Kune mamwe mazwi anounza nyonganiso mumutauro wemazuva ese. Pakati pemazwi aya tine luminescence, fluorescence uye phosphorescence. Matemu akaenzana here? Zvakasiyana sei uye chimwe nechimwe chinorevei?
Tichaona zvese izvi muchinyorwa chino, saka usazvipotse.
Chii chinonzi luminescence
Izwi rokuti luminescence rinoreva kubudiswa kwechiedza. Munharaunda yedu, zvinhu zvizhinji zvinobudisa chiedza nekuda kwesimba ravanowana kubva kuzuva, iro Ndiro rakajeka zvikuru rinoonekwa kwatiri. Kusiyana nemwedzi, unoita sokuti unobudisa chiedza, iwo unotoratidza chiedza chezuva, uchishanda zvakafanana negirazi rebwe guru.
Chaizvoizvo, kune matatu makuru marudzi e luminescence: fluorescence, phosphorescence uye chemiluminescence. Pakati pavo, fluorescence uye phosphorescence inorondedzerwa semhando dze photoluminescence. Musiyano pakati pe photoluminescence uye chemiluminescence uri mukugadzirisa kushandiswa kwe luminescence; Mu photoluminescence, chiedza chinoshanda sechinhu chinokonzera, asi mu chemiluminescence, kemikari inogadzirisa inotanga kubuda kwechiedza.
Zvese zviri zviviri fluorescence uye phosphorescence, ari mafomu ephotoluminescence, zvinoenderana nekugona kwechinhu kutora mwenje uye wozoiburitsa pakareba wavelength, zvichiratidza kudzikiswa kwesimba. Zvisinei, Nguva yekuita izvi inosiyana zvakanyanya. Mukuita kwefluorescent, kubuda kwechiedza kunoitika pakarepo uye kunongoonekwa chete apo mwenje unoramba uchishanda (senge ultraviolet mwenje).
Kusiyana neizvi, maitiro ephosphorescent anobvumira zvinhu kuti zvichengetedze simba rakanyura, zvichiita kuti ribudise chiedza gare gare, zvichiita kuti kupenya kunopfuurira kunyange mushure mokunge chiedza chadzimwa. Nokudaro, kana luminescence ikanyangarika pakarepo, inorondedzerwa se fluorescence; Kana ikaramba iripo, inozivikanwa se phosphorescence; uye kana ichida makemikari kuita kuti ishande, inonzi chemiluminescence.
Semuenzaniso, munhu anogona kufungidzira kirabhu yeusiku umo machira uye mazino anoburitsa kupenya kwakajeka pasi pechiedza dema (fluorescence), chiratidzo chekubuda chekukurumidzira chinopenya chiedza (phosphorescence), uye matanda anopenya anoburitsawo kuvhenekera (chemiluminescence).
Fluorescence
Zvishandiso zvinoburitsa mwenje ipapo zvinodaidzwa kuti fluorescent. Muzvinhu izvi, maatomu anotora simba, zvichiita kuti vapinde mune "mafaro" mamiriro. Vachidzokera kumugariro wavo wenguva dzose muinenge zana rezviuru zvesekondi (kubva pamasekonzi 10-9 kusvika ku10-6), vanobudisa simba iri muchimiro chetunhu tuduku-duku kechiedza chinozivikanwa semafotoni.
Kutaura zviri pamutemo, Fluorescence inzira inopenya umo maerekitironi anofara anoenda kubva kunzvimbo yakaderera yekunakidzwa (S1) kuenda kupasi (S0). Mukati mekuchinja uku, erekitironi inobvisa chikamu chesimba rayo kuburikidza nekuzorora kwekuzunguza, zvichikonzera kuti fotoni inoburitswa ine simba rakadzikiswa uye, nekudaro, kureba kwewavelength.
Phosphorescence
Kuti unzwisise mutsauko uripo pakati pefluorescence uye phosphorescence, zvinodikanwa kuongorora muchidimbu pfungwa ye electron spin. Spin inomiririra hunhu hwakakosha hweerekitironi, ichiita serudzi rweangular manyawi inokanganisa maitiro ayo mukati memunda wemagetsi. Ichi chivakwa chinongotora kukosha kwe½ uye chinogona kuratidza kumusoro kana pasi kutaridzika. Nekuda kweizvozvo, kutenderera kweerekitironi kunoratidzwa se +½ kana -½, kana neimwe nzira inomiririrwa se ↑ kana ↓. Mukati meiyo orbital yakafanana yeatomu, maerekitironi anogara achiratidza antiparallel spin kana ari mu singlet ground state (S0). Pakusimudzirwa kune imwe nyika inonakidza, erekitironi inochengetedza kutenderera kwayo, zvichikonzera kuumbwa kweiyo singlet inonakidzwa nyika (S1), uko ese ari maviri spin orientation anoramba akabatana mune antiparallel configuration. Zvakakosha kuziva kuti maitiro ese ekuzorodza anoenderana nefluorescence ari spin-neutral, kuve nechokwadi chekuti electron spin orientation inochengetedzwa nguva dzese.
Muchiitiko che phosphorescence, Maitiro acho anosiyana zvakanyanya. Shanduko dzekukurumidza (kubva pa10 ^ -11 kusvika 10 ^ -6 masekonzi) dzinoitika pakati pemasisitimu anoenda kubva ku singlet excited state (S1) kuenda ku triplet excited state (T1) iyo ine simba zvakanyanya kunaka. Kuchinja uku kunoguma nekudzokera shure kwe electron spin; Izvo zvinokonzeresa nyika zvinoratidzwa ne parallel spins mune ese maerekitironi uye anoiswa senge metastable. Muchiitiko ichi, kusununguka kunoitika ne phosphorescence, iyo inotungamirira kune imwe kushanduka kwe electron spin uye kunotevera kubudiswa kwe photon.
Shanduko yekudzoka kune yakasununguka singlet state (S0) inogona kuitika mushure mekunonoka kwenguva refu (kubva pa10 ^ -3 kusvika kune anopfuura 100 seconds). Munguva iyi yekuzorora, nzira dzisiri dzemagetsi dzinopedza simba rakawanda mukuzorora kwephosphorescent zvichienzaniswa nefluorescence, zvichikonzera musiyano mukuru wesimba pakati pekutorwa uye kuburitswa kwemafotoni uye nekudaro shanduko huru mukureba.
Excitation uye emission spectra
Luminescence inoitika apo maerekitironi echinhu anenge anakidzwa nekutora mafotoni, zvichizoburitsa simba iroro muchimiro chemwaranzi. Mune zvimwe zviitiko, Mwaranzi inoburitswa inogona kuve nemaphoton ane simba rakafanana uye wavelength seaya akabatwa; Ichi chiitiko chinozivikanwa se resonance fluorescence. Kazhinji, mwaranzi inoburitswa ine yakarebesa wavelength, inoratidza yakaderera simba kana ichienzaniswa neyakatorwa mafotoni.
Iyi shanduko kune yakareba wavelengths inozivikanwa seStokes shift. Kana maerekitironi achifadzwa nemwaranzi pfupi, isingaonekwe, anokwira kumatunhu esimba repamusoro. Pakudzokera kumugariro wadzo wepakutanga, dzinobudisa chiedza chinooneka chine urefu hwakafanana, kuratidzira resonance fluorescence. Zvisinei, maerekitironi anofara aya anogonawo kudzoka kune imwe simba repakati, zvichikonzera kubuda kwephoton inopenya inotakura simba shoma pane iro remanyawi ekutanga. Nzira iyi, kana yakakonzerwa nechiedza che ultraviolet, inowanzoratidza se fluorescence mukati memutambo unooneka. Panyaya yezvigadzirwa zvephosphorescent, pane kunonoka pakati pekuputika kwema electrons kusvika kune simba repamusoro uye kudzokera kumamiriro epasi.
Chinhu chaicho hachipindure kune ese mawavelengths. Nekudaro, panowanzo kuve nehukama pakati peiyo excitation wavelength uye amplitude yekubuda kunobuda. Hukama uhwu hunoziikanwa sechipo chekunyandura. Saizvozvowo, Kuwirirana kunogona kucherechedzwa pakati peamplitude uye wavelength yemwaranzi yakaburitswa, inozivikanwa seye emission spectrum.
Izvo zvakakosha kuti uzive kuti emission wavelength haibvi pane excitation wavelength, kunze kwezviitiko apo zvinhu zvine akawanda luminescence mechanisms. Nekuda kweizvozvo, zvicherwa zvinoratidza kugona kwakasiyana kutora ultraviolet mwenje pane chaiyo wavelengths; mamwe fluoresce pasi pepfupi-wavelength ultraviolet mwenje, nepo mamwe fluoresce pasi pemafungu akareba, uye mamwe anoratidza kujeka fluorescence. Rudzi rwechiedza chakaburitswa kazhinji rinosiyana zvakanyanya neakasiyana excitation wavelengths.
Kuitika kwezviitiko izvi hakungogumiri pakushandiswa kwemwaranzi ye ultraviolet; asi, kufara kunogona kuwanikwa nemwaranzi chero ipi zvayo ine simba rakakodzera. Semuyenzaniso, X-rays inokwanisa kukonzera fluorescence muzvinhu zvakasiyana-siyana, mazhinji acho anopindurawo kumhando dzakasiyana dzemwaranzi. Magnesium tungstate, semuenzaniso, inoratidza kunzwa kunenge kwese kwemwaranzi ine wavelengths isingasviki 300 nm, inotora ultraviolet neX-ray spectrum Pamusoro pezvo, zvimwe zvinhu zvinogona kunakidzwa zviri nyore nemaerekitironi, sezvinoratidzwa nemachisi anoshandiswa mumachubhu eterevhizheni.
Ndinovimba kuti neruzivo urwu unogona kudzidza zvakawanda nezve mutsauko pakati pefluorescence, phosphorescence uye luminescence.