Tijaabada dhalada buluugga ah: kimistariga, habraaca, iyo indho-indhaynta

Dhalo hufan ayaa miiska shaybaarka saaran. Waxay u egtahay biyo. Qof ayaa ruxa, dareerihiina wuxuu isu beddelaa buluug aad u muuqda. Marka la dejiyo, buluuggu wuu baaba'aa hal ama laba daqiiqo gudahood. Mar kale rux, buluugguna wuu soo noqdaa. Hal mar oo la buuxiyo ayaa sidan loogu celin karaa labaatan jeer ama ka badan.

Ardaydu badanaa waxay qiyaasaan in wax dhalada ku qarsoonaayeen, ama in ruxistu isku qastay laba lakab. Labada qiyaasba si waxbarasho leh ayay u khaldan yihiin. Midabku wuxuu ka yimaadaa hal dheeh, methylene blue, oo ku baahsan dareeraha oo dhan. Waxa isbeddelaya waa tirada electron-yada uu dheehu sido. Bandhiggu waa wareeg redox oo muuqda, doorsoome kasta oo fasalku arki karo—waqtiga ruxista, heerkulka, concentration—wuxuu u dhigmaa qodob ka mid ah kimistariga.

Laba qaab oo isla dheeh ah

Methylene blue-ka oksaydhaysan waa nidaam giraan fidsan oo leh charge togan. Wuxuu si xooggan u nuugaa qiyaastii 600 ilaa 700 nanometres, taas oo ishu u aragto buluug qoto dheer. Labada qaab iyo spectra-dooda waxaa lagu faahfaahiyey hagaha qaab-dhismeedka iyo sifooyinka methylene blue.

Reduction-ku wuxuu ku daraa laba electrons iyo proton, taas oo dhalisa leucomethylene blue: aan charge lahayn, aan fidsanayn, oo ficil ahaan aan midab lahayn. Xalka alkaline-ka ah, half-reaction-ku wuxuu u qoran yahay MB+ + H2O + 2 e- ⇌ LMB + OH-. Tallaabadu si buuxda ayay u rogman kartaa. Buluuggu wuxuu ka dhigan yahay oksaydhaysan, midab-la'aantuna waxay ka dhigan tahay reduced, mana jiro xaalad saddexaad oo la raaco, taas ayaana ka dhigaysa hordhac nadiif ah oo redox chemistry ah.

Wareegga: glucose-ku wuu yareeyaa, oxygen-kuna dib ayuu u oksaydheeyaa

Dhaladu waxay siddaa saddex walxood oo shaqaynaya: methylene blue, glucose, iyo alkali xooggan, potassium ama sodium hydroxide. Alkali-gu wuxuu glucose-ka u beddelaa qaabab reactive deprotonated ah oo electron-yo siiya dheeha:

reducing sugar + MB (blue, oxidised) -> oxidised sugar products + LMB (colourless)

Tallaabadan gaabiska ahi waxay tirtirtaa midabka marka dhaladu taagan tahay. Glucose-ku waa donor-ka la huro waana la isticmaalaa. Dheehu electron-yada ayuu keliya qaadaa oo gudbiyaa, sidaas darteed dhowr dhibcood ayaa u adeega dhalo dhan. Sharaxaadaha fasallada ee hore waxay sheegaan in glucose-ku isu beddelo gluconic acid. Soo koobistaasi waxay saadaalisaa waxa la indho-indhaynayo, laakiin macallimiintu waa inay ogaadaan inay dhammaystirnayn: falanqayn mechanistic ah oo lagu daabacay Royal Society Open Science waxay oxidation-ka ka raadraacdaa enediolate reactive ah ilaa dicarbonyl u kala jajaba acids yaryar.

Ruxistu waxay beddeshaa natiijada muuqata. Dhaqdhaqaaqu wuxuu oxygen ka milaa hawada ku xanniban headspace-ka, oxygen-kuna wuxuu dib u oksaydheeyaa dheeha reduced-ka ah:

LMB (colourless) + O2 -> MB (blue) + reduced oxygen products

Marka la daayo isagoo taagan, oxygen-ka milmay wuu dhammaadaa, glucose-kuna mar kale ayuu dheeha yareeyaa, midabkuna wuu libdhaa. Wareegyo badan kadib, kimistariga saafiga ahi waa oxidation-ka sonkorta ee hawadu samayso, iyadoo dheehu aan isbeddelin oo u wareegaya sida redox mediator. Waa mediator halkii uu ka ahaan lahaa catalyst adag, maadaama oxidation-ka sonkortu dhaco isaga la'aantiis, libdhashaduna ma aha decomposition: dheeh burburay dib looguma soo celin karo ruxis. Si kaydka dheeha loogu ilaaliyo xasilloonida inta u dhexeysa bandhigyada, eeg qoraallada ku saabsan maaraynta iyo kaydinta xalalka methylene blue.

Habraaca bandhig la kormeero

Kani waa bandhig la kormeero, ma aha hawl guriga lagu sameeyo. Alkali-gu wuxuu u baahan yahay ilaalinta indhaha, galoofyo, iyo macallin mas'uul ka ah diyaarinta iyo nadiifinta. Laba formulation oo la diiwaangeliyey ayaa isku qaab ah, balse cabbirkoodu kala duwan yahay.

Xaashida tilmaamaha ee bandhigga sida ay u daabacday waaxda chemistry-ga ee Indiana University waxay isticmaashaa qiyaastii 5 percent potassium hydroxide, 4 percent glucose, iyo 1 percent methylene blue aqueous ah. Ku shub mug isku mid ah oo xalalka alkali iyo glucose ah dhalo hufan oo 250 ama 500 millilitre ah ilaa ay kala bar buuxsanto, inta soo hartayna uga tag air headspace. Ku dar dhowr dhibcood oo dheeh ah, dabool, xidh meesha daboolku kaga xirmo, kadibna u daa ilaa buluuggu ka baaba'o. Habraaca Royal Society of Chemistry wuxuu isla fikraddaas ku ballaadhiyaa dhalo shaybaar oo 1 litre ah oo stopper leh: 300 millilitres oo biyo ah, 10 grams oo glucose ah, 8 grams oo potassium hydroxide ah (ama 6 grams oo sodium hydroxide ah), iyo dhowr millilitres oo kayd dheeh la khafiifiyey ah.

Si loo sameeyo, si xooggan u rux. Buluug buuxa wuxuu samaysmaa ilbiriqsiyo gudahood. Dhalada shaybaarka dhig oo cabbir waqtiga libdhashada. Royal Society of Chemistry waxay sheegaysaa in hal buuxin laga heli karo in ka badan labaatan wareeg. Weligaa dhalada ilaa afka ha ka buuxin: hawo ku xanniban la'aanteed ma jiro kayd oxygen ah oo milmi kara.

Waxa la indho-indhaynayo, iyo waxa beddela waqtiga

Cabbir saddex waxyaalood: ruxista ilaa buluug buuxa (seconds), taagnaanshaha ilaa midab-la'aan (ilaa dhowr daqiiqo), iyo tirada wareegyada ka hor inta buluuggu daciifin. Marka libdhasho kastaa dhammaad ku dhow yahay, eeg dusha sare. Lakab buluug khafiif ah ayaa inta badan ku sii nagaada xadka hawada, halkaas oo oxygen-ku weli gudaha ugu diffusion-gareeyo. Khadkaasi waa diffusion oo muuqda.

Falcelinta dhalada buluugga ahi waxay raacdaa empirical rate law-ka lagu sheegay habraaca Royal Society of Chemistry: rate = k[MB oxidised][glucose]OH-. Qodob kasta wuxuu noqon karaa tijaabo fasal. Glucose, alkali, ama dheeh badan waxay gaabiyaan muddada buluugga. Kuleylku wuxuu dedejiyaa libdhashada; dhalo shaybaar qabow ahi waxay noqotaa mid gaabis ah. Ruxis xooggan wuxuu milaa oxygen badan, sidaas darteed buluuggu wuxuu sii jiraa muddo dheer. Headspace weyn wuxuu dheereeyaa socodka tijaabada. Marka wareegyadu ugu dambayn daciifaan oo dareeruhu huruud noqdo, sonkortu way dhammaatay, side products-na way urureen. Endpoint-kaas laftiisu waa natiijo mudan in la diiwaangeliyo.

Xaashida indho-indhaynta

Jadwalkan ku nuqul buugaagta qoraalka, hal saf tijaabo kasta. Xaashidan iyo jaantuska falcelinta ee kore waa agabka la daabici karo ee maqaalkan.

Su'aalaha saadaasha, oo la jawaabayo ka hor tijaabo kasta:

• Dhaladu waa buluug isla markiiba ruxista kadib. Qaabkee dheeha ah ayaa badan, maxaase xaaladdaas geliyey?
• Dhaladu way taagan tahay oo midabku wuu libdhaa. Falcelintee ayaa ka xoog badan, walaxdeese la isticmaalayaa?
• Wareegyo badan kadib buluuggu wuxuu noqdaa khafiif oo huruud u janjeera. Ma ku soo celi dheeh, alkali, mise glucose, maxaase sabab ah?
• Sawir midabka marka loo eego waqtiga hal wareeg. Calaamadee halka oxygen-ku xalka ka galo. Jawaabaha macallinka: (1) methylene blue oksaydhaysan, oo dib loogu oksaydheeyey oxygen-ka milmay ee headspace-ka; (2) reduction uu glucose-ku sameeyo, glucose-na waa la isticmaalaa; (3) glucose, donor-ka xaddidaya, maadaama dheehu isagoon isbeddelin wareego; (4) koror degdeg ah marka la ruxo, hoos-u-dhac tartiib ah marka la dejiyo, oxygen-kuna wuxuu galaa inta kororku socdo oo keliya.

Noocyo dhow oo mudan in la magacaabo

Bandhigga traffic light-ka wuxuu adeegsadaa indigo carmine halkii, wuxuuna marka oxygen la geliyo maraa huruud, casaan, iyo cagaar. Magaca green bottle si dabacsan ayaa loo isticmaalaa: mararka qaar noocaas, mararka qaar formulations ka cagaaran sida nidaamyada ascorbic acid ama nidaam enzymatic cycling ah oo ay sharaxday American Chemical Society. Magacow nooca miiska shaybaarka saaran si ardaydu aysan isugu darin indho-indhaynta kimistariyo kala duwan.

Badbaadada iyo maaraynta

Kormeer joogto ah. Ilaalinta indhaha ee chemical splash-ka iyo galoofyo marka la qabanayo xalka alkaline-ka ah ama la ruxayo weelka stopper-ka leh. Alkali-gu wuxuu sababi karaa gubasho, dheehuna wuxuu wasakheeyaa maqaarka iyo dharka, kaydka dheeh ee ethanol lagu diyaariyeyna wuxuu miiska shaybaarka ku daraa solvent guban kara. Weelka dabool ku hay marka la ruxayo. Kadib, xalalka la isticmaalay hay si loogu maareeyo xeerarka shaybaarka ee hay'addaada. Shuruudaha qashinka alkaline-ka ah ee dheehu ku jiro way ku kala duwan yihiin hay'adaha iyo jurisdictions-ka, sidaas darteed raac habraaca shaybaarkaaga halkii aad mid meel kale laga keenay adeegsan lahayd.

Haddii aad rabto tirooyin halkii isbeddel midab, quantitative assays-ka methylene blue waxay ka bilaabmaan meesha bandhiggan ku dhammaado.

Sababta macallimiintu dhaladan u sii isticmaalaan

Hal dhalo shaybaar ayaa isku soo koobaysa afar fikradood. Redox-ku wuxuu noqdaa midab halkii uu ka ahaan lahaa qeexitaan. Mediator wuxuu muujinayaa sida qaddar yar oo walax ahi xog uga bixiyo qaddar badan oo walax kale ah. Kinetics-ku wuxuu si muuqata uga soocmaa thermodynamics: oxygen-ku wuu adkaadaa inta ruxistu keenayso, glucose-kuna wuu adkaadaa marka keenistu joogsato. Diffusion-na, habka ugu aamusan kimistariga, ayaa suurtageliya bandhigga oo dhan, sababtoo ah iftiin kasta oo buluug ahi wuxuu ka bilaabmaa oxygen ka gudbaya hawada una gudbaya biyaha. Bandhig u oggolaanaya ardayda inay saadaaliyaan, waqtiga cabbiraan, oo waxaas oo dhan ku sharxaan saacad-cabbire iyo jadwal wuxuu mudan yahay booska uu ka haysto miiska shaybaarka.