Fragrance with trimethylsilyl modified aerogel as carrier

Abstract

The invention provides an aromatherapy product taking trimethylsilyl modified aerogel as a carrier. According to the aromatherapy, trimethylsilyl modified aerogel is used as a carrier to adsorb a Schiff base precursor and / or nitrone precursor. Wherein the Schiff base precursor at least contains enamine and / or aminal as a reaction product of cinnamyl aldehyde, citral or citronellal with methyl anthranilate, and the reaction product is obtained by reacting cinnamyl aldehyde, citral or citronellal with methyl anthranilate according to a molar ratio of 1: 1; the nitrone precursor is one or more of methyl nitrone of cinnamyl aldehyde, isopropyl nitrone of cinnamyl aldehyde, methyl nitrone of citral, isopropyl nitrone of citral, methyl nitrone of citronellal and isopropyl nitrone of citronellal. Synergistic slow release is generated between the carrier trimethylsilyl modified aerogel and the Schiff base precursor / nitrone precursor in the aromatherapy, and finally the aroma of the aromatherapy is more durable and stable; according to environment humidity, pH and the like, the saturated adsorption capacity of the aromatherapy can be adjusted by adjusting the density of the trimethylsilyl modified aerogel, and then release of the Schiff base precursor / nitrone precursor is adjusted, so that release is controllable, or controllable mosquito repelling is achieved according to the environment preference of mosquitoes.

Description

Technical Field

[0001] The invention belongs to the technical field of aromatherapy, and in particular relates to an aromatherapy using trimethylsilyl modified aerogel as a carrier. Background Art

[0002] Schiff base flavors and fragrances are compounds prepared by Schiff reaction, usually generated by the reaction of aldehydes and amino compounds (such as methyl anthranilate) under heating and vacuum conditions, and have an imine structure. Most of these compounds have a dark color, but some are light orange and have a strong aroma, and are good additives in flavors. Schiff base flavors have been widely used in daily flavors and edible flavors, especially in grape-flavored edible flavors, and can also be used in various berry, melon and honey flavors, etc. Its effect on perfumes is particularly obvious. After adding, it can enrich the aroma, and can cover up the shortcomings of the aldehyde aroma to achieve the purpose of synergy.

[0003] However, Schiff base flavors may undergo different chemical reactions under different environmental conditions (such as temperature, humidity, pH, etc.), resulting in changes in the content of each component and the aroma. In addition, the carrier that carries the Schiff base flavors and fragrances will also affect the formation and hydrolysis reaction of the Schiff base and change the structure and properties of certain components in the flavor, thereby affecting its volatility and stability. The formation and hydrolysis reaction of Schiff base in certain media may change the physical and chemical properties of the flavor, thereby affecting the persistence and stability of its aroma.

[0004] Nitrones flavors and fragrances have good latent fragrance effects, which require oxidative breakage or hydrolysis in a humid environment. Acidic conditions will accelerate their hydrolysis to release aldehyde / ketone fragrances.

[0005] Similarly, different chemical reactions may occur in nitrone essence under different environmental conditions (such as temperature, humidity, pH etc.), resulting in the variation of each composition content and fragrance. Moreover, the carriers loaded with nitrone essence and fragrance, especially the carriers in liquid detergents and shampoo products, directly affect the oxidation and hydrolysis reaction of nitrone and change the structure and property of some components in the essence, thereby affecting its volatility and stability. The oxidation and hydrolysis reaction of nitrone in some media may change the physicochemical properties of the essence, thereby affecting the persistence and stability of its fragrance.

[0006] Therefore, it is particularly important to improve the stability of Schiff base flavors and nitrone flavors to enhance the persistence and stability of their aroma. Summary of the invention

[0007] In order to solve the problems in the prior art, the present invention provides an aromatherapy device using trimethylsilyl modified aerogel as a carrier.

[0008] The specific technical solutions of the present invention are as follows:

[0009] The aroma diffuser using trimethylsilyl modified aerogel as a carrier provided by the present invention is characterized in that the aroma diffuser uses trimethylsilyl modified aerogel as a carrier to adsorb Schiff base latent aroma and / or nitrone latent aroma.

[0010] The aromatherapy with trimethylsilyl modified aerogel as carrier provided by the present invention also has the following technical characteristics, wherein the Schiff base latent fragrance contains at least enamine and / or aminal which are the reaction products of cinnamaldehyde, citral or citronellal and methyl anthranilate.

[0011] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also has the following technical features, wherein the reaction product is obtained by reacting cinnamaldehyde, citral or citronellal with methyl anthranilate in a molar ratio of 1:1.

[0012] The aromatherapy with trimethylsilyl modified aerogel as carrier provided by the present invention also has the following technical characteristics, wherein the nitrone latent fragrance body is one or more of methyl nitrone of cinnamaldehyde, isopropyl nitrone of cinnamaldehyde, methyl nitrone of citral, isopropyl nitrone of citral, methyl nitrone of citronellal and isopropyl nitrone of citronellal.

[0013] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also has such a technical feature, wherein the molecular structures of methyl nitrone of cinnamaldehyde, isopropyl nitrone of cinnamaldehyde, methyl nitrone of citral, isopropyl nitrone of citral, methyl nitrone of citronellal and isopropyl nitrone of citronellal are respectively shown in the following formulas Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ:

[0014] The aromatherapy with trimethylsilyl modified aerogel as a carrier provided by the present invention also has such technical characteristics, wherein the preparation method of trimethylsilyl modified aerogel comprises the following steps: step S1, mixing a silicon source, a solvent 1 and water for hydrolysis reaction to obtain a hydrolysis solution; step S2, adjusting the pH to make the hydrolysis solution gel, heat-drying and curing the gel, and obtaining a gel after heat-drying and curing; step S3, mixing the solvent 2 and the modifier evenly to obtain a modified liquid, immersing the gel after heat-drying and curing in the modified liquid, heat-drying and curing again, and obtaining a gel after heat-drying and curing again; step S4, supercritical CO 2 The gel is extracted and heat-dried and cured again to obtain trimethylsilyl-modified aerogel.

[0015] The aromatherapy with trimethylsilyl modified aerogel as carrier provided by the present invention also has the following technical features, wherein the silicon source in step S1 is methyl orthosilicate or ethyl orthosilicate; the solvent 1 is methanol or ethanol; the temperature of the hydrolysis reaction is 50-70°C, the pH is 1.0-3.0, and the time is 6-10h; the mass ratio of the silicon source, the solvent 1 and water is 1:(4-6):(0.1-0.3).

[0016] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also has the following technical features: wherein, in step S2, the pH is adjusted to 7.5-8.5; the temperature of the heat drying curing is 60-80° C., and the time is 6-12 hours.

[0017] The aromatherapy with trimethylsilyl modified aerogel as carrier provided by the present invention also has the following technical features, wherein, in step S3, solvent 2 is one or more of acetone, ethanol, n-hexane and n-heptane; the modifier is hexamethyldisilazane, trimethylchlorosilane or triphenylchlorosilane; the mass ratio of solvent 2 to modifier is (8-20):1; the temperature of the second heat drying curing is 60-80°C, and the time is 6-12h.

[0018] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also has the following technical features: wherein in step S4, supercritical CO 2 The extraction stage temperature is 50-70℃, the extraction stage pressure is 10-15MPa, the separation stage temperature is 35-60℃, the separation stage pressure is 4.5-5.5MPa, and the supercritical CO 2 The extraction time is 6-12h.

[0019] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also includes at least one of the following technical features: a1) the density of the trimethylsilyl modified aerogel is 0.050-0.165 g / cm 3 ; a2) the adsorption is saturated adsorption; a3) the trimethylsilyl modified aerogel is in the form of blocks, particles or powder.

[0020] The aromatherapy using trimethylsilyl modified aerogel as a carrier provided by the present invention also has the technical feature that the aromatherapy is used as mosquito repellent aromatherapy or environmental aromatherapy.

[0021] Functions and Effects of the Invention

[0022] The present invention utilizes the adsorption and sustained-release properties of trimethylsilyl modified aerogels and combines the characteristics of Schiff base latent fragrance / nitrone latent fragrance that releases fragrance by hydrolysis in humid and acidic environments to provide an aromatherapy using trimethylsilyl modified aerogels as carriers.

[0023] The Schiff base latent fragrance / nitrone latent fragrance in the aromatherapy of the present invention has a sustained release capability, and a synergistic sustained release is generated between the carrier trimethylsilyl modified aerogel and the Schiff base latent fragrance / nitrone latent fragrance, thereby finally making the fragrance more persistent and stable.

[0024] The aromatherapy of the present invention can adjust the saturated adsorption capacity (its saturated adsorption capacity can reach 5-20 times the weight of the aerogel) by adjusting the density of trimethylsilyl modified aerogel according to environmental humidity, pH, etc., and then adjust the release of Schiff base latent fragrance / nitrone latent fragrance to achieve controllable release; or controllable mosquito repellent according to the environment preferred by mosquitoes. DETAILED DESCRIPTION

[0025] The terms used in the present invention, unless otherwise specified, generally have the meanings that are commonly understood by those of ordinary skill in the art.

[0026] In the following examples, various processes and methods not described in detail are conventional methods well known in the art.

[0027] The reagents used in the following examples were purchased from common commercial sources, and the experimental operations and experimental conditions not specified were referred to the conventional operations and conventional conditions in the art.

[0028] The specific implementation of the present invention is described below with reference to embodiments.

[0029] <Example 1>

[0030] This embodiment provides a method for preparing trimethylsilyl modified aerogel, and the preparation steps are as follows:

[0031] Step S1, mixing the silicon source, solvent 1 and water for hydrolysis reaction to obtain a hydrolysis solution. The specific process is:

[0032] Tetraethyl orthosilicate, ethanol and water were mixed in a mass ratio of 1:5:0.2, and hydrolysis reaction was carried out at 60° C. and pH 2.0 for 8 hours to obtain a hydrolysis solution.

[0033] Step S2, adjusting the pH to make the hydrolyzed solution gel, and heat-drying and curing the gel to obtain a heat-drying and curing gel.

[0034] The specific process is:

[0035] The pH of the hydrolyzed solution was adjusted to 7.6, and the solution was injected into a mold to gel. After gelation, the solution was placed in a 70° C. oven for curing for 12 hours to obtain a gel block after heat curing.

[0036] Step S3, the solvent 2 and the modifier are mixed evenly to obtain a modified liquid, the gel after heat curing is immersed in the modified liquid, and heat-cured again to obtain a gel after heat curing again. The specific process is:

[0037] The solvent 2 (a mixture of acetone and ethanol, with a mixing mass ratio of 2:1) and the modifier hexamethyldisilazane are uniformly mixed in a mass ratio of 10:1 to obtain a modified solution, and the gel block after heat curing obtained in step S2 is immersed in the modified solution and placed in an oven at 70°C for curing for 12 hours to obtain a gel block after heat curing again.

[0038] Step S4, supercritical CO 2 The gel is extracted and heat-dried again to obtain trimethylsilyl modified aerogel. The specific process is:

[0039] Take out the gel block after heat drying and put it into supercritical CO 2 The extraction reactor was set at an extraction stage temperature of 55°C, an extraction stage pressure of 10 MPa, a separation stage temperature of 45°C, a separation stage pressure of 5.5 MPa, and the extraction was performed for 6 hours to obtain trimethylsilyl-modified aerogel blocks.

[0040] In this embodiment, the density of the trimethylsilyl modified aerogel is adjusted by adjusting the mass ratio of the silicon source, solvent 1 and water in step S1; ethylene glycol is added in step S1 to adjust the pore size distribution of the trimethylsilyl modified aerogel, and the mass of ethylene glycol is 0.5, 1, 1.5, 2, 2.5, 1.25, and 2.25 times that of the silicon source. Through adjustment, the density range of 0.062-0.153 g / cm 3 Trimethylsilyl-modified aerogel blocks.

[0041] The present invention can adjust the density of trimethylsilyl modified aerogel to 0.050-0.165g / cm 3 , so that its saturated adsorption capacity reaches 5-20 times the weight of the aerogel. The density of trimethylsilyl modified aerogel is basically inversely proportional to its adsorption capacity.

[0042] Therefore, for aromatherapy using trimethylsilyl modified aerogel as a carrier, when the adsorption capacity of aerogel needs to be enhanced, the density of aerogel can be reduced to increase its saturated adsorption capacity. When the adsorption capacity of aerogel needs to be weakened, the density of aerogel can be increased to reduce its saturated adsorption capacity.

[0043] <Example 2>

[0044] The density of the sample prepared in Example 1 is 0.057 g / cm 3 The trimethylsilyl modified aerogel block was used as a carrier to saturately adsorb the Schiff base latent fragrance 1 to obtain aromatherapy 1. The Schiff base latent fragrance 1 is a reaction product obtained by reacting cinnamaldehyde and methyl anthranilate in a molar ratio of 1:1 at 50 mbar and 75°C for 7 hours (the two main components in the reaction product are enamine and aminal).

[0045] Take 0.24g of Aromatherapy 1 for fragrance test. The test method is: the test sample is placed in a 4mL transparent glass bottle, and 10 volunteers with good senses are randomly selected to evaluate the fragrance intensity of the sample in the glass bottle. The fragrance concentration is scored on a scale of 0-5 points, and the higher the score, the better the fragrance intensity.

[0046] Similarly, 0.24 g of cinnamaldehyde and 0.24 g of Schiff base latent fragrance 1 were taken for fragrance testing, and the testing method was the same as above.

[0047] All test results are listed in Table 1.

[0048] Table 1

[0049] Spice Name Cinnamaldehyde Schiff base latent fragrance 1 Aromatherapy 1 Amount of spices / g 0.24 0.24 0.24 Day 1 5.0 5.0 3.0 Day 2 4.5 2.8 2.0 Day 4 4.0 3.8 3.0 Day 6 1.3 3.3 3.2 Day 15 0 0 3.1 Day 20 \ \ 3.1

[0050] As shown in Table 1, the cinnamaldehyde score becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration of cinnamaldehyde becomes smaller and smaller after volatilization. For the fragrance with Schiff base latent fragrance 1, the total aroma weakens at the beginning due to the volatilization of the fragrance raw materials (because Schiff base latent fragrance 1 is a mixture containing fragrance raw materials), but with the sustained release of Schiff base latent fragrance 1, its aroma gradually increases. From the comparison between Schiff base latent fragrance 1 and aromatherapy 1, it can be seen that the trimethylsilyl-modified aerogel significantly enhances the aroma persistence and stability of Schiff base latent fragrance 1, and can still maintain a strong aroma (3.1) on the 20th day.

[0051] The above test results show that the Schiff base latent fragrance 1 in the aromatherapy 1 has a sustained release ability. The carrier trimethylsilyl modified aerogel and the Schiff base latent fragrance 1 produce a synergistic sustained release, which ultimately makes the fragrance more lasting and stable.

[0052] <Example 3>

[0053] The density of the sample prepared in Example 1 is 0.057 g / cm 3 The trimethylsilyl modified aerogel block was used as a carrier to saturately adsorb Schiff base latent fragrance 2 to obtain aromatherapy 2. Schiff base latent fragrance 2 is a reaction product obtained by reacting citral and methyl anthranilate in a molar ratio of 1:1 at 50 mbar and 75°C for 7 hours (the two main components in the reaction product are enamine and aminal).

[0054] 0.24 g of aromatherapy 2, 0.24 g of citral, and 0.24 g of Schiff base latent fragrance 2 were taken for fragrance testing. The testing method was the same as that of Example 2. The test results are listed in Table 2.

[0055] Table 2

[0056] Spice Name Citral Schiff base latent fragrance 2 Aromatherapy 2 Amount of spices 0.24g 0.24g 0.24g Day 1 5.0 5.0 2.7 Day 2 4.3 3.8 1.5 Day 4 3.8 3.3 2.0 Day 6 0 3.5 3.0 Day 15 \ 0 2.8 Day 20 \ \ 3.5

[0057] As shown in Table 2, the citral score becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration of citral becomes smaller and smaller after volatilization. For the fragrance with Schiff base latent fragrance 2, the total aroma is weakened at the beginning due to the volatilization of the fragrance raw materials (because Schiff base latent fragrance 2 is a mixture containing fragrance raw materials), but with the sustained release of Schiff base latent fragrance 2, its aroma gradually increases. From the comparison between Schiff base latent fragrance 2 and aromatherapy 2, it can be seen that the trimethylsilyl modified aerogel significantly enhances the aroma persistence and stability of Schiff base latent fragrance 2, and the aroma reaches 3.5 on the 20th day.

[0058] The above test results show that the Schiff base latent fragrance 2 in the aromatherapy 2 has a sustained release ability. The carrier trimethylsilyl modified aerogel and the Schiff base latent fragrance 2 produce a synergistic sustained release, which ultimately makes the fragrance more lasting and stable.

[0059] <Example 4>

[0060] The density of the sample prepared in Example 1 is 0.057 g / cm 3 The trimethylsilyl modified aerogel block was used as a carrier to saturately adsorb Schiff base latent fragrance 3 to obtain aromatherapy 3. Schiff base latent fragrance 3 is the reaction product of citronellal and methyl anthranilate in a molar ratio of 1:1 at 50 mbar and 75°C for 7 hours (the two main components in the reaction product are enamine and aminal).

[0061] 0.24 g of aromatherapy 3, 0.24 g of citronellal, and 0.24 g of Schiff base latent fragrance 3 were taken for fragrance testing. The testing method was the same as that of Example 2. The test results are listed in Table 3.

[0062] Table 3

[0063] Spice Name Citronellal Schiff base latent fragrance 3 Aromatherapy 3 Amount of spices 0.24g 0.24g 0.24g Day 1 5.0 5.0 2.7 Day 2 4.5 4.3 1.8 Day 4 4.1 3.3 3.3 Day 6 0 3.5 3.2 Day 15 \ 0 3.3 Day 20 \ \ 3.5

[0064] As shown in Table 3, the citronellal score becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration of citronellal becomes smaller and smaller after volatilization. For the fragrance with Schiff base latent fragrance 3, the total aroma weakens at the beginning due to the volatilization of the fragrance raw materials (because Schiff base latent fragrance 3 is a mixture containing fragrance raw materials), but with the sustained release of Schiff base latent fragrance 3, its aroma gradually increases. From the comparison between Schiff base latent fragrance 3 and aromatherapy 3, it can be seen that the trimethylsilyl modified aerogel significantly enhances the aroma persistence and stability of Schiff base latent fragrance 3, and the aroma reaches 3.5 on the 20th day.

[0065] The above test results show that the Schiff base latent fragrance 3 in the aromatherapy 3 has a sustained release ability. The carrier trimethylsilyl modified aerogel and the Schiff base latent fragrance 3 produce a synergistic sustained release, which ultimately makes the fragrance more lasting and stable.

[0066] <Example 5>

[0067] This example uses three trimethylsilyl modified aerogel blocks with different densities prepared in Example 1 (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturate the methyl nitrone of cinnamaldehyde and the isopropyl nitrone of cinnamaldehyde to obtain aromatherapy 4-9, and three trimethylsilyl modified aerogel blocks with different densities (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturately adsorb cinnamaldehyde to obtain aromatherapy 10-12.

[0068] The molecular structures of methyl nitrone of cinnamaldehyde and isopropyl nitrone of cinnamaldehyde are shown in formulas Ⅰ and Ⅱ.

[0069]

[0070] 0.24 g of the prepared aromatherapy, 0.24 g of cinnamaldehyde, 0.24 g of methyl nitrone of cinnamaldehyde, and 0.24 g of isopropyl nitrone of cinnamaldehyde were respectively taken for fragrance testing. The testing method was the same as that of Example 2. The test results are listed in Table 4.

[0071] Table 4

[0072]

[0073]

[0074] As shown in Table 4, the score of the fragrance without nitrone becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration becomes smaller and smaller after volatilization, while the score of the fragrance with nitrone becomes stronger as time goes on, because as the nitrone is hydrolyzed or oxidized and slowly released, its aroma intensity gradually increases. The intensity of methyl nitrone is stronger than that of isopropyl nitrone under the same conditions, because the steric hindrance of isopropyl is greater than that of methyl, and it is more difficult to hydrolyze or oxidize to release the fragrance raw materials.

[0075] From the comparison of methyl nitrone of cinnamaldehyde and aromatherapy 4, 5, and 6, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of methyl nitrone of cinnamaldehyde, with the aroma reaching 2.5-2.9 on the 15th day and 2.8-3.0 on the 20th day, while methyl nitrone of cinnamaldehyde had no aroma on the 15th day.

[0076] From the comparison of isopropyl nitrone of cinnamaldehyde and aromas 7, 8, and 9, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of isopropyl nitrone of cinnamaldehyde, with the aroma reaching 2.1-2.5 on the 15th day and 2.5-2.7 on the 20th day, while isopropyl nitrone of cinnamaldehyde had no aroma on the 15th day.

[0077] The aroma of Aromatherapy 10-12 was 2.1-2.2 on the 20th day, which was weaker than Aromatherapy 4-9.

[0078] The above test results show that the methyl nitrone of cinnamaldehyde / isopropyl nitrone of cinnamaldehyde in aromatherapy 4-9 has sustained release ability, and a synergistic sustained release is produced between the carrier trimethylsilyl modified aerogel and the methyl nitrone of cinnamaldehyde / isopropyl nitrone of cinnamaldehyde, which ultimately makes the fragrance more lasting and stable.

[0079] <Example 6>

[0080] This example uses three trimethylsilyl modified aerogel blocks with different densities prepared in Example 1 (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturate the methyl nitrone of citral and the isopropyl nitrone of citral to obtain aromatherapy 13-18, three trimethylsilyl modified aerogel blocks with different densities (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturately adsorb citral to obtain aromatherapy 19-21.

[0081] The molecular structures of methyl nitrone of citral and isopropyl nitrone of citral are shown in formula III and IV.

[0082] 0.24 g of the prepared aromatherapy, 0.24 g of citral, 0.24 g of methyl nitrone of citral, and 0.24 g of isopropyl nitrone of citral were taken for fragrance test respectively. The test method was the same as that of Example 2. The test results are listed in Table 5.

[0083] Table 5

[0084]

[0085] As can be seen from Table 5, the score of the fragrance without nitrone becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration becomes smaller and smaller after volatilization, while the score of the fragrance with nitrone becomes stronger as time goes on, because as the nitrone is hydrolyzed or oxidized and slowly released, its aroma intensity gradually increases. The intensity of methyl nitrone is stronger than that of isopropyl nitrone under the same conditions, because the steric hindrance of isopropyl is greater than that of methyl, and it is more difficult to hydrolyze or oxidize to release the fragrance raw materials.

[0086] From the comparison of citral methyl nitrone and aromas 13, 14, and 15, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of citral methyl nitrone, with the aroma reaching 2.7-2.9 on the 15th day and 2.5-2.9 on the 20th day, while citral methyl nitrone had no aroma on the 15th day.

[0087] From the comparison of isopropyl nitrone of citral and aromas 16, 17, and 18, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of isopropyl nitrone of citral, with the aroma reaching 2.0-2.5 on the 15th day and 2.2-2.5 on the 20th day, while isopropyl nitrone of citral had no aroma on the 15th day.

[0088] The aroma of Aromatherapy 19-21 was 2.0-2.3 on the 20th day, which was weaker than Aromatherapy 13-18.

[0089] The above test results show that the methyl nitrone of citral / isopropyl nitrone of citral in Aromatherapy 13-18 has sustained release ability, and a synergistic sustained release is produced between the carrier trimethylsilyl modified aerogel and the methyl nitrone of citral / isopropyl nitrone of citral, which ultimately makes its fragrance more lasting and stable.

[0090] <Example 7>

[0091] This example uses three trimethylsilyl modified aerogel blocks with different densities prepared in Example 1 (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturate the methyl nitrone of citronellal and the isopropyl nitrone of citronellal to obtain aromatherapy 22-27, and three trimethylsilyl modified aerogel blocks with different densities (A1 density 0.122 g / cm 3 、A2 density 0.108g / cm 3 、A3 density 0.057g / cm 3 ) were used as carriers to saturately adsorb citronellal to obtain aromatherapy 28-30.

[0092] The molecular structures of methyl nitrone of citronellal and isopropyl nitrone of citronellal are shown in formula V and VI.

[0093]

[0094] 0.24 g of the prepared aromatherapy, 0.24 g of citronellal, 0.24 g of methyl nitrone of citronellal, and 0.24 g of isopropyl nitrone of citronellal were taken for fragrance testing respectively. The testing method was the same as that of Example 2. The test results are listed in Table 6.

[0095] Table 6

[0096]

[0097] As shown in Table 6, the score of the fragrance without nitrone becomes lower and lower as time goes by because the aroma gradually weakens, because the concentration becomes smaller and smaller after volatilization, while the score of the fragrance with nitrone becomes stronger as time goes on, because as the nitrone is hydrolyzed or oxidized and slowly released, its aroma intensity gradually increases. The intensity of methyl nitrone is stronger than that of isopropyl nitrone under the same conditions, because the steric hindrance of isopropyl is greater than that of methyl, and it is more difficult to hydrolyze or oxidize to release the fragrance raw materials.

[0098] From the comparison of methyl nitrone of citronellal and aromas 22, 23, and 24, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of methyl nitrone of citronellal, with the aroma reaching 3.3-3.5 on the 15th day and 3.5-3.6 on the 20th day, while methyl nitrone of citronellal had no aroma on the 15th day.

[0099] From the comparison of isopropyl nitrone of citronellal and aromas 25, 26, and 27, it can be seen that the trimethylsilyl-modified aerogel significantly enhanced the aroma persistence and stability of isopropyl nitrone of citronellal, with the aroma reaching 3.3-3.5 on the 15th day and 3.2-3.4 on the 20th day, while isopropyl nitrone of citronellal had no aroma on the 15th day.

[0100] The aroma of Aromatherapy 28-30 was 2.1-2.8 on the 20th day, which was weaker than Aromatherapy 22-27.

[0101] The above test results show that the methyl nitrone of citronellal / isopropyl nitrone of citronellal in Aromatherapy 22-27 has sustained release ability, and a synergistic sustained release is produced between the carrier trimethylsilyl modified aerogel and the methyl nitrone of citronellal / isopropyl nitrone of citronellal, which ultimately makes its fragrance more lasting and stable.

[0102] The above is a detailed description of the embodiments, which is convenient for those skilled in the art to correctly understand and use the present invention. Any improvements or modifications to the technical solutions obtained by those skilled in the art based on the present invention on the basis of the prior art, without innovative work, only through analysis, analogy or limited enumeration, etc., should be within the scope of protection determined by the claims.

Claims

1. An aromatherapy device using trimethylsilyl modified aerogel as a carrier, characterized in that: The aromatherapy uses trimethylsilyl modified aerogel as a carrier to absorb Schiff base latent aroma and / or nitrone latent aroma.

2. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 1, characterized in that: in, The Schiff base latent fragrance body contains at least enamine and / or aminal which is a reaction product of cinnamaldehyde, citral or citronellal with methyl anthranilate.

3. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 2, characterized in that: in, The reaction product is obtained by reacting the cinnamaldehyde, the citral or the citronellal with the methyl anthranilate in a molar ratio of 1:

1.

4. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 1, characterized in that: in, The nitrone latent aroma is one or more of methyl nitrone of cinnamaldehyde, isopropyl nitrone of cinnamaldehyde, methyl nitrone of citral, isopropyl nitrone of citral, methyl nitrone of citronellal and isopropyl nitrone of citronellal.

5. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 4, characterized in that: in, The molecular structures of the methyl nitrone of cinnamaldehyde, the isopropyl nitrone of cinnamaldehyde, the methyl nitrone of citral, the isopropyl nitrone of citral, the methyl nitrone of citronellal and the isopropyl nitrone of citronellal are shown in the following formulas Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ and Ⅵ respectively:

6. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 1, characterized in that: in, The preparation method of the trimethylsilyl modified aerogel comprises the following steps: Step S1, mixing a silicon source, a solvent 1 and water to perform a hydrolysis reaction to obtain a hydrolysis solution; Step S2, adjusting the pH to make the hydrolysis solution gel, and heat-drying and curing the gel to obtain a heat-drying and curing gel; Step S3, uniformly mixing the solvent 2 and the modifier to obtain a modified liquid, immersing the heat-cured gel in the modified liquid, and heat-curing again to obtain a heat-cured gel; Step S4, extracting the gel after heat drying and curing again with supercritical CO2 to obtain the trimethylsilyl modified aerogel.

7. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 6, characterized in that: in, The silicon source in step S1 is methyl orthosilicate or ethyl orthosilicate; The solvent 1 is methanol or ethanol; The hydrolysis reaction temperature is 50-70°C, the pH is 1.0-3.0, and the time is 6-10h; The mass ratio of the silicon source, the solvent 1 and the water is 1:(4-6):(0.1-0.3).

8. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 6, characterized in that: in, The step S2 wherein the pH is adjusted to 7.5-8.5; The temperature of the heat baking curing is 60-80°C and the time is 6-12h.

9. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 6, characterized in that: in, In step S3, the solvent 2 is one or more of acetone, ethanol, n-hexane and n-heptane; The modifier is hexamethyldisilazane, trimethylchlorosilane or triphenylchlorosilane; The mass ratio of the solvent 2 to the modifier is (8-20):1; The temperature of the second heat drying and curing is 60-80°C and the time is 6-12h.

10. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 6, characterized in that: in, The extraction stage temperature of the supercritical CO2 extraction in step S4 is 50-70°C, the extraction stage pressure is 10-15MPa, the separation stage temperature is 35-60°C, the separation stage pressure is 4.5-5.5MPa, and the supercritical CO2 extraction time is 6-12h.

11. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to claim 1, characterized in that: It also includes at least one of the following technical features: a1) The density of the trimethylsilyl modified aerogel is 0.050-0.165 g / cm 3 ; a2) the adsorption is saturated adsorption; a3) The trimethylsilyl modified aerogel is in the form of blocks, particles or powder.

12. The aromatherapy using trimethylsilyl modified aerogel as a carrier according to any one of claims 1 to 11, characterized in that: The aromatherapy is used as mosquito repellent aromatherapy or environmental aromatherapy.

Images