CN114130317A

CN114130317A - Submicron hollow microsphere containing aromatic

Info

Publication number: CN114130317A
Application number: CN202111450201.8A
Authority: CN
Inventors: 高文颖
Original assignee: Beijing Wuxingxing Technology Co ltd
Current assignee: Beijing Wuxingxing Technology Co ltd
Priority date: 2021-12-01
Filing date: 2021-12-01
Publication date: 2022-03-04

Abstract

The invention discloses a submicron hollow microsphere containing aromatic, which comprises a shell layer with a hollow structure and formed by compounding organic chemical materials and inorganic chemical materials, wherein the shell layer mainly comprises silicon-containing polymers; the shell layer is provided with a hydrophobic inner surface and a hydrophilic outer surface, and a hollow inner cavity defined by the hydrophobic inner surface is filled with aromatic filler. In the invention, an additional non-polymerizable liquid phase is added into the core, and small hollow particles are prepared by a Pickering emulsion polymerization method; in this case, the liquid can be removed at normal temperature.

Description

Submicron hollow microsphere containing aromatic

Technical Field

The invention relates to the fields of catalysis, biomedicine and the like, in particular to a submicron hollow microsphere containing an aromatic.

Background

Hollow colloidal particles have been of interest for the past few decades because of their potential for use in catalysis, biomedicine, and the like. Hollow particles provide a large space for guest molecules with a high loading, and thus hollow particles are also promising for the collection of contaminants. The most common strategy for preparing hollow colloidal particles is a multi-step template synthesis, i.e., first synthesizing core-shell particles from template particles and then removing the core. The template may be a polymer emulsion, emulsion droplets, inorganic nanoparticles, or micelles. Such methods typically involve cumbersome processes such as rinsing, calcining or chemical etching to remove the surfactant or template. The structure of the housing may be damaged during handling. In addition, the method has difficulty in controlling the permeability of the shell, which hinders its application as a carrier.

The Pickering emulsion is a stable emulsion, and can be used for preparing a complex with a colloidal particle array as a shell and a liquid phase as a core. However, the cohesion between the colloidal particles is generally insufficient to maintain the integrity of the shell, and therefore the shell is typically broken after removal of the liquid core. This phenomenon is widely used to prepare Janus colloidal particles. Once the liquid core can be polymerized, the core-shell structure can still be maintained after the liquid core is polymerized, and the hollow particles with controllable shell layer air permeability can be obtained after the core layer is removed by a proper method. Bon et al successfully demonstrated that core-shell particles were prepared using laponite or silica nanoparticles as stabilizers by Pickering emulsion polymerization to form shell structures. If a series of acrylate monomers are used as the core material, the core material is removed to obtain hollow particles. Philips et al report for the first time that when 3- (trimethoxysilyl) propyl methacrylate (TPM) is used as a liquid core, silicon dioxide or Fe3O4 nanoparticles can form a Pickering emulsion with stable thermodynamics, so that core-shell colloidal particles with small particle size and narrow particle size distribution can be easily prepared after polymerization of TPM core. The TPM type-silica/Fe 3O4 system provides a good platform for preparing hollow particles with smaller size overall by adopting a Pickering emulsion polymerization method. However, the core in such core-shell particles is typically a solid polymer and therefore requires further processing, such as calcination, to produce a hollow structure. But the handling process may damage the integrity of the shell or reduce the colloidal stability of the resulting hollow particles.

Disclosure of Invention

The invention aims to provide a submicron hollow microsphere containing aromatic; in the invention, an additional non-polymerizable liquid phase is added into the core, and small hollow particles are prepared by a Pickering emulsion polymerization method; in this case, the liquid can be removed at normal temperature.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a submicron hollow microsphere containing aromatic comprises a shell layer with a hollow structure and formed by compounding organic chemical materials and inorganic chemical materials, and mainly comprises silicon-containing polymers, wherein silica colloid particles are embedded in the shell layer and partially exposed outside; the shell layer is provided with a hydrophobic inner surface and a hydrophilic outer surface, and a hollow inner cavity defined by the hydrophobic inner surface is filled with aromatic filler.

Further, the particle size of the submicron hollow microsphere is 100-300 nanometers, and a nanometer pore channel is formed in the shell layer; the shell layer is obtained by emulsion polymerization of raw materials comprising silicon dioxide colloid particles, a thermodynamically stable Pickering emulsion system is adopted in the emulsion polymerization, and a template is volatile isoprene acetate; the emulsion in the emulsion polymerization comprises a silane coupling agent, silica colloid particles and isoamyl acetate; the mass ratio of the volatile solvent to the silane coupling agent is 1: l-6: 10, and the mass ratio of the silica colloid particles to the silane coupling agent is 1: 2-1: 14; the silane coupling agent is methoxy silane or ethoxy silane with a double-bond structure;

further, the preparation method of the aromatic-containing submicron hollow microsphere comprises the following steps:

preparing a hollow submicron sphere with an internal hydrophobic and external hydrophilic structure by adopting a thermodynamically stable Pickering emulsion system and an emulsion polymerization method by taking acetic acid isoprene as a template; the shell layer of the hollow submicron sphere is of an organic-inorganic composite structure and mainly comprises silicon-containing polymers, and silica colloidal particles are embedded in the shell layer and partially exposed outside;

dissolving the hollow nano microspheres into water until the hollow nano microspheres are saturated to obtain a mixed solution;

dispersing the fragrance filler into the mixed solution in step S1, and filling the fragrance filler into the submicron hollow microspheres.

Further, the shell preparation method comprises the following steps:

s1: adding 40 wt% of silicon dioxide aqueous dispersion into water to obtain new dispersion;

s2: adding the mixture of TPM and PEA to the new dispersion in step S1; gently stirring the formed emulsion;

s3: bubbling and deoxidizing for 30min by using nitrogen, then heating to 70 ℃, and adding KPS to initiate polymerization;

s4: the polymer was centrifuged 3 times at 12000 rpm and then washed with ethanol; dispersing the final product in water or freeze drying to form submicron hollow microsphere.

Further, the ratio of silica to water in step S1 was 0.225: 40.

Further, in step S2, the ratio of TPM to PEA is 1: 3; the stirring time was 24 h.

Further, the ratio of TPM and PEA to water in step 1 was 0.5:1.5: 40.

Further, the reaction temperature of the polymerization reaction in the step S3 was 70 ℃ and the reaction time was 24 hours.

Further, the ratio of KPS to water is 1: 4.

Compared with the prior art, the invention has the advantages and positive effects that:

the invention uses mesoporous structure shell type submicron hollow microsphere prepared by emulsion polymerization to wrap solid, liquid and gas; submicron hollow microspheres with mesoporous structure shell layers, hollow structures taking silicon dioxide as shells, such as nano bubbles; BET result shows that the shell layer of the hollow particle is a mesoporous structure, and the specific surface area is more than 400m²·g^-1(ii) a In the special structure, the shell is composed of inert molecules and has amphipathy; the cavity can be wrapped with various active ingredients, such as natural products, active molecules, essence, etc., and the wrapped substances are effectively wrapped and protected, so that the original chemical properties of the wrapped substances are protected without any damage, and then the functions of the target substances can be released when the functions are externally presented through certain external stimulation or slow release action. The coated submicron hollow microspheres can improve the stability of the product and prevent the mutual interference among various components. For example, the essence submicron hollow microspheres can wrap the essence and flavor in the submicron hollow microspheres to isolate the essence and flavor from the outside, thereby protecting the essence and flavor from the external environment and reducing the escape of the fragrance. When the essence submicron hollow microspheres are used, the essence submicron hollow microspheres in the carrier (toothpaste, laundry detergent, shower gel, shampoo and the like) are deposited on the surface of an object, the essence submicron hollow microspheres are broken through slight friction, and the essence in the carrier slowly releases fragrance, so that the effect of lasting fragrance is achieved.

The invention also provides a preparation method of the aromatic-containing submicron hollow microsphere, which does not need any complicated step of removing the core; the invention is based on the existing thermodynamically stable TPMS-water Pickering emulsion system, and volatile oil PEA is taken as a hydrophobic core; after TPM polymerization, the hydrophobic property is strongerPEA forms the liquid nucleus; the liquid core is removed after evaporation to form a hollow structure; silica particles (25nm, 12nm and 7nm) of different sizes were also used as particle stabilizers in this study to change the surface roughness of the resulting submicron hollow microspheres; BET result shows that the shell layer of the hollow particle is in a mesoporous structure and has specific surface area>400m²·g^-1And the submicron hollow microspheres have good dispersibility in water. Because the microspheres have large hydrophobic cavities in the middle, the microsphere can be used as a good colloidal collector for hydrophobic pollutants in water (the adsorption capacity of toluene in water is at least 1.25 mL-g^-1)。

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a TEM image of hollow particles made with TM40 as stabilizer and different PEA addition amounts: (a)0mL, (b)1.0mL, (c)2.0mL, and (d)3.0 mL;

figure 2 is a TEM image of submicron hollow microspheres of different TPM content using TM40 as a particle stabilizer: (a)0.5mL, (b)1.0mL, and (c)1.5 mL;

FIG. 3 is SEM and TEM images of submicron hollow microspheres with silica particles of different particle sizes as particle stabilizers (a, d) TM40(25nm) (Table 1, t 3); (b, e) HS40(12nm) (table 1, h 1); and (c, f) SM30(7nm) (Table 1, s 1); inset d-f is an enlarged view of the product;

FIG. 4 is an SEM and TEM image of the hollow microspheres of FIG. 3 after HF etching: (a, d) TM40(25nm), (b, e) HS40(12nm), and (c, f) SM30(7 nm); inset d-f is an enlarged view;

FIG. 5 shows UV spectra of toluene solution in water before and after hollow particle adsorption.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance, and furthermore, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As shown in figures 1-5 of the drawings,

a fragrance-containing submicron hollow microsphere, the inside of which is filled with a fragrance filler; the submicron hollow microsphere is a hollow structure with silicon dioxide as a shell; the fragrance filling is filled inside the case.

In this embodiment, the perfume filler is a perfume and an active material, and the filling method of the perfume filler includes the following steps:

s1: dissolving the hollow nano microspheres into water until the hollow nano microspheres are saturated to obtain a mixed solution;

s2: dispersing the aromatic filler into the mixed solution in the step S1, and filling the aromatic filler into the hollow nano-microspheres

A preparation method of submicron hollow microspheres containing aromatic comprises the following steps:

In this example, the ratio of silica to water in step S1 was 0.225: 40.

In this embodiment, the ratio of TPM to PEA in step S2 is 1: 3; the stirring time was 24 h.

In this example, the ratio of TPM and PEA to water in step 1 was 0.5:1.5: 40.

In this example, the reaction temperature of the polymerization reaction in step S3 was 70 ℃ and the reaction time was 24 hours.

In this embodiment, the ratio of KPS to water is 1: 4.

The material of this example was purchased from isoamyl acetate (PEA) from beijing chemical plant; 3- (trimethoxysilyl) propyl methacrylate (TPM) and potassium persulfate (KPS) from Alfa; purchased from Sigma-Aldrich

TM-40 colloidal silica (25nm), HS40(12nm), and SM30(7 nm); all materials were used as received; pure water was prepared using the ElgaPurelab system with a resistance greater than 18.2 M.OMEGA.cm.

The method for synthesizing the submicron hollow microsphere comprises the following steps: the mass fraction is 40 wt%

Aqueous silica dispersion (0.225 g of silica in colloidal dispersion per 0.56 mL) was added to water (40mL) and then a mixture of TPM (0.5mL) and PEA (1.5mL) was added to the dispersion; gently stirring the formed emulsion; stirring for 24h, then carrying out bubbling deoxygenation for 30min by using nitrogen, then heating to 70 ℃, adding KPS (10mg) to initiate polymerization, carrying out reaction at 70 ℃ for 24h, centrifuging for 3 times at 12000 r/min, and then washing by using ethanol; finally, the final product is dispersed in water or freeze-dried for later use.

Adsorption and emulsification of toluene in Water toluene (25. mu.L, 100. mu.L, 500. mu.L and 1000. mu.L) was added to 3mL of water containing 20mg of hollow particles; equilibrating the mixture on a tumbling machine for 12h to allow for absorption in a sealed glass bottle; the toluene content was determined by means of an ultraviolet spectrophotometer.

Characterization Transmission Electron Microscopy (TEM) was performed on a JEM2200FS Electron microscope (200kV) and a JEM2011 Electron microscope (200kV) in Jierou (JEOL); scanning Electron Microscopy (SEM) on a jealow JSM6700 electron microscope; uv spectroscopy on TU 1901; the average particle size and particle size dispersion of the nanoparticles were measured by Dynamic Light Scattering (DLS) using a malvern zetasizer nano. Specific surface area and porosity were measured by ASAP2020 nitrogen adsorption; before measurement, the sample is degassed at 100 ℃ for 12h, and the BET specific surface area is calculated by using adsorption data in a relative pressure range of P/P0-0.01-0.99; the total pore volume was estimated from the adsorption amount at a relative pressure (P/P0) of 0.97.

According to the above experiment, after the synthesis and the characteristic of the submicron hollow microsphere are completely hydrolyzed, the interfacial tension of TPM and water can be as low as 3 mN.m^-1Far lower than the common oil-water interfacial tension by 50 mN.m^-1So that a thermodynamically stable fine Pickering emulsion can be formed. However, in the absence of colloidal particles, only large droplets of TPM were observed in the experiment, indicating that the interfacial tension between water and TPM was not low enough, probably due to the low degree of hydrolysis of TPM in the design of the experiment. Thus, after polymerization, TPM agglomerates are obtained, rather than colloidal particles. When a mixture of PEA and TPM is added to dioxygenWhen in colloidal silica dispersion, under the action of Pickering effect, the silica particles play a role in stabilizing PEA-TPM droplets, thereby forming smaller emulsion droplets. Due to the high affinity of TPM to silica, the silica particles are primarily in contact with the TPM molecules in the composite emulsion droplets, thereby minimizing the total interfacial energy. Several formulations were tested using different sized silica particles in this study and the results are shown in table 1.

TABLE 1

The effect of different amounts of PEA (0, 1mL, 2mL, 3mL and 4mL) on the product structure with TM40 as a particle stabilizer was investigated while the content of other components remained unchanged (see Table 1, t1-t 5; FIG. 1). In the absence of PEA, the experiment yielded homogeneous raspberry-like solid particles, with silica particles embedded on the surface, similar to the previous report (fig. 1 a). When the amount of PEA was increased from 1mL to 3mL, the total particle size and polydispersity index of the composite particles increased. When the amount of PEA used was 1mL, the hollow structure became apparent (FIG. 1 b). The larger the amount of PEA used, the more pronounced the hollow structure (fig. 1 c). When the amount of PEA was 3mL, the hollow particles were still observed, but the particle size of the hollow particles was much larger (> 1 μm diameter) and many free silica particles were found to be present at the same time (see fig. 1d), indicating that it is no longer a thermodynamically stable conventional Pickering emulsion, since the size of conventional Pickering emulsions is typically in the micrometer range. When the amount of PEA exceeds 3mL, a stable emulsion can no longer be obtained. Therefore, no single particle is produced after polymerization. The above observations prove that the experiment is reasonable, because the interfacial tension between the PEA-TPM mixture and water is correspondingly increased with the increase of the PEA dosage, the standard of thermodynamically stable Pickering emulsion can not be satisfied any more; the experiment predicts that the product should be converted into a kinetically stable Pickering emulsion.

In the above experiment, the shell thickness was almost the same (about 30nm) regardless of the ratio of PEA to TPM, indicating that the content of TPM is a major factor in determining the shell thickness of the hollow particle. Then, the effect of TPM content on shell layer thickness was investigated in this study using TM40 as particle stabilizer with different amounts (0.5mL, 1.0mL and 1.5mL) of TPM (tables 1, t3, t6 and t 7). The results are shown in FIG. 2. As the amount of TPM increases, the shell of the hollow particle becomes thicker (fig. 2 a-c). When the TPM is used in an amount of 0.5mL, the thickness of the shell layer is about 30 nm. When the TPM level was increased to 1.0mL, the shell layer became nearly 40nm thick even using two different sized colloidal silica particles HS40 (table 1, h1) and SM30 (table 1, s1) as particle stabilizers. When the amount of TPM was further increased to 1.5mL, the shell thickness was about 50 nm. The above experimental results seem to justify the speculation that the colloidal silica particles in the composite Pickering emulsion are primarily in contact with the TPM. This is consistent with results derived from thermodynamic aspects, by way of inference. Thus, the polymerized PTPM constitutes a shell layer together with the silica particles by TEM observation (fig. 1 and 2).

The test uses colloidal silica particles of constant size as a stabilizer to test the versatility of the preparation method of such hollow particles. Fig. 3 shows typical TEM and SEM images of the synthesized submicron hollow microspheres. As can be seen from the above figure, the particle has a large hollow core and a thin shell (FIGS. 3 a-c). The shell contains fine silica particles. According to the SEM images (FIGS. 3d-f), the silica particles were partially exposed on the surface, making the surface quite rough. When silica particles of different sizes are added, the surface roughness of the hollow particles can be adjusted to a certain extent (fig. 3d-f), which is of great technical significance for controlling the surface-related adsorption process.

For TM40 silica particles containing 0.5mLTPM (table 1, t3), the shell thickness was approximately 30nm, approximately equal to the diameter of the TM40 silica particles, so the shell should be a single layer of TM40 silica particles (fig. 3 a). After HF etching, hollow particles with through channels on the shell are obtained by a sacrificial template method (figures 4a, d). For the HS40 and SM30 silica particles, higher TPM to silica ratios were required to form stable emulsions due to the larger specific surface area of the small silica particles (table 1, h1 and s1), where shell thicknesses of about 40nm (fig. 3b, c) were found to be much thicker than the corresponding silica particles; thus, only a few indentations, not through channels, were found on the surface of the hollow particles after etching with HF (fig. 4b, c, e, f).

The specific surface areas of the resulting hollow particles (FIG. s1) are summarized in Table 2, and are each greater than 400m²·g^-1. The specific surface area of TM40 particle is only 120m²·g^-1The large increase in specific surface area indicates the formation of mesoporous structures in the shell, probably due to hydrolysis-polycondensation (similar to the-gel process) and TPM polymerization, forming a crosslinked network with pores. From the thermogravimetric analysis curve, it can be seen that after heating to 500 ℃ in air (graph S2), all of the organic fraction was consumed, losing nearly 40 wt%. After calcination at 500 ℃ the hollow structure remained good (FIG. S3), but the specific surface area decreased somewhat (Table 2, TM-500 ℃). In contrast to the etching results (table 2, TM and TM-etching), it can be speculated that the porous structure is mainly supported by the organic moiety. When the organic portion is consumed by heating, the mesoporous structure is no longer present, resulting in a decrease in specific surface area. Although the HF etch consumes only the silica portion, the mesoporous structure remains unchanged and it is observed that the increase in specific surface area may be due to more pores being created by the lost silica portion.

TABLE 2

The adsorption and emulsification of toluene in water takes PEA as a core and silicon dioxide as a shell, and the prepared hollow particles should have hydrophobic cavities and amphiphilic surfaces. These hollow particles are well dispersed in water and are therefore potentially good collectors of organic contaminants dissolved in water. The results are shown in FIG. 5, using a saturated toluene aqueous solution as a model system. Most of toluene in the aqueous solution was adsorbed as seen from the change of characteristic absorption peak of toluene around 260nm before and after the absorption.

The resulting hollow particles were also found experimentally to be good particle emulsifiers, probably because of the amphiphilicity of the silicate and polymer moieties at the surface. When the amount of toluene exceeds the amount of toluene in the hollow coreThe adsorption capacity of the particles results in a separate milky phase, and the toluene droplets are stabilized by the hollow particles. The absorption capacity of the hollow particles should not be less than 1.25 mL-g^-1Since no separate milky phase is observed at this composition, only colloidal dispersion is observed. This is a relatively high loading, much greater than monolayer adsorption of toluene molecules, indicating that the large cavity in the middle of the hollow particle is a good advantage for its application as a colloidal adsorbent. After removing the hollow particles by centrifugation, almost no toluene residue was found from the appearance. With further increase in the amount of toluene added, the toluene-water-hollow particle mixture was emulsified with only slight shaking. When left undisturbed for a few minutes, a separate milky phase (pinkish) was observed floating on the colorless aqueous phase. However, once the toluene content exceeded 1mL, a separate oil phase was observed, with an aqueous phase at the bottom and a milky phase in the middle. The internal phase of the emulsion is expected to be up to 50% by volume of the emulsion. With further increase in the amount of toluene, no phase inversion was observed, indicating that the hollow particles still have strong hydrophilicity.

The present study therefore devised a method for the preparation of fragrance-containing submicron hollow microspheres without any complicated core removal step. The method is based on the existing thermodynamically stable TPMS-water Pickering emulsion system, and volatile oil PEA is used as a hydrophobic core. After polymerization of TPM, the more hydrophobic PEA forms a liquid core. The liquid core is removed after evaporation, forming a hollow structure. Silica particles of varying sizes (25nm, 12nm and 7nm) were also used in this study as particle stabilizers to modify the surface roughness of the resulting submicron hollow microspheres. BET result shows that the shell layer of the hollow particle is in a mesoporous structure and has specific surface area>400m²·g^-1And the submicron hollow microspheres have good dispersibility in water. Because the microspheres have large hydrophobic cavities in the middle, the microsphere can be used as a good colloidal collector for hydrophobic pollutants in water (the adsorption capacity of toluene in water is at least 1.25 mL-g^-1)。

All other embodiments, which can be derived from the embodiments of the present invention by a person skilled in the art without any creative effort, should be included in the protection scope of the present invention.

Claims

1. A submicron hollow microsphere containing aromatic, characterized in that: the silicon dioxide gel particle; the shell layer is provided with a hydrophobic inner surface and a hydrophilic outer surface, and a hollow inner cavity defined by the hydrophobic inner surface is filled with aromatic filler.

2. The fragrance-containing submicron hollow microsphere of claim 1, characterized in that: the particle size of the submicron hollow microsphere is 100-300 nanometers, and a nanometer pore channel is formed in the shell layer; the shell layer is obtained by emulsion polymerization of raw materials comprising silicon dioxide colloid particles, a thermodynamically stable Pickering emulsion system is adopted in the emulsion polymerization, and a template is volatile isoprene acetate; the emulsion in the emulsion polymerization comprises a silane coupling agent, silica colloid particles and isoamyl acetate; the mass ratio of the volatile solvent to the silane coupling agent is 1: l-6: 10, and the mass ratio of the silica colloid particles to the silane coupling agent is 1: 2-1: 14; the silane coupling agent is methoxy silane or ethoxy silane with a double-bond structure;

the preparation method of the submicron hollow microsphere comprises the following steps:

3. The fragrance-containing submicron hollow microsphere of claim 2, characterized in that: the preparation method of the submicron hollow microsphere comprises the following steps:

4. The fragrance-containing submicron hollow microsphere of claim 1, characterized in that: the ratio of silica to water in step S1 was 0.225: 40.

5. The fragrance-containing submicron hollow microsphere of claim 1, characterized in that: in step S2, the ratio of TPM to PEA is 1: 3; the stirring time was 24 h.

6. The fragrance-containing submicron hollow microsphere of claim 5, characterized in that: the ratio of TPM and PEA to water in step 1 was 0.5:1.5: 40.

7. The fragrance-containing submicron hollow microsphere of claim 1, characterized in that: the reaction temperature of the polymerization reaction in step S3 was 70 ℃ and the reaction time was 24 hours.

8. The fragrance-containing submicron hollow microsphere of claim 5, characterized in that: the ratio of KPS to water is 1: 4.