HIGH INTERNAL PHASE EMULSION STABILIZED BY LOW CONTENT OF SURFACTANT AND PREPARATION METHOD THEREOF

Abstract

A high internal phase emulsion stabilized by a low content of surfactant and its preparation method thereof are provided. An oil ethoxylate is added to a vegetable oil, and the resulting mixture is uniformly mixed under a low-speed stirring at room temperature. Water is added dropwise to the mixture of surfactant and vegetable oil under stirring, and a homogenization is performed on the obtained dispersed system by a high-shear dispersion emulsification homogenizer to obtain the high internal phase emulsion stabilized by oil ethoxylate. The preparation method requires a low content of surfactant, mild preparation conditions and simple operations. When the oil-phase volume fraction is 83 vol %, the minimum mass fraction of the oil ethoxylate to stabilize the high internal phase emulsion is 0.6 wt %, and the prepared oil-in-water type high internal phase emulsion has excellent stability and shows bright color, delicate odor, hydra feel and being easy to apply.

Claims

1. A high internal phase emulsion stabilized by a low content of a surfactant, wherein the surfactant is an oil ethoxylate, and the oil ethoxylate accounts for 0.6-2.0 wt % of a total mass of the emulsion.

2. The high internal phase emulsion stabilized by a low content of a surfactant according to claim 1, wherein the oil ethoxylate comprises one or two selected from the group consisting of a palm kernel oil ethoxylate, a soybean oil ethoxylate, and a coconut oil ethoxylate, and when two of the palm kernel oil ethoxylate, the soybean oil ethoxylate and the coconut oil ethoxylate are selected, a ratio of the selected two oil ethoxylates is (0.5-2):(0.5-2).

3. A method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 1, comprising the following steps: (1) mixing the oil ethoxylate with a vegetable oil, and stirring at 10-50° C. until a resulting solution is mixed evenly; (2) adding water dropwise to the resulting solution of the oil ethoxylate and the vegetable oil under stirring to obtain a dispersed system; and (3) performing a homogenization on the obtained dispersed system by a high-shear dispersion emulsification homogenizer, to obtain the high internal phase emulsion.

4. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein the vegetable oil in step (1) is one selected from the group consisting of a soybean oil, a rapeseed oil, a coconut oil, an olive oil, a sunflower oil, a sesame oil, and a peanut oil.

5. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein a volume fraction of the vegetable oil in step (1) is 74-88 vol %.

6. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein process conditions in step (1) comprise: a temperature of 10-50° C., a speed of a low-speed stirring being 1000-4000 rpm, and a stirring time of 5-10 min.

7. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein a stirring speed in step (2) is 5000-8000 rpm, and the water is dropwise added to the resulting solution in step (1) at a speed of 0.4-0.8 mL/min.

8. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein the homogenization in step (3) is performed at 8000-12000 rpm for 8-15 min.

9. The method for preparing the high internal phase emulsion stabilized by a low content of a surfactant according to claim 3, wherein the high internal phase emulsion with an oil-phase volume fraction up to 74-86 vol % is obtained when the oil ethoxylate is used at an amount of 0.6-2.0 wt %.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] FIG. 1 shows an optical microscopy image of the freshly prepared HIPE obtained in Embodiment 1.

[0024] FIG. 2 shows an optical microscopy image of the HIPE obtained in Embodiment 1 after the emulsion is placed for one month.

[0025] FIG. 3 shows an optical microscopy image of the freshly prepared HIPE obtained in Embodiment 2.

[0026] FIG. 4 shows an optical microscopy image of the HIPE obtained in Embodiment 2 after the emulsion is placed for one month.

[0027] FIG. 5 shows an optical microscopy image of the freshly prepared HIPE obtained in Embodiment 3.

[0028] FIG. 6 shows an optical microscopy image of the HIPE obtained in Embodiment 3 after the emulsion is placed for one month.

[0029] FIG. 7 shows an optical microscopy image of the freshly prepared HIPE obtained in Embodiment 4.

[0030] FIG. 8 shows an optical microscopy image of the HIPE obtained in Embodiment 4 after the emulsion is placed for one month.

[0031] FIG. 9 shows an optical microscopy image of the freshly prepared HIPE obtained in Embodiment 5.

[0032] FIG. 10 shows an optical microscopy image of the HIPE obtained in Embodiment 5 after the emulsion is placed for one month.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The invention is further illustrated by the following embodiments, but is not limited thereto.

Embodiment 1

[0034] The embodiment 1 of the invention provides a method for preparing a HIPE stabilized by an oil ethoxylate, including the following steps:

[0035] (1) a palm kernel oil ethoxylate with a mass fraction of 1.0% is weighed;

[0036] (2) a soybean oil with a volume fraction of 74% is weighed;

[0037] (3) the palm kernel oil ethoxylate and the soybean oil in steps (1) and (2) are mixed uniformly at 3000 rpm at 15° C.;

[0038] (4) deionized water with a volume fraction of 26% is accurately taken;

[0039] (5) the water in step (4) is added dropwise to the mixture in step (3) at 6000 rpm;

[0040] (6) a homogenization is performed on the dispersed system obtained in step (5) with a high-shear dispersion emulsification homogenizer at 10000 rpm for 10 min to obtain an HIPE stabilized by the palm kernel oil ethoxylate.

[0041] In Embodiment 1, the soybean oil in step (2) with different volume fractions including 74%, 77%, 80%, 83%, 86%, and 88% (vol %) is used to obtain HIPEs with different oil-phase volume fractions stabilized by a constant mass fraction of palm kernel oil ethoxylate, thereby investigating the effect of oil-water ratio on the stability of the formed HIPE. The optical microscopy image of the freshly prepared HIPE is shown in FIG. 1, and the optical microscopy image of the HIPE after the emulsion is placed at 25° C. for one month is shown in FIG. 2. When the mass concentration of palm kernel oil ethoxylate is 1% (wt %), and the volume fraction of the stabilized soybean oil is 83% (vol %), the prepared emulsion maintains good stability after being placed at 25° C. for six months. Its heat-resistant stability and cold-resistant stability are shown in Table 1. It can be seen from FIG. 1 and FIG. 2 that the prepared emulsion maintains good stability during storage.

[0042] FIG. 1 shows the HIPE in Embodiment 1 freshly prepared by a homogenization at 15° C. and a rotating speed of 10000 rpm for 10 min using the palm kernel oil ethoxylate with a mass fraction of 1.0% (wt %) and the oil phrase with a volume fraction of 83% (vol %). FIG. 2 shows the optical microscopy image of the HIPE in Embodiment 1 prepared by a homogenization at 15° C. and a rotating speed of 10000 rpm for 10 min using the palm kernel oil ethoxylate with a mass fraction of 1.0% (wt %) and the oil phrase with a volume fraction of 83% (vol %) after the emulsion is placed for one month.

Embodiment 2

[0043] The embodiment 2 of the invention provides a method for preparing a HIPE stabilized by an oil ethoxylate, including the following steps:

[0044] (1) a rapeseed oil with a volume fraction of 83% is weighed;

[0045] (2) a palm kernel oil ethoxylate with a mass fraction of 0.4% (wt %) is weighed;

[0046] (3) the rapeseed oil and the palm kernel oil ethoxylate in steps (1) and (2) are mixed uniformly at 3000 rpm at 25° C.;

[0047] (4) deionized water with a volume fraction of 17% is accurately taken;

[0048] (5) the water in step (4) is added dropwise to the mixture in step (3) at a 6000 rpm;

[0049] (6) a homogenization is performed on the dispersed system obtained in step (5) with a high-shear dispersion emulsification homogenizer at a 10000 rpm for 10 min to obtain a HIPE stabilized by the palm kernel oil ethoxylate.

[0050] In Embodiment 2, the palm kernel oil ethoxylate in step (2) with different mass concentrations including 0.4%, 0.6%, 0.8%, 1.0%, and 1.5% (wt %) is used to obtain HIPEs stabilized by different mass fractions of palm kernel oil ethoxylates, thereby investigating the effect of palm kernel oil ethoxylate concentration on the stability of the emulsion. The optical microscopy image of the freshly prepared high internal phase emulsion is shown in FIG. 3, and the optical microscopy image of the HIPE after the emulsion is placed for one month is shown in FIG. 4. When the mass concentration of the palm kernel oil ethoxylate is 0.6% (wt %), the volume fraction of the stabilized rapeseed oil is 83% (vol %), and the prepared emulsion maintains good stability after being placed at 25° C. for six months. Its heat-resistant stability and cold-resistant stability are shown in Table 1. It can be seen from FIG. 3 and FIG. 4 that the prepared emulsion maintains good stability during storage.

[0051] The HIPE with a constant oil-phase volume fraction of 83% (vol %) in Embodiment 2 is prepared by a homogenization at 25° C. and a rotating speed of 10000 rpm for 10 min using the palm kernel oil ethoxylate respectively with a mass concentration of 0.4%, 0.6%, 0.8%, 1.0%, and 1.5% (wt %). FIG. 3 shows the optical microscopy image of the freshly prepared HIPE with 0.6% (wt %) of the palm kernel oil ethoxylate and the oil-phase volume fraction of 83% (vol %), and FIG. 4 shows the optical microscopy image of the HIPE with 0.6% (wt %) of the palm kernel oil ethoxylate and the oil-phase volume fraction of 83% (vol %) after the emulsion is placed for one month.

Embodiment 3

[0052] The embodiment 3 of the invention provides a method for preparing a HIPE stabilized by an oil ethoxylate, including the following steps:

[0053] (1) an oil ethoxylate with a mass fraction of 0.6% (wt %) is weighed;

[0054] (2) a coconut oil with a volume fraction of 83% (vol %) is weighed;

[0055] (3) the oil ethoxylate and the coconut oil in steps (1) and (2) are mixed uniformly at 3000 rpm at 30° C.;

[0056] (4) tri-distilled water with a volume fraction of 17% is accurately taken;

[0057] (5) the water in step (4) is added dropwise to the mixture in step (3) at 6000 rpm;

[0058] (6) a homogenization is performed on the dispersed system obtained in step (5) with a high-shear dispersion emulsification homogenizer at 10000 rpm for 10 min to obtain the HIPE stabilized by the oil ethoxylate.

[0059] In Embodiment 3, the oil ethoxylate in step (1) of the same series including a coconut oil ethoxylate, a palm kernel oil ethoxylate, and a soybean oil ethoxylate is used to obtain HIPEs stabilized by oil ethoxylate of the same serious, thereby investigating the effect of the types of surfactant on the stability of the HIPE. The optical microscopy image of the freshly prepared emulsion and the optical microscopy image of the emulsion after being placed at 25° C. for one month are observed and shown in FIG. 5 and FIG. 6. When the surfactant is the soybean oil ethoxylate, the prepared emulsion still maintains good stability after being placed at 25° C. for six months, and its heat-resistant stability and cold-resistant stability are shown in Table 1. It can be seen from FIG. 5 and FIG. 6 that the prepared emulsion maintains good stability during storage.

[0060] The HIPEs in Embodiment 3 are prepared by a homogenization at 30° C. and a rotating speed of 10000 rpm for 10 min, wherein the HIPEs have a constant oil-phase volume fraction of 83% (vol %) and 0.6% (wt %) of the oil ethoxylate selected from the coconut oil ethoxylate, the palm kernel oil ethoxylate, or the soybean oil ethoxylate. FIG. 5 shows the optical microscopy image of the freshly prepared HIPE with 0.6% (wt %) of the soybean oil ethoxylate and the oil-phase volume fraction of 83% (vol %), and FIG. 6 shows the optical microscopy image of the HIPE with 0.6% (wt %) of the soybean oil ethoxylate and the oil-phase volume fraction of 83% (vol %) after the emulsion is placed for one month.

Embodiment 4

[0061] The embodiment 4 of the invention provides a method for preparing a HIPE stabilized by an oil ethoxylate, including the following steps:

[0062] (1) an oil ethoxylate with a total mass fraction of 0.6% (wt %) is accurately weighed, where a palm kernel oil ethoxylate is accounted for 0.3% (wt %) and a coconut oil ethoxylate is accounted for 0.3% (wt %);

[0063] (2) a sunflower oil with a volume fraction of 83% (vol %) is weighed;

[0064] (3) the oil ethoxylate and the sunflower oil in steps (1) and (2) are mixed uniformly at 3000 rpm at 35° C.;

[0065] (4) deionized water with a volume fraction of 17% is accurately taken;

[0066] (5) the water in step (4) is added dropwise to the mixture in step (3) at 6000 rpm;

[0067] (6) a homogenization is performed on the dispersed system obtained in step (5) with a high-shear dispersion emulsification homogenizer at 10000 rpm for 10 min to obtain the HIPE stabilized by the oil ethoxylate.

[0068] In Embodiment 4, the palm kernel oil ethoxylate and the coconut oil ethoxylate in step (1) are used at different ratios including 1:0.5, 1:1, and 1:2 to obtain HIPEs co-stabilized by the palm kernel oil ethoxylate and the coconut oil ethoxylate, thereby investigating the effect of the ratio of the palm kernel oil ethoxylate to the coconut oil ethoxylate on the stability of the HIPE. The optical microscopy image of the freshly prepared emulsion and the optical microscopy image of the emulsion after being placed at 25° C. for one month are observed and shown in FIG. 7 and FIG. 8. When the ratio of the palm kernel oil ethoxylate to the coconut oil ethoxylate is 1:1, the prepared emulsion still maintains good stability after being placed at 25° C. for four months, and its heat-resistant stability and cold-resistant stability are shown in Table 1. It can be seen from FIG. 7 and FIG. 8 that the prepared emulsion maintains good stability during storage.

[0069] The HIPEs co-stabilized by the palm kernel oil ethoxylate and the coconut oil ethoxylate in Embodiment 4 are prepared by a homogenization at 35° C. and a 10000 rpm for 10 min, wherein the HIPEs have a constant oil-phase volume fraction of 83% (vol %), and 0.6% (wt %) of the oil ethoxylate composed of the palm kernel oil ethoxylate and the coconut oil ethoxylate at the ratios of 1:0.5, 1:1, and 1:2, respectively. FIG. 7 shows the optical microscopy image of the freshly prepared HIPE co-stabilized by the palm kernel oil ethoxylate and the coconut oil ethoxylate at the ratio of 1:1, and FIG. 8 shows the optical microscopy image of the HIPE co-stabilized by the palm kernel oil ethoxylate and the coconut oil ethoxylate at the ratio of 1:1 after the emulsion is placed for one month.

Embodiment 5

[0070] The embodiment 5 of the invention provides a method for preparing a HIPE stabilized by an oil ethoxylate, including the following steps:

[0071] (1) an oil ethoxylate with a total mass fraction of 2.0% (wt %) is accurately weighed, where a palm kernel oil ethoxylate is accounted for 1% (wt %) and a soybean oil ethoxylate is accounted for 1% (wt %);

[0072] (2) a sunflower oil with a volume fraction of 83% (vol %) is weighed;

[0073] (3) the oil ethoxylate and the sunflower oil in steps (1) and (2) are mixed uniformly at of 3000 rpm at 45° C.;

[0074] (4) deionized water with a volume fraction of 17% is accurately taken;

[0075] (5) the water in step (4) is added dropwise to the mixture in step (3) at 6000 rpm;

[0076] (6) a homogenization is performed on the dispersed system obtained in step (5) with a high-shear dispersion emulsification homogenizer at 10000 rpm for 10 min to obtain the HIPE stabilized by the oil ethoxylate.

[0077] In Embodiment 5, the palm kernel oil ethoxylate and the soybean oil ethoxylate in step (1) are used at different ratios including 1:0.5, 1:1, and 1:2 to obtain HIPEs co-stabilized by the palm kernel oil ethoxylate and the soybean oil ethoxylate, thereby investigating the effect of the ratio of the palm kernel oil ethoxylate to the soybean oil ethoxylate on the stability of the HIPE. The optical microscopy image of the freshly prepared emulsion and the optical microscopy image of the emulsion after being placed for one month are observed and shown in FIG. 9 and FIG. 10. When the ratio of the palm kernel oil ethoxylate to the soybean oil ethoxylate is 1:1, the prepared emulsion still maintains good stability after being placed at 25° C. for four months, and its heat-resistant stability and cold-resistant stability are shown in Table 1. It can be seen from FIGS. 9 and 10 that the prepared emulsion maintains good stability during storage.

[0078] The HIPEs co-stabilized by the palm kernel oil ethoxylate and the soybean oil ethoxylate of Embodiment 5 are prepared by a homogenization at 45° C. and a 10000 rpm for 10 min, wherein the HIPEs have a constant oil-phase volume fraction of 83% (vol %), and 2.0% (wt %) of the oil ethoxylate composed of the palm kernel oil ethoxylate and the soybean oil ethoxylate at the ratios of 1:0.5, 1:1, and 1:2, respectively. FIG. 9 shows the optical microscopy image of the freshly prepared HIPE co-stabilized by the palm kernel oil ethoxylate and the soybean oil ethoxylate at the ratio of 1:1, and FIG. 10 shows the optical microscopy image of the HIPE co-stabilized by the palm kernel oil ethoxylate and the soybean oil ethoxylate at the ratio of 1:1 after the emulsion is placed for one month.

[0079] In accordance with the Safety and Technical Specifications for Cosmetics 2015 and the physical and chemical testing standards of GB/T 22965-2013 skin care lotion, a stability test of the HIPEs stabilized by oil ethoxylate is carried out. Table 1 shows the stability test results of the emulsions prepared in Embodiments 1-5.

TABLE-US-00001 TABLE 1 Stability test results of the HIPEs stabilized by oil ethoxylate Embodiment Embodiment Embodiment Embodiment 4 Embodiment 5 1 2 3 SOE-N-60: SOE-N-60: Item 1-81 0.6-81 S-0.6-81 SOE-C-60=1:1 SOE-S-60=1:1 heat-resis- No No No No No tant test.sup.(1) abnormality abnormality abnormality abnormality abnormality cold-resis- No No No No No tant test.sup.(2) abnormality abnormality abnormality abnormality abnormality Notes: .sup.(1)maintaining at (40 ± 1)° C. for 48 h, no obvious properly difference is found after returning to room temperature as compared to that before test .sup.(2)maintaining at (+31 5 ± 1)° C. for 48 h, no obvious property difference is found after returning to room temperature as compared to that before test

[0080] Finally, it should be illustrated that the above preferred embodiments are only used to illustrate the technical solutions of the invention and not to limit them. Although the invention has been described in detail through the above preferred embodiments, those skilled in the art can make equivalent substitutions or variations in form and details to the invention according to the technical solutions of the invention without departing from the scope defined by the claims of the invention.