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Microbial corrosion (MIC) ndi vuto lalikulu m'mafakitale ambiri chifukwa likhoza kuwononga kwambiri chuma.2707 super duplex stainless steel (2707 HDSS) yakhala ikugwiritsidwa ntchito m'madera a m'nyanja chifukwa cha kukana kwake kwa mankhwala.Komabe, kukana kwake kwa MIC sikunawonetsedwe moyesera. Kufufuza kwa Electrochemical kunasonyeza kuti pamaso pa Pseudomonas aeruginosa biofilm mu 2216E sing'anga, panali kusintha kwabwino kwa dzimbiri komanso kuwonjezeka kwa kuchuluka kwa dzimbiri. aeruginosa biofilm inapanga dzenje lakuya la 0.69 μm m'masiku a 14. Ngakhale izi ndizochepa, zimasonyeza kuti 2707 HDSS sichitetezedwa mokwanira ndi MIC ya P. aeruginosa biofilms.
Duplex zitsulo zosapanga dzimbiri (DSS) zimagwiritsidwa ntchito kwambiri m'mafakitale osiyanasiyana chifukwa cha kuphatikiza kwawo koyenera kwa makina abwino kwambiri komanso kukana kwa dzimbiri1,2.Komabe, kupindika komweko kumachitikabe ndipo kumakhudza kukhulupirika kwa steel3,4.DSS iyi sikulimbana ndi kuwonongeka kwa tizilombo toyambitsa matenda (MIC) 5,6.Ngakhale kuti pali mitundu yosiyanasiyana ya DSS yomwe ilipobe, malo ogwiritsira ntchito DSS akadali osakanizidwa ndi DSS. kwa nthawi yayitali.Izi zikutanthawuza kuti zipangizo zamtengo wapatali zokhala ndi zowonongeka zowonongeka ndizofunikira.Jeon et al7 adapeza kuti ngakhale super duplex zitsulo zosapanga dzimbiri (SDSS) zimakhala ndi zofooka zina zokhudzana ndi kukana kwa dzimbiri.Choncho, zitsulo zosapanga dzimbiri zosapanga dzimbiri (HDSS) zokhala ndi zitsulo zosapanga dzimbiri (HDSS) zokhala ndi chiwombankhanga chapamwamba zimafunika mu ntchito zina.Izi zinayambitsa chitukuko cha HDSS chapamwamba kwambiri.
Kukana kwa dzimbiri kwa DSS kumadalira chiŵerengero cha magawo a alpha ndi gamma ndipo Cr, Mo ndi W zatha madera 8, 9, 10 moyandikana ndi gawo lachiwiri.HDSS ili ndi zinthu zambiri za Cr, Mo ndi N11, choncho ili ndi kukana kwa dzimbiri komanso mtengo wapamwamba (45-50) Pitting Resistance Equitance + 3% Cr. (wt.% Mo + 0.5 wt% W) + 16 wt% N12. Kukaniza kwake kwakukulu kwa dzimbiri kumadalira kapangidwe kake kamene kamakhala ndi pafupifupi 50% ferrite (α) ndi 50% austenite (γ) magawo, HDSS ili ndi makina abwino kwambiri komanso kukana kwambiri kuposa DSS13 wamba. Chloride corrosion properties.Kukaniza bwino kwa dzimbiri kumakulitsa kugwiritsa ntchito HDSS m'malo owononga kwambiri a chloride, monga malo am'madzi.
Ma MIC ndi vuto lalikulu m'mafakitale ambiri monga mafuta ndi gasi ndi zinthu zamadzi14.MIC imapanga 20% ya zowonongeka zonse15.MIC ndi bioelectrochemical corrosion yomwe ingakhoze kuwonedwa m'madera ambiri.Mafilimu omwe amapangidwa pazitsulo amasintha zinthu zamagetsi zamagetsi, motero zimakhudza njira ya corrosion yomwe imakhulupirira kuti MIC imayambitsa kwambiri. biofilms.Ma microorganisms a Electrogenic corrode zitsulo kuti apeze mphamvu zowonjezera kuti apulumuke17.Kafukufuku waposachedwapa wa MIC wasonyeza kuti EET (extracellular electron transfer) ndiyo kuchepetsa mlingo wa MIC wopangidwa ndi electrogenic microorganisms.Zhang et al. 18 inasonyeza kuti oyimira ma electron amafulumizitsa kusamutsidwa kwa ma elekitironi pakati pa maselo a Desulfovibrio sessificans ndi 304 zitsulo zosapanga dzimbiri, zomwe zimapangitsa kuti pakhale kuukira koopsa kwa MIC.Enning et al. 19 ndi Venzlaff et al. 20 idawonetsa kuti ma corrosive sulfate-reducing bacteria (SRB) biofilms amatha kuyamwa ma elekitironi mwachindunji ku magawo azitsulo, zomwe zimapangitsa kuti pakhale dzimbiri.
DSS imadziwika kuti imakhudzidwa ndi MIC m'madera omwe ali ndi SRB, mabakiteriya ochepetsa chitsulo (IRB), etc. 21 .Mabakiteriyawa amachititsa kupindika kumalo a DSS pansi pa biofilms22,23. Mosiyana ndi DSS, MIC ya HDSS24 imadziwika bwino.
Pseudomonas aeruginosa ndi gram-negative motile-rod-rod bacterium yomwe imafalitsidwa kwambiri mu chilengedwe25.Pseudomonas aeruginosa imakhalanso gulu lalikulu la tizilombo toyambitsa matenda m'nyanja, zomwe zimapangitsa kuti MIC ikhale chitsulo.Pseudomonas imakhudzidwa kwambiri ndi njira zowonongeka ndipo imadziwika kuti ndi bioMahalmt colonizer. 28 ndi Yuan et al. 29 idawonetsa kuti Pseudomonas aeruginosa ili ndi chizolowezi chowonjezera kuchuluka kwa dzimbiri kwa chitsulo chochepa komanso ma aloyi m'malo amadzi.
Cholinga chachikulu cha ntchitoyi chinali kufufuza katundu wa MIC wa 2707 HDSS woyambitsidwa ndi mabakiteriya a aerobic Pseudomonas aeruginosa pogwiritsa ntchito njira za electrochemical, njira zowunikira pamwamba ndi kusanthula kwazinthu zowonongeka.Kafukufuku wa Electrochemical kuphatikizapo Open Circuit Potential (OCP), Linear Polarization Resistance (LPR), Electrochemical Resistance (LPR) ndi Electoscopy Dynamic Polarization anachitidwa kuti aphunzire khalidwe la MIC la 2707 HDSS.Kusanthula kwa Energy dispersive spectrometer (EDS) kunachitidwa kuti apeze zinthu za mankhwala pamtunda wa corrod.Kuonjezera apo, X-ray photoelectron spectroscopy (XPS) anagwiritsidwa ntchito kuti adziwe kukhazikika kwa filimu ya oxide passivation pansi pa chisonkhezero cha chilengedwe choyezedwa cha m'madzi chomwe chili ndi Pseuruginosa scanning laser pierugonosa scanning. microscope (CLSM).
Table 1 imatchula mankhwala a 2707 HDSS.Table 2 ikuwonetsa kuti 2707 HDSS ili ndi makina abwino kwambiri omwe ali ndi mphamvu zokolola za 650 MPa. Chithunzi 1 chikuwonetsa kuwala kwa microstructure ya yankho la kutentha kwa 2707 HDSS.Elongated band of austenite and ferrite phases without the secondary phases and 5 0 magawo a ferrite.
Chithunzi 2a limasonyeza lotseguka dera kuthekera (Eocp) motsutsana kukhudzana deta nthawi 2707 HDSS mu abiotic 2216E sing'anga ndi P. aeruginosa msuzi kwa masiku 14 pa 37 °C.Zimasonyeza kuti kusintha kwakukulu ndi kwakukulu mu Eocp kumachitika mkati mwa maola oyambirira a 24. The Eocp. 16 h kenako anatsika kwambiri, kufika -477 mV (vs. SCE) ndi -236 mV (vs. SCE) kwa abiotic chitsanzo ndi P, motero ). Pseudomonas aeruginosa makuponi, motsatana.Pambuyo pa maola 24, mtengo wa Eocp wa 2707 HDSS wa P. aeruginosa unali wosasunthika pa -228 mV (vs. SCE), pamene mtengo wofanana wa zitsanzo zomwe sizinali zamoyo zinali pafupifupi -442 mV (vs. S.SCE. SCE).
Kuyesa kwa electrochemical kwa zitsanzo za 2707 HDSS mu abiotic medium ndi Pseudomonas aeruginosa msuzi pa 37 °C:
(a) Eocp monga ntchito ya nthawi yowonekera, (b) polarization curves pa tsiku 14, (c) Rp monga ntchito ya nthawi yowonekera ndi (d) icorr monga ntchito ya nthawi yowonekera.
Table 3 imatchula za electrochemical corrosion parameter values ​​​​2707 HDSS samples zowonekera ku abiotic medium ndi Pseudomonas aeruginosa inoculated sing'anga kwa masiku 14. Ma tangent a anodic ndi cathodic curves adatulutsidwa kuti afike panjira zomwe zimatulutsa dzimbiri (corrosion current density) and corrosion current density (corrision) otsetsereka (βα ndi βc) molingana ndi njira zokhazikika30,31.
Monga momwe tawonetsera mu Chithunzi 2b, kusuntha kwapamwamba kwa P. aeruginosa curve kunapangitsa kuti Ecorr iwonjezeke poyerekeza ndi ma curve abiotic. Mtengo wa icorr, womwe uli wofanana ndi kuchuluka kwa dzimbiri, unawonjezeka kufika ku 0.328 μA cm-2 mu Pseudomonas aeruginosa chitsanzo (μAeruginosa chitsanzo, μA-7 nthawi zinayi).
LPR ndi njira yachikale yosawonongeka ya electrochemical yowunikira mofulumira kutu.Inagwiritsidwanso ntchito pophunzira MIC32.Figure 2c imasonyeza kukana kwa polarization (Rp) monga ntchito ya nthawi yowonekera. Mtengo wapamwamba wa Rp umatanthauza kuchepa pang'ono.Mkati mwa maola 24 oyambirira, Rp ya 2707 HDSS inafika pa 5 kbiotic 9 cm29 ndi 5 kbiotic 9 cm 9. kΩ cm2 ya zitsanzo za Pseudomonas aeruginosa. Chithunzi 2c chimasonyezanso kuti mtengo wa Rp unatsika mofulumira pambuyo pa tsiku limodzi ndipo umakhalabe wosasintha kwa masiku otsatirawa a 13. Mtengo wa Rp wa chitsanzo cha Pseudomonas aeruginosa ndi pafupifupi 40 kΩ cm2, yomwe ili yotsika kwambiri kuposa 450 cm2 yamtengo wapatali ya kΩ.
Mtengo wa icorr ndi wolingana ndi kuchuluka kwa dzimbiri kofanana.
Kutsatira Zou et al. 33, mtengo wamba wa Tafel otsetsereka B mu ntchitoyi unkaganiziridwa kuti ndi 26 mV/dec. Chithunzi 2d chikusonyeza kuti icorr ya chitsanzo chosakhala chamoyo 2707 chinakhalabe chokhazikika, pamene chitsanzo cha P. aeruginosa chinasintha kwambiri pambuyo pa maola 24 oyambirira. kuposa maulamuliro omwe si achilengedwe.Mchitidwewu umagwirizana ndi zotsatira za polarization resistance.
EIS ndi njira ina yosawonongeka yomwe imagwiritsidwa ntchito kuwonetsa momwe ma electrochemical amachitira pazida zowonongeka. Zowoneka bwino komanso kuwerengetsera kuchuluka kwa zinthu zomwe zimawonetsedwa ndi abiotic media ndi yankho la Pseudomonas aeruginosa, Rb kukana kwa filimu / biofilm yopangidwa pamwamba pa fanizo, Rct chargence kukana, Cdl capatant kukana, Cdl capatant Magawo a Phase Element (CPE).Zigawozi zinawunikidwanso mwa kuyika deta pogwiritsa ntchito chitsanzo chofanana cha dera (EEC).
Chithunzi cha 3 chikuwonetsa ziwembu za Nyquist (a ndi b) ndi ziwembu za Bode (a' ndi b') za zitsanzo za 2707 HDSS mu abiotic sing'anga ndi msuzi wa P. aeruginosa nthawi zosiyanasiyana zomakulitsira. Impedance.Chidziwitso cha nthawi yopumula nthawi zonse chikhoza kuperekedwa ndi gawo la maxima.Chithunzi 4 chikuwonetsa monolayer (a) ndi bilayer (b) zochokera kuzinthu zakuthupi ndi ma EEC.CPE omwe amafanana nawo amalowetsedwa mu chitsanzo cha EEC.
Zitsanzo ziwiri zakuthupi ndi mabwalo ofanana kuti agwirizane ndi mawonekedwe a 2707 HDSS:
kumene Y0 ndi kukula kwa CPE, j ndi nambala yongoganizira kapena (-1) 1 / 2, ω ndi mafupipafupi a angular, ndipo n ndi CPE mphamvu index yocheperapo unity35. Zotsutsana ndi kukana kutengerapo malipiro (ie 1 / Rct) zimagwirizana ndi kuchuluka kwa dzimbiri.Smaller Rct imatanthauza mofulumira corrosion rate 14 masiku a Rct 27. Zitsanzo za Pseudomonas aeruginosa zinafika 32 kΩ cm2, zocheperapo kuposa 489 kΩ cm2 za zitsanzo zomwe sizinali zamoyo (Table 4).
Zithunzi za CLSM ndi zithunzi za SEM mu Chithunzi 5 zimasonyeza bwino kuti kuphimba kwa biofilm pamtunda wa 2707 HDSS chitsanzo pambuyo pa masiku 7 ndi wandiweyani. makulidwe a biofilm adasintha kuchokera ku 23.4 μm pambuyo pa masiku 7 kupita ku 18.9 μm pambuyo pa masiku 14. Kuchuluka kwa biofilm kunatsimikiziranso izi.Inatsika kuchokera ku 22.2 ± 0.7 μm pambuyo pa masiku 7 kufika 17.8 ± 1.0 μm pambuyo pa masiku 14.
(a) Chithunzi cha 3-D CLSM patatha masiku 7, (b) chithunzi cha 3-D CLSM patatha masiku 14, (c) Chithunzi cha SEM patatha masiku 7 ndi (d) chithunzi cha SEM pambuyo pa masiku 14.
EDS inavumbulutsa zinthu za mankhwala mu biofilms ndi mankhwala dzimbiri pa zitsanzo zowonekera kwa P. aeruginosa kwa masiku 14. Chithunzi 6 chikusonyeza kuti zili C, N, O, ndi P mu biofilms ndi mankhwala dzimbiri ndi apamwamba kwambiri kuposa zitsulo opanda kanthu, chifukwa zinthu zimenezi kugwirizana ndi biofilms ndi metabolites. biofilm ndi zinthu dzimbiri pamwamba pa zitsanzo zimasonyeza kuti zitsulo masanjidwewo wataya zinthu chifukwa dzimbiri.
Pambuyo pa masiku a 14, pitting ndi popanda P. aeruginosa inawonedwa mu 2216E sing'anga.Asanayambe kukulitsidwa, chithunzithunzi chapamwamba chinali chosalala komanso chopanda chilema (mkuyu 7a) .Pambuyo pa kuyika ndi kuchotsedwa kwa biofilm ndi zinthu zowonongeka, maenje ozama kwambiri pamwamba pa zitsanzozo zinayesedwa pansi pa 7 pigus zowonekera pa CLSM. Kuzama kwa dzenje lopangidwa ndi Pseudomonas aeruginosa kunali 0.52 μm patatha masiku 7 ndi 0.69 μm patatha masiku 14, kutengera kuzama kwa dzenje la 3 zitsanzo (10 pazipita dzenje 00 ± 2 2) μm ndi 0.52 ± 0.15 μm, motsatana (Table 5). Miyezo yakuzama kwa dzenje ndi yaying'ono koma yofunika.
(a) Asanaonedwe, (b) masiku 14 mu abiotic medium ndi (c) masiku 14 mu Pseudomonas aeruginosa msuzi.
Chithunzi 8 chikuwonetsa mawonekedwe a XPS a mawonekedwe osiyanasiyana a zitsanzo, ndipo mapangidwe a mankhwala omwe amawunikidwa pa malo aliwonse akufotokozedwa mwachidule mu Table 6. Mu Table 6, ma atomiki peresenti ya Fe ndi Cr pamaso pa P. aeruginosa (zitsanzo A ndi B) zinali zochepa kwambiri kusiyana ndi zomwe sizinali zamoyo zowonongeka zitsanzo (Zitsanzo za C, zitsanzo za C ndi Cr. core-level spectral curve idayikidwa pazigawo zinayi zapamwamba zokhala ndi mphamvu zomangirira (BE) za 574.4, 576.6, 578.3 ndi 586.8 eV, zomwe zitha kukhala za Cr, Cr2O3, CrO3 ndi Cr(OH)3, motsatana, 9biological ndi Cr. 2p core-level sipekitiramu ili ndi nsonga ziwiri zazikulu za Cr (573.80 eV kwa BE) ndi Cr2O3 (575.90 eV kwa BE) mu Fig. 9c ndi d, motero.Kusiyana kwakukulu pakati pa zitsanzo za abiotic ndi P. aeruginosa kunali kukhalapo kwa Cr6 + 68BE wachibale wa Cr6 + (68BE) H. eV) pansi pa biofilm.
Mawonekedwe otakata a XPS a pamwamba pa chithunzi cha 2707 HDSS pama media awiriwa ndi masiku 7 ndi masiku 14, motsatana.
(a) Masiku 7 okhudzana ndi P. aeruginosa, (b) masiku 14 okhudzana ndi P. aeruginosa, (c) masiku 7 mu abiotic medium ndi (d) masiku 14 mu abiotic medium.
HDSS imawonetsa kukana kwambiri kwa dzimbiri m'malo ambiri.Kim et al. 2 inanena kuti UNS S32707 HDSS imatanthauzidwa kuti ndi DSS yosakanikirana kwambiri ndi PREN yoposa 45. Mtengo wa PREN wa chitsanzo cha 2707 HDSS mu ntchitoyi unali 49. Izi ndi chifukwa cha chromium yochuluka komanso milingo ya molybdenum ndi Nii, yomwe imakhala yopindulitsa mu chilengedwe cha acidic komanso chopanda chloride. microstructure ndi yothandiza pakukhazikika kwadongosolo komanso kukana kwa dzimbiri.Komabe, ngakhale kuti ali ndi mphamvu zotsutsana ndi mankhwala, deta yoyesera mu ntchitoyi imasonyeza kuti 2707 HDSS sichitetezedwa kwathunthu ndi MIC ya P. aeruginosa biofilms.
Zotsatira za electrochemical zasonyeza kuti kuchuluka kwa dzimbiri kwa 2707 HDSS mu P. aeruginosa msuzi kunawonjezeka kwambiri patatha masiku 14 poyerekeza ndi sing'anga yosagwirizana ndi zachilengedwe. wokhazikika36.Komabe, mlingo wa Eocp wachilengedwe unali wapamwamba kwambiri kuposa wa Eocp wosakhala wachilengedwe.Pali chifukwa chokhulupirira kuti kusiyana kumeneku ndi chifukwa cha mapangidwe a P. aeruginosa biofilm.Mumkuyu 2d, pamaso pa P. aeruginosa, mtengo wa icorr wa 2707 HDSS, womwe unafika pa magnide 0. M'masiku angapo oyambirira, kusokonezeka kwa P. aeruginosa msuzi kumawonjezeka chifukwa cha kulumikizidwa kwa maselo a P. aeruginosa ndi mapangidwe a biofilms. kupangika kwa biofilms ndi biofilm metabolites.Chotero, kukana kwa dzimbiri kunachepa pakapita nthawi, ndipo kulumikizidwa kwa P. aeruginosa kunayambitsa dzimbiri m'deralo.Zomwe zimachitika mu abiotic media zinali zosiyana.Kukana kwakudziwikirana kwa zinthu zosagwirizana ndi zachilengedwe kunali kwakukulu kwambiri kuposa mtengo wofananira wa zitsanzo zomwe zimawonekera ku P. aeruginosa broth, aeruginosa broth. 2707 HDSS inafika 489 kΩ cm2 pa tsiku la 14, lomwe linali 15 nthawi ya Rct mtengo (32 kΩ cm2) pamaso pa P. aeruginosa.Choncho, 2707 HDSS ili ndi kukana kwa dzimbiri kwabwino kwambiri m'malo osabala, koma sichigonjetsedwa ndi MIC kuukira kwa P. aeruginosa biofilm
Zotsatirazi zikhoza kuwonedwanso kuchokera ku polarization curves mu Chithunzi 2b.Nthambi ya anodic imatchedwa Pseudomonas aeruginosa biofilm formation ndi metal oxidation reactions.Pa nthawi yomweyi cathodic reaction ndi kuchepetsa kwa oxygen.Kupezeka kwa P. aeruginosa kunachulukitsa kwambiri kulamulira kwa corrosion ndi kulamulira kwapamwamba kwambiri kuposa kuchuluka kwa magnitu. kuti P. aeruginosa biofilm imawonjezera dzimbiri m'dera la 2707 HDSS.Yuan et al29 anapeza kuti kachulukidwe ka 70/30 Cu-Ni alloy wawonjezeka chifukwa cha zovuta za P. aeruginosa biofilm. 2707 HDSS mu ntchitoyi.Aerobic biofilms angakhalenso ndi mpweya wochepa pansi pawo.Choncho, kulephera kubwezeretsanso pamwamba pazitsulo ndi mpweya kungakhale chinthu chothandizira ku MIC pa ntchitoyi.
Dickinson ndi al. 38 inanena kuti mitengo ya mankhwala ndi electrochemical reactions ikhoza kukhudzidwa mwachindunji ndi ntchito ya metabolic ya mabakiteriya a sessile pamwamba pa chitsanzo ndi chikhalidwe cha zinthu zowonongeka. Monga momwe tawonetsera mu Chithunzi 5 ndi Table 5, chiwerengero cha selo ndi biofilm makulidwe achepa pambuyo pa masiku 14. Izi zikhoza kufotokozedwa momveka bwino kuti pambuyo pa masiku 14 a SSsile a 270 omwe anafa chifukwa cha maselo a HD 270 pamwamba pa HD kuchepa kwa michere mu sing'anga ya 2216E kapena kutulutsa ayoni achitsulo chapoizoni kuchokera ku matrix a 2707 HDSS. Uku ndikuchepetsa kuyesa kwa batch.
Mu ntchito iyi, P. aeruginosa biofilm inalimbikitsa kuchepa kwa Cr ndi Fe pansi pa biofilm pa 2707 HDSS pamwamba (mkuyu 6) . Mu Table 6, kuchepetsa Fe ndi Cr mu chitsanzo D poyerekeza ndi chitsanzo C, kusonyeza kuti kusungunuka Fe ndi Cr chifukwa cha P. aeruginosa kupyola sing'anga yogwiritsidwa ntchito masiku a 21E 27 yoyamba. yerekezerani malo a m'madzi.Ili ndi 17700 ppm Cl-, yomwe ikufanana ndi yomwe imapezeka m'madzi a m'nyanja achilengedwe.Kupezeka kwa 17700 ppm Cl- kunali chifukwa chachikulu chochepetsera Cr mu 7- ndi 14-day abiotic zitsanzo zofufuzidwa ndi XPS. ku mphamvu ya Cl - kukana kwa 2707 HDSS m'madera a abiotic. Chithunzi 9 chikuwonetsa kukhalapo kwa Cr6 + mufilimu ya passivation.Ikhoza kukhudzidwa ndi kuchotsedwa kwa Cr kuchokera kuzitsulo zazitsulo ndi P. aeruginosa biofilms, monga momwe Chen ndi Clayton anafotokozera.
Chifukwa cha kukula kwa bakiteriya, pH ya sing'anga isanayambe kapena itatha kulima inali 7.4 ndi 8.2, motero, pansi pa P. aeruginosa biofilm, organic acid corrosion sichingakhale chothandizira pa ntchitoyi chifukwa cha pH yochuluka kwambiri mu sing'anga. 7.5) pa nthawi ya mayesero a masiku 14. Kuwonjezeka kwa pH mu inoculation sing'anga pambuyo poyamwitsa kunali chifukwa cha ntchito ya kagayidwe kachakudya ya P. aeruginosa ndipo inapezeka kuti imakhala ndi zotsatira zofanana pa pH popanda mizere yoyesera.
Monga momwe tawonetsera pa Chithunzi 7, kuzama kwakukulu kwa dzenje komwe kunayambitsidwa ndi P. aeruginosa biofilm kunali 0.69 μm, yomwe inali yaikulu kwambiri kuposa ya abiotic medium (0.02 μm) .Izi zimagwirizana ndi deta ya electrochemical yomwe yafotokozedwa pamwambapa. Kuzama kwa dzenje la 0.69 μm kuli kocheperako kakhumi kuposa μ2m205 ya DSS yofanana ndi 9. deta imasonyeza kuti 2707 HDSS imasonyeza kukana kwa MIC bwino poyerekeza ndi 2205 DSS. Izi siziyenera kudabwitsa, monga 2707 HDSS ili ndi chromium yapamwamba, yomwe imapatsa chisangalalo chokhalitsa, chifukwa cha dongosolo loyenera la gawo popanda kuwonongeka kwachiwiri, zomwe zimapangitsa kuti P. aeruginosa ikhale yovuta kuti idutse ndikuyamba mfundo za kadamsana.
Pomaliza, MIC pitting inapezedwa pamwamba pa 2707 HDSS mu P. aeruginosa msuzi poyerekeza ndi pitting yosasamala mu abiotic media.Ntchitoyi ikuwonetsa kuti 2707 HDSS ili ndi kukana kwa MIC bwino kuposa 2205 DSS, koma sichitetezedwa mokwanira ndi MIC chifukwa cha P. aeruginosa biofilm.Zosankhika zomwe zimayesedwa kuti zigwiritsidwe ntchito pazitsulo zamoyo zam'madzi.
Kuponi kwa 2707 HDSS kumaperekedwa ndi School of Metallurgy of Northeastern University (NEU) ku Shenyang, China.Chigawo choyambirira cha 2707 HDSS chikuwonetsedwa mu Table 1, yomwe inafufuzidwa ndi NEU Materials Analysis and Testing Department.Zitsanzo zonse zinagwiritsidwa ntchito pa 1180 ° C kwa 1-SSor 1 corped HDS kapena 1 corped yoyesedwa ya SS. yokhala ndi malo owonekera pamwamba pa 1 cm2 idapukutidwa mpaka grit 2000 ndi pepala la silicon carbide ndikupukutidwanso ndi kuyimitsidwa kwa ufa kwa 0.05 μm Al2O3. M'mbali ndi pansi zimatetezedwa ndi utoto wocheperako. Atatha kuyanika, zitsanzozo zimatsukidwa ndi madzi osabala a deionized ndi chosawilitsidwa ndi 5vl / v5. kenako kuumitsa mpweya pansi pa ultraviolet (UV) kuwala kwa maola 0,5 musanagwiritse ntchito.
Marine Pseudomonas aeruginosa MCCC 1A00099 strain anagulidwa ku Xiamen Marine Culture Collection Center (MCCC), China. Qingdao, China).Zapakatikati (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, 0.2, 0.2 SrCl2, 0.2, 0.24 SrCl2, 0.2. 0.004 NaSiO3, 0016 NH3, 0016 NH3, 0016 NaH2PO4, 5.0 peptone, 1.0 chotsitsa yisiti ndi 0.1 ferric citrate.Autoclave pa 121 ° C kwa mphindi 20 musanayambe inoculation.Kuwerengera sessile pansi ndi ma cell a planktonic a planktonic 400meter pogwiritsa ntchito ma cell a planktonic a planktonic pa 121 ° C. magnification.Kuyamba kwa maselo a planktonic Pseudomonas aeruginosa mwamsanga pambuyo pa inoculation anali pafupifupi 106 maselo / ml.
Electrochemical mayesero anachitidwa mu tingachipeze powerenga atatu electrode galasi selo ndi sing'anga voliyumu 500 ml. A platinamu pepala ndi ano zimalimbikitsa calomel elekitirodi (SCE) anali olumikizidwa ku riyakitala kudzera Luggin capillaries wodzazidwa ndi mchere milatho, ntchito ngati kauntala ndi Buku maelekitirodi, motero. cm2 ya malo owonekera amtundu umodzi wamtundu wa electrode yogwira ntchito.Panthawi ya kuyeza kwa electrochemical, zitsanzo zinayikidwa mu 2216E sing'anga ndi kusungidwa pa kutentha kosalekeza (37 ° C) mu bafa lamadzi.OCP, LPR, EIS ndi deta yomwe ingathe kuphatikizira polarization inayesedwa pogwiritsa ntchito Autolab potentiostat (Reference 600, Instrument scan, USA, Inc. mlingo wa 0.125 mV s-1 pa osiyanasiyana -5 ndi 5 mV ndi Eocp ndi zitsanzo pafupipafupi 1 Hz.EIS anachitidwa ndi sine yoweyula mu pafupipafupi osiyanasiyana 0.01 kuti 10,000 Hz ntchito 5 mV ntchito voteji pa okhazikika boma Eocp.Asanakhale zotheka mode anali kusesa, ma electrodes omasuka anali kusesa mtengo wa incors-omasuka kusesa, ma electrodes omasuka anali kusesa. anafika.Polarization curves ndiye anathamanga kuchokera -0.2 kuti 1.5 V vs. Eocp pa mlingo jambulani 0.166 mV / s.Chiyeso chilichonse chinabwerezedwa 3 nthawi ndi popanda P. aeruginosa.
Zitsanzo za kusanthula kwa metallographic zidapukutidwa ndi pepala lonyowa la 2000 la grit la SiC ndikupukutidwanso ndi kuyimitsidwa kwa ufa kwa 0.05 μm Al2O3 poyang'anitsitsa.
Pambuyo makulitsidwe, zitsanzo anatsukidwa 3 nthawi phosphate-buffered saline (PBS) njira (pH 7.4 ± 0.2) ndiyeno 2.5% (v/v) glutaraldehyde kwa maola 10 kukonza biofilms. 95% ndi 100% v / v) ya ethanol isanayambe kuyanika mpweya.Potsirizira pake, pamwamba pa chitsanzocho ndi filimu ya golide kuti apereke conductivity kwa SEM observation.Zithunzi za SEM zinkayang'ana pa mawanga omwe ali ndi maselo a sessile a P. aeruginosa pamwamba pa chitsanzo chilichonse.Perform EDSAcal Analysis. (LSM 710, Zeiss, Germany) idagwiritsidwa ntchito kuyeza kuya kwa dzenje.Kufuna kuyang'ana maenje owononga pansi pa biofilm, chidutswa choyesera chinatsukidwa molingana ndi Chinese National Standard (CNS) GB/T4334.4-2000 kuchotsa zinthu zowonongeka ndi biofilm pamwamba pa chidutswa choyesera.
X-ray photoelectron spectroscopy (XPS, ESCALAB250 system analysis of surface, Thermo VG, USA) kusanthula kunachitika pogwiritsa ntchito monochromatic X-ray source (aluminium Kα mzere pa 1500 eV mphamvu ndi 150 W mphamvu) pa mphamvu zambiri zomangirira 0 pansi pazikhalidwe -1350 eV. kukula.
Zitsanzo zowonongeka zinachotsedwa ndikutsukidwa mofatsa ndi PBS (pH 7.4 ± 0.2) kwa 15 s45. Kuti muwone mphamvu ya bakiteriya ya biofilms pa zitsanzo, ma biofilms anali odetsedwa pogwiritsa ntchito LIVE / DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, Eugene, Eugene, Eugene, T. Utoto wa fulorosenti wa SYTO-9 ndi utoto wofiira wa propidium iodide (PI) wofiyira. Pansi pa CLSM, madontho okhala ndi fulorosenti obiriwira ndi ofiira amayimira maselo amoyo ndi akufa, motsatana. zitsanzo zinawonedwa pa mafunde awiri (488 nm kwa maselo amoyo ndi 559 nm kwa maselo akufa) pogwiritsa ntchito makina a Nikon CLSM (C2 Plus, Nikon, Japan) .
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Luo, H., Dong, CF, Li, XG & Xiao, K. Electrochemical khalidwe la 2205 duplex zitsulo zosapanga dzimbiri muzitsulo zamchere za pH zosiyana pamaso pa chloride.Electrochim.Journal.64, 211-220 (2012).
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