3 powder suspension. Mativi nepasi zvakadzivirirwa nependi isina kusimba. Mushure mekuomeswa, sampuli dzakasukurudzwa nemvura isina kuchena uye dzakacheneswa ne75% (v/v) ethanol kwemaawa 0.5. Dzakazoomeswa nemhepo pasi pechiedza cheultraviolet (UV) kwemaawa 0.5 dzisati dzashandiswa.
Mushonga weMarine Pseudomonas aeruginosa MCCC 1A00099 wakatengwa kubva kuXiamen Marine Culture Collection Center (MCCC), China. Pseudomonas aeruginosa yakakurirwa pa37°C mumaflasks e250 ml uye 500 ml electrochemical glass cells uchishandisa Marine 2216E liquid medium (Qingdao Hope Biotechnology Co., Ltd., Qingdao, China). Pakati (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 SrBr2, 0.022 H3BO3, 0.004 NaSiO3, 0016 NH3, 0016 NH3, 0016 NaH2PO4 , 5.0 peptone, 1.0 yeast extract uye 0.1 ferric citrate. Ingovhara pa121°C kwemaminitsi makumi maviri usati wabaya. Verenga masero e sessile ne planktonic uchishandisa hemocytometer pasi pe microscope yakajeka pa400X magnification. Kuwanda kwekutanga kwePseudomonas aeruginosa planktonic mushure mekubaya kwaive masero angangoita 106/ml.
Miedzo yemagetsi yakaitwa mugirazi rekare rine maerekitironi matatu rine huwandu hwepakati hwe500 ml. Pepa replatinum neelectrode ye calomel yakaguta (SCE) zvakabatana ne reactor kuburikidza neLuggin capillaries yakazadzwa nemabhiriji emunyu, zvichishanda semaerekitironi ecounter uye reference, zvichiteerana. Kuti maerekitironi ashande, waya yemhangura yakaputirwa nerabha yakasungirirwa kune imwe neimwe sampuli ndokufukidzwa ne epoxy, zvichisiya nzvimbo inosvika 1 cm2 yenzvimbo yakaratidzwa ye single-sided ye electrode inoshanda. Munguva yekuyerwa kwemagetsi, sampuli dzakaiswa mu 2216E medium uye dzakachengetwa pakupisa kwe incubation (37 °C) mumvura yekugezera. OCP, LPR, EIS uye data re potential dynamic polarization zvakayerwa uchishandisa Autolab potentiostat (Reference 600TM, Gamry Instruments, Inc., USA). Miedzo yeLPR yakanyorwa pachiyero che scan che 0.125 mV s-1 pamusoro pe -5 ne 5 mV ne Eocp uye frequency ye sampling ye 1 Hz. EIS yakaitwa ne sine wave mu frequency range. 0.01 kusvika 10,000 Hz uchishandisa voltage ye5 mV yakaiswa paEocp inogadzikana. Potential sweep isati yatanga, maelectrode aive mu open-circuit mode kusvika pasvika stable free corrosion potential value. Polarization curves dzakabva dzatanga kubva pa -0.2 kusvika 1.5 V vs. Eocp pa scan rate ye 0.166 mV/s. Bvunzo yega yega yakadzokororwa katatu neP. aeruginosa uye isina.
Mienzaniso yekuongorora metallographic yakakweshwa ne 2000 grit wet SiC paper ndokuzokweshwazve ne 0.05 μm Al2O3 powder suspension kuti iongororwe nemaziso. Kuongororwa kwemetallographic kwakaitwa uchishandisa maikorosikopu yemaziso. Mienzaniso yacho yakachekwa ne 10 wt.% potassium hydroxide solution 43.
Mushure mekuiswa musanganiswa wezvinhu zvakasanganiswa, sampuli dzakagezwa katatu ne phosphate-buffered saline (PBS) solution (pH 7.4 ± 0.2) uye dzakazogadziriswa ne 2.5% (v/v) glutaraldehyde kwemaawa gumi kuti dzigadzire biofilms. Dzakazobviswa mvura ne graded series (50%, 60%, 70%, 80%, 90%, 95% uye 100% v/v) ye ethanol isati yaoma. Pakupedzisira, pamusoro pemuenzaniso pakaiswa firimu regoridhe kuti pave ne conductivity yeSEM. Mifananidzo yeSEM ​​yakatarisana nenzvimbo dzine masero eP. aeruginosa anonyanya kusvuta pamusoro pemuenzaniso wega wega. Ita EDS analysis kuti uwane makemikari. Zeiss Confocal Laser Scanning Microscope (CLSM) (LSM 710, Zeiss, Germany) yakashandiswa kuyera kudzika kwegomba. Kuti uone makomba ekuora pasi pe biofilm, test piece yakatanga yacheneswa zvichienderana ne Chinese National Standard (CNS) GB/T4334.4-2000 yekubvisa zvinhu zvakaora uye biofilm pamusoro pechinhu chekuyedza.
Kuongorora kweX-ray photoelectron spectroscopy (XPS, ESCALAB250 surface analysis system, Thermo VG, USA) kwakaitwa uchishandisa monochromatic X-ray source (aluminium Kα line pa 1500 eV energy uye 150 W power) pamusoro pe wide binding energy range 0 pasi pemamiriro akajairwa -1350 eV. High-resolution spectra dzakarekodhwa uchishandisa 50 eV pass energy uye 0.2 eV step size.
Zviyero zvakaiswa mu incubation zvakabviswa ndokusukurudzwa zvinyoro nyoro nePBS (pH 7.4 ± 0.2) kwemasekonzi gumi nemashanu nemakumi mana nemashanu. Kuti vaone kushanda kwebhakitiriya kwema biofilms ari pamasamples, biofilms dzakaiswa mavara achishandisa LIVE/DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, OR, USA). Kit iyi ine madhayi maviri e fluorescent, dhayi re green fluorescent SYTO-9 uye dhayi re red fluorescent propidium iodide (PI). Pasi peCLSM, madotsi ane fluorescent green ne tsvuku anomiririra masero mhenyu neakafa, zvichiteerana. Pakusvibisa, musanganiswa we 1 ml une 3 μl SYTO-9 uye 3 μl PI solution wakaiswa mu incubation kwemaminitsi makumi maviri patembiricha yemumba (23 oC) murima. Mushure mezvo, masamples akaiswa mavara akaonekwa pama wavelength maviri (488 nm yemasero mhenyu uye 559 nm yemasero akafa) uchishandisa muchina weNikon CLSM (C2 Plus, Nikon, Japan). Ukobvu hweBiofilm hwakayerwa mu Maitiro ekuskena e3-D.
Maitiro ekutaura chinyorwa chino: Li, H. et al. Kuora kwesimbi isina tsvina ye2707 super duplex yakagadzirwa nePseudomonas aeruginosa biofilm.science.Rep. 6, 20190; doi: 10.1038/srep20190 (2016).
Zanotto, F., Grassi, V., Balbo, A., Monticelli, C. & Zucchi, F. Kupwanyika kwesimbi isina tsvina yeLDX 2101 duplex mumushonga wechloride paine thiosulfate.coros.science.80, 205–212 (2014).
Kim, ST, Jang, SH, Lee, IS & Park, YS Mhedzisiro yekurapa kupisa kwemvura uye nitrogen mugasi rekudzivirira pakudzivirira ngura yesimbi isina tsvina ye super duplex welds.coros.science.53, 1939–1947 (2011).
Shi, X., Avci, R., Geiser, M. & Lewandowski, Z. Chidzidzo cheKuenzanisa kweMakemikoro eKuora kweMabhakitiriya neMakemikoro mu316L Stainless Steel.coros.science.45, 2577–2595 (2003).
Luo, H., Dong, CF, Li, XG & Xiao, K. Maitiro emagetsi esimbi isina tsvina ye2205 duplex mumhinduro dzealkaline dzepH dzakasiyana kana paine chloride.Electrochim.Journal.64, 211–220 (2012).
Little, BJ, Lee, JS & Ray, RI Mhedzisiro yema biofilms emugungwa pakuora: ongororo pfupi.Electrochim.Journal.54, 2-7 (2008).