METHOD FOR SYNTHESIZING MAGADIITE/PMMA NANO COMPOSITE MICROSPHERES BY USING PH VALUE REGULATION IN PICKERING EMULSION

Abstract

The disclosure discloses a method for synthesizing magadiite/PMMA nano composite microspheres by using pH value regulation in a Pickering emulsion. According to the method, organic modified magadiite is used as an emulsifier, deionized water of which a pH value is regulated with a buffer solution is used as a solvent, and a methylmethacrylate monomer is used as an oil phase of a Pickering emulsion; stirring is performed to form the stable Pickering emulsion, and then a water-soluble free-radical initiator is added to initiate emulsion polymerization, thereby synthesizing magadiite/PMMA nano composite microspheres.

Claims

1. A method for synthesizing magadiite/PMMA nano composite microspheres by using pH value regulation in a Pickering emulsion, wherein the method comprises the following steps: step 1: adding a deionized water into a reaction container, adding a buffer solution to regulate a pH value, then adding an organic modified magadiite, and stirring and heating to 50° C. to 80° C., so that the organic modified magadiite is uniformly dispersed in the water; step 2: cooling to 30° C. to 40° C., adding a methylmethacrylate monomer, and continuously stirring to form a uniform and stable Pickering emulsion; and step 3: heating the Pickering emulsion to 60° C. to 90° C., adding a water-soluble free-radical initiator, heating and keeping a temperature at 80° C. to 90° C., reacting for 3 hours to 5 hours, cooling to a temperature lower than 50° C., stopping stirring, drying in vacuum and grinding to obtain the magadiite/PMMA nano composite microspheres.

2. The method according to claim 1, wherein in the step 1, a mass of the deionized water accounts for 50 wt % to 90 wt % of a total mass of the Pickering emulsion.

3. The method according to claim 1, wherein in the step 1, the buffer solution is an HCl solution or a sodium bicarbonate solution.

4. The method according to claim 1, wherein in the step 1, the pH value is regulated between 3.0 and 11.0.

5. The method according to claim 1, wherein in the step 1, the organic modified magadiite comprises one of magadiite modified by quaternary ammonium salt, quaternary phosphonium salt or silane.

6. The method according to claim 1, wherein in the step 1, a dosage of the organic modified magadiite is 0.01 wt % to 1 wt % of a mass of the methylmethacrylate monomer.

7. The method according to claim 1, wherein in the step 3, the water-soluble free-radical initiator comprises persulfate; and the persulfate comprises potassium persulfate, sodium persulfate or ammonium persulfate.

8. The method according to claim 1, wherein in the step 3, a dosage of the water-soluble free-radical initiator is 0.1 wt % to 0.5 wt % of a mass of the methylmethacrylate monomer.

9. The method according to claim 1, wherein the magadiite/PMMA nano composite microspheres have a particle size ranging from 200 nm to 1000 nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Brief Description of the Drawings

[0026] FIG. 1 is an infrared spectrogram of magadiite modified by dodecyltrimethylammonium bromide in Embodiment 1;

[0027] FIG. 2 is an infrared spectrogram of magadiite/PMMA nano composite microspheres synthesized in Embodiment 1;

[0028] FIG. 3 is an SEM of the magadiite/PMMA nano composite microspheres synthesized in Embodiment 1;

[0029] FIG. 4 is an SEM of magadiite/PMMA nano composite microspheres synthesized in Embodiment 2;

[0030] FIG. 5 is an SEM of magadiite/PMMA nano composite microspheres synthesized in Embodiment 3.

DESCRIPTION OF THE EMBODIMENTS

Description of the Embodiments

[0031] The technical solution of the present disclosure is further described in detail hereinafter with reference to the specific embodiments and the accompanying drawings, but the scope of protection and the implementations of the present disclosure are not limited to this.

Embodiment 1

[0032] A method for synthesizing magadiite/PMMA nano composite microspheres by using pH value regulation in a Pickering emulsion included the following steps.

[0033] (1) Deionized water accounting for 50% of a total mass of an emulsion was added into a three-necked flask, a pH value was regulated to 3.0 by a dilute hydrochloric acid buffer solution with a concentration of 0.01 mol/L, and then magadiite modified by dodecyltrimethylammonium bromide and accounting for 0.01% of a methylmethacrylate monomer (an infrared spectrogram was shown in FIG. 1) was added, stirred, and heated to 50° C. to uniformly disperse the organic modified magadiite in the water.

[0034] (2) The solution was cooled to 30° C., and added with 50 g of methylmethacrylate monomer; then, the mixed solution was continuously stirred with a mechanical impeller to enable the mixed solution to form a uniform and stable Pickering emulsion, which was white and milky without precipitates.

[0035] (3) The Pickering emulsion was heated to 60° C., then 0.05 g of ammonium persulfate was weighed and added into the flask through a constant pressure dropping funnel. A container was washed with deionized water after dropping, and the mixture was added into the flask. The mixture was heated to 80° C., continued to react for 3 hours, and then cooled. When a temperature of a reaction material was lower than 50° C., stirring was stopped, and a product was discharged. An infrared spectrogram of the product was shown in FIG. 2. A wave peak at 3400 cm.sup.−1 was a characteristic peak of Si—OH in magadiite, and wave peaks at 3003 cm.sup.−1, 2953 cm.sup.−1 and 2839 cm.sup.−1 were stretching vibration peaks of methyl and methylene. A wave peak at 1734 cm.sup.−1 was a stretching vibration characteristic peak of C═O. Wave peaks at 1488 cm.sup.−1 and 1447 cm.sup.−1 were bending vibration peaks of C—H. Wave peaks at 1281 cm.sup.−1, 1244 cm.sup.−1, 1197 cm.sup.−1 and 1150 cm.sup.−1 were stretching vibration absorption peaks of C—O—C, with a peak width covering an absorption peak of the magadiite at 1000 cm.sup.−1. Wave peaks at 1067 cm.sup.−1 and 844 cm.sup.−1 were respectively antisymmetric and symmetric stretching vibration peaks of Si—O—Si, and a wave peak at 478 cm.sup.−1 was a bending vibration absorption peak of Si—O. The above confirmed that the magadiite/PMMA composite microspheres were obtained. The materials were dried in vacuum and grinded to obtain the magadiite/PMMA nano composite microspheres.

[0036] FIG. 3 shows a Scanning Electron Microscope (SEM) image of the synthesized magadiite/PMMA nano composite microspheres. It can be seen from FIG. 3 that the synthesized magadiite/PMMA nano composite microspheres have uniform sizes ranging from 200 nm to 210 nm.

Embodiment 2

[0037] A method for synthesizing magadiite/PMMA nano composite microspheres by using pH value regulation in a Pickering emulsion included the following steps.

[0038] (1) Deionized water accounting for 70% of a total mass of an emulsion was added into a three-necked flask, a pH value was regulated to 6.0 by a sodium bicarbonate buffer solution with a concentration of 0.01 mol/L and a dilute hydrochloric acid buffer solution with a concentration of 0.01 mol/L, and then magadiite modified by hexadecyltriphenylphosphonium bromide and accounting for 0.5% of a methylmethacrylate monomer was added, stirred, and heated to 65° C. to uniformly disperse the organic modified magadiite in the water.

[0039] (2) The solution was cooled to 35° C., and added with 50 g of methylmethacrylate monomer; then, the mixed solution was continuously stirred with a mechanical impeller to enable the mixed solution to form a uniform and stable Pickering emulsion, which was white and milky without precipitates.

[0040] (3) The Pickering emulsion was heated to 75° C., then 0.15 g of ammonium persulfate was weighted and added into the flask through a constant pressure dropping funnel. A container was washed with deionized water after dropping, and the mixture was added into the flask. The mixture was heated to 85° C., continued to react for 3 hours, and then cooled. When a temperature of a reaction material was lower than 50° C., stirring was stopped, and a product was discharged. The materials were dried in vacuum and grinded to obtain the magadiite/PMMA nano composite microspheres.

[0041] FIG. 4 shows a SEM image of the synthesized magadiite/PMMA nano composite microspheres. It can be seen from FIG. 4 that the synthesized magadiite/PMMA nano composite microspheres have uniform sizes ranging from 410 nm to 420 nm.

Embodiment 3

[0042] A method for synthesizing magadiite/PMMA nano composite microspheres by using pH value regulation in a Pickering emulsion included the following steps.

[0043] (1) Deionized water accounting for 90% of a total mass of an emulsion was added into a three-necked flask, a pH value was regulated to 11.0 by a sodium bicarbonate buffer solution with a concentration of 0.01 mol/L, and then magadiite modified by γ-aminopropyltriethoxysilane and accounting for 1% of a methylmethacrylate monomer was added, stirred, and heated to 80° C. to uniformly disperse the organic modified magadiite in the water.

[0044] (2) The solution was cooled to 40° C., and added with 50 g of methylmethacrylate monomer; then, the mixed solution was continuously stirred with a mechanical impeller to enable the mixed solution to form a uniform and stable Pickering emulsion, which was white and milky without precipitates.

[0045] (3) The Pickering emulsion was heated to 90° C., then 0.25 g of ammonium persulfate was weighed and added into the flask through a constant pressure dropping funnel. A container was washed with deionized water after dropping, and the mixture was added into the flask. The mixture was heated to 90° C., continued to react for 3 hours, and then cooled. When a temperature of a reaction material was lower than 50° C., stirring was stopped, and a product was discharged. The materials were dried in vacuum and grinded to obtain the magadiite/PMMA nano composite microspheres.

[0046] FIG. 5 shows a SEM image of the synthesized magadiite/PMMA nano composite microspheres. It can be seen from FIG. 5 that the synthesized magadiite/PMMA nano composite microspheres have uniform sizes ranging from 900 nm to 1000 nm.

[0047] The above embodiments are the preferred embodiments of the present disclosure, but the embodiments of the present disclosure are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present disclosure shall be equivalent substitute modes, and shall be included in the scope of protection of the present disclosure.