Titanium dioxide nanomaterials, methods of making and applications thereof

Abstract

The application relates to a nanometer material, discloses a titanium dioxide nanometer material and a preparation method and application thereof, the nanometer material is a hollow dendritic structure, and comprises small mesopores with a pore diameter not greater than 6nm and large mesopores with a pore diameter not smaller than 20nm. The nanometer material provided by the application is a titanium dioxide nanometer material, has a dendritic hollow structure and two mesopore channels, and can efficiently and durably remove odor and VOCs.

Description

Technical Field

[0001] This invention relates to nanomaterials, specifically to a titanium dioxide nanomaterial, its preparation method, and its applications. Background Technology

[0002] With increasingly stringent environmental regulations and growing consumer focus on health, OEMs are placing higher demands on the air quality inside vehicles. The substances that contribute most significantly to the odor of polymer resins include alcohols, aldehydes, acids, and benzene compounds. Currently, material suppliers in the industry primarily control the odor and volatile organic compound (VOC) content of polypropylene materials used in automotive interiors through methods such as odor absorbers, jellyfish pellets, and post-drying.

[0003] CN117624779A discloses a low-odor, low-emission polypropylene composite material for automotive interiors and its preparation method. Molecular sieves are used as odor adsorbents, and sepiolite, starch solution, and bismuth-modified bamboo fiber are used to adsorb irritating odors. However, the whole process involves many steps, and metallic bismuth is a slightly toxic substance.

[0004] CN101817953A discloses a low-emission modified polypropylene composite material and its preparation method. By adding three adsorbents from clay, bentonite, porous silica, activated alumina or molecular sieve, the odor emission of the product is reduced. However, the odor adsorbents are of many types and have a single pore size, which cannot guarantee the adsorption of molecules of different sizes. Moreover, the gas adsorption is not targeted and cannot completely remove the odor. At high temperatures, the adsorbed substances will desorb again, and the odor control effect is unsatisfactory.

[0005] Therefore, an adsorbent that can effectively adsorb odors and VOCs urgently needs to be developed. Summary of the Invention

[0006] To overcome the problem that existing adsorbents cannot effectively adsorb odors and VOCs, this invention provides a titanium dioxide nanomaterial, its preparation method, and its application. This nanomaterial can effectively adsorb odors and volatile substances such as VOCs, especially the volatile substances in polypropylene composite materials.

[0007] To achieve the above objectives, the first aspect of the present invention provides a titanium dioxide nanomaterial, wherein the nanomaterial has a hollow dendritic structure, including small mesopores with a pore size of not more than 6 nm and large mesopores with a pore size of not less than 20 nm.

[0008] A second aspect of this invention provides a method for preparing titanium dioxide nanomaterials, the method comprising the following steps:

[0009] (1) The solvent is mixed with the template agent, structure directing agent and stabilizer, then mixed with the silicon source, aged and separated to obtain a solid substance;

[0010] (2) After dispersing the solid material obtained in step (1) in an alkaline solution, it is mixed with a titanium source and then separated to obtain the solid material.

[0011] (3) Calcine the solid material obtained in step (2) in air;

[0012] (4) After cooling the calcined solid material, it is immersed in an alkaline solution to remove silicon from the solid material and obtain titanium dioxide nanomaterial.

[0013] The third aspect of the present invention provides a titanium dioxide nanomaterial prepared by the method provided in the second aspect of the present invention.

[0014] The fourth aspect of this invention provides an application of the titanium dioxide nanomaterials provided in the first and third aspects of this invention in polypropylene composite materials.

[0015] The beneficial technical effects of this invention are as follows:

[0016] 1. Titanium dioxide can selectively adsorb polar volatile organic compounds such as polyaldehydes and benzenes, thereby further improving the adsorption capacity of nanomaterials for volatile compounds. It has a strong purpose of deodorization and obvious odor improvement effect. Titanium dioxide also has the ability to photocatalytically decompose volatile organic compounds, and can decompose the adsorbed volatile organic compounds in situ.

[0017] 2. The nanomaterial provided by this invention has a dendritic hollow structure and two types of mesoporous channels. Small mesopores no larger than 6 nm can improve the adsorption capacity for odor substances and volatile substances such as VOCs, while large mesopores no smaller than 20 nm can improve the adsorption rate of volatile substances. The hollow dendritic structure further absorbs and stores volatile substances. The three structures work synergistically with titanium dioxide to achieve efficient and long-lasting deodorization and VOC removal. Attached Figure Description

[0018] Figure 1 This is a transmission electron microscope (TEM) image of titanium dioxide nanomaterial A.

[0019] Figure 2 This is a scanning electron microscope image of titanium dioxide nanomaterial A1.

[0020] Figure 3 (a) is the XRD pattern of titanium dioxide nanomaterial A1, and (b) is the XRD pattern of nanomaterial a1.

[0021] Figure 4 This is the N2 adsorption-desorption isotherm diagram for titanium dioxide nanomaterial Al.

[0022] Figure 5 This is a pore size distribution diagram of titanium dioxide nanomaterial A1. Detailed Implementation

[0023] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] The first aspect of the present invention provides a titanium dioxide nanomaterial, the nanomaterial comprising small mesopores with a pore size of not more than 6 nm and large mesopores with a pore size of not less than 20 nm.

[0025] In this invention, pore size refers to the equivalent diameter of the pore as determined by the N2 adsorption-desorption method.

[0026] In this invention, micropores, mesopores, and macropores have conventional definitions in the art.

[0027] Specifically, micropores refer to pores with a diameter of less than 2 nm; mesopores refer to pores with a diameter of 2-50 nm; and macropores refer to pores with a diameter of more than 50 nm.

[0028] In this invention, titanium dioxide has photocatalytic decomposition ability and can selectively adsorb polar volatile organic compounds. In synergy with the hollow dendritic structure and the two types of mesoporous channels, it can efficiently and persistently remove odors and VOCs.

[0029] According to a preferred embodiment of the present invention, the mesoporous content of the nanomaterial is 70-90%.

[0030] In this invention, when the mesoporous ratio of the nanomaterial is within the above-mentioned range, the adsorption capacity of the nanomaterial for odor substances and VOCs can be improved.

[0031] More preferably, the mesoporous content of the nanomaterial is 75-80%.

[0032] In this invention, the pore ratio refers to the ratio of the volume of a corresponding type of pore to the total pore volume. For example, the mesopore ratio refers to the ratio of the volume of mesopores to the total pore volume.

[0033] According to a preferred embodiment of the present invention, the proportion of small mesopores in the nanomaterial is 35-50%, and the proportion of large mesopores is 30-40%.

[0034] In this invention, when the proportion of small mesopores and the proportion of large mesopores in the nanomaterial are within the above-mentioned range, the adsorption capacity and adsorption rate of the nanomaterial can be further balanced, thereby improving the adsorption capacity.

[0035] More preferably, the proportion of small mesopores in the nanomaterial is 35-45%, and the proportion of large mesopores is 32-37%.

[0036] More preferably, the pore volume ratio of the small mesopores to the large mesopores is 1:0.75-0.9.

[0037] According to the present invention, in a further preferred embodiment, the differential pore size distribution of the nanomaterial has a peak with a half-width of no more than 1 nm at the 3-4 nm position and a peak with a half-width of no more than 20 nm at the 24-25 nm position.

[0038] The differential pore size distribution of the nanomaterials described in this invention was calculated using the BJH model via the N2 adsorption-desorption method.

[0039] According to a preferred embodiment of the present invention, the total pore volume of the nanomaterial is 0.7-1.5 cm³. 3 / g.

[0040] In this invention, when the total pore volume of the nanomaterial is within the above-mentioned range, the adsorption capacity of the nanomaterial can be further improved.

[0041] More preferably, the total pore volume of the nanomaterial is 1-1.3 cm³. 3 / g.

[0042] According to the present invention, preferably, the specific surface area of ​​the nanomaterial is 300-500 m². 2 / g.

[0043] In this invention, when the specific surface area of ​​the nanomaterial is within the above-mentioned range, the number of adsorption sites of the nanomaterial can be further increased.

[0044] More preferably, the specific surface area of ​​the nanomaterial is 390-470 m². 2 / g.

[0045] According to the present invention, the average particle size of the nanomaterial is 180-250 nm.

[0046] In this invention, when the average particle size of the nanomaterial is within the above-mentioned range, the adsorption capacity of the nanomaterial can be improved.

[0047] More preferably, the average particle size of the nanomaterial is 190-210 nm.

[0048] A second aspect of this invention provides a method for preparing titanium dioxide nanomaterials, the method comprising the following steps:

[0049] (1) Mix the solvent with the template agent, structure directing agent and stabilizer, then mix with the silicon source, age, and separate the solid substances;

[0050] (2) Disperse the solid material obtained in step (1) in an alkaline solution, mix it with the titanium source, and separate the solid material;

[0051] (3) Calcine the solid material obtained in step (2) in air;

[0052] (4) After cooling the calcined solid material, it is immersed in an alkaline solution to remove silicon from the solid material and obtain titanium dioxide nanomaterial.

[0053] In this invention, the above preparation method can obtain titanium dioxide nanomaterials with a dendritic hollow structure, including small mesopores with a pore size of no more than 6 nm and large mesopores with a pore size of no less than 20 nm.

[0054] In this invention, removing silicon is beneficial to increasing the small mesopore volume of titanium dioxide nanomaterials.

[0055] According to a preferred embodiment of the present invention, the calcination temperature in step (3) is 700-800℃ and the time is 1-7h.

[0056] In this invention, when the calcination temperature and time are within the above-mentioned range, the specific surface area and adsorption capacity of titanium dioxide nanomaterials can be improved.

[0057] More preferably, the calcination temperature in step (3) is 720-760℃ and the time is 2-6h.

[0058] According to the present invention, preferably, the pH value of the alkaline solution in step (2) is 9-11.

[0059] In this invention, when the pH value of the solvent in step (2) is within the above range, it helps to accelerate the hydrolysis and polycondensation reaction of the titanium source, which is beneficial to increasing the specific surface area of ​​the titanium dioxide nanomaterial.

[0060] According to a preferred embodiment of the present invention, in step (4), the pH value of the alkaline solution is 9-13, the soaking temperature is 50-80℃, and the soaking time is 3-8h.

[0061] In this invention, when the pH value, soaking temperature and time of the alkaline solution in step (4) are within the above range, the small mesopore volume of the titanium dioxide nanomaterial can be increased, thereby further improving the adsorption capacity of the titanium dioxide nanomaterial.

[0062] The present invention does not impose any particular limitations on the temperature, mixing method, and aging time in step (1), and those skilled in the art can make conventional choices. According to the present invention, preferably, step (1) is carried out at 60-80°C, the mixing method is stirring, and the aging time is 2-3 hours.

[0063] The present invention does not impose any particular limitation on the mixing temperature, time, and method in step (2), and those skilled in the art can make conventional choices. According to the present invention, preferably, the mixing temperature in step (2) is 20-40°C, the time is 15-20 hours, and the mixing method is stirring.

[0064] The present invention does not particularly limit the specific type of alkaline solution in step (4). Those skilled in the art can choose conventionally, as long as it meets the pH requirement. According to the present invention, preferably, the alkaline solution is selected from at least one aqueous solution of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

[0065] According to the present invention, preferably, the titanium source is selected from at least one of tetramethyl titanate, tetrabutyl titanate, titanium tetrachloride, and sodium titanate. More preferably, the titanium source is tetrabutyl titanate.

[0066] According to the present invention, preferably, the silicon source is selected from at least one of sodium silicate, ammonium silicate, methyl orthosilicate, ethyl orthosilicate, and sodium ethylsilanetriol. More preferably, the silicon source is ethyl orthosilicate.

[0067] According to the present invention, preferably, the template agent is selected from at least one of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, hexadecylpyridine, and polyethylene glycol octylphenyl ether. More preferably, the template agent is hexadecyltrimethylammonium bromide.

[0068] According to the present invention, preferably, the structure-directing agent is selected from at least one of sodium salicylate, sodium benzoate, and sodium p-hydroxybenzoate. More preferably, the structure-directing agent is sodium salicylate.

[0069] According to the present invention, preferably, the stabilizer is selected from at least one of ethylenediamine, ethanolamine, and triethanolamine. More preferably, the stabilizer is triethanolamine.

[0070] According to a preferred embodiment of the present invention, based on the addition of 1 part by mass of the titanium source, the amount of silicon source added is 0.8-1.6 parts by mass;

[0071] The amount of the template agent added is 0.1-0.3 parts by weight;

[0072] The amount of the structure-directing agent added is 0.04-0.08 parts by weight;

[0073] The amount of stabilizer added is 0.01-0.04 parts by mass.

[0074] In this invention, when the amounts of the titanium source, silicon source, template agent, structure directing agent, and stabilizer are within the above-mentioned ranges, the total pore volume and mesopore ratio of the nanomaterial can be increased. In particular, when the amount of the structure directing agent is within the above-mentioned range, it is beneficial to increase the proportion of macropores in the mesopores of the titanium dioxide nanomaterial.

[0075] In this invention, when the amount of silicon source added is within the above range, the titanium source can be uniformly coated on the silicon dioxide surface and will not self-aggregate into spheres.

[0076] More preferably, based on adding 1 part by mass of the titanium source, the amount of silicon source added is 1.3-1.5 parts by mass;

[0077] The amount of the template agent added is 0.1-0.2 parts by weight;

[0078] The amount of the structure-directing agent added is 0.05-0.07 parts by weight;

[0079] The amount of stabilizer added is 0.02-0.03 parts by mass.

[0080] In this invention, when the amounts of the titanium source, silicon source, template agent, structure directing agent, and stabilizer are within the above-mentioned range, the specific surface area of ​​the nanomaterial can be further increased.

[0081] The third aspect of the present invention provides a nanomaterial prepared by the method provided in the second aspect of the present invention.

[0082] The fourth aspect of the present invention provides an application of the nanomaterials provided in the first and third aspects of the present invention in polypropylene composite materials.

[0083] The present invention will be described in detail below through embodiments.

[0084] In the following examples, the pore size distribution of the nanomaterials was obtained using the N2 adsorption-desorption method and the BJH model;

[0085] The specific surface area of ​​nanomaterials was obtained using the BET model;

[0086] The average particle size of the nanomaterials was measured using a laser particle size analyzer.

[0087] Emission performance test of polypropylene composite materials: Odor test according to VS-00.28-L-06021-2018, VOCs test according to VS-00.28-L-06017-2018.

[0088] Specifically, the copolymer PP was purchased from Zhenhai Refining & Chemical Co., Ltd., grade M30RH;

[0089] The ethylene-octene copolymer elastomer was purchased from SABIC, grade C5070D.

[0090] Talc powder was purchased from Liaoning Aihai, brand name AH51210L;

[0091] Antioxidant purchased from Tianjin Lialong, brand name 1010 / 168;

[0092] The light stabilizer was purchased from Xinxiu Chemical, brand name 5585;

[0093] The odor absorbent was purchased from Qingdao Century Zhuoxin, brand name XW-17.

[0094] Unless otherwise specified, all other raw materials and reagents are commercially available.

[0095] Example 1

[0096] (1) Dissolve 3g of triethanolamine in 1L of water and stir at 70°C until dissolved. Add 15g of cetyltrimethylammonium bromide and 7g of sodium salicylate and stir until uniform. Slowly add 140g of tetraethyl orthosilicate and age for 3h. Centrifuge to collect the product and wash with hydrochloric acid and ethanol. After vacuum drying, obtain a white powder.

[0097] (2) Disperse the white powder in 3L of ethanol solution containing ammonia (NH3·H2O / C2H6O=1 / 500, v / v, pH=10), add 100g of tetrabutyl titanate, stir at room temperature for 15h, collect the product, and wash with ethanol.

[0098] (3) Calcine in air at 750℃ for 3 hours, then cool to obtain nanomaterial a1.

[0099] (4) The nanomaterial a1 was dispersed in a 2M sodium carbonate aqueous solution (pH=12) at 60℃ and soaked for 4 hours. The titanium dioxide nanomaterial A1 was obtained by centrifugation.

[0100] Figure 1 and Figure 2 The images shown are transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of titanium dioxide nanomaterial A1, respectively. It can be seen that titanium dioxide nanomaterial A1 has a dendritic hollow structure.

[0101] Figure 3 (a) is the XRD pattern of titanium dioxide nanomaterial A1, which shows that titanium dioxide nanomaterial A1 has anatase crystal structure; (b) is the XRD pattern of nanomaterial a1, which shows that the nanomaterial before silicon removal contains an amorphous structure.

[0102] Figure 4 The N2 adsorption-desorption isotherm of titanium dioxide nanomaterial A1 is shown. Fitting the isotherm using the BET method yields a specific surface area of ​​473 m² for titanium dioxide nanomaterial A1. 2 / g.

[0103] Figure 5The pore size distribution diagram of titanium dioxide nanomaterial A1 shows that the mesopore volume of titanium dioxide nanomaterial A is 0.56 cm³. 3 / g, with a macropore volume of 0.48cm³. 3 / g, micropore volume is 0.01cm³ 3 / g, macropore volume is 0.05cm³ 3 / g, total pore volume is 1.3cm³ 3 / g.

[0104] The average particle size of titanium dioxide nanomaterial A1 was measured to be 202 nm using a laser particle size analyzer.

[0105] Example 2

[0106] (1) Dissolve 2g of triethanolamine in 1L of water and stir at 70°C until dissolved. Add 10g of hexadecyltrimethylammonium bromide and 6g of sodium salicylate and stir until uniform. Slowly add 130g of tetraethyl orthosilicate and age for 3h. Centrifuge to collect the product and wash with hydrochloric acid and ethanol. After vacuum drying, obtain a white powder.

[0107] (2) Disperse the white powder in 3L of ethanol solution containing ammonia (NH3·H2O / C2H6O=1 / 500, v / v, pH=10), add 100g of tetrabutyl titanate, stir at room temperature for 15h, collect the product, and wash with ethanol.

[0108] (3) Calcine in air at 750℃ for 3 hours, then cool to obtain nanomaterial a2.

[0109] (4) The nanomaterial a2 was dispersed in a 2M sodium carbonate aqueous solution (pH=12) at 60℃ and soaked for 4 hours. The titanium dioxide nanomaterial A2 was obtained by centrifugation.

[0110] Characterization revealed that the mesopore volume of the titanium dioxide nanomaterial A2 was 0.44 cm³. 3 / g, with a macropore volume of 0.34cm³. 3 / g, micropore volume is 0.02cm³ 3 / g, macropore volume is 0.06cm³ 3 / g, total pore volume is 1.0cm³ 3 / g; specific surface area is 392m² 2 / g, with an average particle size of 210nm.

[0111] Example 3

[0112] (1) Dissolve 3g of triethanolamine in 1L of water and stir at 70°C until dissolved. Add 20g of cetyltrimethylammonium bromide and 7g of sodium salicylate and stir until uniform. Slowly add 150g of tetraethyl orthosilicate and age for 3h. Centrifuge to collect the product and wash with hydrochloric acid and ethanol. After vacuum drying, obtain a white powder.

[0113] (2) Disperse the white powder in 3L of ethanol solution containing ammonia (NH3·H2O / C2H6O=1 / 500, v / v, pH=10), add 100g of tetrabutyl titanate, stir at room temperature for 15h, collect the product, and wash with ethanol.

[0114] (3) Calcine in air at 750℃ for 3 hours, then cool.

[0115] (4) Dispersed in 2M sodium carbonate aqueous solution at 60℃ for 4 hours, and centrifuged to obtain titanium dioxide nanomaterial A3.

[0116] Characterization revealed that the mesopore volume of titanium dioxide nanomaterial A3 was 0.50 cm³. 3 / g, with a macropore volume of 0.42cm³. 3 / g, micropore volume is 0.01cm³ 3 / g, macropore volume is 0.06cm³ 3 / g, total pore volume is 1.2cm³ 3 / g; specific surface area is 429m² 2 / g, with an average particle size of 193nm.

[0117] Example 4

[0118] (1) Dissolve 1g of triethanolamine in 1L of water and stir at 70°C until dissolved. Add 10g of cetyltrimethylammonium bromide and 4g of sodium salicylate and stir until uniform. Slowly add 80g of tetraethyl orthosilicate and age for 3h. Centrifuge to collect the product and wash with hydrochloric acid and ethanol. After vacuum drying, obtain a white powder.

[0119] (2) Disperse the white powder in 3L of ethanol solution containing ammonia (NH3·H2O / C2H6O=1 / 500, v / v, pH=10), add 100g of tetrabutyl titanate, stir at room temperature for 15h, collect the product, and wash with ethanol.

[0120] (3) Calcine in air at 750℃ for 3 hours, then cool.

[0121] (4) Dispersed in 2M sodium carbonate aqueous solution at 60℃ for 4 hours, and centrifuged to obtain titanium dioxide nanomaterial A4.

[0122] Characterization revealed that the mesopore volume of titanium dioxide nanomaterial A4 was 0.35 cm³. 3 / g, with a macropore volume of 0.26cm³. 3 / g, micropore volume is 0.01cm³ 3 / g, macropore volume is 0.04cm³ 3 / g, total pore volume is 0.7cm³ 3 / g; specific surface area is 305m²2 / g, with an average particle size of 239nm.

[0123] Example 5

[0124] (1) Dissolve 4g of triethanolamine in 1L of water and stir at 70°C until dissolved. Add 30g of cetyltrimethylammonium bromide and 8g of sodium salicylate and stir until uniform. Slowly add 160g of tetraethyl orthosilicate and age for 3h. Centrifuge to collect the product and wash with hydrochloric acid and ethanol. After vacuum drying, obtain a white powder.

[0125] (2) Disperse the white powder in 3L of ethanol solution containing ammonia (NH3·H2O / C2H6O=1 / 500, v / v, pH=10), add 100g of tetrabutyl titanate, stir at room temperature for 15h, collect the product, and wash with ethanol.

[0126] (3) Calcine in air at 750℃ for 3 hours, then cool.

[0127] (4) Dispersed in 2M sodium carbonate aqueous solution at 60℃ for 4 hours, and centrifuged to obtain titanium dioxide nanomaterial A5.

[0128] Characterization revealed that the mesopore volume of titanium dioxide nanomaterial A5 was 0.41 cm³. 3 / g, with a macropore volume of 0.30cm³. 3 / g, micropore volume is 0.01cm³ 3 / g, macropore volume is 0.05cm³ 3 / g, total pore volume is 0.9cm³ 3 / g; specific surface area is 361m² 2 / g, with an average particle size of 182nm.

[0129] Comparative Example 1

[0130] Nanomaterials were prepared according to the raw materials and methods of Example 1, except that sodium salicylate was not added, resulting in nanomaterial D1.

[0131] Characterization revealed that the mesopore volume of nanomaterial D1 was 0.04 g / cm³. 3 The mesopore volume is 0.11 g / cm³. 3 The micropore volume is 0.01 cm³. 3 / g, macropore volume is 0.22cm³ 3 / g, total pore volume is 0.41cm³ 3 / g; specific surface area is 214cm³ 2 / g, with an average particle size of 58nm.

[0132] Comparative Example 2

[0133] Nanomaterials were prepared according to the raw materials and methods of Example 1, except that tetrabutyl titanate was not added, resulting in nanomaterial D2.

[0134] Characterization revealed that the mesopore volume of nanomaterial D2 was 0.3 cm³. 3 / g, with a macroporous volume of 1.4cm³. 3 / g, micropore volume is 0.04cm³ 3 / g, macropore volume is 0.6cm³ 3 / g, total pore volume is 2.9cm³ 3 / g; specific surface area is 680m² 2 / g, with an average particle size of 200nm.

[0135] Application Example 1-5 and Comparative Example 1-2

[0136] Weigh the raw materials according to the formula in Table 1, mix them evenly, and feed them into the main feed port of a twin-screw extruder. Extrusion and granulation are then carried out to obtain polypropylene composite materials.

[0137] The temperature at the rear of the barrel of the twin-screw extruder is 180℃, the temperature in the middle of the barrel is 220℃, the temperature at the front of the barrel is 230℃, and the main extruder speed is 500 rpm.

[0138] Table 1

[0139]

[0140] Comparative Application Example 3

[0141] Polypropylene composite materials were prepared in the same manner as in Application Example 1, except that 1 part by mass of XW-17 odor adsorbent was added, but titanium dioxide nanomaterials were not added.

[0142] Comparative Application Example 4

[0143] Polypropylene composite materials were prepared in the same manner as in Application Example 1, except that titanium dioxide nanomaterials were not added.

[0144] Test case

[0145] The odor and VOC emissions of the polypropylene composite materials obtained in Application Examples 1-5 and Comparative Application Examples 1-4 were tested according to the test methods described in the Specific Embodiments section of this invention. The test results are shown in Table 2.

[0146] Table 2

[0147]

[0148] Note: ND indicates Not Detected.

[0149] The results of the above test examples show that the titanium dioxide nanomaterials provided by the present invention can effectively adsorb the odor and VOCs of polypropylene composite materials, and can meet the low odor and low emission requirements of OEM interior materials without post-drying.

[0150] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A titanium dioxide nanomaterial, characterized in that, The nanomaterial has a dendritic hollow structure, including small mesopores with a pore size of no more than 6 nm and large mesopores with a pore size of no less than 20 nm.

2. The nanomaterial according to claim 1, characterized in that, The mesoporous content of the nanomaterial is 70-90%.

3. The nanomaterial according to claim 1 or 2, characterized in that, The nanomaterial has a small mesopore ratio of 35-50% and a large mesopore ratio of 30-40%. Preferably, the ratio of the pore volume of the small mesopores to that of the large mesopores is 1:0.75-0.

9.

4. The nanomaterial according to any one of claims 1-3, characterized in that, The total pore volume of the nanomaterial is 0.7-1.5 cm³. 3 / g; Preferably, the specific surface area of ​​the nanomaterial is 300-500 m². 2 / g; Preferably, the average particle size of the nanomaterial is 180-250 nm.

5. A method for preparing silica nanomaterials, characterized in that, The method includes the following steps: (1) The solvent is mixed with the template agent, structure directing agent and stabilizer, then mixed with the silicon source, aged and separated to obtain a solid substance; (2) After dispersing the solid material obtained in step (1) in an alkaline solution, it is mixed with a titanium source and then separated to obtain the solid material. (3) Calcine the solid material obtained in step (2) in air; (4) After cooling the calcined solid material, it is immersed in an alkaline solution to remove silicon from the solid material and obtain titanium dioxide nanomaterial.

6. The method according to claim 5, characterized in that, The calcination temperature in step (3) is 700-800℃, and the calcination time is 2-6h; And / or, in step (4), the pH value of the alkaline solution is 9-13, the soaking temperature is 60-80℃, and the soaking time is 3-8h.

7. The method according to claim 5 or 6, characterized in that, The titanium source is selected from at least one of tetramethyl titanate, tetrabutyl titanate, titanium tetrachloride, and sodium titanate; Preferably, the silicon source is selected from at least one of sodium silicate, ammonium silicate, methyl orthosilicate, ethyl orthosilicate, and sodium ethylsilanetriol. Preferably, the template agent is selected from at least one of sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, hexadecylpyridine, and polyethylene glycol octylphenyl ether; Preferably, the structure directing agent is selected from at least one of sodium salicylate, sodium benzoate, and sodium p-hydroxybenzoate; Preferably, the stabilizer is selected from at least one of ethylenediamine, ethanolamine, and triethanolamine.

8. The method according to any one of claims 5-7, characterized in that, Based on 1 part by weight of the titanium source, the amount of silicon source added is 0.8-1.6 parts by weight, preferably 1.3-1.5 parts by weight; The amount of the template agent added is 0.1-0.3 parts by weight; The amount of the structure-directing agent added is 0.04-0.08 parts by weight; The amount of stabilizer added is 0.01-0.04 parts by mass.

9. A titanium dioxide nanomaterial prepared by the method according to any one of claims 5-8.

10. The application of the titanium dioxide nanomaterial according to any one of claims 1-4 and 9 as an odor adsorbent.

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