Daalụ maka ileta Nature.com. Ụdị ihe nchọgharị ị na-eji nwere nkwado dị nta maka CSS. Maka ahụmịhe kachasị mma, anyị na-akwado ka ị jiri ihe nchọgharị emelitere (ma ọ bụ gbanyụọ ọnọdụ ndakọrịta na Internet Explorer) .Ka ọ dị ugbu a, iji hụ na nkwado na-aga n'ihu, anyị ga-egosipụta saịtị na-enweghị ụdị na Javascript.
Microbial corrosion (MIC) bụ nsogbu siri ike n'ọtụtụ ụlọ ọrụ n'ihi na ọ nwere ike ịkpata nnukwu mfu akụ na ụba .2707 super duplex igwe anaghị agba nchara (2707 HDSS) ka ejiri mee ihe na gburugburu mmiri n'ihi nguzogide kemịkalụ ya dị mma. Otú ọ dị, egosiputaghị nguzogide ya na MIC. enyochara.Electrochemical analysis gosiri na n'ihu Pseudomonas aeruginosa biofilm na 2216E ọkara, e nwere ezigbo mgbanwe na corrosion nwere ike na-abawanye na corrosion ugbu density.X-ray photoelectron spectroscopy (XPS) analysis gosiri mbelata nke Cr ọdịnaya n'elu nke ihe atụ pi. biofilm na-emepụta ihe omimi olulu kachasị nke 0.69 μm n'ime ụbọchị 14 nke incubation. Ọ bụ ezie na nke a dị ntakịrị, ọ na-egosi na 2707 HDSS adịghị echebe kpamkpam na MIC nke P. aeruginosa biofilms.
Duplex igwe anaghị agba nchara (DSS) na-ọtụtụ ebe na-eji dị iche iche industries n'ihi na ha ezigbo Nchikota magburu onwe n'ibu Njirimara na corrosion resistance1,2.However, localized pitting ka emee na ọ na-emetụta ndị iguzosi ike n'ezi ihe nke a steel3,4.DSS bụ adịghị eguzogide microbial corrosion (MIC) 5,6.N'agbanyeghị na mbara nso nke ngwa nke DSS, na e nwere ka corrosion na-eguzogide n'ihi na gburugburu ebe obibi bụ ogologo oge nke ngwa nke DSS, na e nwere ka corrosion na-eguzogide na gburugburu ebe obibi. use.This pụtara ihe ndị ọzọ dị oké ọnụ ahịa na elu corrosion eguzogide chọrọ.Jeon et al7 chọpụtara na ọbụna super duplex igwe anaghị agba nchara (SDSS) nwere ụfọdụ adịghị ike na okwu nke corrosion resistance.Ya mere, super duplex igwe anaghị agba nchara (HDSS) na elu corrosion eguzogide na-chọrọ na ụfọdụ ngwa.This dugara mmepe nke ukwuu alloyed HDSS.
Nguzogide corrosion nke DSS na-adabere na nha nke alpha na gamma na mpaghara Cr, Mo na W depleted 8, 9, 10 n'akụkụ akụkụ nke abụọ.HDSS nwere ọdịnaya dị elu nke Cr, Mo na N11, n'ihi ya, ọ nwere nguzogide corrosion magburu onwe ya na uru dị elu (45-50) Pitting Resistance Equivalent kpebisiri ike site na PREN + 3% .wt. 0.5 wt% W) + 16 wt% N12. Ya magburu onwe corrosion eguzogide na-adabere na a kwesịrị ekwesị mejupụtara nwere mkpokọta 50% ferrite (α) na 50% austenite (γ) n'ụzọ, HDSS nwere mma n'ibu Njirimara na elu nguzogide karịa ot DSS13. Njirimara corrosion chloride. Nguzogide corrosion emelitere na-agbasawanye ojiji nke HDSS na gburugburu chloride na-emebi emebi, dị ka gburugburu mmiri.
MIC bụ nnukwu nsogbu n'ọtụtụ ụlọ ọrụ dị ka mmanụ na gas na mmiri mmiri14.MIC na-akpata 20% nke mmebi mmebi ọ bụla15.MIC bụ bioelectrochemical corrosion nke nwere ike ịhụ na ọtụtụ gburugburu. metal corrode iji nweta ume na-adịgide adịgide ka ọ dị ndụ17. Nnyocha MIC na nso nso a egosila na EET (nfefe elektrọn ọzọ) bụ ihe na-ebelata ọnụego na MIC nke microorganisms electrogenic na-ebute.Zhang et al. 18 gosipụtara na ndị mgbasa ozi elektrọn na-eme ka nnyefe elektrọn dị n'etiti mkpụrụ ndụ Desulfovibrio sessificans na 304 igwe anaghị agba nchara, na-eduga na mwakpo MIC ka njọ.Enning et al. 19 na Venzlaff et al. 20 gosiri na nje bacteria na-ebelata sulfate na-emebi emebi (SRB) biofilms nwere ike ịmịnye elektrọn ozugbo site na mkpụrụ igwe, na-ebute corrosion siri ike.
A maara DSS na ọ nwere ike ịnweta MIC na gburugburu ebe nwere SRB, nje bacteria na-ebelata ígwè (IRB), wdg.
Pseudomonas aeruginosa bụ gram-adịghị mma motile mkpanaka nke nje bacteria na-ekesa n'ọtụtụ ebe na ọdịdị25. 28 na Yuan et al. 29 gosipụtara na Pseudomonas aeruginosa nwere ọchịchọ ịbawanye ọnụego corrosion nke ígwè dị nro na alloys na gburugburu mmiri.
Ebumnuche bụ isi nke ọrụ a bụ iji nyochaa njirimara MIC nke 2707 HDSS kpatara site na mmiri aerobic bacterium Pseudomonas aeruginosa site na iji usoro electrochemical, usoro nyocha nke elu na nyocha ngwaahịa corrosion.Electrochemical Studies gụnyere Open Circuit Potential (OCP), Linear Polarization Resistance (LPR), Electroscopy Impedance, Polarization Impedance, Polarization na Polarization Specter. na-amụ omume MIC nke 2707 HDSS.Energy dispersive spectrometer (EDS) analysis e mere iji chọta chemical ọcha n'elu corroded. Tụkwasị na nke a, X-ray photoelectron spectroscopy (XPS) analysis na-eji chọpụta nkwụsi ike nke oxide film passivation n'okpuru mmetụta nke mmiri mmiri nwere Pseudomonas aeruginosa (ihe omimi nke laser) na-enyocha microscope.
Isiokwu 1 depụtara chemical mejupụtara nke 2707 HDSS. Isiokwu 2 na-egosi na 2707 HDSS nwere magburu onwe n'ibu Njirimara na a mkpụrụ ike nke 650 MPa.Figure 1 na-egosi na ngwa anya microstructure nke ngwọta okpomọkụ mesoo 2707 HDSS.Elongated ìgwè nke austenite na ferrite n'ụzọ na-enweghị nke abụọ n'ụzọ na-enweghị nke abụọ n'ụzọ nwere ike hụrụ na 5% microstruite. usoro ferrite.
Ọnụ ọgụgụ 2a na-egosi ike imeghe oghere (Eocp) na oge ikpughe data maka 2707 HDSS na abiotic 2216E medium na P. aeruginosa broth maka ụbọchị 14 na 37 Celsius C. Ọ na-egosi na mgbanwe kachasị ukwuu na mgbanwe dị ịrịba ama na Eocp na-eme n'ime awa 24 mbụ. Ọnụ ahịa Eocp na abụọ ahụ ruru na -145.6 m. nke ọma, na-eru -477 mV (vs. SCE) na -236 mV (vs. SCE) maka ihe atụ abiotic na P, n'otu n'otu). Pseudomonas aeruginosa Kupọns, karị. Mgbe awa 24 gasịrị, uru Eocp nke 2707 HDSS maka P. aeruginosa dị ntakịrị na -228 mV (vs. SCE), ebe ọnụ ahịa kwekọrọ na ihe ndị na-abụghị nke ndu bụ ihe dịka -442 mV (vs. SCE) .Eocp na ọnụnọ Po.
Nnwale electrochemical nke ụdị 2707 HDSS n'ime abiotic media na Pseudomonas aeruginosa broth na 37 Celsius C:
(a) Eocp dị ka ọrụ nke oge ikpughe, (b) ntụgharị polarization na ụbọchị 14, (c) Rp dị ka ọrụ nke oge ikpughe na (d) icorr dị ka ọrụ nke oge ikpughe.
Tebụl 3 depụtara ụkpụrụ parameter corrosion electrochemical nke 2707 HDSS sample ekpughere na abiotic media na Pseudomonas aeruginosa inoculated ọkara maka ụbọchị 14. The tangents nke anodic na cathodic curves e extrapolated na-abata na intersections na-enye corrosion ugbu njupụta ugbu a (icorr), corrosion β na corrosion (corrosion). dị ka ọkọlọtọ usoro30,31.
Dị ka e gosiri na foto 2b, ngbanwe nke elu nke P. aeruginosa na-eme ka mmụba na Ecorr jiri ya tụnyere abiotic curve. Ọnụ ahịa icorr, nke kwekọrọ na ọnụ ọgụgụ corrosion, mụbara na 0.328 μA cm-2 na Pseudomonas aeruginosa sample, ugboro anọ karịa ihe atụ nke na-abụghị nke 082 cm. μ.
LPR bụ usoro electrochemical na-adịghị emebi emebi ngwa ngwa maka nyocha nke corrosion ngwa ngwa. A na-ejikwa ya na-amụ MIC32.Figure 2c na-egosi nkwụsịtụ polarization (Rp) dị ka ọrụ nke oge ikpughe. A elu Rp uru pụtara obere corrosion. N'ime awa 24 mbụ, Rp nke 2707 HDSS ruru uru nke 1955 aΩ Ω2 kΩ 2 kΩ 1925 cm 2. Pseudomonas aeruginosa samples.Figure 2c na-egosikwa na ọnụ ahịa Rp na-ebelata ngwa ngwa mgbe otu ụbọchị gasịrị wee nọgide na-agbanwe agbanwe maka ụbọchị 13 na-esote. Ọnụ ahịa Rp nke Pseudomonas aeruginosa sample bụ ihe dịka 40 kΩ cm2, nke dị ala karịa 450 kΩ cm2 nke ihe nlele na-abụghị nke ndu.
Ọnụ ahịa icorr dabara na ọnụego corrosion otu. Enwere ike gbakọọ ọnụ ahịa ya site na ngụkọ Stern-Geary na-esonụ.
Na-esote Zou et al. 33, a ahụkarị uru nke Tafel mkpọda B na ọrụ a chere na-26 mV / dec. Figure 2d na-egosi na icorr nke na-abụghị ndu 2707 sample nọgidere dịtụ kwụsiri ike, mgbe P. aeruginosa sample fluctuated ukwuu mgbe mbụ 24 hours. The icorr ụkpụrụ nke iji usoro magntu nonbiological karịa P. njikwa. Nke a na-emekarị kwekọrọ na nsonaazụ nguzogide polarization.
EIS bụ usoro ọzọ na-adịghị emebi emebi nke a na-eji akọwa mmeghachi omume electrochemical na interfaces corroded. Impedance spectra and gbakọọ capacitance ụkpụrụ nke ihe atụ kpughere abiotic media na Pseudomonas aeruginosa ngwọta, Rb eguzogide nke passive film / biofilm kpụrụ n'elu nke ihe atụ, Rct ụgwọ eletriki okpukpu abụọ, Cdcitance eletriki na-eguzogide, PE Usoro Element (CPE) . A na-enyochakwa ihe ndị a site n'itinye data ahụ site na iji ụdị sekit (EEC).
Ọgụgụ 3 na-egosi ụdị Nyquist plots (a na b) na Bode plots (a' na b') nke 2707 HDSS samples na abiotic medium na P. aeruginosa broth maka dị iche iche incubation times.The dayameta nke Nyquist mgbanaka mbelata na ọnụnọ Pseudomonas aeruginosa. The Bode ibé (Fig. 3. Mmụba na ngụkọta nke ihe ọmụma) Enwere ike inye oge izu ike mgbe niile site na usoro maxima.Ọgụgụ 4 na-egosi monolayer (a) na bilayer (b) ihe owuwu anụ ahụ dabere na EEC ndị kwekọrọ.
Modelsdị anụ ahụ abụọ na sekit dabara adaba maka ịkwado ụdịdị impedance nke ụdị 2707 HDSS:
ebe Y0 bụ ịdị ukwuu nke CPE, j bụ nọmba e chepụtara echepụta ma ọ bụ (-1) 1/2, ω bụ ugboro ugboro, na n bụ CPE ike index na-erughị ịdị n'otu35. The inverse nke ụgwọ nnyefe eguzogide (ie 1 / Rct) kwekọrọ na corrosion rate. obere Rct pụtara ngwa ngwa corrosion rate27, the Rmon incuudos rate27. Ihe nlele aeruginosa ruru 32 kΩ cm2, pere mpe karịa 489 kΩ cm2 nke ihe nlele na-abụghị nke ndu (Table 4).
Ihe oyiyi CLSM na ihe oyiyi SEM dị na Figure 5 na-egosi n'ụzọ doro anya na mkpuchi biofilm n'elu ihe ngosi 2707 HDSS mgbe ụbọchị 7 gasịrị. Otú ọ dị, mgbe ụbọchị 14 gasịrị, ihe mkpuchi biofilm dị ntakịrị na ụfọdụ mkpụrụ ndụ nwụrụ anwụ pụtara. Tebụl 5 na-egosi nha nke biofilm na 2707 HDSS samples a7. ọkpụrụkpụ biofilm gbanwere site na 23.4 μm mgbe ụbọchị 7 gasịrị na 18.9 μm mgbe ụbọchị 14 gasịrị. Nkezi biofilm ọkpụrụkpụ kwadoro usoro a. Ọ na-ebelata site na 22.2 ± 0.7 μm mgbe ụbọchị 7 gasịrị na 17.8 ± 1.0 μm mgbe ụbọchị 14 gasịrị.
(a) onyonyo 3-D CLSM mgbe ụbọchị asaa gachara, (b) onyonyo 3-D CLSM ka ụbọchị iri na anọ gachara, (c) onyonyo SEM ka ụbọchị asaa gachara yana (d) onyonyo SEM ka ụbọchị iri na anọ gachara.
EDS kpughere chemical ọcha na biofilms na corrosion ngwaahịa na samples kpughere P. aeruginosa maka ụbọchị 14. Figure 6 na-egosi na ọdịnaya nke C, N, O, na P na biofilms na corrosion ngwaahịa dị nnọọ elu karịa nke ahụ na iferi ọla, n'ihi na ihe ndị a na-ejikọta ya na biofilms na ha metabolites.Microbes naanị mkpa Chọpụta ego na ígwè na Fegh ọkwa nke chrome. ngwaahịa corrosion n'elu ihe nlere anya na-egosi na matriks metal ahụ furu efu ihe n'ihi mmebi.
Mgbe ụbọchị 14 gasịrị, a na-ahụ pitting na na-enweghị P. aeruginosa na 2216E medium. Tupu ịmalite ịmalite, ihe atụ ahụ dị n'elu dị nro na enweghị ntụpọ (Fig 7a) . Mgbe ntinye na mwepụ nke biofilm na corrosion ngwaahịa, olulu miri emi dị n'elu nke ihe atụ ahụ, a na-enyocha ma chọpụta n'okpuru CL. elu nke ndị na-abụghị nke ndu akara sample (kachasị olulu omimi 0.02 μm) .The kacha olulu omimi mere Pseudomonas aeruginosa bụ 0.52 μm mgbe 7 ụbọchị na 0.69 μm mgbe 14 ụbọchị, dabere na nkezi kacha olulu omimi nke 3 samples (10 olulu omimi ụkpụrụ) 2 ± 0 ruru 10 μm nke ọ bụla ruru 4. 0.52 ± 0.15 μm, n'otu n'otu (Table 5) .Ndị a ụkpụrụ omimi nke olulu dị obere ma dị mkpa.
(a) Tupu ikpughe, (b) ụbọchị iri na anọ n'ime usoro abiotic na (c) ụbọchị iri na anọ na broth Pseudomonas aeruginosa.
Ọgụgụ 8 na-egosi ụdị XPS dị iche iche nke ihe atụ dị iche iche, na ihe mejupụtara kemịkalụ nke a na-enyocha maka elu ọ bụla na-achikota na Tebụl 6. Na tebụl 6, ọnụọgụ atomic nke Fe na Cr n'ihu P. aeruginosa (ihe atụ A na B) dị nnọọ ala karịa nke ndị na-adịghị na-achịkwa ihe ndị dị ndụ (ihe atụ C na D) .N'ihi na P. a-core Cr. spectral curve e dabara na akụkụ anọ kachasị elu nwere ụkpụrụ ike (BE) nke 574.4, 576.6, 578.3 na 586.8 eV, nke enwere ike ịsị na Cr, Cr2O3, CrO3 na Cr (OH) 3, n'otu n'otu (Fig 9a na bological 2). ụdịdị dị iche iche nwere ọnụ ọgụgụ abụọ kachasị elu maka Cr (573.80 eV maka BE) na Cr2O3 (575.90 eV maka BE) na Fig. 9c na d, n'otu n'otu. Ihe dị iche iche dị ịrịba ama n'etiti abiotic na P. aeruginosa samples bụ ọnụnọ nke Cr6+ na ọnụ ọgụgụ dị elu nke Cr.6+ na Cr.8.8. biofilm.
Ihe ngosi XPS sara mbara nke elu nke ụdị 2707 HDSS na mgbasa ozi abụọ ahụ bụ ụbọchị 7 na ụbọchị iri na anọ, n'otu n'otu.
(a) Ụbọchị 7 nke ikpughe P. aeruginosa, (b) ụbọchị 14 nke ikpughe P. aeruginosa, (c) ụbọchị 7 n'ime usoro abiotic na (d) ụbọchị 14 n'ime usoro abiotic.
HDSS na-egosipụta ọkwa dị elu nke nguzogide corrosion n'ọtụtụ gburugburu.Kim et al. 2 kọrọ na UNS S32707 HDSS kọwara dị ka a ukwuu alloyed DSS na a PREN nke ihe karịrị 45. The PREN uru nke 2707 HDSS specimen na ọrụ a bụ 49. Nke a bụ n'ihi na ya elu chromium ọdịnaya na elu molybdenum na Ni ọkwa, bụ ndị bara uru na acidic na elu chloride n'ọkwa, na mgbakwunye na microorganisms adịghị arụ ọrụ. bara uru maka nkwụsi ike nke nhazi na nguzogide corrosion. Otú ọ dị, n'agbanyeghị ezigbo nguzogide kemịkalụ, data nnwale na ọrụ a na-egosi na 2707 HDSS adịghị egbochi kpamkpam na MIC nke P. aeruginosa biofilms.
Nsonaazụ Electrochemical gosiri na ọnụ ọgụgụ corrosion nke 2707 HDSS na broth P. aeruginosa mụbara nke ukwuu mgbe ụbọchị 14 gasịrị ma e jiri ya tụnyere usoro ndụ na-abụghị nke ndu. Na eserese 2a, a na-ahụ mbelata Eocp na ma abiotic medium na P. stable36.Otu ọ dị, ọkwa nke Eocp dị ndụ dị elu karịa nke Eocp na-abụghị nke ndu.Enwere ihe mere ị ga-eji kwere na ọdịiche a bụ n'ihi nhazi nke P. aeruginosa biofilm. Na Fig. 2d, n'ihu P. aeruginosa, icorr uru nke 2707 HDSS ruru 0.627 na-achịkwa μA nke dị elu karịa nke a na-achịkwa μA na-achịkwa μA. (0.063 μA cm-2), nke kwekọrọ na ọnụ ahịa Rct tụrụ site na EIS. N'ime ụbọchị ole na ole mbụ, ụkpụrụ impedance na P. aeruginosa broth mụbara n'ihi ntinye nke mkpụrụ ndụ P. Biofilm metabolites.Ya mere, nguzogide corrosion na-ebelata ka oge na-aga, na mgbakwunye nke P. aeruginosa mere ka corrosion dị n'ógbè ahụ dị iche iche. Ihe na-emekarị na mgbasa ozi abiotic dị iche iche. Nguzogide corrosion nke nchịkwa na-abụghị nke ndu dị elu karịa uru kwekọrọ ekwekọ nke ihe nlele ahụ gosipụtara na broth P. cm2 na ụbọchị 14, nke bụ 15 ugboro Rct uru (32 kΩ cm2) n'ihu P. aeruginosa. Ya mere, 2707 HDSS nwere ezigbo nguzogide corrosion na gburugburu ebe obibi na-adịghị mma, ma ọ dịghị eguzogide MIC ọgụ site na P. aeruginosa biofilms.
A pụkwara ịhụ nsonaazụ ndị a site na ọkpụkpụ polarization na Fig 2b. A na-akpọ alaka anodic na Pseudomonas aeruginosa biofilm formation na metal oxidation reaction. aeruginosa biofilm na-abawanye corrosion mpaghara nke 2707 HDSS.Yuan et al29 chọpụtara na njupụta corrosion ugbu a nke 70/30 Cu-Ni alloy mụbara n'okpuru ihe ịma aka nke P. na-arụ ọrụ.Aerobic biofilms nwekwara ike inwe obere oxygen n'okpuru ha. Ya mere, ọdịda ịghaghachite elu igwe site na ikuku oxygen nwere ike ịbụ ihe na-enye aka na MIC na ọrụ a.
Dickinson et al. 38 tụrụ aro na ọnụego nke mmeghachi omume nke kemịkalụ na electrochemical nwere ike imetụta kpọmkwem site na ọrụ metabolic nke sessile bacteria n'elu ihe atụ ahụ na ọdịdị nke ngwaahịa corrosion. Dị ka e gosiri na Figure 5 na Tebụl 5, ma nọmba cell na biofilm ọkpụrụkpụ belatara mgbe 14 days. Nke a nwere ike ezi uche kọwara na mgbe 14 ụbọchị, ọtụtụ n'ime 7 sesent sel nwụrụ n'elu HDSS2 sel n'ihi na 7 n'elu. na 2216E ọkara ma ọ bụ ntọhapụ nke ions metal na-egbu egbu site na 2707 HDSS matrix. Nke a bụ njedebe nke nyocha batch.
N'ime ọrụ a, P. aeruginosa biofilm kwalitere mmebi mpaghara nke Cr na Fe n'okpuru biofilm na 2707 HDSS elu (Fig 6) .Na Tebụl 6, Mbelata Fe na Cr na sample D tụnyere C, na-egosi na agbaze Fe na Cr mere site na P. O nwere 17700 ppm Cl-, nke yiri nke a na-ahụ na mmiri mmiri eke. Ọnụnọ nke 17700 ppm Cl- bụ isi ihe kpatara mbelata Cr na 7- na 14 ụbọchị abiotic samples nke XPS nyochara. 2707 HDSS na gburugburu ebe obibi abiotic. Foto 9 na-egosi ọnụnọ Cr6 + na ihe nkiri passivation. Ọ nwere ike itinye aka na mwepụ nke Cr site na nchara ígwè site na P. aeruginosa biofilms, dị ka Chen na Clayton tụrụ aro.
N'ihi na nje ibu, na pH ụkpụrụ nke na-ajụ tupu na mgbe cultivation bụ 7.4 na 8.2, karị.Ya mere, n'okpuru P. aeruginosa biofilm, organic acid corrosion bụ eleghi anya na-eme ka ihe na-eme ka a na-eme ka ọrụ a n'ihi na dịtụ elu pH na nnukwu medium.The pH nke na-abụghị nke ndu na-agbanwe agbanwe na mbụ (4). 7.5).
Dị ka e gosiri na foto 7, ihe omimi olulu kachasị nke P. aeruginosa biofilm kpatara bụ 0.69 μm, nke dị nnọọ ukwuu karịa nke abiotic media (0.02 μm) .Nke a kwekọrọ na data electrochemical nke akọwara n'elu. Ihe omimi nke 0.69 μm dị ihe karịrị okpukpu iri karịa nke 9.5 μm20 na-egosi data maka data DSS. 2707 HDSS na-egosipụta nguzogide MIC ka mma ma e jiri ya tụnyere 2205 DSS. Nke a ekwesịghị ịbụ ihe ijuanya, dị ka 2707 HDSS nwere ọdịnaya chromium dị elu, na-enye ogologo oge na-adịgide adịgide, n'ihi usoro nhazi nke ọma na-enweghị ihe mgbochi nke abụọ na-emerụ ahụ, na-eme ka ọ sie ike maka P. aeruginosa ka ọ daa mbà ma malite isi n'ehihie.
N'ikpeazụ, a chọtara MIC pitting n'elu 2707 HDSS na P. aeruginosa broth tụnyere negligible pitting na abiotic media.Nke a na-arụ ọrụ na-egosi na 2707 HDSS nwere mma MIC mgbochi karịa 2205 DSS, ma ọ bụghị zuru ezu dịghịzi MIC n'ihi P. aeruginosa biofilm. Ndị a nchoputa nke kwesịrị ekwesị na-arụ ọrụ na igwe anaghị agba nchara.
A na-enye coupon maka 2707 HDSS site na Ụlọ Akwụkwọ Metallurgy nke North Eastern University (NEU) na Shenyang, China. E gosipụtara ihe mejupụtara nke elemental nke 2707 HDSS na Tebụl 1, nke a nyochara site na NEU Materials Analysis and Testing Department. All samples were ngwọta na-emeso na 1180 °C maka 1 hour.Prior na-egosi na cortex na-emepụta ihe na-eme ka ọ dị elu na 1180 ° C maka 1 hour. Ebe elu nke 1 cm2 na-egbu maramara na 2000 grit na akwụkwọ silicon carbide na-eme ka ọ dịkwuo mma na nkwụsịtụ ntụ ntụ 0.05 μm Al2O3. A na-echebe akụkụ na ala site na agba inert. Mgbe ihichachara, a na-asacha ihe ndị ahụ na mmiri na-adịghị mma na mmiri na-ekpo ọkụ na igba ogwu na 75.5% (vol.) n'okpuru ultraviolet (UV) ọkụ maka 0,5 awa tupu eji.
A zụrụ mmiri Pseudomonas aeruginosa MCCC 1A00099 eriri site na Xiamen Marine Culture Collection Center (MCCC), China. China).Ọkara (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, 0.034 SrCl2, 0.0234 SrB0, HBO0, 0.08 Sr0, 0.00, 0,000, 0,000, 0. NaSiO3, 0016 NH3, 0016 NH3, 0016 NaH2PO4, 5.0 peptone, 1.0 yist wepụ na 0.1 ferric citrate.Autoclave na 121 ° C maka nkeji 20 tupu inoculation. Gụọ sessile na planktonic cell site na iji a hemo. Nleta nke planktonic Pseudomonas aeruginosa ozugbo inoculation gasịrị bụ ihe dịka 106 sel / ml.
Electrochemical ule e rụrụ na a kpochapụwo atọ-electrode iko cell na a ọkara olu nke 500 ml. A platinum mpempe akwụkwọ na a jujuru calomel electrode (SCE) e jikọọ chernobyl via Luggin capillaries jupụtara nnu àkwà mmiri, na-eje ozi dị ka counter na akwụkwọ electrodes, karị. Iji mee ka ndị na-arụ ọrụ electrodes, a roba-ntekwasa n'uko na nke ọ bụla n'ime ihe mkpuchi ọla kọpa 1 cm gbakwunyere na epocimen nke ọ bụla na-eji ọla kọpa 1 cm. nke kpughere otu akụkụ elu ebe maka electrode na-arụ ọrụ. N'oge electrochemical nha, samples e debere na 2216E ọkara na nọgidere na-enwe mgbe nile incubation okpomọkụ (37 Celsius C) na a mmiri bath.OCP, LPR, EIS na ike dynamic polarization data e tụrụ site na iji ihe Autolab potentiostat (Ntụaka 600 TM, a na-enyocha ihe nyocha nke USA ). 0.125 mV s-1 n'elu nso nke -5 na 5 mV na Eocp na a sample ugboro nke 1 Hz.EIS e rụrụ na a sine ife na ugboro nso 0.01 ka 10,000 Hz site na iji 5 mV etinye voltaji na guzosie ike steeti Eocp.Tupu nwere ike ihicha na-emeghe na-eme ka ọnọdụ na-emeghe electrocircu free ruo mgbe e nwere ike ihicha na electrocircu mode. erute.Polarization curves na-agba ọsọ site na -0.2 ruo 1.5 V vs. Eocp na nyocha nyocha nke 0.166 mV / s. A na-emegharị ule ọ bụla ugboro 3 na na-enweghị P. aeruginosa.
A na-eji mpempe akwụkwọ 2000 grit wet SiC na-ehicha ihe atụ maka nyocha nke metallographic wee mee ka ọ dịkwuo mma na 0.05 μm Al2O3 ntụ ntụ maka nlele anya.
Mgbe incubation gasịrị, a na-asacha ihe nlele 3 ugboro 3 na ngwọta phosphate-buffered saline (PBS) (pH 7.4 ± 0.2) wee dozie ya na 2.5% (v / v) glutaraldehyde maka awa 10 iji dozie biofilms. E mesịa dehydrated ya na usoro akara akara (50%, 7% 0,9% 90,9). na 100% v / v) nke ethanol tupu ikpochapu ikuku. N'ikpeazụ, a na-efesa elu nke ihe nlele ahụ na ihe nkiri ọla edo iji nye conductivity maka nlele SEM. Ihe oyiyi SEM na-elekwasị anya na ntụpọ ndị nwere mkpụrụ ndụ P. aeruginosa kachasị dị n'elu nke ọ bụla. Mee nyocha EDS iji chọta ihe ndị na-emepụta ihe. 710, Zeiss, Germany) jiri tụọ omimi nke olulu ahụ. Iji hụ na olulu corrosion n'okpuru biofilm, a na-ebu ụzọ kpochapụ ihe nlele ahụ dị ka Chinese National Standard (CNS) GB / T4334.4-2000 si ewepu ngwaahịa corrosion na biofilm n'elu mpempe ule.
X-ray photoelectron spectroscopy (XPS, ESCALAB250 surface analysis system, Thermo VG, USA) nyocha e mere site na iji a monochromatic X-ray iyi (aluminom Kα akara na 1500 eV ike na 150 W ike) n'elu a wide adịgide adịgide ike nso 0 n'okpuru ọkọlọtọ ọnọdụ -1350 eV.High-mkpebi e dere spectra eV. nha.
A na-ewepụ ihe ndị a na-emepụta ma jiri nwayọọ na-ehichapụ ya na PBS (pH 7.4 ± 0.2) maka 15 s45. Iji hụ na nje bacteria nke biofilms dị na samples, a na-eji ihe ndị na-emepụta ihe na-emepụta ihe na-eji LIVE / DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, Eugene na-acha akwụkwọ ndụ akwụkwọ ndụ abụọ). fluorescent SYTO-9 dye na red fluorescent propidium iodide (PI) dye. N'okpuru CLSM, ntụpọ na fluorescent green na red na-anọchi anya mkpụrụ ndụ ndụ na ndị nwụrụ anwụ. abụọ wavelengths (488 nm maka ndụ ndụ na 559 nm maka ndị nwụrụ anwụ mkpụrụ ndụ) iji a Nikon CLSM igwe (C2 Plus, Nikon, Japan) .Biofilm ọkpụrụkpụ e tụrụ na 3-D scanning mode.
Otu esi akọwa akụkọ a: Li, H. et al.Microbial corrosion of 2707 super duplex igwe anaghị agba nchara site marine Pseudomonas aeruginosa biofilm.science.Rep. 6, 20190; doi: 10.1038/srep20190 (2016).
Zanotto, F., Grassi, V., Balbo, A., Monticelli, C. & Zucchi, F. Stress corrosion cracking nke LDX 2101 duplex igwe anaghị agba nchara na chloride ngwọta na ọnụnọ nke thiosulfate.coros.science.80, 205-212 (2014).
Kim, ST, Jang, SH, Lee, IS & Park, YS mmetụta nke ngwọta okpomọkụ ọgwụgwọ na nitrogen na-echebe gas na pitting corrosion eguzogide nke super duplex igwe anaghị agba nchara welds.coros.science.53, 1939-1947 (2011).
Shi, X., Avci, R., Geiser, M. & Lewandowski, Z. A Comparative Chemical Study of Microbial and Electrochemically Induced Pitting Corrosion in 316L Stainless Steel.coros.science.45, 2577-2595 (2003).
Luo, H., Dong, CF, Li, XG & Xiao, K. Electrochemical omume nke 2205 duplex igwe anaghị agba nchara na alkaline ngwọta nke dị iche iche pH na ọnụnọ nke chloride.Electrochim.Journal.64, 211-220 (2012).
Obere, BJ, Lee, JS & Ray, RI Mmetụta nke biofilms mmiri na corrosion: nyocha nkenke.Electrochim.Journal.54, 2-7 (2008).