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He pilikia koʻikoʻi ka microbial corrosion (MIC) i nā ʻoihana he nui no ka mea hiki iā ia ke kumu i nā poho waiwai nui. Ua hoʻohana ʻia ka 2707 super duplex stainless steel (2707 HDSS) i nā kaiaola kai ma muli o kona kūʻē ʻana i nā kemika maikaʻi loa. investigated.Electrochemical analysis hoike mai i ke alo o Pseudomonas aeruginosa biofilm ma 2216E medium, aia he hoololi maikai i ka corrosion hiki a me ka hoonui ana i ka corrosion o keia manawa. ka hohonu o ka 0.69 μm i nā lā 14 o ka incubation. ʻOiai he liʻiliʻi kēia, e hōʻike ana ʻaʻole ʻoi loa ka 2707 HDSS i ka MIC o nā biofilm P. aeruginosa.
Hoʻohana nui ʻia nā Duplex stainless steels (DSS) i nā ʻoihana like ʻole no kā lākou hui maikaʻi ʻana o nā waiwai mechanical maikaʻi loa a me ke kūpaʻa corrosion1,2. Akā naʻe, ke kū mau nei ka pitting localized a pili i ka pono o kēia steel3,4.DSS ʻaʻole kū i ka microbial corrosion (MIC) 5,6. 'O ia ho'i, 'oi aku ka nui o nā mea waiwai me ka 'oi aku ka nui o ka 'ino. 'Ike 'ia 'o Jeon et al7 he mau palena 'ole ka super duplex stainless steels (SDSS).
ʻO ke kūpaʻa ʻino o DSS e pili ana i ka ratio o ka alpha a me ka gamma phases a me ka Cr, Mo a me W i hoʻopau ʻia nā ʻāpana 8, 9, 10 e pili ana i ka lua o ka māhele.HDSS loaʻa i nā mea kiʻekiʻe o Cr, Mo a me N11, no laila he kūpaʻa maikaʻi loa ia a me kahi waiwai kiʻekiʻe (45-50) Pitting Resistance Equivalent Number (PREN) + 0.5 wt% W) + 16 wt% N12. ʻO kona kūpaʻa corrosion maikaʻi loa e hilinaʻi ʻia ma kahi ʻano kaulike i loaʻa ma kahi o 50% ferrite (α) a me 50% austenite (γ), ʻoi aku ka maikaʻi o ka HDSS a me ke kūpaʻa kiʻekiʻe ma mua o ka DSS13 maʻamau. ʻO nā waiwai corrosion Chloride. ʻO ka hoʻomaikaʻi ʻana i ka corrosion resistance e hoʻonui i ka hoʻohana ʻana i ka HDSS i nā kaiapuni chloride corrosive, e like me nā kaiapuni moana.
He pilikia nui ka MIC i nā ʻoihana he nui e like me ka aila a me ke kinoea a me nā pono wai14. ʻO MIC ka 20% o nā pōʻino corrosion a pau15. ʻO MIC ka microelectrochemical corrosion hiki ke ʻike ʻia ma nā wahi he nui. ʻino nā metala no ka loaʻa ʻana o ka ikehu e ola ai. 18 hōʻike i ka electron mediators accelerate electron hoʻoili ma waena o Desulfovibrio sessificans cell a me 304 stainless steel, e alakaʻi ana i ka hoʻouka kaua MIC koʻikoʻi. Enning et al. 19 a me Venzlaff et al. 20 ua hōʻike ʻia e hiki i nā biofilms corrosive sulfate-reducing bacteria (SRB) ke hoʻopaʻa pololei i nā electrons mai nā substrate metala, e hopena i ka ʻinoʻino pitting koʻikoʻi.
Ua ʻike ʻia ʻo DSS hiki ke maʻalahi i ka MIC ma nā wahi i loaʻa iā SRB, iron-reducing bacteria (IRB), etc.
ʻO Pseudomonas aeruginosa kahi huaʻona gram-negative motile rod-shaped bacterium i hoʻolaha nui ʻia ma ke ʻano25. ʻO Pseudomonas aeruginosa kekahi pūʻulu microbial nui i loko o ke kai moana, e hana ana i ka MIC i ke kila. Ua pili pono ʻo Pseudomonas i nā hana corrosion a ua ʻike ʻia ʻo ia he colonizer paionia i ka wā o ka hoʻokumu ʻana o biofilm. 28 a me Yuan et al. 29 ua hōʻike ʻo Pseudomonas aeruginosa i ka hoʻonui ʻana i ka nui o ka corrosion o ke kila māmā a me nā mea hoʻohui i nā wahi wai.
ʻO ka pahuhopu nui o kēia hana ʻo ia ka noiʻi ʻana i nā waiwai MIC o 2707 HDSS i hana ʻia e ka marine aerobic bacterium Pseudomonas aeruginosa me ka hoʻohana ʻana i nā ʻano electrochemical, nā ʻenehana analytical surface a me ka nānā ʻana i nā huahana corrosion. e aʻo i ka MIC ʻano o 2707 HDSS.Energy dispersive spectrometer (EDS) ka nānā ʻana no ka ʻimi ʻana i nā mea kemika ma ka ʻaoʻao corroded.
Hōʻike ka Papa 1 i ka haku mele ʻana o 2707 HDSS. Hōʻike ka papa 2 he ʻano mechanical maikaʻi loa ka 2707 HDSS me ka ikaika o ka hoʻoulu ʻana o 650 MPa. Hōʻike ka Figure 1 i ka microstructure optical o ka hopena wela i mālama ʻia 2707 HDSS. Hiki ke ʻike ʻia nā hui elongated o austenite a me ferrite me ka ʻole o ka micro structure 5% hiki ke ʻike ʻia e pili ana i ka microstructure 5% austen5. nā pae ferrite.
Hōʻike ka Figure 2a i ka hiki ke kaapuni wehe (Eocp) versus i ka ʻikepili manawa hōʻike no 2707 HDSS i ka abiotic 2216E medium a me ka broth P. aeruginosa no 14 mau lā ma 37 ° C. Hōʻike ia i ka loli nui loa a koʻikoʻi ma Eocp i loko o nā hola 24 mua. ʻO nā waiwai Eocp ​​ma nā hihia ʻelua ua piʻi ma -145 hCE a laila hāʻule i ka -145 hCE. ʻoi loa, hiki i -477 mV (vs. SCE) a me -236 mV (vs. SCE) no ka hāpana abiotic a me P, kēlā me kēia. Pseudomonas aeruginosa coupons. Ma hope o 24 hola, ka Eocp waiwai o 2707 HDSS no P. aeruginosa ua 'ano pa'a ma -228 mV (vs. SCE), oiai ka waiwai e pili ana no non-biological laana ma kahi o -442 mV (vs. SCE).
ʻO ka hoʻāʻo electrochemical o 2707 HDSS specimens i loko o ke ʻano abiotic a me ka broth Pseudomonas aeruginosa ma 37 °C:
(a) Eocp ma ke ano he hana o ka manawa hoolaha, (b) ka polarization curves i ka la 14, (c) Rp ma ke ano he hana o ka manawa hoike a (d) icorr ma ke ano he hana o ka manawa hoike.
Papa 3 papa inoa i ka electrochemical corrosion parameter waiwai o 2707 HDSS laana i hōʻike ʻia i ka abiotic medium a me Pseudomonas aeruginosa inoculated medium no 14 lā. Ua extrapolated nā tangents o ka anodic a me ka cathodic curves a hiki i nā intersections yielding corrosion current density (icorr), corrosion β a me ka hiki (Ecorr β) hiki (Ecorr β) i nā hana maʻamau30,31.
E like me ka mea i hōʻike ʻia ma ka Figure 2b, ʻo ka neʻe ʻana i luna o ka P. aeruginosa curve i hoʻonui ʻia i ka Ecorr i hoʻohālikelike ʻia me ka curve abiotic. ʻO ka waiwai icorr, i kūlike me ka corrosion rate, ua hoʻonui ʻia i ka 0.328 μA cm-2 i ka hāpana Pseudomonas aeruginosa, ʻehā mau manawa o ka hāpana non-biological 7 (0μA8 cm).
LPR mea he maʻamau non-destructive electrochemical hana no ka wikiwiki corrosion kālailai.It ua hoʻohana 'ia e aʻo MIC32.Figure 2c hōʻike i ka polarization kū'ē (Rp) e like me ka hana o ka hoolaha manawa.A kiekie Rp waiwai 'o ia hoʻi emi corrosion.I loko o ka mua 24 hola, ka Rp o 2707 HDSS i hiki i ka nui o ka waiwai o 1955 kΩ cm 2 kΩ. Pseudomonas aeruginosa samples.Figure 2c hoike no hoi ua emi koke ke kumu waiwai Rp ma hope o ka la hookahi, a laila noho mau no na la 13 e hiki mai ana. ʻO ka waiwai Rp o ka hāpana Pseudomonas aeruginosa ma kahi o 40 kΩ cm2, he haʻahaʻa loa ia ma mua o ka waiwai 450 kΩ cm2 o ka hāpana non-biological.
Hoʻohālikelike ka waiwai icorr i ka helu corrosion like ʻole. Hiki ke helu ʻia kona waiwai mai ka hoʻohālikelike Stern-Geary,
Ma hope o Zou et al. 33, he typical value of the Tafel slope B i keia hana i manaoia he 26 mV/dec. Figure 2d hoike mai i ka icorr o ka non-biological 2707 sample i noho paʻa, oiai ka P. aeruginosa sample fluctuated nui ma hope o ka mua 24 hola. The icorr values ​​was order of the magnitude samples of the magnitude samples. non-biological controls. Ua kūlike kēia ʻano me nā hopena kū'ē polarization.
ʻO EIS kekahi ʻano hana nondestructive i hoʻohana ʻia e hōʻike i nā hopena electrochemical i nā interface corroded. Impedance spectra a me nā helu capacitance helu o nā specimens i hōʻike ʻia i ka media abiotic a me ka Pseudomonas aeruginosa solution, Rb kū'ē o ka passive film/biofilm i hoʻokumu ʻia ma ka ʻili o ka specimen, Rct charge transfer resistance, QCPE electric double layer capacitance) Ph. Nā palena.
Kiʻi 3 hōʻike typical Nyquist paʻa (a a me b) a me Bode 'āpana (a' a me b') o 2707 HDSS laana i loko o abiotic medium a me P. aeruginosa broth no okoa incubation times.The anawaena o ka Nyquist apo emi i ke alo o Pseudomonas aeruginosa.The Bode kuʻina (Fig. 3b. Ma ka manawa hoʻomaha mau hiki ke hāʻawi ʻia e ka pae maxima. Hōʻike ʻo 4 i ka monolayer (a) a me ka bilayer (b) i hoʻokumu ʻia i nā hale kino a me kā lākou EECs pili.
ʻElua mau hiʻohiʻona kino a me nā kaapuni like like no ka hoʻopili ʻana i ka spectrum impedance o ka specimen 2707 HDSS:
kahi Y0 ka nui o ka CPE, j ka helu noonoo a i ole (-1)1/2, ω ke alapine angular, a o n ka CPE mana kuhikuhi emi malalo o unity35. ʻO ke kuʻekuʻe o ke kuʻi hoʻoili kālā (ie 1/Rct) pili i ka corrosion rate. Smaller Rct 'o ia hoʻi ka wikiwiki o ka corrosion rate27 o ka Rct intter rate27. Ua hiki i ka Pseudomonas aeruginosa nā laʻana i 32 kΩ cm2, ʻoi aku ka liʻiliʻi ma mua o ka 489 kΩ cm2 o nā laʻana non-biological (Papa 4).
ʻO nā kiʻi CLSM a me nā kiʻi SEM ma ke Kiʻi 5 e hōʻike maopopo ana i ka uhi ʻana o ka biofilm ma ka ʻili o ka specimen 2707 HDSS ma hope o nā lā 7 he paʻa. 23.4 μm ma hope o nā lā 7 i 18.9 μm ma hope o nā lā 14. Ua hōʻoia ʻia ka mānoanoa biofilm maʻamau i kēia ʻano.
(a) 3-D CLSM kiʻi ma hope o 7 lā, (b) 3-D CLSM kiʻi ma hope o 14 lā, (c) SEM kiʻi ma hope o 7 lā a (d) SEM kiʻi ma hope o 14 lā.
Ua hōʻike ʻo EDS i nā mea kemika i loko o nā biofilms a me nā huahana corrosion ma nā laʻana i hōʻike ʻia i ka P. aeruginosa no nā lā 14. Hōʻike ka Figure 6 i ka ʻike o C, N, O, a me P i loko o nā biofilms a me nā huahana corrosion ʻoi aku ka kiʻekiʻe ma mua o nā metala ʻole, no ka mea pili kēia mau mea me nā biofilms a me kā lākou mau metabolites. a me nā huahana corrosion ma ka ʻili o nā specimens e hōʻike ana ua nalowale ka matrix metala ma muli o ka ʻino.
Ma hope o 14 mau lā, ʻike ʻia ka lua me ka ʻole o P. aeruginosa ma 2216E medium. Ma mua o ka hoʻoulu ʻana, ua maʻalahi ka ʻili o ka specimen a me ke kīnā ʻole (Fig. 7a). ka ili o ka non-biological control samples (maximum pit depth 0.02 μm) .ʻO ka nui o ka lua hohonu i hanaʻia e Pseudomonas aeruginosa he 0.52 μm ma hope o 7 lā a me 0.69 μm ma hope o 14 mau lā, e pili ana i ka awelika o ka lua hohonu hohonu o 3 samples (10 helu kiʻekiʻe 2 samples) 0.12 μm a me 0.52 ± 0.15 μm, i kēlā me kēia (Papa 5).
(a) Ma mua o ka hoʻolaha ʻana, (b) 14 mau lā i loko o ke ʻano abiotic a (c) 14 mau lā i ka broth Pseudomonas aeruginosa.
Hōʻike ka Figure 8 i ka XPS spectra o nā ʻāpana like ʻole, a ua hōʻuluʻulu ʻia nā haku mele i hoʻopaʻa ʻia no kēlā me kēia ʻili ma ka Papa 6. Ma ka Papa 6, ʻoi aku ka haʻahaʻa o nā pākēneka atomika o Fe a me Cr i mua o P. aeruginosa (nā laʻana A a me B) ma mua o nā mea hoʻokele non-biological control samples (nā laʻana C a me Drug spectral). Hoʻopili ʻia i nā ʻāpana kiʻekiʻe ʻehā me nā waiwai hoʻopaʻa ikaika (BE) o 574.4, 576.6, 578.3 a me 586.8 eV, hiki ke hoʻopili ʻia iā Cr, Cr2O3, CrO3 a me Cr(OH)3, kēlā me kēia (Fig. 9a a me b). (573.80 eV no BE) a me Cr2O3 (575.90 eV no BE) ma ka Fig. 9c a me ka d. ʻO ka ʻokoʻa ʻoi loa ma waena o nā mea hoʻohālike abiotic a me P. aeruginosa ʻo ia ka noho ʻana o Cr6+ a me kahi hakina pili kiʻekiʻe o Cr(OH)3 (BE o 586.8 eV).
ʻO ka laulā XPS spectra o ka ʻili o ka 2707 HDSS specimen i loko o nā media ʻelua he 7 mau lā a me 14 mau lā.
(a) 7 lā o ka ʻike ʻana i ka P. aeruginosa, (b) 14 mau lā o ka ʻike ʻana iā P. aeruginosa, (c) 7 mau lā ma ke ʻano abiotic a (d) 14 mau lā i ka ʻano abiotic.
Hōʻike ʻo HDSS i nā pae kiʻekiʻe o ka pale ʻana i ka corrosion ma ka hapa nui o nā kaiapuni. Kim et al. Ua hōʻike ʻo 2 ua wehewehe ʻia ʻo UNS S32707 HDSS ma ke ʻano he DSS i hoʻohui ʻia me ka PREN ʻoi aku ma mua o 45. ʻO ka waiwai PREN o ka 2707 HDSS specimen i kēia hana ʻo 49. ʻO kēia ma muli o kona kiʻekiʻe chromium a me ka molybdenum kiʻekiʻe a me nā pae Ni, he mea pono i ka acidic a me ke kiʻekiʻe o ka chloride hoʻohui maikaʻi ʻole no ka hoʻohui maikaʻi ʻana i ka micro chloride. ʻO ke kūpaʻa paʻa a me ka pale ʻana i ka corrosion. Akā naʻe, ʻoiai ʻo kona kūpaʻa kemika maikaʻi loa, ʻo ka ʻikepili hoʻokolohua ma kēia hana e hōʻike ana ʻaʻole pale loa ʻo 2707 HDSS i ka MIC o nā biofilms P. aeruginosa.
Ua hōʻike ʻia nā hopena electrochemical i ka nui o ka corrosion o 2707 HDSS i ka broth P. aeruginosa i hoʻonui nui ʻia ma hope o 14 mau lā i hoʻohālikelike ʻia me ka non-biological medium. stable36. Eia naʻe, ʻoi aku ka kiʻekiʻe o ka Eocp biological ma mua o ka Eocp non-biological. Aia ke kumu e manaʻoʻiʻo ai kēia ʻokoʻa ma muli o ka hoʻokumu ʻana o ka biofilm P. aeruginosa. (0.063 μA cm-2), i kūlike me ka Rct waiwai i ana ʻia e EIS. I nā lā mua, ua hoʻonui ʻia nā waiwai impedance i loko o ka broth P. aeruginosa ma muli o ka hoʻopili ʻana o nā cell P. aeruginosa a me ka hoʻokumu ʻana o nā biofilms. metabolites.No laila, ua emi ka corrosion kū'ē ma luna o ka manawa, a me ka pili ana o P. aeruginosa kumu localized corrosion.The au i loko o abiotic media ua okoa.O ka corrosion kū'ē o ka non-biological mana i oi loa aku mamua o ka pili waiwai o na laana i hoikeia i ka P. aeruginosa broth. lā 14, he 15 manawa o ka Rct waiwai (32 kΩ cm2) ma ke alo o P. aeruginosa. No laila, 2707 HDSS i ka corrosion kū'ē maikaʻi i loko o sterile kaiapuni, akā,ʻaʻole kū'ē i ka MIC hoouka e P. aeruginosa biofilms.
Hiki ke ʻike ʻia kēia mau hopena mai nā ʻāpana polarization ma Fig. 2b. ʻO ka lālā anodic i pili i ka Pseudomonas aeruginosa biofilm hoʻokumu a me ka hoʻoheheʻe ʻana o ka metala. piʻi localized corrosion o 2707 HDSS.Yuan et al29 ike i ka corrosion o keia manawa density o 70/30 Cu-Ni alloy ma lalo o ka ho'āʻo o P. aeruginosa biofilm.Eia paha ma muli o ka biocatalysis o ka oxygen ho'ēmi e Pseudomonas aeruginosa biofilms.This nānā 'ana i hiki no hoi ke wehewehe i ka MIC o ka biofilm 270. ma lalo o lākou. No laila, ʻo ka hiki ʻole ke hoʻololi hou i ka ʻili metala e ka oxygen he mea kōkua ia i ka MIC ma kēia hana.
ʻO Dickinson et al. Ua manaʻo ʻo 38 e hiki ke hoʻopili pololei ʻia nā pākēneka o nā kemika a me ka electrochemical e ka metabolic activity o sessile bacteria ma ka ʻili o ka specimen a me ke ʻano o nā huahana corrosion. ka pau ʻana o ka meaʻai ma ka 2216E a i ʻole ka hoʻokuʻu ʻia ʻana o nā ion metala ʻona mai ka matrix HDSS 2707. He palena kēia o nā hoʻokolohua pūʻulu.
Ma keia hana, ka P. aeruginosa biofilm paipai i ka local depletion o Cr a me Fe ma lalo o ka biofilm ma ka 2707 HDSS ili (Fig. 6). Ma ka Papa 6, ka hoemi ana o Fe a me Cr i ka laana D i hoohalikeia me ka laana C, e hoike ana i ka Fe a me Cr i dissolved i hanaia e P. aeruginosa biofilm hoomau aku ma mua o ka mua 227 biofilm. kaiapuni. Loaʻa iā 17700 ppm Cl-, ka mea i hoʻohālikelike ʻia me ka mea i loaʻa i ka wai kai maoli. ʻO ka hele ʻana o 17700 ppm Cl- ʻo ia ke kumu nui o ka emi ʻana o Cr i nā lā 7- a me 14 mau lā abiotic i kālailai ʻia e XPS. 2707 HDSS i loko o nā kaiapuni abiotic. Hōʻike ka Figure 9 i ka nohoʻana o Cr6 + i loko o ke kiʻi passivation. Hiki ke komo i ka weheʻana o Cr mai nā mea kila e nā biofilms P. aeruginosa, e like me ka manaʻo o Chen a me Clayton.
Ma muli o ka ulu ʻana o ka bacteria, ʻo 7.4 a me 8.2 nā kumu pH o ka waena ma mua a ma hope o ka mahi ʻana. No laila, ma lalo o ka biofilm P. aeruginosa, ʻaʻole paha e lilo ka corrosion acid organik i mea hoʻohui i kēia hana ma muli o ke kiʻekiʻe o ka pH i loko o ka nui. ʻO ka manawa ho'āʻo 14-lā. ʻO ka piʻiʻana o ka pH i loko o ka inoculation medium ma hope o ka hoʻouluʻana ma muli o ka hana metabolic o P. aeruginosa a uaʻikeʻia he hopena like i ka pH i ka loaʻaʻole o nā'āpana ho'āʻo.
E like me ka mea i hōʻike ʻia ma ka Figure 7, ʻo ka hohonu o ka lua nui i hana ʻia e P. aeruginosa biofilm he 0.69 μm, ʻoi aku ka nui ma mua o ka mea abiotic medium (0.02 μm). Ua kūlike kēia me ka ʻikepili electrochemical i hōʻike ʻia ma luna. hōʻike i ka 2707 HDSS hōʻike ʻoi aku ka maikaʻi o ka MIC kūʻē ma mua o 2205 DSS. ʻAʻole kēia he mea kupanaha, no ka mea, ʻo 2707 HDSS ka mea kiʻekiʻe o ka chromium maʻiʻo, e hāʻawi ana i ka passivation lōʻihi, ma muli o ke ʻano o ka pae kaulike me ka ʻole o nā precipitates lua pōʻino, ʻoi aku ka paʻakikī o ka P. aeruginosa e hoʻopau a hoʻomaka i ka eclipse.
I ka hopena, ua loaʻa ka MIC pitting ma ka ʻili o 2707 HDSS i ka P. aeruginosa broth i hoʻohālikelike ʻia me ka negligible pitting i loko o ka media abiotic. Hōʻike kēia hana i ka 2707 HDSS i ʻoi aku ka maikaʻi o ka MIC kūʻē ma mua o 2205 DSS, akā ʻaʻole ia e pale ʻia i ka MIC ma muli o ka biofilm P. aeruginosa. ʻO kēia mau ʻike i koho ʻia i ke ola kino kūpono a me ke koho ʻana i ke ola kino kūpono i ke koho ʻana i ke ola kino ma ke koho.
Hāʻawi ʻia ka coupon no 2707 HDSS e ke Kula ʻo Metallurgy o Northeastern University (NEU) ma Shenyang, Kina. Ua hōʻike ʻia ka ʻāpana elemental o 2707 HDSS i ka Papa 1, i hoʻopaʻa ʻia e ka NEU Materials Analysis and Testing Department. All samples were solution treated at 1180 °C for 1 corrosion-SS2 or top testing. ʻO ka ʻili i hōʻike ʻia o 1 cm2 ua poni ʻia i ka 2000 grit me ka pepa silicon carbide a hoʻomaʻamaʻa hou ʻia me ka 0.05 μm Al2O3 pauka hoʻokuʻu ʻia. Ua pale ʻia nā ʻaoʻao a me lalo e ka pena inert. (UV) kukui no 0.5 mau hola ma mua o ka hoʻohana ʻana.
Ua kūʻai ʻia ʻo Marine Pseudomonas aeruginosa MCCC 1A00099 strain mai Xiamen Marine Culture Collection Center (MCCC), Kina. Ua ulu ʻia ʻo Pseudomonas aeruginosa i ka aerobically ma 37 ° C i 250 ml flasks a me 500 ml electrochemical glass cell me ka hoʻohana ʻana i ka Marine 2216E Biotechnology wai medium (Qingdao. Kina) .Medium (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, 0.02 SrCl2, 0.02 SrCl2, 0.08 SrB42 NaSiO3, 0016 NH3, 0016 NH3, 0016 NaH2PO4 , 5.0 peptone, 1.0 mea hū a me 0.1 ferric citrate.Autoclave ma 121 ° C no 20 mau minuke ma mua o ka inoculation. E helu i ka sessile a me ka planktonic cell ma lalo o ka 4 hemocy0. ka nui o ka planktonic Pseudomonas aeruginosa ma hope koke iho o ka inoculation ma kahi o 106 cell/ml.
Ua ho'āʻo Electrochemical i loko o ka Classic ekolu-electrode aniani keena me ka medium volume o 500 ml.A platinum pepa a me ka saturated calomel electrode (SCE) ua pili i ka reactor ma Luggin capillaries piha me ka paakai alahaka, e lawelawe ana e like me ka counter a me ka kuhikuhi electrodes, pakahi. cm2 o ka 'ilikai o ka 'ao'ao ho'okahi no ka electrode hana. I ka wā o nā ana electrochemical, ua ho'okomo 'ia nā la'ana ma 2216E medium a mālama 'ia ma kahi mahana incubation mau (37 °C) i loko o ka wai auau.OCP, LPR, EIS a me nā 'ikepili polarization hiki ke ana i ka ho'ohana 'ana i ka Autolab potentiostat (Reference 600TM, Inc. 0.125 mV s-1 ma luna o ka laulā o -5 a me 5 mV me Eocp a me ka la'ana la'ana o 1 Hz.EIS i hana 'ia me ka hawewe sine ma ke alapinepine 0.01 a hiki i 10,000 Hz me ka hoohana 'ana i ka 5 mV i ho'ohana 'ia voli ma ka steady state Eocp. Ma mua o ka hikiwawe o ka hikiwawe ana i ka waiwai poai hikiwawe i ka wehe 'ana. Ua hoʻokō ʻia nā ʻōkuhi polarization mai -0.2 a i ka 1.5 V vs. Eocp ma ka helu scan o 0.166 mV / s. Ua hana hou ʻia kēlā me kēia hoʻokolohua 3 mau manawa me ka P. aeruginosa.
ʻO nā hiʻohiʻona no ka nānā ʻana i ka metallographic i kālai ʻia me ka 2000 grit wet SiC pepa a laila hoʻomaʻamaʻa hou ʻia me ka 0.05 μm Al2O3 pauka hoʻokuʻu no ka nānā ʻana. Ua hana ʻia ka loiloi metallographic me ka microscope optical.
Ma hope o ka incubation, holoi ʻia nā laʻana i 3 mau manawa me ka phosphate-buffered saline (PBS) solution (pH 7.4 ± 0.2) a laila hoʻopaʻa ʻia me 2.5% (v / v) glutaraldehyde no 10 mau hola e hoʻoponopono ai i nā biofilms. 95% a me 100% v / v) o ka ethanol ma mua o ka maloʻo ʻana o ka ea. ʻO ka hope, ua sputtered ka ʻili o ka hāpana me kahi kiʻi gula e hāʻawi i ka conductivity no ka nānā ʻana SEM. Ua kālele ʻia nā kiʻi SEM i nā kiko me nā pūnaewele P. aeruginosa sessile loa ma ka ʻili o kēlā me kēia specimen. E hana i ka EDS analysis no ka loaʻa ʻana o nā mea chemical. Ua hoʻohana ʻia ʻo Zeiss, Kelemānia) e ana i ka hohonu o ka lua. No ka nānā ʻana i nā lua ʻino ma lalo o ka biofilm, ua hoʻomaʻemaʻe mua ʻia ka ʻāpana hoʻāʻo e like me ka Chinese National Standard (CNS) GB/T4334.4-2000 e wehe i nā huahana corrosion a me biofilm ma ka ʻili o ka ʻāpana hoʻāʻo.
X-ray photoelectron spectroscopy (XPS, ESCALAB250 surface analysis system, Thermo VG, USA) ua hana 'ia me ka monochromatic X-ray source (aluminika Kα laina ma 1500 eV ikehu a me 150 W mana) ma luna o ka laulā ikehu pa'a 0 ma lalo o nā kūlana ma'amau -1350 eV.High-resolution step spectra ua ho'opa'a 'ia ka ikehu eV.
Ua wehe ʻia nā mea hoʻoheheʻe incubated a holoi ʻia me ka PBS (pH 7.4 ± 0.2) no 15 s45. No ka nānā ʻana i ka hiki ʻana o ka maʻi bacteria o nā biofilms ma nā mea hoʻohālike, ua hoʻopaʻa ʻia nā biofilms me ka hoʻohana ʻana i ka LIVE / DEAD BacLight Bacterial Viability Kit (Invitrogen, Eugene, OR ka lua fluorescent, USA). SYTO-9 dye a me ka ʻulaʻula fluorescent propidium iodide (PI). Ma lalo o CLSM, nā kiko me ka ʻōmaʻomaʻo a me ka ʻulaʻula e hōʻike ana i nā cell ola a me nā mea make, kēlā me kēia. ma nā nalu nalu ʻelua (488 nm no nā cell ola a me 559 nm no nā mea make) me ka mīkini Nikon CLSM (C2 Plus, Nikon, Iapana).
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