Nanotechnology thiab Nanomaterials: Nanometer Titanium Dioxide hauv tshuaj pleev thaiv hnub pleev xim

Nanotechnology thiab Nanomaterials: Nanometer Titanium Dioxide hauv tshuaj pleev thaiv hnub pleev xim

Quote lus

Kwv yees li 5% ntawm cov rays tawg los ntawm lub hnub muaj ultraviolet rays nrog lub wavelength ≤400 nm.Ultraviolet rays nyob rau hauv tshav ntuj yuav muab faib ua: ntev-yoj ultraviolet rays nrog ib tug wavelength ntawm 320 nm ~ 400 nm, hu ua A-hom ultraviolet rays (UVA);Nruab nrab-yoj ultraviolet rays nrog lub wavelength ntawm 290 nm mus rau 320 nm yog hu ua B-hom ultraviolet rays (UVB) thiab luv-yoj ultraviolet rays nrog lub wavelength ntawm 200 nm mus rau 290 nm hu ua C-hom ultraviolet rays.

Vim nws luv luv wavelength thiab lub zog siab, ultraviolet rays muaj lub zog puas tsuaj loj, uas tuaj yeem ua rau tib neeg cov tawv nqaij puas, ua rau mob lossis tshav kub, thiab ua rau mob qog noj ntshav.UVB yog qhov tseem ceeb ua rau daim tawv nqaij o thiab sunburn.

1. lub hauv paus ntsiab lus ntawm shielding ultraviolet rays nrog nano TiO2

TiO _2 yog N-hom semiconductor.Cov ntaub ntawv siv lead ua ntawm nano-TiO _ 2 siv rau hauv cov tshuaj pleev thaiv hnub tshuaj pleev ib ce feem ntau yog rutile, thiab nws qhov txwv tsis pub band dav yog 3.0 eV Thaum UV rays nrog wavelength tsawg dua 400nm irradiate TiO _2, electrons ntawm valence band tuaj yeem nqus tau UV rays thiab zoo siab rau cov conduction band, thiab electron-qhov khub yog tsim nyob rau tib lub sij hawm, yog li TiO _2 muaj nuj nqi ntawm absorbing UV rays.Nrog rau qhov me me me me thiab ntau qhov feem ntau, Qhov no ua rau muaj qhov tshwm sim ntawm kev thaiv lossis cuam tshuam cov kab hluav taws xob ultraviolet.

2. Cov yam ntxwv ntawm nano-TiO2 nyob rau hauv tshuaj pleev thaiv hnub tshuaj pleev ib ce

2.1

High UV shielding efficiency

Lub peev xwm tiv thaiv ultraviolet ntawm cov tshuaj pleev thaiv hnub tshuaj pleev ib ce yog qhia los ntawm kev tiv thaiv lub hnub (SPF tus nqi), thiab qhov siab dua tus nqi SPF, qhov zoo dua cov tshuaj pleev thaiv hnub.Qhov piv ntawm lub zog yuav tsum tau ua kom pom qhov qis tshaj plaws ntawm erythema rau daim tawv nqaij coated nrog cov khoom siv tshuaj pleev thaiv hnub rau lub zog uas yuav tsum tau tsim erythema ntawm tib qib rau daim tawv nqaij yam tsis muaj tshuaj pleev thaiv hnub.

Raws li nano-TiO2 absorbs thiab scatters ultraviolet rays, nws raug suav hais tias yog lub hnub ci zoo tshaj plaws hauv tsev thiab txawv teb chaws.Feem ntau, lub peev xwm ntawm nano-TiO2 los tiv thaiv UVB yog 3-4 npaug ntawm nano-ZnO.

2.2

Haum particle loj ntau yam

Lub peev xwm tiv thaiv ultraviolet ntawm nano-TiO2 yog txiav txim siab los ntawm nws lub peev xwm nqus thiab tawg muaj peev xwm.Qhov me me ntawm qhov loj me me ntawm nano-TiO2, lub zog nqus ultraviolet muaj peev xwm.Raws li Rayleigh txoj cai lij choj ntawm lub teeb tawg, muaj qhov zoo tshaj qhov qub particle loj rau qhov siab tshaj plaws tawg peev xwm ntawm nano-TiO2 rau ultraviolet rays nrog txawv wavelengths.Cov kev sim kuj qhia tau hais tias qhov ntev ntawm lub wavelength ntawm ultraviolet rays, lub shielding peev xwm ntawm nano-TiO 2 nyob ntawm seb nws muaj peev xwm tawg;Qhov luv luv wavelength, qhov ntau nws shielding nyob ntawm nws lub peev xwm nqus.

2.3

Zoo heev dispersibility thiab pob tshab

Tus thawj particle loj ntawm nano-TiO2 yog qis dua 100 nm, deb tsawg tshaj qhov wavelength ntawm pom lub teeb.Txoj kev xav, nano-TiO2 tuaj yeem xa cov teeb pom kev thaum nws tawg tag, yog li nws yog pob tshab.Vim lub pob tshab ntawm nano-TiO2, nws yuav tsis npog daim tawv nqaij thaum ntxiv rau cov tshuaj pleev thaiv hnub tshuaj pleev ib ce.Yog li ntawd, nws tuaj yeem ua rau pom kev zoo nkauj ntawm daim tawv nqaij.Transparency yog ib qho tseem ceeb indexes ntawm nano-TiO2 nyob rau hauv tshuaj pleev ib ce tshuaj pleev ib ce.Qhov tseeb, nano-TiO2 yog pob tshab tab sis tsis yog pob tshab hauv cov tshuaj pleev ib ce, vim hais tias nano-TiO2 muaj cov khoom me me, qhov loj tshwj xeeb ntawm qhov chaw thiab lub zog siab heev, thiab nws yooj yim rau kev sib sau ua ke, yog li cuam tshuam cov dispersibility thiab pob tshab ntawm cov khoom.

2.4

Zoo huab cua tsis kam

Nano-TiO 2 rau tshuaj pleev thaiv hnub tshuaj pleev ib ce yuav tsum tau tej huab cua tiv thaiv (tshwj xeeb tshaj yog lub teeb kuj).Vim hais tias nano-TiO2 muaj cov khoom me me thiab kev ua haujlwm siab, nws yuav tsim cov electron-qhov khub tom qab nqus cov kab hluav taws xob ultraviolet, thiab qee qhov hluav taws xob-qhov khub yuav txav mus rau saum npoo, uas ua rau atomic oxygen thiab hydroxyl radicals hauv dej adsorbed rau ntawm qhov chaw. nano-TiO2, uas muaj zog oxidation muaj peev xwm.Nws yuav ua rau discoloration ntawm cov khoom thiab tsw vim decomposition ntawm txuj lom.Yog li ntawd, ib los yog ntau dua pob tshab txheej txheej, xws li silica, alumina thiab zirconia, yuav tsum tau coated rau saum npoo ntawm nano-TiO2 los inhibit nws photochemical kev ua.

3. Hom thiab kev loj hlob tiam sis ntawm nano-TiO2

3.1

Nano-TiO2 hmoov

Cov khoom siv nano-TiO2 yog muag hauv daim ntawv ntawm cov hmoov hmoov, uas tuaj yeem muab faib ua cov hmoov hydrophilic thiab lipophilic hmoov raws li cov khoom nto ntawm nano-TiO2.Hydrophilic hmoov yog siv rau hauv cov tshuaj pleev ib ce dej, thaum lipophilic hmoov yog siv hauv cov tshuaj pleev ib ce roj.Hydrophilic hmoov feem ntau tau txais los ntawm kev kho qhov chaw inorganic.Feem ntau ntawm cov nano-TiO2 txawv teb chaws cov hmoov no tau txais kev kho mob tshwj xeeb raws li lawv daim ntawv thov teb.

3.2

Daim tawv nqaij xim nano TiO2

Vim hais tias nano-TiO2 particles zoo thiab yooj yim rau tawg xiav lub teeb nrog luv luv wavelength nyob rau hauv pom lub teeb, thaum ntxiv rau cov tshuaj pleev ib ce tshuaj pleev ib ce, daim tawv nqaij yuav pom xiav thiab saib tsis zoo.Txhawm rau kom phim cov xim ntawm daim tawv nqaij, cov xim liab xws li hlau oxide feem ntau ntxiv rau cov qauv tshuaj pleev ib ce nyob rau theem pib.Txawm li cas los xij, vim qhov sib txawv ntawm qhov ntom thiab ntub dej ntawm nano-TiO2 _ 2 thiab hlau oxide, Floating xim feem ntau tshwm sim.

4. Cov xwm txheej ntau lawm ntawm nano-TiO2 hauv Suav teb

Kev tshawb fawb me me ntawm nano-TiO2 _ 2 nyob rau hauv Suav teb yog nquag nquag, thiab cov kev tshawb fawb theoretical tau mus txog qib siab hauv ntiaj teb, tab sis kev tshawb fawb thiab kev tshawb fawb engineering kuj tseem rov qab, thiab ntau qhov kev tshawb fawb tsis tuaj yeem hloov mus rau hauv cov khoom lag luam.Kev lag luam tsim khoom ntawm nano-TiO2 hauv Suav teb tau pib xyoo 1997, ntau tshaj 10 xyoo tom qab Nyiv.

Muaj ob qhov laj thawj uas txwv qhov zoo thiab kev ua lag luam kev sib tw ntawm nano-TiO2 khoom hauv Suav teb:

① Kev tshawb fawb thev naus laus zis tau poob qab

Daim ntawv thov kev tshawb fawb thev naus laus zis xav tau los daws cov teeb meem ntawm kev ntxiv cov txheej txheem thiab kev ntsuam xyuas cov txiaj ntsig ntawm nano-TiO2 hauv kev sib xyaw ua ke.Daim ntawv thov kev tshawb fawb ntawm nano-TiO2 nyob rau hauv ntau lub teb tsis tau tsim tag nrho, thiab cov kev tshawb fawb nyob rau hauv ib co teb, xws li tshuaj pleev thaiv hnub tshuaj pleev ib ce, tseem yuav tsum tau kom tob.Vim cov lag luam ntawm kev siv technology tshawb fawb, Tuam Tshoj tus nano-TiO2 _ 2 khoom. tsis tuaj yeem tsim cov npe serial kom tau raws li cov kev cai tshwj xeeb ntawm cov teb sib txawv.

② Cov txheej txheem kho saum npoo ntawm nano-TiO2 xav tau kev kawm ntxiv

Kev kho deg muaj xws li inorganic nto kev kho mob thiab kev kho mob saum npoo av.Kev kho deg tshuab yog tsim los ntawm tus neeg saib xyuas tus neeg saib xyuas tus qauv, kev siv thev naus laus zis thiab cov cuab yeej kho deg.

5. Cov lus xaus

Lub transparency, ultraviolet shielding kev ua tau zoo, dispersibility thiab lub teeb tsis kam ntawm nano-TiO2 nyob rau hauv cov tshuaj pleev ib ce tshuaj pleev ib ce yog ib qho tseem ceeb technical indexes los txiav txim nws zoo, thiab cov txheej txheem synthesis thiab nto kho tus txheej txheem ntawm nano-TiO2 yog tus yuam sij los txiav txim cov kev indexes.