Core-shell structured anionic nano microemulsion system, and preparation and application thereof
The invention discloses a core-shell structured anionic nano microemulsion system, and preparation and application thereof. The system comprises an anionic Gemini surfactant, an oil phase material, a solubilizer and water; wherein the microemulsion has a core-shell structure, with the outer shell being an anionic Gemini surfactant, and the inner core being an oil phase material. The anionic Gemini surfactant is N,N,N′,N′-dodecyl tetrasubstituted diphenyl ether sulfonate having the structural formula: The anionic nano-microemulsion system of the present invention is homogeneous and transparent, has a spherical core-shell structure, has a nanometer size (3 to 40 nm) as droplets, has a narrow particle size distribution, is not easy to agglomerate, has good stability, and has an ultra-low interfacial tension and a capability of reducing viscosity of crude oil.
1. A core-shell structured anionic nano microemulsion system, wherein the system comprises: an anionic Gemini surfactant, an oil phase material, a solubilizer and water;
wherein the microemulsion has a core-shell structure, with the outer shell being the anionic Gemini surfactant, and the inner core being the oil phase material; and
the anionic Gemini surfactant is N,N,N′,N′-dodecyl tetrasubstituted diphenyl ether sulfonate having the structural formula:
2. The anionic nano microemulsion system according to claim 1 , wherein the microemulsion has a droplet size ranging from 5 to 300 nm.
3. The anionic nano microemulsion system according to claim 1 , wherein the microemulsion has an effective concentration of of 0.05 to 0.5%, wherein the effective concentration is the total concentration of the anionic Gemini surfactant, the oil phase material and the solubilizer.
4. The anionic nano microemulsion system according to claim 3 , wherein the anionic Gemini surfactant accounts for 5 to 77% by mass, the oil phase material accounts for 5 to 46% by mass, and the solubilizer accounts for 5 to 31% by mass.
5. The anionic nano microemulsion system according to claim 1 , wherein the oil phase material is selected from an aromatic hydrocarbon compound, a heterocyclic compound, and a terpene compound, or a combination thereof.
6. The anionic nano microemulsion system according to claim 5 , wherein the oil phase material is selected from xylene, pyrrolidone, menthol, alpha-pinene, beta-myrcene, limonene, or a combination thereof.
7. The anionic nano microemulsion system according to claim 1 , wherein the solubilizer is selected from one or more small molecule alcohol compounds.
8. The anionic nano microemulsion system according to claim 7 , wherein the solubilizer is selected from ethanol, propanol, isopropanol, ethylene glycol, butanol, pentanol, or a combination thereof.
9. The anionic nano microemulsion system according to claim 1 , wherein the anionic nano microemulsion system further comprises an inorganic salt.
10. The anionic nano microemulsion system according to claim 9 , wherein the inorganic salt has a mass content of 0 to 15%, excluding 0.
11. A preparation method for the anionic nano microemulsion system according to claim 1 , wherein the method comprises:
S1, mixing an anionic Gemini surfactant, an oil phase material, a solubilizer and water well, to obtain a homogeneous mixed solution; or
mixing an anionic Gemini surfactant, an oil phase material, and a solubilizer well, to obtain a homogeneous mixed solution; and
S2, diluting the homogeneous mixed solution using water or inorganic brine to a low concentration condition, to obtain the core-shell structured anionic nano microemulsion system.
12. The preparation method according to claim 11 , wherein the homogeneous mixed solution from S1 comprises by mass: 5 to 50% of the anionic Gemini surfactant, 5 to 30% of the oil phase material, 5 to 20% of the solubilizer, and water to balance.
13. The preparation method according to claim 11 , wherein the low concentration condition is that the effective concentration of the microemulsion is 0.05 to 0.5%.
14. The preparation method according to claim 11 , wherein the oil phase material is selected from an aromatic hydrocarbon compound, a heterocyclic compound, a terpene compound, or a combination thereof.
15. The preparation method according to claim 11 , wherein the oil phase material is selected from xylene, pyrrolidone, menthol, alpha-pinene, beta-myrcene, limonene, or a combination thereof.
16. The preparation method according to claim 11 , wherein the solubilizer is selected from ethanol, propanol, isopropanol, ethylene glycol, butanol, pentanol, or a combination thereof.
17. The preparation method according to claim 11 , wherein in S2, the inorganic salt brine is used for diluting, and the obtained anionic nano microemulsion system has an inorganic salt mass content of 0 to 15%, excluding 0.
18. The preparation method according to claim 11 , wherein the microemulsion in the anionic nano microemulsion system has a droplets size ranged from 5 to 300 nm.
19. The preparation method according to claim 11 , wherein the mixing and diluting are carried out under an agitation at 10 to 400 rpm.