Indian Patents. 279623:METHOD FOR THE PREPARATION OF AQUEOUS DISPERSIONS OF TIO2 IN THE FORM OF NANOPARTICLES, AND DISPERSIONS OBTAINABLE WITH THIS METHOD''

Title of Invention	METHOD FOR THE PREPARATION OF AQUEOUS DISPERSIONS OF TIO2 IN THE FORM OF NANOPARTICLES, AND DISPERSIONS OBTAINABLE WITH THIS METHOD''
Abstract	The invention relates to a method for the preparation of aqueous dispersions of Ti02 in the crystalline form anatase, as well as the dispersions obtained with said method, useful for the preparation of photocatalytic coatings for surfaces, and for the photocatalytic decontamination of gases and liquids.

Full Text	Method for the preparation of aqueous dispersions of Ti02 in the form of nanoparticies, and dispersions obtainable with this method FIELD OF THE INVENTION The present invention relates to the field of methods for the preparation of compounds in the form of nanometric particles, and in particular, to a method relating to a way for preparing TJO2 dispersions in the form of nanoparticies. PRIOR ART. Titanium dioxide Is a white pigment with a very strong covering capacity used in particular in paints, and in the production of paper and synthetic rubber. Among the most recent applications of Titanium dioxide is the attempt to use its photocatalytic activities to best advantage. In other words, through the action c2 ultraviolet light, to use this capacity to generate radical species able to catalysi the oxidising degradation of harmful or toxic substances, such as benzene, dioxir and other organic pollutants, but also unpleasant and sickness-provokin substances such as mould and bacteria. These applications are therefore used i wide environmental fields ranging from combating pollutants to detergents an sterilising products. For these applications, Titanium dioxide is used as a coating on the-surfaces to b treated In order to maximise the photocatatyctic effect. The crystalline form c Titanium dioxide called "anatase" is the most popular for this type of applicatio because, as well as being chemically stable and easily available, it also possesse a photocatalytic activity that is higher than the other two crystalline forms, rutil and brookite. On the other hand, the superposition of the Titanium dioxide absorption spectrun —Qitf-n in anatacTP fnrm, nn thp g;nlajL_qpRntnim 1.=; not very large and this resiilt.q low photocatalytic efficiency levels. For this reason various attempts have bee made to modify TiO2, for example, by doping it with other metals, or by preparir the compound In question in the form of nanoparticies; in fact this increases tf surface area enormously and thus, also the photocatalytic efficiency. Several methods exist for preparing TiO2 anatase, including in nanopartlcle fort that provide TiO2 in powder form. In order to be suitable for the preparation Dhotocatalvtic coatings, this powder must be dispersed in an appropriate solvent and formulated with other possible additives to improve coating adhesion, but this causes the coagulation of the Titanium dioxide particles making it impossible to maintain the photocatalytic efficiency and activity of the particulate material. Moreover, over a period of time, the TiO2 particles in these dispersions tend to settle in the bottom of the containers where they are stored creating stability problems during storage. Furthermore, the patent application n° FI2004A252 (by the same Applicant) describes a method that allows the preparation of stable nanopartiole dispersions of Titanium dioxide in anatase form where water and suitable complexing solvents are used as the solvents SUMMARY OF THE INVENTION, Recently the Applicant created a method for obtaining nanoparticles of Titanium dioxide in anatase form already dispersed in water only, and directly usable for the preparation of photocatalytic coatings. The dispersions obtained with the method according to the invention did not provoke particle coagulation even after prolonged storage, thus allowing the preparation of coatings which maintain the photocatalytic activity of the particulate material thanks to dispersion homogeneity. Therefore the aim of the present invention is a method for the preparation of nanoparticie dispersions of Titanium dioxide in anatase form in water, wherein a Titanium alkoxide is made to react under heat in water in the presence of mineral acid and a non-ionic surfactant and where necessary, the solution is finally reduced to a small volume. A further aim of the invention is the use of the nanopartiole dispersions of Titanium dioxide in anatase form in water, obtained using this method, as well as their use for the preparation of photocatalytic surface coatings, for the photocatalytic decontamination of gases and liquids, and for the preparation of formula for cosmetics that provide a protective action against sun rays for the human skin , The characteristics and advantages of the invention will be illustrated in detail in the following descnption. BRIEF DESCRIPTION OF THE APPENDED FIGURE Figure 1 shows a difractogram of the dried product powder, where the y-axis shows the radiation intensity while the x-axis shows the amplitude of the radiation incidence angle. This analysis demonstrates how crystalline titanium dioxide in anatase form is obtained using this method. DETAILED DESCRIPTION OF THE INVENTION. The method of the present invention is able to produce TiO2 in anatase form.directly in water, and to obtain a dispersion of TiO2 particles at the end of the process with a size between 30-50 nm. Particle measurement was performed using various methods well known to those skilled in the art, such as XRD {X-Ray Diffraction), FEG-SEM (Field Emission Gun - Scanning Electron Microscopy), TEM (Transmission Electron Microscopy) and DLS (Dynamic Light Scattering). Unlike those prepared dispersing nanometric powders in the solvent mixtures or in water, these dispersions show no signs of conglomeration or coagulation and solid precipitation, even after prolonged periods of the dispersion product storage. The advantages to be gained with dispersions of this type are obvious and associated with the photo catalytic efficiency and uniformity of the coatings that can be prepared with said dispersions. The dispersion index obtainable with the method according to the present invention, measured with DLS (Dynamic Light Scattering) techniques, is lower than 0.3, and thus the dispersion according to the invention differs from those obtained using prior methods composed of the preparation of nanoparticle powder, subsequently dispersed in solvent. The titanium aikoxide used as the starting product in this method can be chosen from the group composed of titanium methoxids, ethoxide, normal-propoxide, iso- propoxide, normal-butoxide, and isobutoxide. Particularly preferable is Titanium isopropoxlde since it is cheaper and reacts better under the conditions used in the present method. The non-ionic surfactants are surface-active agents composed of an apolar part and a polar function, non-ionisable ether, ester, ether-ester; particularly preferable JsTritonX-lOO(TX-IOO) The term mineral acid according to the invention refers, for example, to an acid perchloric acid, hydrobromic acid and hydrogen iodide; preferably halogen acids are used, and in particular hydrochloric acid. The alcoholate molar ratio of titanium alkoxide /mineral acid is between 0.005 and 15, and preferably between 5 and 5. The reaction temperature ranges between 15°C and 95°C, preferably between 45°C and 55°C. Reaction times range between 12 h and 72 h, and preferably 24 h. Where necessary, when used for coating preparations, the present dispersions can possibly be formulated using additives and diluents commonly employed in the field of surface coatings, such as adhesion improved agents or solvents such as water or ethanol for example, in order to obtain the required dilution level. On the other hand, when used to decontaminate liquid or gaseous products, the present dispersions are adsorbed respectively on a silica gel support, or on some other suitable inorganic support with adsorbent characteristics, that is then immersed in the liquid, or placed in its current state or diluted, in containers in which the gas to be purified is bubbled through for washing. The supports on which surface coatings prepared with the present dispersion can be applied are widely varied, from woven fibre products in rolls or already made up into garments, to ceramic products, as well as supports in glass, metal, mirror, and similar materials. The photocatalytic activity of the surface coating according to the present invention is explained as a result of the exposure of the coating in question to light with a suitable wave length, typically less than 388 nm, which produces a surface with bacteria-proof, bacteriostatic and super-hydrophilic properties after its exposure to UV light. In fact, supports coated with Ti02 show a total lack of water repellent capacity, so-called super-hydrophilic capacity, that makes surfaces treated with Ti02 self-cleaning. Moreover, given the extremely small size of the Ti02 particles, the present dispersions are practically transparent, leaving the appearance of the surface on which they are applied, totally unchanged. This transparency also makes the product suitable for use in cosmetic fields for the preparation of sun filters with high UV ray protection levels. A further advantage of the present dispersions, is their behaviour at high temperatures. In fact, the application of the surface coating on ceramic supports requires high temperature processing of the support on which the dispersion is applied and the present dispersions maintain exactly the same appearance, crystalline form of anatase and nanopartlcle nature of the coating as before the heating process. According to a particular embodiment of the present method, the Ti can be doped with a metal selected from the transition metal series^ and in particular Ag, Cu and Ce by means of the addition of a salt of one of these metals to the starting solution. In this way, the method will lead to the forming of a dispersion of Ti02 doped with Ag, Cu or Ce, which are able to perform their catalytic activities even without UV light rays. Below are certain examples of the invention provided as illustrations but to be considered by no means limiting. Example 5 grams of concentrated HCI, 7.5 grms of TX-100, and water up to a total weight of 750 grams are placed in a 2 Litre reactor heated by means of diathermal oil circulating in the externa! jacket. The temperature is raised to 50 °C. At this point 50 grams of Ti[OCH{CH3)2]4 (TIP) are added very rapidly and a white flock precipitate can be seen immediately. After 7 hours a very stable transparent sol is formed. Characterisation The characterisation occurs by determining the concentration of the Titanium dioxide present in the solution (ICP technique) and by determining the size of the particles (DLS technique). Concentration; 1.5 % in weight of TlOs Size: 36.67 nm with a polydispersivity index of =0.282 Example 2 5 grams of concentrated HCI, 7.5 grams of TX-100, and water up to a total weight of 750 grams are placed in a 2 Litre reactor heated by means of diathermal oil circulating in the external jacket. The temperature is raised to 50°C. At this point 50 grams of TIP are added very rapidly and a white flock precipitate can be seen immediately. ^fter 24 hours a very stable transparent sol is formed. Characterisation Concentration: 1.45 % in weight of Ti02 Size: 30.26 nm with a polydispersivity index: of =0.216 Example 3 500 cc of the product obtained through hydroiysis02 synthesis is placed in the rotavapor and concentrated. The bath is heated to 40 °C and an oil-powered vacuum pump creates a vacuum in the bath. 110 cc of solution are obtained. Gharactehsation CONCENTRATION: 6.69 % IN WEIGHT OF TIO2 SIZE: 25.72 nm with a polydispersivity index of =0.269 Example 4 5 grams of concentrated HCI, 1,0 gram of TX-100, and water up to a total weight of 336 grams are placed in a 2 Litre reactor heated by means of diathermal oil circulating in the external jacket. The temperature is raised to 50 °C. At this point 64 grams of TIP are added very rapidly and a white flock precipitate can be seen immediately. After 24 hours a very stable transparent sol is formed. Characterisation Concentration: 1.8 % in weight of TiO2 Size: 49.62 nm with a polydispersivity index of =0.246 Example 5 5 grams of concentrated HCI, and water up to a total weight of 936 grams are placed in a 2 Litre reactor heated by means of diathermal oil circulating in the external jacket. The temperature is raised to 50°C. At this point 64 grams of TIP are added very rapidly and a white flock precipitate can be seen immediately. After 24 hours a very stable transparent sot is formed. Characterisation Concentration: 1.8 % in weight of Ti02 Size: 52.71 nm with a polydispersivity index of =0.286 Example 6 Application of nanoparticle,dispersion of TIP? in water on fabric The suspension obtained as described in the examples 1 - 5 can be used for treating fabrics and make them absorbent to ultraviolet radiation which is harmful to the skin, thus reducing the risk of developing skin cancer. 15 Kg of a 0.5M solution of sodium acetate and 0.5 Kg of Pimasil (siloxane resin) are added to 13Kg of the product prepared in water and concentrated to 6%. The compound obtained is applied to a fabric using a padding technique followed by rameuse drying. The fabric thus obtained has an UPF value comparable to 20 times the value of a non-treated fabric of the same type. Example 7 Application of nanoparticie dispersion of TiO? in water on ceramic or glass surfaces. The suspension obtained as described in the examples 1-5 can be applied to ceramic or glass surfaces (using airbrush or dip-coating techniques) in the current concentration or diluted (with water or alcohol) The surface obtained maintains its initial characteristics because the applied layer is completely transparent. The suri'ace assumes all the functions with photo catalytic characteristics: self-cleaning, bacteria-proof, degrading capacity for organic pollutants. CLAIMS 1. Method for the preparation of nanoparticle dispersions of Ti02 in anatine form, wherein a titanium alkoxide is made to react under heat in water in the presence of mineral acids and a non-ionic surfactant, the solution thus obtained is possibly reduced to a small volume if necessary. 2. Method according to claim 1, wherein said Titanium alkoxide is chosen from a group composed of titanium methoxide, ethoxide, normal-propoxide, iso-pfopoxide, normal-butoxide, and isobutoxide. 3. Method according to claim 2, wherein said Titanium alkoxide is Titanium iso-propoxide. 4. Method according to claims 1 - 3 wherein said mineral acid is a halogen acid 5. Method according to claim 4 wherein said halogen acid is HCI. 6. Method according to claims 1 - 5 wherein said non-ionic surfactants possess the pokier function of an ether or ester type. 7. Method according to claim 6 wherein said non-ionic surfactant is Triton X-100 (TX-100). 8. Method according to claims 1 - 7 wherein the titanium alkoxide/ halogen acid molar ratio is between 0.005 and 15. 9. Method according to claim 8 wherein the titanium alkoxide/ halogen acid molar ratio is between 5 and 6. 10. Method according to claims 1 - 9 wherein the reaction temperature is between 15°C and 95°C, and the reaction times are between 12 and 72 hours. 11. Method according to claim 10 wherein the reaction temperature is between 45^0 and 55°C, and the reaction time is 24 hours. 12. Method according to claims 1-11 wherein a metal salt Ag, or Cu or Ce, is added to the solution containing the titanium alkoxide, the mineral acid, and the surfactant. 13. Nanoparticle dispersions of Ti02 in anatine form in water, obtainable using the method as defined in claims 1-11. 14. Nanoparticle dispersions of Ti02 in water, wherein the Ti Is doped with a metal selected from the series of transition metals obtainable using the method according to claim 12. 15. Dispersions according to claim 14 wherein said transition metal is selected from the group composed of: Ag, Cu and Ce. 16. Use of nanoparticle dispersions of Ti02 according to claims 13 - 15, for the preparation of photocatalytic coatings on surfaces that require said treatment. 17. Use according to claim 16, wherein said surfaces are selected among the surfaces of textile fabric, metal, ceramic and enameller products. 18. Use of nanoparticle dispersions of Ti02 according to claims 13 - 15, for photocatalytic decontamination of gases and liquids. 19. Use of nanoparticle dispersions of TiO2 according to claims 13 - 15, for the preparation of cosmetics with a protective action for the human skin against sun rays.

Full Text

Method for the preparation of aqueous dispersions of Ti02 in the form of nanoparticies, and dispersions obtainable with this method
FIELD OF THE INVENTION
The present invention relates to the field of methods for the preparation of
compounds in the form of nanometric particles, and in particular, to a method
relating to a way for preparing TJO2 dispersions in the form of nanoparticies.
PRIOR ART.
Titanium dioxide Is a white pigment with a very strong covering capacity used in
particular in paints, and in the production of paper and synthetic rubber. Among
the most recent applications of Titanium dioxide is the attempt to use its
photocatalytic activities to best advantage. In other words, through the action c2
ultraviolet light, to use this capacity to generate radical species able to catalysi
the oxidising degradation of harmful or toxic substances, such as benzene, dioxir
and other organic pollutants, but also unpleasant and sickness-provokin
substances such as mould and bacteria. These applications are therefore used i
wide environmental fields ranging from combating pollutants to detergents an
sterilising products.
For these applications, Titanium dioxide is used as a coating on the-surfaces to b
treated In order to maximise the photocatatyctic effect. The crystalline form c
Titanium dioxide called "anatase" is the most popular for this type of applicatio
because, as well as being chemically stable and easily available, it also possesse
a photocatalytic activity that is higher than the other two crystalline forms, rutil
and brookite.
On the other hand, the superposition of the Titanium dioxide absorption spectrun
—Qitf-n in anatacTP fnrm, nn thp g;nlajL_qpRntnim 1.=; not very large and this resiilt.q
low photocatalytic efficiency levels. For this reason various attempts have bee made to modify TiO2, for example, by doping it with other metals, or by preparir the compound In question in the form of nanoparticies; in fact this increases tf surface area enormously and thus, also the photocatalytic efficiency. Several methods exist for preparing TiO2 anatase, including in nanopartlcle fort that provide TiO2 in powder form. In order to be suitable for the preparation

Dhotocatalvtic coatings, this powder must be dispersed in an appropriate solvent
and formulated with other possible additives to improve coating adhesion, but this
causes the coagulation of the Titanium dioxide particles making it impossible to
maintain the photocatalytic efficiency and activity of the particulate material.
Moreover, over a period of time, the TiO2 particles in these dispersions tend to
settle in the bottom of the containers where they are stored creating stability
problems during storage.
Furthermore, the patent application n° FI2004A252 (by the same Applicant)
describes a method that allows the preparation of stable nanopartiole dispersions
of Titanium dioxide in anatase form where
water and suitable complexing solvents are used as the solvents
SUMMARY OF THE INVENTION,
Recently the Applicant created a method for obtaining nanoparticles of Titanium
dioxide in anatase form already dispersed in water only, and directly usable for the
preparation of photocatalytic coatings. The dispersions obtained with the method
according to the invention did not provoke particle coagulation even after
prolonged storage, thus allowing the preparation of coatings which maintain the
photocatalytic activity of the particulate material thanks to dispersion
homogeneity.
Therefore the aim of the present invention is a method for the preparation of
nanoparticie dispersions of Titanium dioxide in anatase form in water, wherein a
Titanium alkoxide is made to react under heat in water in the presence of mineral
acid and a non-ionic surfactant and where necessary, the solution is finally
reduced to a small volume. A further aim of the invention is the use of the
nanopartiole dispersions of Titanium dioxide in anatase form in water, obtained
using this method, as well as their use for the preparation of photocatalytic surface
coatings, for the photocatalytic decontamination of gases and liquids, and for the
preparation of formula for cosmetics that provide a protective action against sun
rays for the human skin ,
The characteristics and advantages of the invention will be illustrated in detail in
the following descnption.

BRIEF DESCRIPTION OF THE APPENDED FIGURE
Figure 1 shows a difractogram of the dried product powder, where the y-axis
shows the radiation intensity while the x-axis shows the amplitude of the radiation
incidence angle. This analysis demonstrates how crystalline titanium dioxide in
anatase form is obtained using this method.
DETAILED DESCRIPTION OF THE INVENTION.
The method of the present invention is able to produce TiO2 in anatase form.directly
in water, and to obtain a dispersion of TiO2 particles at the end of the process with a
size between 30-50 nm. Particle measurement was performed using various
methods well known to those skilled in the art, such as XRD {X-Ray Diffraction),
FEG-SEM (Field Emission Gun - Scanning Electron Microscopy), TEM
(Transmission Electron Microscopy) and DLS (Dynamic Light Scattering). Unlike
those prepared dispersing nanometric powders in the solvent mixtures or in water,
these dispersions show no signs of conglomeration or coagulation and solid
precipitation, even after prolonged periods of the dispersion product storage.
The advantages to be gained with dispersions of this type are obvious and
associated with the photo catalytic efficiency and uniformity of the coatings that
can be prepared with said dispersions. The dispersion index obtainable with the
method according to the present invention, measured with DLS (Dynamic Light
Scattering) techniques, is lower than 0.3, and thus the dispersion according to the
invention differs from those obtained using prior methods composed of the
preparation of nanoparticle powder, subsequently dispersed in solvent.
The titanium aikoxide used as the starting product in this method can be chosen
from the group composed of titanium methoxids, ethoxide, normal-propoxide, iso-
propoxide, normal-butoxide, and isobutoxide.
Particularly preferable is Titanium isopropoxlde since it is cheaper and reacts
better under the conditions used in the present method.
The non-ionic surfactants are surface-active agents composed of an apolar part
and a polar function, non-ionisable ether, ester, ether-ester; particularly preferable
JsTritonX-lOO(TX-IOO)
The term mineral acid according to the invention refers, for example, to an acid

perchloric acid, hydrobromic acid and hydrogen iodide; preferably halogen acids are
used, and in particular hydrochloric acid.
The alcoholate molar ratio of titanium alkoxide /mineral acid is between 0.005 and 15,
and preferably between 5 and 5.
The reaction temperature ranges between 15°C and 95°C, preferably between 45°C
and 55°C.
Reaction times range between 12 h and 72 h, and preferably 24 h.
Where necessary, when used for coating preparations, the present dispersions
can possibly be formulated using additives and diluents commonly employed in
the field of surface coatings, such as adhesion improved agents or solvents such
as water or ethanol for example, in order to obtain the required dilution level.
On the other hand, when used to decontaminate liquid or gaseous products, the
present dispersions are adsorbed respectively on a silica gel support, or on some
other suitable inorganic support with adsorbent characteristics, that is then immersed
in the liquid, or placed in its current state or diluted, in containers in which the gas to
be purified is bubbled through for washing.
The supports on which surface coatings prepared with the present dispersion can
be applied are widely varied, from woven fibre products in rolls or already made up
into garments, to ceramic products, as well as supports in glass, metal, mirror, and
similar materials.
The photocatalytic activity of the surface coating according to the present
invention is explained as a result of the exposure of the coating in question to light
with a suitable wave length, typically less than 388 nm, which produces a surface
with bacteria-proof, bacteriostatic and super-hydrophilic properties after its
exposure to UV light. In fact, supports coated with Ti02 show a total lack of water
repellent capacity, so-called super-hydrophilic capacity, that makes surfaces
treated with Ti02 self-cleaning.
Moreover, given the extremely small size of the Ti02 particles, the present
dispersions are practically transparent, leaving the appearance of the surface on
which they are applied, totally unchanged. This transparency also makes the
product suitable for use in cosmetic fields for the preparation of sun filters with
high UV ray protection levels.

A further advantage of the present dispersions, is their behaviour at high
temperatures. In fact, the application of the surface coating on ceramic supports
requires high temperature processing of the support on which the dispersion is
applied and the present dispersions maintain exactly the same appearance,
crystalline form of anatase and nanopartlcle nature of the coating as before the
heating process.
According to a particular embodiment of the present method, the Ti can be doped
with a metal selected from the transition metal series^ and in particular Ag, Cu and
Ce by means of the addition of a salt of one of these metals to the starting
solution. In this way, the method will lead to the forming of a dispersion of Ti02
doped with Ag, Cu or Ce, which are able to perform their catalytic activities even
without UV light rays.
Below are certain examples of the invention provided as illustrations but to be
considered by no means limiting.
Example 5 grams of concentrated HCI, 7.5 grms of TX-100, and water up to a total
weight of 750 grams are placed in a 2 Litre reactor heated by means of diathermal
oil circulating in the externa! jacket. The temperature is raised to 50 °C. At this
point 50 grams of Ti[OCH{CH3)2]4 (TIP) are added very rapidly and a white flock
precipitate can be seen immediately.
After 7 hours a very stable transparent sol is formed.
Characterisation
The characterisation occurs by determining the concentration of the Titanium
dioxide present in the solution (ICP technique) and by determining the size of the
particles (DLS technique).
Concentration; 1.5 % in weight of TlOs
Size: 36.67 nm with a polydispersivity index of =0.282
Example 2
5 grams of concentrated HCI, 7.5 grams of TX-100, and water up to a total weight
of 750 grams are placed in a 2 Litre reactor heated by means of diathermal oil
circulating in the external jacket. The temperature is raised to 50°C. At this point
50 grams of TIP are added very rapidly and a white flock precipitate can be seen
immediately.

^fter 24 hours a very stable transparent sol is formed.
Characterisation
Concentration: 1.45 % in weight of Ti02
Size: 30.26 nm with a polydispersivity index: of =0.216
Example 3
500 cc of the product obtained through hydroiysis02 synthesis is placed in the
rotavapor and concentrated. The bath is heated to 40 °C and an oil-powered
vacuum pump creates a vacuum in the bath.
110 cc of solution are obtained.
Gharactehsation
CONCENTRATION: 6.69 % IN WEIGHT OF TIO2
SIZE: 25.72 nm with a polydispersivity index of =0.269
Example 4
5 grams of concentrated HCI, 1,0 gram of TX-100, and water up to a total weight
of 336 grams are placed in a 2 Litre reactor heated by means of diathermal oil
circulating in the external jacket. The temperature is raised to 50 °C.
At this point 64 grams of TIP are added very rapidly and a white flock precipitate
can be seen immediately.
After 24 hours a very stable transparent sol is formed.
Characterisation
Concentration: 1.8 % in weight of TiO2
Size: 49.62 nm with a polydispersivity index of =0.246
Example 5
5 grams of concentrated HCI, and water up to a total weight of 936 grams are
placed in a 2 Litre reactor heated by means of diathermal oil circulating in the
external jacket. The temperature is raised to 50°C. At this point 64 grams of TIP
are added very rapidly and a white flock precipitate can be seen immediately.
After 24 hours a very stable transparent sot is formed.
Characterisation
Concentration: 1.8 % in weight of Ti02
Size: 52.71 nm with a polydispersivity index of =0.286
Example 6

Application of nanoparticle,dispersion of TIP? in water on fabric
The suspension obtained as described in the examples 1 - 5 can be used for
treating fabrics and make them absorbent to ultraviolet radiation which is harmful
to the skin, thus reducing the risk of developing skin cancer.
15 Kg of a 0.5M solution of sodium acetate and 0.5 Kg of Pimasil (siloxane resin)
are added to 13Kg of the product prepared in water and concentrated to 6%. The
compound obtained is applied to a fabric using a padding technique followed by
rameuse drying. The fabric thus obtained has an UPF value comparable to 20
times the value of a non-treated fabric of the same type.
Example 7
Application of nanoparticie dispersion of TiO? in water on ceramic or glass
surfaces.
The suspension obtained as described in the examples 1-5 can be applied to
ceramic or glass surfaces (using airbrush or dip-coating techniques) in the current
concentration or diluted (with water or alcohol) The surface obtained maintains its
initial characteristics because the applied layer is completely transparent. The
suri'ace assumes all the functions with photo catalytic characteristics: self-cleaning,
bacteria-proof, degrading capacity for organic pollutants.

CLAIMS
1. Method for the preparation of nanoparticle dispersions of Ti02 in anatine form, wherein a titanium alkoxide is made to react under heat in water in the presence of mineral acids and a non-ionic surfactant, the solution thus obtained is possibly reduced to a small volume if necessary.
2. Method according to claim 1, wherein said Titanium alkoxide is chosen from a group composed of titanium methoxide, ethoxide, normal-propoxide, iso-pfopoxide, normal-butoxide, and isobutoxide.
3. Method according to claim 2, wherein said Titanium alkoxide is Titanium iso-propoxide.
4. Method according to claims 1 - 3 wherein said mineral acid is a halogen acid
5. Method according to claim 4 wherein said halogen acid is HCI.
6. Method according to claims 1 - 5 wherein said non-ionic surfactants possess the pokier function of an ether or ester type.
7. Method according to claim 6 wherein said non-ionic surfactant is Triton X-100 (TX-100).

8. Method according to claims 1 - 7 wherein the titanium alkoxide/ halogen acid molar ratio is between 0.005 and 15.
9. Method according to claim 8 wherein the titanium alkoxide/ halogen acid molar ratio is between 5 and 6.

10. Method according to claims 1 - 9 wherein the reaction temperature is between 15°C and 95°C, and the reaction times are between 12 and 72 hours.
11. Method according to claim 10 wherein the reaction temperature is between 45^0 and 55°C, and the reaction time is 24 hours.
12. Method according to claims 1-11 wherein a metal salt Ag, or Cu or Ce, is added to the solution containing the titanium alkoxide, the mineral acid, and the surfactant.
13. Nanoparticle dispersions of Ti02 in anatine form in water, obtainable using the method as defined in claims 1-11.
14. Nanoparticle dispersions of Ti02 in water, wherein the Ti Is doped with a metal selected from the series of transition metals obtainable using the method according to claim 12.

15. Dispersions according to claim 14 wherein said transition metal is selected from the group composed of: Ag, Cu and Ce.
16. Use of nanoparticle dispersions of Ti02 according to claims 13 - 15, for the preparation of photocatalytic coatings on surfaces that require said treatment.
17. Use according to claim 16, wherein said surfaces are selected among the
surfaces of textile fabric, metal, ceramic and enameller products.
18. Use of nanoparticle dispersions of Ti02 according to claims 13 - 15, for
photocatalytic decontamination of gases and liquids.
19. Use of nanoparticle dispersions of TiO2 according to claims 13 - 15, for the
preparation of cosmetics with a protective action for the human skin against sun
rays.

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Patent Number

279623

Indian Patent Application Number

4589/CHENP/2008

PG Journal Number

05/2017

Publication Date

03-Feb-2017

Grant Date

27-Jan-2017

Date of Filing

29-Aug-2008

Name of Patentee

COLOROBBIA ITALIA S.P.A.

Applicant Address

VIA PIETRAMARINA 53, I-50050 SOVIGLIANA- VINCI,

Inventors:

#	Inventor's Name	Inventor's Address
1	BALDI, GIOVANNI	VIA TIZZAVOLI, 4, I-50025 MONTESPERTOLI
2	BITOSSI, MARCO,	VIA BOTTINACCIO, 14 I-50056 MONTELUPO FIORENTINO ,
3	BARZNTI, ANDREA,	VIA SAN GIUSEPPE 8, I-50056 MONTELUPO FIORENTINO,

PCT International Classification Number

C01G23/053

PCT International Application Number

PCT/EP07/50826

PCT International Filing date

2007-01-29

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	FI2006A000030	2006-02-01	Italy