MESOPOROUS SILICA WRAPPED NANOPARTICLE COMPOSITE MATERIAL, PREPARATION METHOD THEREOF, AND USE THEREOF

Abstract

The present disclosure relates to mesoporous silica wrapped nanoparticle composite nanomaterial, preparation method thereof, and use thereof. In the present disclosure, a nanoparticle is dispersed in an aqueous ethanol solution. Then, ammonia water is added to adjust the pH. After that, cetyltrimethylammonium bromide in an aqueous ethanol solution is added dropwise, and ultrasound is continued, before tetraethyl orthosilicate is added dropwise. The mixture is purified to produce a composite nanomaterial that is stable, controllable, and consistent in size; the shell of the composite nanomaterial is mesoporous silica, the core of the composite nanomaterial is a nanoparticle. Dual-core or triple-core nanoparticles of different kinds/functions can be wrapped into a single mesoporous silica shell to achieve multi-core wrapping. The method is universal and may be used to wrap various nanometers. The preparation procedure is environmentally friendly, efficient, and may be carried out at room temperature.

Claims

1. A method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following procedures: (1) dispersing a nanoparticle in an aqueous ethanol solution, then adding ammonia water and stirring thoroughly to obtain solution A; dissolving cetyltrimethylammonium bromide in an identical aqueous ethanol solution to obtain solution B; (2) adding solution B dropwise to solution A under ultrasound, and then continue performing ultrasound to obtain solution C; (3) adding tetraethyl orthosilicate dropwise to solution C, followed by consecutive stirring, solid-liquid separation and purification to obtain the composite nanomaterial; wherein the nanoparticle has a particle size of 1-20 nm.

2. The method according to claim 1, wherein in the aqueous ethanol solution, a volume ratio of ethanol to water is 1:3-4.

3. The method according to claim 1, wherein solution A has a pH of 9-10.

4. The method according to claim 1, wherein a ratio of mass of the cetyltrimethylammonium bromide to a specific surface area of the nanoparticle is 1 mg-3 mg: 10.sup.14 nm.sup.2-10.sup.17 nm.sup.2.

5. The method according to claim 1, wherein a volume ratio of solution B to solution A is 1:9.

6. The method according to claim 1, wherein in step (2), the cetyltrimethylammonium bromide has a concentration of 30 mg/mL in solution B, the ultrasound is continued for at least 30 minutes.

7. The method according to claim 1, wherein in step (3), a ratio of the tetraethyl orthosilicate to the cetyltrimethylammonium bromide is 1 mL:5 g, the stirring is performed for 12 h.

8. A composite nanomaterial prepared by the method according to claim 1.

9. A composite nanomaterial prepared by the method according to claim 2.

10. A composite nanomaterial prepared by the method according to claim 3.

11. A composite nanomaterial prepared by the method according to claim 4.

12. A composite nanomaterial prepared by the method according to claim 5.

13. A composite nanomaterial prepared by the method according to claim 6.

14. A composite nanomaterial prepared by the method according to claim 7.

15. The composite nanomaterial according to claim 8, wherein the composite nanomaterial has a particle size of 50-80 nm.

16. The composite nanomaterial according to claim 9, wherein the composite nanomaterial has a particle size of 50-80 nm.

17. The composite nanomaterial according to claim 10, wherein the composite nanomaterial has a particle size of 50-80 nm.

18. The composite nanomaterial according to claim 11, wherein the composite nanomaterial has a particle size of 50-80 nm.

19. The composite nanomaterial according to claim 12, wherein the composite nanomaterial has a particle size of 50-80 nm.

20. The composite nanomaterial according to claim 13, wherein the composite nanomaterial has a particle size of 50-80 nm.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0034] FIG. 1 is a process flow diagram of the preparation method of the present disclosure.

[0035] FIGS. 2A-2L are TEM (Transmission Electron Microscope) images of four of the mesoporous silica wrapped nanoparticle composite nanomaterials prepared according to the preparation method of the present disclosure and their corresponding nanoparticles. Scale bars for these images are all 100 nm. FIG. 2A is the TEM image of Gd.sub.2O.sub.3NPs; FIGS. 2B and 2C are the TEM images of SiO.sub.2@Gd.sub.2O.sub.3NPs; FIG. 2D is the TEM image of Fe.sub.3O.sub.4NPs; FIGS. 2E and 2F are the TEM images of SiO.sub.2@Fe.sub.3O.sub.4NPs; FIG. 2G is the TEM image of UCNPs; FIGS. 2H and 2I are the TEM images of SiO.sub.2@UCNPs; FIG. 2J is the TEM image of CeO.sub.2NPs; FIGS. 2K and 2L are the TEM images of SiO.sub.2@CeO.sub.2NPs.

[0036] FIGS. 3A-3B are TEM images and elemental analysis spectra of one of the mesoporous silica wrapped nanoparticle composite nanomaterials prepared according to the preparation method of the present disclosure. FIG. 3A shows representative TEM images (left: scale bar 100 nm, right: scale bar 20 nm) of double-core nanocomposites combining superparamagnetic metal oxide NPs (Fe.sub.3O.sub.4) and metallic NPs (AgNPs) in the same mesoporous silica shell. FIG. 3B shows representative TEM and High Angle Annular Dark Field (HAADF) and the elemental mapping of the different elements (O, Si, Fe and Ag).

[0037] FIGS. 4A-4D are TEM images and elemental analysis spectra of one of the mesoporous silica wrapped nanoparticle composite nanomaterials prepared according to the preparation method of the present disclosure. FIG. 4A is a representative TEM image of double core nanocomposites combining metallic NPs (AuNPs) and anti-inflammatory metal oxide NPs (CeO.sub.2NPs). FIG. 4B is a higher magnification TEM image of one of the nanocomposites. FIG. 4C is a representative HAADF image. In this case, the AuNPs can also be easily distinguished as brighter NPs in the HAADF image owing to the higher density of Au. FIG. 4D is the overlap of the elemental mapping of the different elements (Si, Ce and Au). The scale bars for FIGS. 4A-D are all 100 nm.

[0038] FIG. 5A shows the key factors affecting the preparation of SiO.sub.2@CeO2NPs according to the preparation method of the present disclosure; FIG. 5B shows the TEM images of the SiO.sub.2@CeO.sub.2NPs (scale bar: 50 nm); FIG. 5C shows the effect of different parameters on the structure and morphology of SiO.sub.2@CeO.sub.2NPs; FIG. 5D shows the effect of varying volume ratios of ethanol to water in the ethanol aqueous solution on the size of SiO.sub.2@CeO.sub.2NPs (scale bar: 100 nm).

DETAILED DESCRIPTION OF EMBODIMENTS

[0039] The present disclosure will be further explained below with reference to the embodiments in order to more clearly demonstrate the technical solutions, embodiments, and beneficial effects of the present disclosure.

Embodiment 1

[0040] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following steps:

[0041] (1) dispersing Gd.sub.2O.sub.3NPs (particle size 4 nm, TEM diagram shown in FIG. 2A) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10 (the specific surface area of the nanoparticles are calculated according to their particle sizes; for the ratio of mass of CTAB (cetyltrimethylammonium bromide) to the specific surface area of the nanoparticles to be 3 mg: 10.sup.17 nm.sup.2, the concentration of Gd.sub.2O.sub.3NPs in solution A should be 0.5 mg/mL); adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0042] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0043] (3) adding TEOS (tetraethyl orthosilicate) dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@Gd.sub.2O.sub.3NPs, its TEM diagrams are shown in FIGS. 2B and 2C.

Embodiment 2

[0044] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following steps:

[0045] (1) dispersing Fe.sub.3O.sub.4NPs (particle size 7 nm, TEM diagram shown in FIG. 2D) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10 (the specific surface area of the nanoparticles are calculated according to their particle sizes; for the ratio of mass of CTAB to the specific surface area of the nanoparticles to be 3 mg: 10.sup.17 nm.sup.2, the concentration of Fe.sub.3O.sub.4NPs in solution A should be 0.6 mg/mL); adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0046] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0047] (3) adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@Fe.sub.3O.sub.4NPs, its TEM diagrams are shown in FIGS. 2E and 2F.

Embodiment 3

[0048] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial of the present disclosure, comprising the following steps:

[0049] (1) dispersing UCNPs (that is, Tm.sup.3+ co-doped NaYF.sub.4 nanocrystals, Tm.sup.3+ upconversion nanophosphors; particle size 15 nm, TEM diagram shown in FIG. 2G) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10 (the specific surface area of the nanoparticles are calculated according to their particle sizes; for the ratio of mass of CTAB to the specific surface area of the nanoparticles to be 3 mg: 10.sup.17 nm.sup.2, the concentration of UCNPs in solution A should be 1.5 mg/mL); adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0050] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0051] (3) adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@UCNPs, its TEM diagrams are shown in FIGS. 2H and 2I.

Embodiment 4

[0052] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following steps:

[0053] (1) dispersing CeO.sub.2NPs (particle size 12 nm, TEM diagram shown in FIG. 2J) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10 (the specific surface area of the nanoparticles are calculated according to their particle sizes; for the ratio of mass of CTAB to the specific surface area of the nanoparticles to be 3 mg: 10.sup.17 nm.sup.2, the concentration of CeO.sub.2NPs in solution A should be 1.5 mg/mL); adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0054] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0055] (3) adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@CeO.sub.2NPs, its TEM diagrams are shown in FIGS. 2K and 2L.

Embodiment 5

[0056] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following steps:

[0057] (1) dispersing AgNPs (particle size 10 nm) and Fe.sub.3O.sub.4NPs (particle size 7 nm) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10, a AgNPs concentration of 0.05 mg/mL, a Fe.sub.3O.sub.4NPs concentration of 0.6 mg/mL; adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0058] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9, the ratio of mass of CTAB to the total specific surface area of AgNPs and Fe.sub.3O.sub.4NPs is 3 mg: 10.sup.17 nm.sup.2), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0059] (3) adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@AgNPs+Fe.sub.3O.sub.4NPs, its TEM diagrams and elemental analysis spectra are shown in FIGS. 3A-3B.

Embodiment 6

[0060] This embodiment is an example of a method for preparing a mesoporous silica wrapped nanoparticle composite nanomaterial, comprising the following steps:

[0061] (1) dispersing AuNPs (particle size 10 nm), Fe.sub.3O.sub.4NPs (particle size 7 nm), and CeO.sub.2NPs (particle size 4 nm) in an aqueous ethanol solution (volume ratio of ethanol to water=1:4), then adding ammonia water and stirring for 30 min to obtain solution A having a pH of 10, a AuNPs concentration of 0.05 mg/mL, a Fe.sub.3O.sub.4NPs concentration of 0.3 mg/mL, a CeO.sub.2NPs concentration of 0.3 mg/mL; adding CTAB to an identical aqueous ethanol solution and stirring for 30 min to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL;

[0062] (2) adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9, the ratio of mass of CTAB to the total specific surface area of AuNPs, Fe.sub.3O.sub.4NPs, and CeO.sub.2NPs is 3 mg: 10.sup.17 nm.sup.2), and then continue performing the ultrasound for at least 30 minutes to obtain solution C;

[0063] (3) adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@AuNPs+Fe.sub.3O.sub.4NPs+CeO.sub.2NPs, its TEM diagrams and elemental analysis spectra are shown in FIGS. 4A-4D.

Embodiment 7

[0064] In this embodiment, the key influencing factors and optimal process conditions for the preparation of SiO.sub.2@CeO.sub.2NPs by the method of the present disclosure are examined. The preparation method under the optimal process conditions (as shown in FIG. 5A) is as follows: dispersing CeO.sub.2NPs (particle size 4 nm) in an aqueous ethanol solution, then adding ammonia water to adjust pH to obtain solution A with a CeO.sub.2NPs concentration of 0.6 mg/mL; adding CTAB to an identical aqueous ethanol solution to obtain solution B, wherein the concentration of CTAB in solution B is 30 mg/mL; adding solution B dropwise to solution A under ultrasound (volume ratio of solution B to solution A=1:9, the ratio of mass of CTAB to the total specific surface area of AgNPs and Fe.sub.3O.sub.4NPs is 3 mg: 10.sup.17 nm.sup.2), and then continue performing the ultrasound for at least 30 minutes to obtain solution C; adding TEOS dropwise to solution C at a ratio of TEOS:CTAB=1 mL:5 g, followed by 12 hours of stirring, then centrifuging, and washing the solid collected 3 times (each time, the solid is added to the washing liquid, mixed for half an hour, and then centrifuged to obtain the composite nanomaterial; the washing liquid is prepared from ammonium nitrate and ethanol at a ratio of ammonium nitrate:ethanol=2 g:100 mL). The composite nanomaterial is SiO.sub.2@CeO.sub.2NPs, its TEM diagrams are shown in FIG. 5B.

[0065] (a) When studying the effect of the ratio of the mass of CTAB to the specific surface area of CeO.sub.2NPs on SiO.sub.2@CeO.sub.2NPs, the other conditions were the same as the optimal process conditions. When the ratio of the mass of CTAB to the specific surface area of CeO.sub.2NPs was higher than 3 mg/10.sup.14 nm.sup.2 or lower than 1 mg/10.sup.17 nm.sup.2, the TEM diagrams of the SiO2@CeO.sub.2NPs obtained are respectively shown in FIG. 5C. When the ratio of the mass of CTAB to the specific surface area of the nanoparticles was greater than 3 mg/10.sup.14 nm.sup.2, some part of the nanoparticles was coated with silica and some part was not. It was difficult to control the size of the final material, the coating was uneven or unsuccessful. When the ratio of the mass of CTAB to the specific surface area of the nanoparticles was less than 1 mg/10.sup.17 nm.sup.2, the core-shell structure produced was not uniform, its size was uncontrollable, or the coating was unsuccessful.

[0066] (b) When studying the effect of pH of solution A on SiO.sub.2@CeO.sub.2NPs, the other conditions were the same as the optimal process conditions. The TEM diagrams of the SiO2 @ CeO2NPs obtained when the pH of solution A was greater than 10 or less than 9 are respectively shown in FIG. 5C.

[0067] (c) When studying the effect of the ratio of ethanol to water in the aqueous ethanol solution on SiO.sub.2@CeO.sub.2NPs, the other conditions were the same as the optimal process conditions. The TEM diagram of the SiO.sub.2@CeO.sub.2NPs obtained when the volume ratio of ethanol to water was less than 1/4 is shown in FIG. 5C. The TEM diagrams of the SiO.sub.2@CeO.sub.2NPs obtained when the volume ratios of ethanol to water were 2:8, 2.2:7.8, 2.5:7.5, or 3:7 are respectively shown in FIG. 5D. From the TEM diagrams of these SiO.sub.2@CeO.sub.2NPs, it can be concluded that when preparing SiO.sub.2@CeO.sub.2NPs, the ratio of the mass of CTAB to the specific surface area of CeO.sub.2NPs, the pH of solution A, and the volume ratio of ethanol to water in the aqueous ethanol solution should be moderate to avoid failure of wrapping the CeO.sub.2NPs or failure for SiO.sub.2 to form a uniform and stable spherical shape. In addition, during the research process, it was found that the volume ratio of ethanol to water in the aqueous ethanol solution is the main factor impacting SiO.sub.2@CeO.sub.2NPs. As shown in FIG. 5D, when the volume ratio of ethanol to water in the aqueous ethanol solution increases, the particle size of the SiO.sub.2@CeO.sub.2NPs produced increases.

[0068] It should be finally noted that the embodiments described above are only intended to illustrate the technical solutions of the present disclosure. They do not limit the scope of protection of the present disclosure. Those skilled in the art understand that various alterations and modifications can be carried out without departing from the spirit and scope of the present invention.