Gas-phase titanium dioxide P25 has the characteristics of no scattering effect on incident visible light, strong ultraviolet shielding ability and excellent transparency. As a new material, it is widely used in cosmetics, coatings and other products. Used in plastic, rubber and functional fiber products, it can improve the anti-aging ability, anti-pulverization ability, weather resistance and strength of the products, while maintaining the color of the products and prolonging the service life of the products; Used in inks, coatings and textiles to improve their adhesion, aging resistance and scrubbing resistance; Used in paper industry, it can improve printability and impermeability; Because of its small particle size and high activity, it can not only reflect and scatter ultraviolet rays, but also absorb ultraviolet rays, so it has strong blocking ability to ultraviolet rays and is widely used in sunscreen cosmetics. Good light stability, non-toxicity and high photoelectric conversion rate are the most commonly used materials for photoelectric solar energy conversion. AEROXIDE TiO2 P25 gas-phase nano-TiO _ 2 is a highly dispersed nano-TiO _ 2 P25 produced by AEROSIL process. CASNo.: 13463-67-7
Preparation method of gas-phase titanium dioxide P25: gas-phase nanometer titanium dioxide P25 is obtain by flame combustion of titanium tetrachloride, and that reaction mode is as follows:
TiCl4+2H2+O2 =TiO2+4HCl
Physical and chemical data of pyrolytic titanium dioxide P25;
Properties of Oxide Titanium Dioxide P25
Unit typical value
Specific surface area (BET method) m2/g50 15
Average particle size nm 2 1
Compaction density * (approximate value) g/l is about 130.
Water content * 105℃ for 2 hours Wt. % ≤ 1.5.
Burning loses weight. % ≤2.0
The pH value of the 4% dispersion is 3.4-4.5.
The content of titanium dioxide is weight percentage. % ≥99.5.
Al2O3 content Wt% ≤0.300
The content of silicon dioxide is weight percentage. % ≤0.200.
Fe2O3 content Wt% ≤0.0 10
HCL content% by weight ≤ 0.300
Mechanism of action of gas-phase titanium dioxide P25: Gas-phase nanometer titanium dioxide P25 has a large specific surface area. With the decrease of particle size, the number of surface atoms, surface energy and surface tension increase sharply. Due to the small size effect, surface effect, quantum size effect and macroscopic quantum tunneling effect, the thermal, magnetic, optical, sensitive characteristics and surface stability of nanoparticles are different from those of conventional particles. Due to the electronic structure characteristics of TiO2 _ 2, superoxide anion radical and hydroxyl radical with strong chemical activity will be produced under illumination, which will attack organic substances and degrade organic pollutants. When it encounters bacteria, it directly attacks the cells of bacteria, degrading the organic matter in the cells of bacteria, thus killing bacteria and decomposing them. Nano-titanium dioxide can not only affect the reproduction of bacteria, but also destroy the cell membrane structure of bacteria, thus completely degrading bacteria and preventing secondary pollution caused by endotoxin. Nano-titanium dioxide is an insoluble substance, which does not decompose and dissolve itself while degrading organic pollutants and sterilizing, and has a lasting photocatalytic effect and a lasting bactericidal degradation effect.
Application skills of gas-phase titanium dioxide P25: Adding organic dye sensitizer or transition metal elements to P25 can enlarge the wavelength range of light. When P25 is attached to activated carbon, the catalytic performance will be greatly improved. The catalytic performance of P25 can also be improved by adding hydrophilic fumed silica.
The hydroxyl group on the surface of gas-phase titanium dioxide P25 makes it hydrophilic, and the product has no pigment characteristics. The average particle size of basic particles is about 2 1nm, and the particle size and density of 4g/cm3 make it have a specific surface area of 50m2/g. Vapor-phase titanium dioxide P25 belongs to mixed crystal type, and the weight ratio of anatase to rutile is about 80/20. Due to the mixing of the two structures, the defect density, carrier concentration and the number of electrons and holes in TiO2 lattice increase, which makes it better to capture the solution components (water, oxygen and organic matter) on TiO2 surface. P25 nano-titanium dioxide has excellent ultraviolet absorption, photocatalytic sterilization, decomposition of organic pollutants and other properties, and can be used in nano-coatings, air purifiers, self-cleaning glass, ceramics and so on. Nano-titanium dioxide has broad application prospects in antibacterial, mildew-proof, water treatment, tail gas purification, deodorization, anti-pollution, weather resistance, anti-aging, automobile topcoat and other fields, and has broad application prospects in information, materials, energy, environment, health, medical care and other fields.
Function of fumed titanium dioxide P25
Gas-phase titanium dioxide P25 has good optical properties and shows good development prospects in automobile industry and many fields. Gas-phase titanium dioxide P25 also has high chemical stability, thermal stability, non-toxicity, super hydrophilicity, non-migration, and can completely contact with food, so it is widely used in the fields of anti-ultraviolet materials, textiles, photocatalytic catalysts, self-cleaning glass, sunscreens, paints, inks, food packaging materials, paper industry, aerospace industry and lithium batteries.
Sterilization function
Long-term sterilization under the action of ultraviolet rays in light. The experiment shows that anatase nano-TiO _ 2 with the concentration of 0. 1mg/cm3 can completely kill malignant Hela cells. With the increase of the amount of superoxide dismutase (SOD), the efficiency of photocatalytic killing cancer cells by gas-phase TiO2 P25 is also improved. The killing rate of Bacillus subtilis is different. Aspergillus Niger spores, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella, Cladosporium and Aspergillus all reached more than 98%. Advanced treatment of tap water by photocatalytic oxidation of gaseous titanium dioxide P25 can greatly reduce the number of bacteria in water, and it has no mutagenic effect after drinking, reaching the standard of safe drinking water. Adding fumed titanium dioxide P25 into the coating can produce antibacterial and antifouling coatings with sterilization, antifouling, deodorization and self-cleaning, which can be used in hospital wards, operating rooms, home bathrooms and other places where bacteria are dense and easy to breed, and play the roles of purifying the air, preventing infection and deodorizing. Can effectively kill harmful bacteria and so on.
Ultraviolet protection function
Gas-phase titanium dioxide P25 can not only absorb ultraviolet rays, but also reflect and scatter ultraviolet rays and transmit visible light. It is a kind of physical ultraviolet shielding agent with excellent performance and great development prospect.
Anti-ultraviolet mechanism of fumed titanium dioxide P25;
According to different wavelengths, ultraviolet light is divided into short-wave region 190 ~ 280 nm, medium-wave region 280~320 nm and long-wave region 320 ~ 400 nm. The ultraviolet energy in the short-wave region is the highest, but it is blocked when it passes through the ozone layer. Therefore, it is generally the ultraviolet rays in the medium wave region and the long wave region that cause harm to the human body.
The strong ultraviolet resistance of fumed titanium dioxide P25 is due to its high refraction and high light activity. Its anti-ultraviolet ability and its mechanism are related to its particle size: when the particle size is large, the blocking of ultraviolet rays is mainly reflection and scattering, and it is effective for both medium-wave and long-wave ultraviolet rays. The sun protection mechanism is simple covering, which belongs to general physical sun protection and has weak sun protection ability; With the decrease of particle size, light can penetrate through the particle surface of gas-phase titanium dioxide P25, and the reflection and scattering of ultraviolet rays in long wave region are not obvious, but the absorption of ultraviolet rays in medium wave region is obviously enhanced. Its sun protection mechanism is to absorb ultraviolet rays, mainly absorbing ultraviolet rays in the medium wave region. It can be seen that the sunscreen mechanism of fumed titanium dioxide P25 to different wavelengths of ultraviolet rays is different, and the barrier to long-wave ultraviolet rays is mainly scattering, while the barrier to medium-wave ultraviolet rays is mainly absorption. Gas-phase titanium dioxide P25 shows excellent absorption performance in different wavelength regions. Compared with other organic sunscreens, fumed titanium dioxide P25 has the characteristics of non-toxicity, stable performance and good effect. Japan Shiseido uses 10- 100nm nano-titanium dioxide as a sunscreen ingredient to add to lipsticks and creams, and its sunscreen coefficient can be as high as SPF1-19.
Because of its small particle size and high activity, gas-phase titanium dioxide P25 can reflect and scatter ultraviolet rays and absorb ultraviolet rays, so it has strong blocking ability to ultraviolet rays. Compared with some organic ultraviolet protectants with the same dosage, the absorption peak of gas-phase titanium dioxide P25 in ultraviolet region is higher, and what is more valuable is that it is also a broad-spectrum shielding agent, unlike organic ultraviolet protectants which only absorb UVA or UVB. It can also transmit visible light, and when added to cosmetics, the skin is white and natural, unlike pigment-grade titanium dioxide, which cannot transmit visible light, resulting in an unnatural pallor on the user's face.
Using the transparency and ultraviolet absorption ability of gas-phase titanium dioxide P25, it can also be used as food packaging film, ink, coating, textile products and plastic filler, which can replace organic ultraviolet absorber and improve the aging resistance of coating.
Photocatalytic function
The results show that gas-phase titanium dioxide P25 can produce free radicals with high catalytic activity and strong photo-oxidation reduction ability when activated by sunlight or ultraviolet rays in light, and can catalyze the photolysis of many organic substances such as formaldehyde and some inorganic substances attached to the surface of objects. Can play a role in purifying indoor air.
Anti-fog and self-cleaning function
The gas-phase titanium dioxide P25 film is super hydrophilic and super durable under illumination, so it has anti-fog function. If a layer of gas-phase titanium dioxide P25 film is coated on the rearview mirror of an automobile, even if the moisture or water vapor in the air condenses, the condensed water will not form a single water drop, but form a water film evenly spread on the surface, so there will be no fog scattered by light on the surface. When the rain rushes through, the rain attached to the surface will quickly spread into a uniform water film, and will not form water droplets that distract the line of sight, so that the surface of the rearview mirror will keep its original brightness and improve driving safety.
Vapor-phase titanium dioxide P25 has strong "superhydrophilicity", and it is not easy to form water droplets on its surface, and can act on hydrocarbons under visible light irradiation. By using this effect, a thin layer of gas-phase titanium dioxide P25 can be coated on the surfaces of glass, ceramics and ceramic tiles, and the organic pollutants adsorbed on the surface of titanium dioxide can be decomposed into CO2 and O2 through the photocatalytic reaction of titanium dioxide, which are washed away by the rain together with the remaining inorganic substances to realize the self-cleaning function. Someone in Tokyo, Japan has successfully developed self-cleaning tiles in the laboratory. The surface of this new product has a thin layer of fumed titanium dioxide P25. Under the irradiation of light, any substance attached to the surface, including oil stains, bacteria, etc., can further oxidize these hydrocarbons into gases or substances that can be easily erased due to the catalytic action of gas-phase titanium dioxide P25. The catalytic effect of gas-phase titanium dioxide P25 makes it easy to clean the glass of high-rise buildings, the sticky tiles in kitchens, rearview mirrors and front windows of automobiles.
Other functions
Gas-phase titanium dioxide P25 also has a good degradation effect on some plastics, freon and surfactant SDBS. It is also found that pyrolytic titanium dioxide P25 can also absorb harmful gases. For example, coating olefin polymer fibers containing pyrolytic titanium dioxide P25 on ceramics containing calcium phosphate can absorb different acid-base gases for a long time. In view of the above functions, gas-phase titanium dioxide P25 has a very broad prospect. Its research and utilization will bring great changes to people's lives.
Application of gas-phase titanium dioxide P25 in various fields
Application of Gas Phase Titanium Dioxide P25 in Gas Purification
Environmental harmful gases can be divided into indoor harmful gases and air pollution gases. Indoor harmful gases mainly include formaldehyde released by decorative materials and methyl mercaptan, hydrogen sulfide and ammonia gas produced by living environment. Gas-phase titanium dioxide P25 can oxidize these substances adsorbed on its surface through photocatalytic decomposition, thus reducing the concentration of these substances in the air and alleviating or eliminating environmental discomfort. Air pollution gases are mainly nitrogen oxides and sulfur oxides brought by automobile exhaust and industrial waste gas. These gases are oxidized into sulfuric acid and nitric acid with low vapor pressure under the catalysis of gas-phase titanium dioxide P25, which are removed during rainfall, thus achieving the purpose of reducing air pollution. Coating the surfaces of building materials such as windows and ceramics in rooms and offices with a gas-phase titanium dioxide P25 photocatalytic film or placing a gas-phase titanium dioxide P25 photocatalytic device indoors can effectively degrade pollutants and purify indoor air.
A kind of anti-peeling photocatalytic thin plate made of gas-phase titanium dioxide P25 can effectively remove nitrogen oxides (NOX) gas in the air by sunlight, and HN03 generated on the surface of the thin plate can be washed away by rain, thus ensuring the stability of catalyst activity.
Application of flue gas titanium dioxide P25 in sewage treatment
1. Treating organic sewage: Industrial sewage and domestic sewage contain a lot of organic pollutants, especially industrial sewage contains a lot of toxic and harmful organic substances, which are difficult to be eliminated by biological treatment technology. Many scholars have systematically studied the photocatalytic decomposition of organic pollutants in water. The results show that hydrocarbons, halides and carboxylic acids in water can undergo oxidation-reduction reaction under light conditions with gas-phase titanium dioxide P25 as photocatalyst, and gradually degrade, and finally completely oxidize into environmentally friendly and harmless substances such as CO2 and H2O.
2. Inorganic sewage treatment: In addition to organic matter, many inorganic substances have optical activity on the surface of gas-phase titanium dioxide P25. For example, when Cr6+ in inorganic sewage comes into contact with the surface of gas-phase titanium dioxide P25 catalyst, it can capture photogenerated electrons on the surface, and a reduction reaction occurs, so that Cr6+ with high valence toxicity is degraded into Cr3+ with low toxicity or no toxicity, thus playing a role in purifying sewage; Some heavy metal ions, such as Pt4+, Hg2+, Au3+, etc. It can also capture electrons on the surface of the catalyst and produce reduction precipitation reaction, and can recover inorganic heavy metal ions from sewage.
Application of Gas Phase Titanium Dioxide P25 in Anti-fog Self-cleaning Products
The gas-phase titanium dioxide P25 film is super hydrophilic and super durable under illumination, so it has anti-fog function. If a titanium oxide film is coated on the rearview mirror of an automobile, even if the moisture or water vapor in the air condenses, the condensed water will not form a single water drop, but a water film will be evenly spread on the surface, so there will be no fog of light scattering on the surface. When the rain rushes through, the rain attached to the surface will quickly spread into a uniform water film, and will not form water droplets that distract the line of sight, so that the surface of the rearview mirror will keep its original brightness and improve driving safety.
Application of pyrolytic titanium dioxide P25 in antibacterial and deodorize products
Antibacterial refers to the inhibition or killing effect of gas-phase titanium dioxide P25 on microorganisms in the environment under illumination. The gas-phase titanium dioxide P25 photocatalyst has strong bactericidal ability against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. When bacteria are adsorbed on the surface of photocatalytic ceramics coated with gas-phase titanium dioxide P25, the reactive superoxide radical (O2-) and hydroxyl radical (OH) generated after the gas-phase titanium dioxide P25 is excited by ultraviolet light can penetrate the cell wall of bacteria, destroy the cell membrane quality, enter the inside of bacteria, prevent the transfer of film-forming substances, and block its respiratory system and electron transfer system, thus effectively killing bacteria and inhibiting bacteria from decomposing organic substances to produce malodorous substances (such as H2S, SO2 and mercaptan). Therefore, gas-phase titanium dioxide P25 can purify air and has deodorization function.
Gas-phase titanium dioxide P25 can replace PVA in textiles.
In the process of spinning fiber into yarn, sizing is necessary to reduce warp breakage. PVA is a polymer compound, which is difficult to degrade in natural environment. It has been used in China since 1950s and 1960s. Therefore, it has been classified as "unclean pulp" in some European countries and has been banned. The EU's restrictions on PVA will also be the focus of China's green trade barriers for cotton textile exports. The domestic textile industry has been seeking to develop green and environmentally friendly slurry to replace refractory PVA, which is the goal of "breaking the wall". Gas-phase titanium dioxide P25 is used for textile sizing. Through the perfect combination with starch, the comprehensive weaving performance of yarn is improved, the dosage of PVA is reduced, the sizing time is short, the sizing cost is reduced, the sizing benefit is improved, and many problems such as difficulty in desizing PVA sizing and environmental pollution are solved. Gas-phase titanium dioxide P25 is mainly used to replace PVA in yarn, which plays a role in fitting hairiness, filling gaps and lubricating.
Application of gas-phase titanium dioxide P25 in high-grade automobile paint
When the mixed pigment of fumed titanium dioxide P25 and aluminum powder or mica pearlescent pigment coated with fumed titanium dioxide P25 is added to the coating, the coating can produce mysterious and changeable color changes with the angle, mainly because when the incident light hits the particles of fumed titanium dioxide P25, the blue light will be strongly scattered, and as a result, the green light and red light (in yellow phase) from which the blue light has been removed are reflected by the aluminum sheet into positive reflection light, that is, the scattered light is blue light and the reflected light is yellow light. The fumed titanium dioxide P25 also endows the coating with metallic luster effect, pearlescent effect, flashing effect and color enhancement effect, which makes the automobile surface shine like pearl scales, giving people a sense of depth and layering. This is the mystery of color-changing cars. As a high-tech technology, nanotechnology is changing our lives!
Application of Gas Phase Titanium Dioxide P25 in Cosmetics
Any titanium dioxide has certain ultraviolet absorption function, and excellent chemical stability, thermal stability, non-toxic and other properties. Gas-phase titanium dioxide P25 has smaller particle size (transparency) and greater activity, so it has stronger ability to absorb ultraviolet rays. In addition, titanium dioxide is the most widely used inorganic raw material in cosmetics because of its decoloring power, hiding power, clear color tone, low wear and good dispersibility. In 1980s, the annual consumption of titanium dioxide in the world cosmetics industry was estimated to be 3500t-4000t, and now it is estimated to be above 5000t and below 10000t. Different qualities of titanium dioxide can be selected according to their different functions in cosmetics.
Using the whiteness and opacity of titanium dioxide, the color range of cosmetics can be very wide. When titanium dioxide is used as a white additive, anatase titanium dioxide is mainly used, but considering the hiding power and light resistance, rutile titanium dioxide is the best.
Titanium dioxide for cosmetics requires high purity and strict content of harmful impurities. For example, the European Food Additives Law (applicable to cosmetics) stipulates that the acid-soluble substance titanium dioxide is used in cosmetics.
According to the food, drug and cosmetic regulations of the US Food and Drug Administration (FDA), the total amount of titanium dioxide used as cosmetic, SiO4 _ 4 _ 4 and/or Al _ 2O _ 3 used as dispersion aid and Pb should not exceed 2%.
Gas-phase titanium dioxide P25 is transparent, so it has many excellent characteristics and functions that ordinary cosmetic raw materials do not have in terms of blocking ultraviolet rays, transmitting visible light and safety. Vapor-phase titanium dioxide P25 can not only scatter ultraviolet rays (wavelength 200 nm-400 nm), but also absorb ultraviolet rays, so it has strong ultraviolet shielding ability and can be used as an excellent sunscreen agent to manufacture sunscreen cosmetics. Because the fumed titanium dioxide P25 is transparent, it can be used as transparent skin cream. This skin cream is very popular in Japan and other countries because of its delicate paste and natural skin feeling. Japan needs 1000 tons of nano-titanium dioxide as a sunscreen for cosmetics every year.
Pyrolytic titanium dioxide P25 can be used as a raw material for lithium batteries and solar cells.
Adding pyrolytic titanium dioxide P25 into a lithium battery;
1. Vapor-phase titanium dioxide P25 has excellent high rate performance, cycle stability, fast charge-discharge performance, high capacity and good reversibility of lithium intercalation, and has a good application prospect in the field of lithium batteries.
1) gaseous titanium dioxide P25 can effectively reduce the capacity attenuation of lithium batteries, increase the stability of lithium batteries and improve the electrochemical performance.
2) Improve the first discharge specific capacity of battery materials.
3) The polarization of LiCoO2 during charge and discharge is reduced, and the material has higher discharge voltage and more stable discharge effect.
4) A proper amount of gas-phase titanium dioxide P25 can exist loosely, which reduces the stress between particles and the tiny strain of structure and volume caused in the cycle process, and increases the stability of the battery.
In chemical energy solar cells, gas-phase titanium dioxide P25 crystal has the characteristics of high photoelectric conversion rate, low cost, simple process and stable performance. Its photoelectric efficiency is stable above 10%, its manufacturing cost is only1/5 ~1/and its service life can reach more than 20 years.
3. In Ni-Cd battery, gas-phase titanium dioxide P25 has the characteristics of good conductivity and wide temperature working range.
Application of Gas Phase Titanium Dioxide P25 in Antimicrobial Agents
At present, gas-phase titanium dioxide P25 has become one of the hot spots in development and research because of its excellent antibacterial properties. Gaseous titanium dioxide P25 is widely used in antibacterial water treatment equipment, food packaging, sanitary daily necessities (antibacterial floor tiles, antibacterial ceramic sanitary facilities, etc. ), cosmetics, textiles, antibacterial tableware and chopping boards, antibacterial carpets, new house decoration and new furniture for removing harmful gases, and durable consumer goods such as refrigerators, medical dressings and medical devices made of antibacterial mortar, antibacterial coatings, antibacterial stainless steel plates and aluminum plates for building.
Antimicrobial agents are mostly organic substances and are widely used in food, detergent, textiles and cosmetics. But they also have some disadvantages, such as poor heat resistance, high volatility, easy decomposition to produce harmful substances and poor safety. Therefore, people actively develop and study some inorganic antibacterial agents, and nano-titanium dioxide is one of them. Because antibacterial agents need to reach a certain amount in the product, the following principles must be followed when selecting antibacterial agents:
(1) is safe and nontoxic to human body and has no irritation to skin;
⑵ Strong antibacterial ability and wide antibacterial range;
(3) No peculiar smell, strange smell, light appearance color and small smell;
(4) Good thermal stability, no discoloration, decomposition, volatilization, deterioration, etc. At high temperature;
5] cheap price, easy source, etc.
Gas-phase titanium dioxide P25 is an inorganic component, which is non-toxic, odorless, non-irritating, good in thermal stability and heat resistance, non-flammable and white in color, completely in line with the above principles.
Application Skills of Gas Phase Titanium Dioxide P25
(1) Adding organic dye sensitizer or transition metal elements to fumed titanium dioxide P25 can expand the wavelength range of light.
(2) The gas-phase titanium dioxide P25 is attached to the activated carbon, and the catalytic performance will be greatly improved.
(3) Adding hydrophilic fumed silica into fumed titanium dioxide P25 can also improve its catalytic performance.
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