Summary of the invention
The object of the invention provides a kind of simple to operate, low temperature and the low high refractive index nanocrystalline TiO of equipment cost
2The method of colloidal sol-gel film preparation.
The object of the present invention is achieved like this: at first make titanium alkoxide complete hydrolysis with a large amount of water, add the mineral acid peptization then, form nanocrystalline colloidal sol through water-heat process, be coated with high refractive index TiO with spin-coating method again
2Optical thin film.
Preparation method of the present invention is as follows:
(1) nanocrystalline colloidal sol preparation:
Titanium isopropylate (TTIP) and ethanol 0.5~1: 1 reaction in molar ratio obtained transparent liquid in 2~10 minutes, this fluid drips is added in the deionized water, the mol ratio that makes titanium isopropylate and water is 1: 80~120, the while violent stirring, after forming white suspension liquid, with inorganic acid for adjusting pH value between 1~3, then through 10~30 minutes supersound process, 80~160 ℃ of reactions 5~20 hours, obtain nanocrystalline colloidal sol;
(2) optical thin film is coated with:
Nanocrystalline colloidal sol is concentrated into TiO under 50~80 ℃
2Mass concentration is 3~5%, adopts spin-coating method between rotating speed 2000~4000rpm, and the nanocrystalline colloidal sol after concentrating is coated with on the substrate, continues rotation 10~30 minutes, and the gained film was 110~120 ℃ of dryings 10~30 minutes.
Aforesaid mineral acid is HCl or HNO
3
The present invention compared with prior art has following advantage:
1. simple to operate, reaction conditions is gentle;
2. can on the irregular substrate of big area, be coated with film;
3. plated film required equipment cost is low;
4. the film refractive index that is coated with of nanocrystalline colloidal sol can reach more than 1.9.
Embodiment
Embodiment 1
The reaction in 0.5: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 2 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 80, simultaneously violent stirring.After forming white suspension liquid, regulating the pH value with HCl is 1, then through 10 minutes supersound process, 160 ℃ of reactions 5 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 50 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 3%.Adopt spin-coating method under rotating speed 2000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the K9 glass substrate, continue rotation 10 minutes, the gained film was 110 ℃ of dryings 10 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9126.
Embodiment 2
The reaction in 0.5: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 5 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 100, simultaneously violent stirring.After forming white suspension liquid, regulating the pH value with HCl is 2, then through 15 minutes supersound process, 100 ℃ of reactions 10 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 50 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 4%.Adopt spin-coating method under rotating speed 3000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the K9 glass substrate, continue rotation 10 minutes, the gained film was 110 ℃ of dryings 15 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9022.
Embodiment 3
The reaction in 1: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 3 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 100, simultaneously violent stirring.After forming white suspension liquid, use HNO
3Regulating the pH value is 1.5, then through 15 minutes supersound process, 150 ℃ of reactions 5 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 80 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 3%.Adopt spin-coating method under rotating speed 2000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the quartz glass substrate, continue rotation 10 minutes, the gained film was 120 ℃ of dryings 10 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9102.
Embodiment 4
The reaction in 0.8: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 5 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 120, simultaneously violent stirring.After forming white suspension liquid, regulating the pH value with HCl is 2, then through 30 minutes supersound process, 150 ℃ of reactions 6 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 60 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 5%.Adopt spin-coating method under rotating speed 4000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the K9 glass substrate, continue rotation 15 minutes, the gained film was 110 ℃ of dryings 30 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9081.
Embodiment 5
The reaction in 0.8: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 5 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 100, simultaneously violent stirring.After forming white suspension liquid, use HNO
3Regulating the pH value is 2, then through 15 minutes supersound process, 80 ℃ of reactions 20 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 70 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 4%.Adopt spin-coating method under rotating speed 3000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the K9 glass substrate, continue rotation 30 minutes, the gained film was 115 ℃ of dryings 20 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9065.
Embodiment 6
The reaction in 1: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 10 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 110, simultaneously violent stirring.After forming white suspension liquid, regulating the pH value with HCl is 1.5, then through 15 minutes supersound process, 120 ℃ of reactions 8 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 60 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 3%.Adopt spin-coating method under rotating speed 2000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the quartz glass substrate, continue rotation 20 minutes, the gained film was 115 ℃ of dryings 20 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9138.
Embodiment 7
The reaction in 0.5: 1 in molar ratio of titanium isopropylate (TTIP) and ethanol obtained transparent liquid in 5 minutes.Afterwards, this fluid drips is added in the deionized water, the mol ratio that makes TTIP and water is 1: 120, simultaneously violent stirring.After forming white suspension liquid, use HNO
3Regulating the pH value is 3, then through 10 minutes supersound process, 150 ℃ of reactions 5 hours, obtains nanocrystalline colloidal sol.
Be concentrated into TiO with under 50 ℃ of the nanocrystalline colloidal sols
2Mass concentration is 5%.Adopt spin-coating method under rotating speed 4000rpm, the nanocrystalline colloidal sol after concentrating is coated with on the quartz glass substrate, continue rotation 20 minutes, the gained film was 110 ℃ of dryings 20 minutes.Film is measured through ellipsometer, and the specific refractory power at the 550nm place is 1.9082.