Optical brighteners yog cov khoom siv ntxiv uas txhim kho cov xim dawb ntawm cov ntaub ntawv los ntawm kev nqus ultraviolet lub teeb thiab hloov mus rau xiav -violet pom lub teeb. Lawv muaj ntau haiv neeg, thiab ntau qhov kev faib tawm tuaj yeem tsim tau raws li cov qauv sib txawv. Ib txoj kev tshawb fawb txog kev faib tawm pab kom nkag siab txog cov txheej txheem ntawm kev ua, siv tau, thiab cov yam ntxwv ntawm kev ua haujlwm ntawm ntau yam brighteners, muab lub hauv paus rau kev xaiv hauv kev tsim khoom tiag tiag.
Los ntawm kev pom cov qauv tshuaj, cov teeb pom kev zoo tuaj yeem muab faib ua plaub pawg. Thawj yog stilbene-raws li, nrog styrene raws li lub cev pob txha, ib qho kev sib txuas ntawm cov molecular ntev, thiab kev ua haujlwm siab fluorescence, dav siv hauv cov hluavtaws fibers thiab cov yas. Qhov thib ob yog coumarin-raws li, muaj lub nplhaib benzopyranone nyob rau hauv nws cov qauv, nrog ib tug luv luv excitation wavelength, haum rau lub teeb - xim los yog pob tshab cov ntaub ntawv, thiab feem ntau pom nyob rau hauv cov coatings thiab detergents. Qhov thib peb yog pyrazoline-raws li, muaj zog molecular rigidity thiab zoo lightfastness, feem ntau yog siv rau sab nraum zoov cov khoom siv. Thib plaub, benzoxazoles thiab benzotriazoles, vim lawv cov qauv heterocyclic, muaj cov thermal stability zoo thiab huab cua tsis kam, thiab feem ntau yog siv nyob rau hauv siab - kub ua los yog ntev - lub sij hawm raug rau lub teeb.
Raws li lawv qhov chaw thiab cov txheej txheem synthesis, lawv tuaj yeem muab faib ua ob pawg loj: hluavtaws thiab ntuj. Tam sim no, cov ntawv thov kev lag luam feem ntau siv cov khoom siv hluavtaws, nws cov qauv thiab cov khoom tuaj yeem tsim tau raws li qhov xav tau. Hom ntuj feem ntau yog muab los ntawm cov nroj tsuag tshwj xeeb lossis microbial metabolites; thaum muab cov txiaj ntsig zoo ib puag ncig, lawv cov fluorescence efficiency thiab cov nqi tseem txwv, thiab lawv feem ntau yog siv rau hauv siab -kawg lossis cov chaw tshwj xeeb.
Raws li physicochemical thaj chaw ntawm daim ntawv thov nruab nrab, lawv tuaj yeem muab faib ua dej -soluble thiab roj- hom soluble. Dej- cov kuab tshuaj yaj yeeb tau yooj yim tawg mus rau hauv cov txheej txheem aqueous xws li papermaking thiab dyeing slurries, thiab feem ntau muaj cov pab pawg hydrophilic xws li sulfonic acid pawg. Roj- ntau hom soluble tau yooj yim ua ke rau hauv cov tsis yog -polar systems xws li resins thiab yas melts, thiab feem ntau muaj cov roj carbon ntev los yog cov qauv ester kom ntseeg tau tias muaj kev sib haum xeeb.
Los ntawm qhov kev xav ntawm excitation thiab emission spectral yam ntxwv, lawv muaj peev xwm muab faib ua nqaim -band thiab broadband hom. Nqaim-Band optical brighteners pom muaj zog nqus nyob rau hauv tej ultraviolet bands, ua rau lawv haum rau cov ntawv thov uas yuav tsum tau illumination meej. Broad-Band brighteners, nrog rau qhov dav dua qhov nqus, tswj kom ruaj khov ua kom dawb huv nyob rau hauv ntau qhov chaw teeb pom kev zoo, muab kev pabcuam dav dav.
Tsis tas li ntawd, lawv tuaj yeem muab faib los ntawm kev ua haujlwm rau hauv - hom phiaj thiab hom tshwj xeeb. General- lub hom phiaj brighteners siv tau rau ntau yam substrates, yooj yim formulation; tshwj xeeb brighteners yog molecularly optimized rau tej yam ntaub ntawv los yog cov txheej txheem, qhia superior kev ua tau zoo nyob rau hauv cov cheeb tsam xws li tsiv teb tsaws tsis kam, siab - kub kuj, thiab tsawg toxicity.
Nrog rau kev txhim kho thev naus laus zis, cov txheej txheem kev faib tawm tau nce ntxiv. Piv txwv li, nws suav nrog cov cim ntsuab chemistry los tsim cov kev ntsuas ib puag ncig, lossis nws tsim kev ntsuas kev ua haujlwm ntev raws li cov ntawv thov scenarios. Kev faib tawm cov kev tshawb fawb pom tseeb ntawm optical brighteners tsis yog tsuas yog pab cov kws tshawb fawb ua cov qauv tsim tab sis kuj muab cov neeg siv qis qis nrog kev ntseeg siab rau kev ua tiav qhov sib npaug ntawm kev ua tau zoo thiab tus nqi hla ntau theem kev lag luam.