Preparation method of aromatic plant essential oil emulsion for fabric antibiosis

Abstract

The invention relates to the technical field of antibacterial fabrics, and particularly discloses a preparation method of an aromatic plant essential oil emulsion for fabric antibiosis. The preparation method of the aromatic plant essential oil emulsion for fabric antibiosis comprises the following steps: mixing the liquid crystal emulsifier, the nonionic surfactant, the anionic surfactant and the liquid grease, heating in a water bath at 60-90 DEG C, and uniformly mixing to obtain an oil phase; uniformly mixing a thickening agent with water, and heating in a water bath at 60-90 DEG C to obtain a water phase; the water bath temperature is adjusted to 60-90 DEG C, the oil phase is poured into the water phase, high-speed shearing and homogeneous mixing are conducted for 1-5 min, the shearing speed is 4000-10000 r / min, and a mixture is obtained; and putting the mixture in a water bath environment at 25-35 DEG C, stirring for 1-3 minutes, adding the aromatic plant essential oil, and continuously stirring for 10-20 minutes. The aromatic plant essential oil liquid crystal emulsion used in the invention is simple in preparation process and has better adhesion.

Description

Technical Field

[0001] The invention relates to the technical field of antibacterial fabrics, in particular to a method for preparing an aromatic plant essential oil emulsion for antibacterial fabrics. Background Art

[0002] There are various microorganisms in nature, such as fungi and bacteria, which are in the air, water and other media. Textiles that are in direct contact with people become carriers of pathogenic microorganisms due to repeated use. Clothes made of cotton, linen, silk, leather, etc. are easy to produce odors and breed a large number of bacteria when worn close to the skin or left in a damp and dark environment for a long time, which affects the quality of textiles and endangers human health. Driven by the concept of green consumption and health, people's demand for antibacterial fabrics is increasing day by day.

[0003] Using antimicrobial fabric finishing agents to functionally finish the fabric surface is a safe, convenient and practical way to care for clothing and protect your health. Common finishing methods include surface coating (obtaining antimicrobial fabrics by coating the surface with antimicrobial agents), padding (dissolving the antimicrobial agent in an adhesive so that the antimicrobial agent is firmly adsorbed on the fabric), grafting (finishing the antimicrobial agent on the fabric through physical and chemical grafting) and microcapsule method (encapsulating the antimicrobial agent in microcapsules and finishing it on the fabric surface through adhesives).

[0004] However, the above technologies have problems such as fast release of antibacterial active ingredients, easy shedding, poor water absorption and air permeability of fabrics after finishing, and changes in feel and color. In addition, the use of chemically synthesized antibacterial substances and the addition of a large number of auxiliaries not only limit their practical application performance, but also have potential biological toxicity and environmental pollution risks. Therefore, it is urgent to develop a fabric antibacterial finishing agent that is safe, green, long-lasting, broad-spectrum antibacterial, and has no effect on fabric quality.

[0005] Essential oils are concentrated liquids with special fragrance and antibacterial effects extracted from different parts of plants, such as fruits, leaves, flowers and seeds. Compared with traditional chemical synthetic antibacterial agents, essential oils have the advantages of being green, safe, non-toxic, enhancing fragrance and removing odors, and having broad-spectrum antibacterial properties. They can be widely used in skin care, oral care, cleaning and disinfection, and other scenarios. There are also literature reports on the use of essential oils in the preparation of functional textiles. However, improving the dispersibility of essential oils in water, slowing down their volatilization, and extending their effective period are technical barriers that essential oil products need to overcome.

[0006] The unique "two-phase three-film" structure of multiple emulsions can isolate, protect, and release the volatile plant essential oils it encapsulates. At the same time, liquid crystal emulsions can encapsulate fat-soluble substances such as plant essential oils in the oil core and oil layer due to their unique water-in-liquid crystal-in-oil (O / LC / W) structure. The water layer and oil layer separated from each other can be compatible with a variety of antibacterial components to enhance the antibacterial performance. Compared with conventional O / W emulsions, their unique multi-layer confined structure significantly improves the thermodynamic stability of the emulsion, and can achieve long-term sustained release of active substances through multi-layer barriers. In addition, the emulsifiers used in liquid crystal emulsions are usually biosurfactants (such as phospholipids and alkyl glycosides). On the basis of ensuring safety and non-toxicity, they do not affect the water absorption, air permeability, cleanliness and softness of the fabric surface, and can significantly reduce the surface tension of water, making it convenient to dilute and use in water. There is no stain residue on the fabric surface after washing.

[0007] Based on this, applying multiple liquid crystal emulsions encapsulating aromatic plant essential oils to fabric antibacterial can effectively solve many problems existing in the above-mentioned antibacterial finishing agents. Summary of the invention

[0008] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for preparing a fragrant plant essential oil emulsion for antibacterial fabrics.

[0009] The invention discloses an aromatic plant essential oil emulsion for antibacterial fabrics. The raw materials thereof include, by mass fraction, 0.1-1% aromatic plant essential oil, 1-6% liquid crystal emulsifier, 0.1-1% nonionic surfactant, 0.1-1% anionic surfactant, 0.1-0.5% thickener, 3-10% liquid grease, and the balance is water.

[0010] The mass fraction of aromatic plant essential oil in the aromatic plant essential oil emulsion can be specifically 0.5% and 1%; the mass fraction of liquid crystal emulsifier in the aromatic plant essential oil emulsion can be specifically 2%, 3% and 4%; the mass fraction of nonionic surfactant in the aromatic plant essential oil emulsion can be specifically 0.2%, 0.4%, 0.6% and 0.8%; the mass fraction of anionic surfactant in the aromatic plant essential oil emulsion can be specifically 0.2%, 0.4%, 0.6% and 0.8%; the mass fraction of thickener in the aromatic plant essential oil emulsion can be specifically 0.2%, 0.3%, 0.4% and 0.5%; the mass fraction of liquid oil in the aromatic plant essential oil emulsion can be specifically 4%, 5%, 6%, 7% and 8%.

[0011] Preferably, the aromatic plant essential oil emulsion has a lamellar structure of oil / liquid crystal / water, and a multiple emulsion structure of water / oil / water.

[0012] Preferably, the aromatic plant essential oil is at least one of citronella essential oil, clove essential oil, sage essential oil, bamboo leaf essential oil, cyperus rotundus essential oil, oregano essential oil and tsaoko essential oil.

[0013] Preferably, the liquid crystal emulsifier is at least one of an alkyl glycoside liquid crystal emulsifier, a phosphate liquid crystal emulsifier, a lecithin liquid crystal emulsifier, a sucrose ester liquid crystal emulsifier, a stearoyl liquid crystal emulsifier, and an olive ester liquid crystal emulsifier.

[0014] Preferably, the nonionic surfactant is sorbitan fatty acid ester or / and polyoxyethylene sorbitan fatty acid ester. Sorbitan fatty acid ester can be specifically Span-20, Span-40, Span-60, Span-65, Span-80, Span-85, and polyoxyethylene sorbitan fatty acid ester can be specifically Tween-20, Tween-40, Tween-60, Tween-80, Tween-85.

[0015] Preferably, the anionic surfactant is at least one of dodecylbenzenesulfonic acid, sodium fatty alcohol ether sulfate, sodium ethoxylated fatty acid methyl ester sulfonate, sodium secondary alkyl sulfonate, and dioctyl sodium sulfosuccinate, preferably dioctyl sodium sulfosuccinate.

[0016] Preferably, the thickener is at least one of gelatin, xanthan gum, carboxymethyl cellulose, hydroxyethyl cellulose, gum arabic, guar gum, chitosan quaternary ammonium salt, and activated chitosan quaternary ammonium salt.

[0017] Chitosan quaternary ammonium salt is a water-soluble chitosan derivative with excellent properties such as moisture absorption and moisture retention. Its molecular chain is positively charged and has good antibacterial properties. Its antibacterial effect on Staphylococcus aureus and Escherichia coli is significantly better than chitosan.

[0018] More preferably, the activation of chitosan quaternary ammonium salt adopts the following specific steps: adding chitosan quaternary ammonium salt to acetic acid aqueous solution and stirring evenly to obtain chitosan solution; adding amino-terminated polyamidoamine to hydrochloric acid and stirring evenly, then adding chitosan solution and stirring evenly, adding glutaraldehyde thereto under stirring, stirring at 40-60° C. for 2-6 hours, cooling to room temperature, washing, and vacuum drying.

[0019] More preferably, in the activated chitosan quaternary ammonium salt, the mass ratio of chitosan quaternary ammonium salt, amino-terminated polyamidoamine, and glutaraldehyde is 1-3:1-2:0.01-0.1.

[0020] More preferably, the concentration of the aqueous acetic acid solution is 0.5-1.2 mol / L, and the concentration of the hydrochloric acid is 0.1-1 mol / L.

[0021] More preferably, the generation number of the amino-terminated polyamidoamine is 1.0-3.0.

[0022] The activated chitosan quaternary ammonium salt has a polyamide-amine dendritic macromolecular structure as its core. It is radial as a whole and has excellent symmetry and a highly branched structure. The chitosan quaternary ammonium salt shell structure is combined at its end. It not only combines the advantages of chitosan quaternary ammonium salt and dendritic macromolecules, has good water solubility and biocompatibility, but also can act on the interface between the two phases to promote the formation of a stable emulsion structure between different phases. There is a large interface area between each phase, which significantly enhances the stability of the emulsion and has a significant synergistic antibacterial effect.

[0023] The experiment found that: the present application uses activated chitosan quaternary ammonium salt as a thickener. Although the antibacterial synergistic effect on Escherichia coli is not obvious, it has a significant antibacterial synergistic effect on Candida albicans and Staphylococcus aureus. At the same time, it has high safety and low cytotoxicity.

[0024] Preferably, the liquid oil is at least one of vegetable oil, animal oil and synthetic oil.

[0025] More preferably, the vegetable oil is at least one of coconut oil, peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, avocado oil, corn oil and palm oil.

[0026] More preferably, the animal fat is squalane and / or squalene.

[0027] More preferably, the synthetic oil is at least one of caprylic capric triglyceride, isooctyl palmitate, isopropyl myristate, isooctyl stearate, isononyl isononanoate, dicaprylyl carbonate, and diisostearyl malate.

[0028] The method for preparing the aromatic plant essential oil emulsion for antibacterial fabric comprises the following steps:

[0029] S1. Mix the liquid crystal emulsifier, nonionic surfactant, anionic surfactant and liquid oil, heat in a water bath at 60-90° C. and mix well to obtain an oil phase;

[0030] S2, mix the thickener and water evenly, heat in a water bath at 60-90°C to obtain an aqueous phase;

[0031] S3, adjusting the water bath temperature to 60-90°C, pouring the oil phase into the water phase, high-speed shearing homogenization mixing for 1-5 minutes, the shear speed is 4000-10000r / min, to obtain a mixture;

[0032] S4. Place the mixture in a 25-35°C water bath, stir at a speed of 300-800r / min for 1-3min, add aromatic plant essential oil and continue stirring for 10-20min.

[0033] The aromatic plant essential oil emulsion for antibacterial fabric is used to improve the antibacterial effect of fabric.

[0034] The aromatic plant essential oil emulsion for fabric antibacterial can be applied to fabric finishing by spraying, soaking and the like.

[0035] Beneficial effects;

[0036] (1) The present invention adopts a multiple emulsion structure of water / oil / water (W / O / W) and a lamellar liquid crystal emulsion system of oil layer / liquid crystal layer / water layer (O / LC / W) to encapsulate one or more aromatic plant essential oils in the oil core and between the oil / water layers separated by liquid crystals. The plant essential oil multiple liquid crystal emulsion formula obtained by the present invention uses all bio-based raw materials and has sustainable ecological values ​​such as green, efficient, biosafe, and environmentally friendly.

[0037] (2) Compared with capsules or coating antibacterial finishing agents containing similar aromatic plant essential oils, the aromatic plant essential oil liquid crystal emulsion used in the present invention has a simple preparation process, is green, has low cost and energy consumption, has better adhesion, does not damage the quality of fabrics, and has the advantages of easy water washing, long-term sustained release, high utilization rate, wide application range, and long-lasting fragrance.

[0038] (3) The aromatic plant essential oil liquid crystal emulsion obtained by the present invention is suitable for the surface of various fabrics, such as pure cotton, silk, linen, wool, leather, etc. It has significant and broad-spectrum antibacterial properties against common harmful bacteria on fabrics, and is easy to use and carry. It can be diluted to a usage multiple for spraying according to needs.

[0039] (4) The present invention constructs a layered liquid crystal structure emulsion system with multiple emulsion structures and oil layer / liquid crystal layer / water layer (O / LC / W), so that the aromatic plant essential oil is confined and solubilized in the oil layer. The preparation process of the aromatic plant essential oil multiple liquid crystal emulsion of the present invention is simple, green, and has low energy consumption. It can be prepared on a large scale and is suitable for a variety of aromatic plant essential oils; it is superior to similar fabric antibacterial finishing agents in terms of fabric surface deposition, fabric protection, and easy washing; compared with mainstream antibacterial agents, it has significant advantages in terms of environmental pollution risk, biosafety, storage and transportation stability, long-term sustained release, high-efficiency antibacterial, and convenient use. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The micro / mesoscopic structure diagram of the citronella oil multiple liquid crystal emulsion obtained in Example 4; wherein (a) is a polarizing microscope image; and (b) is a SAXS and structural schematic diagram.

[0041] Figure 2The water dispersibility characterization diagram of the citronella oil multiple liquid crystal emulsion obtained in Example 4; wherein, (a) is the steady-state rheological curve, (b) is the dynamic viscoelastic curve, (c) is its dispersion photograph in water, (d) is its static surface tension; (e) is its dynamic surface tension; (f) is the fluorescence imaging diagram of the original clean fabric and the citronella oil multiple liquid crystal emulsion obtained in Example 4 before and after being sprayed with the fabric using a fluorescent marker (oil phase-Nile red) for cleaning.

[0042] Figure 3 The figures are performance comparison diagrams of fabrics before and after being treated with 1% citronella oil multiple liquid crystal emulsion obtained in Example 4; wherein (a) is a SEM, (b) is a water contact angle photograph, and (c) is a macroscopic image of the fabric before and after spraying the emulsion.

[0043] Figure 4 The antibacterial test results of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4, the blank liquid crystal emulsion (Blank-LCE) obtained in the comparative example, and the commercial antibacterial agent (CAR). Among them, (a) is the inhibitory effect of CO-LCE and Blank-LCE on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli); (b) is the inhibition rate of CO-LCE on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli); (c) the half effective concentration (EC 50) of cotton fabrics and silk fabrics of CO-LCE, Blank-LCE and CAR on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli). 50 ); (d) is the inhibitory effect of the fabric after being treated with CO-LCE, Blank-LCE and CAR on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli).

[0044] Figure 5 The graphs show the sustained release and long-term antibacterial results of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4. (a) is the release curve of CO-LCE and CO; (b) is the corresponding kinetic curve fitted by the first-order kinetic model; (c) is the long-term antibacterial effect of wool fabric treated with CO-LCE and CO on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli).

[0045] Figure 6The graph shows the results of an in vitro cytotoxicity test on human immortalized epidermal cells (HaCaT) for 24 hours using the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4, the blank liquid crystal emulsion (Blank-LCE) obtained in the comparative example, CO, and commercial antibacterial agents CAR-1 and CAR-2.

[0046] Figure 7 is a stability diagram of the citronella oil multiple liquid crystal emulsion obtained in Example 5; wherein (a1) to (a4) are the citronella oil multiple liquid crystal emulsion and its dilutions of 10, 10, 2 , 10 3 (a) is a microscopic morphology of the sample at a magnification of 100 times; (b) is a macroscopic image of the citronella oil multiple liquid crystal emulsion at 0 days of preparation and after standing at room temperature for 15 days.

[0047] Figure 8 The graph shows the antibacterial effects of the citronella oil multiple liquid crystal emulsion obtained in Example 4 and the citronella oil multiple liquid crystal emulsion obtained in Example 5 on Candida albicans (C.albicans), Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli) at a concentration of 1.25 mg / mL.

[0048] Fig. 9 The graph shows the results of an in vitro cytotoxicity test of the citronella oil multiple liquid crystal emulsion obtained in Example 4 and the citronella oil multiple liquid crystal emulsion obtained in Example 5 on human immortalized epidermal cells (HaCaT) for 24 hours. DETAILED DESCRIPTION

[0049] The present invention will be further explained below in conjunction with specific embodiments.

[0050] Example 1

[0051] The invention discloses an aromatic plant essential oil emulsion for fabric antibacterial. The raw materials thereof include, by mass fraction, 0.1% oregano essential oil, 1% sucrose ester liquid crystal emulsifier, 0.1% Span-60, 0.1% sodium secondary alkyl sulfonate, 0.1% xanthan gum, 3% squalene, and the balance is water.

[0052] The method for preparing the aromatic plant essential oil emulsion for antibacterial fabric comprises the following steps:

[0053] S1. Mix sucrose ester liquid crystal emulsifier, Span-60, sodium secondary alkyl sulfonate and squalene, and heat in a 60° C. water bath to mix well to obtain an oil phase;

[0054] S2, mixing xanthan gum and water evenly, and heating in a water bath at 60°C to obtain an aqueous phase;

[0055] S3, adjusting the water bath temperature to 60°C, pouring the oil phase into the water phase, and high-speed shearing homogenization mixing for 1 min at a shear rate of 4000 r / min to obtain a mixture;

[0056] S4. Place the mixture in a 25°C water bath, stir at 300 r / min for 1 min, add oregano essential oil and continue stirring for 10 min.

[0057] Example 2

[0058] The invention discloses an aromatic plant essential oil emulsion for fabric antibacterial. The raw materials thereof include, by mass fraction, 1% of cyperus rotundus essential oil, 6% of phosphate liquid crystal emulsifier, 1% of Tween-40, 1% of ethoxylated fatty acid methyl ester sulfonate sodium, 0.5% of hydroxyethyl cellulose, 10% of corn oil, and the balance of water.

[0059] The method for preparing the aromatic plant essential oil emulsion for antibacterial fabric comprises the following steps:

[0060] S1, mixing phosphate liquid crystal emulsifier, Tween-40, sodium ethoxylated fatty acid methyl ester sulfonate and corn oil, heating in a 90° C. water bath and mixing evenly to obtain an oil phase;

[0061] S2, mixing hydroxyethyl cellulose and water evenly, and heating in a water bath at 90°C to obtain an aqueous phase;

[0062] S3, adjusting the water bath temperature to 90°C, pouring the oil phase into the water phase, and high-speed shearing homogenization mixing for 5 minutes at a shear rate of 10000r / min to obtain a mixture;

[0063] S4. Place the mixture in a 35°C water bath, stir at 800 rpm for 3 min, add Cyperus rotundus essential oil and continue stirring for 20 min.

[0064] Example 3

[0065] The invention discloses an aromatic plant essential oil emulsion for fabric antibacterial. The raw materials thereof include, by mass fraction, 0.5% sage essential oil, 3.5% alkyl glycoside liquid crystal emulsifier, 0.5% Span-80, 0.5% sodium fatty alcohol ether sulfate, 0.3% gelatin, 6.5% diisostearyl malate, and the balance is water.

[0066] The method for preparing the aromatic plant essential oil emulsion for antibacterial fabric comprises the following steps:

[0067] S1. Mix alkyl glycoside liquid crystal emulsifier, Span-80, sodium fatty alcohol ether sulfate and diisostearyl malate, and heat in a water bath at 75° C. to mix well to obtain an oil phase;

[0068] S2, mix gelatin and water evenly, and heat in a water bath at 75°C to obtain an aqueous phase;

[0069] S3, adjusting the water bath temperature to 75°C, pouring the oil phase into the water phase, and high-speed shearing homogenization mixing for 3 minutes at a shear rate of 7000 r / min to obtain a mixture;

[0070] S4. Place the mixture in a 30°C water bath, stir at 400 r / min for 2 min, add sage essential oil and continue stirring for 15 min.

[0071] Example 4

[0072] A method for preparing a citronella oil multiple liquid crystal emulsion for fabric antibacterial properties comprises the following steps:

[0073] S1. Add 3 g of lecithin liquid crystal emulsifier, 0.15 g of Tween-80, and 0.15 g of docusate sodium (DOSS) to 6 g of coconut oil, and heat in a water bath at 75° C. to dissolve the lecithin liquid crystal emulsifier, Tween-80, and docusate sodium in the coconut oil to obtain an oil phase.

[0074] S2. Slowly add 0.5 g of chitosan quaternary ammonium salt (QCS) into 89.2 g of deionized water while stirring, and keep stirring to form a uniform solution. Then put it into a water bath and heat it to 75° C. to obtain an aqueous phase.

[0075] S3. Pour the oil phase into the water phase rapidly at a water bath temperature of 75°C, and homogenize at a speed of 6500 r / min for 5 minutes to make it uniformly mixed.

[0076] S4. The homogenized emulsion was mechanically stirred at 650 r / min for 15 min under the condition of an external water bath temperature of 28° C. to cool it down. After cooling and stirring for 2 min, 1 g of citronella oil was added to obtain 100 g of citronella oil multiple liquid crystal emulsion (CO-LCE), that is, a 1% citronella oil multiple liquid crystal emulsion with a pH of 7 was obtained.

[0077] Comparative Example

[0078] A method for preparing a blank liquid crystal emulsion comprises the following steps:

[0079] S1. Add 3 g of lecithin liquid crystal emulsifier to 6 g of coconut oil, and heat in a water bath at 75° C. to dissolve the lecithin liquid crystal emulsifier in the coconut oil to obtain an oil phase.

[0080] S2. Slowly add 0.5 g of chitosan quaternary ammonium salt (QCS) into 90.5 g of deionized water (pH=7) under stirring, and continuously stir to form a uniform solution, then put it into a water bath and heat it to 75° C. to obtain an aqueous phase.

[0081] S3. Pour the oil phase into the water phase rapidly at a water bath temperature of 75°C, and homogenize at a speed of 6500 r / min for 5 minutes to make it uniformly mixed.

[0082] S4. The homogenized emulsion was mechanically stirred at 650 r / min for 15 min to cool down the temperature under the condition of an external water bath temperature of 28° C., to obtain 100 g of blank liquid crystal emulsion (Blank-LCE), that is, a blank liquid crystal emulsion with a pH of 7.

[0083] Test Example I

[0084] The liquid crystal emulsions obtained in Example 4 and the comparative example were observed under a polarizing microscope, and their structures were characterized by SAXS. The micro / meso structures are as follows: Figure 1 shown.

[0085] Figure (a) is a polarizing microscope image of the citronella oil multiple liquid crystal emulsion (CO-LCE), from which it can be seen that the citronella oil multiple liquid crystal emulsion obtained in Example 4 has both a multiple emulsion structure and a lamellar liquid crystal structure. Figure (b) is a schematic structural diagram of the citronella oil multiple liquid crystal emulsion (CO-LCE), which has both a "pomegranate seed-like" and a "nesting doll-like" structure.

[0086] However, SAXS results show that both the citronella oil multiple liquid crystal emulsion (CO-LCE) and the blank liquid crystal emulsion (Blank-LCE) have a lamellar liquid crystal structure. In summary, the aromatic plant essential oil multiple liquid crystal emulsion is successfully prepared by the method of the present invention.

[0087] Test Example II

[0088] Improving the water dispersibility of aromatic plant essential oils is a prerequisite for ensuring their performance. The rheological properties, surface tension, water dispersibility of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4, and fluorescent imaging of the original fabric and the fabric sprayed with CO-LCE before and after washing were used to evaluate the water dispersibility of CO-LCE.

[0089] Among them, the steady-state rheological results are as follows Figure 2 As shown in (a), with the increase of shear rate (γ), the steady-state shear viscosity of CO-LCE shows a decreasing trend, showing the shear thinning characteristics of non-Newtonian fluids. This is not only beneficial for the extrusion and canning of the emulsion during the preparation process, but also helps in the dilution and use of CO-LCE.

[0090] From the dynamic viscoelastic curve (such as Figure 2 (b) shows that in the low-frequency region, the storage modulus (G') and the loss modulus (G") are not much different, and in the high-frequency region, G' is smaller than G", and CO-LCE mainly exhibits the viscous properties of a liquid, which is conducive to spraying and atomization during use.

[0091] The state of CO-LCE after dropping into deionized water and shaking is as follows Figure 2As shown in (c), CO-LCE can be evenly dispersed by manual shaking after dropping. This shows that CO-LCE has excellent water dispersibility.

[0092] Static surface tension results (such as Figure 2 (d) shows that the critical micelle concentration (CMC) of CO-LCE is about 1%, that is, the original emulsion is diluted 100 times.

[0093] By dynamic surface tension (such as Figure 2 As shown in (e), CO-LCE can reduce the surface tension of water to 22.57 mN / m within 0.9951 s, making it easier to clean the fabric later. This is due to the rapid diffusion and migration of surfactants in water and their uniform dispersion.

[0094] By fluorescently labeling the oil phase, the fluorescence imaging effects of the original clean fabric and the fabric sprayed with fluorescently labeled CO-LCE before and after washing were compared (e.g. Figure 2 (f) shows that CO-LCE can be effectively deposited on the fabric surface and can be easily washed without residue.

[0095] Test Example III

[0096] The premise for the antibacterial spray to be effective is that the spray can successfully deposit the active ingredients on the surface of the fabric without having an adverse effect on the fabric quality and wearing effect. Therefore, it is necessary to evaluate whether the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 has protective properties for the fabric.

[0097] The protective effect of CO-LCE on the fabric was evaluated by comparing the SEM images, water contact angles and macroscopic images of the fabric surface before and after spraying CO-LCE.

[0098] The citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 was diluted 100 times with deionized water and then simply sprayed on the surface of different fabrics (cotton, linen, silk, wool, leather, etc.).

[0099] By comparing the SEM images of the fabric before and after spraying CO-LCE (such as Figure 3 As shown in (a), it can be seen that the surface of the unsprayed fabric is smooth, the warp and weft are clear, and there is no obvious sediment, while the surface of the fabric sprayed with CO-LCE is no longer smooth, and there is obvious deposition of vesicle-like structured materials. The comparison shows that CO-LCE can be effectively deposited on the fabric surface.

[0100] The water contact angle results of different fabrics (cotton, linen, silk, wool, leather) before and after spraying CO-LCE diluted 100 times are as follows Figure 3 As shown in (b), it can be seen that there is no obvious difference in the water contact angle before and after spraying, indicating that CO-LCE does not change the surface properties and water absorption of the fabric.

[0101] Macroscopic images of different fabrics before and after spraying CO-LCE (e.g. Figure 3 (c) shows that the fabric can still maintain its original cleanliness and softness after being treated with the emulsion, without any stains or hardening. The above results show that the emulsion can be successfully deposited and retained on the surface of the fabric without damaging the fabric, affecting the fabric quality, appearance and wearing experience, and has good protective properties for the fabric.

[0102] Test Example IV

[0103] With reference to GB / T 20944.3-2008 and AATCC 147-2011, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans) were selected as test strains, and the antibacterial effects of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4, the blank liquid crystal emulsion (Blank-LCE) obtained in the comparative example and the commercial antibacterial agent (CAR) were evaluated.

[0104] The antibacterial test results of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 and the blank liquid crystal emulsion (Blank-LCE) obtained in the comparative example are as follows: Figure 4 As shown in (a), when the concentration of CO-LCE emulsion is greater than or equal to 10 mg / mL, the three selected test bacteria can be completely inhibited, and the inhibition rate is as follows: Figure 4 As shown in (b), when the emulsion concentration is equal to 10 mg / mL, the antibacterial rate of CO-LCE against the three bacteria is more than 99%. Figure 4 (c) is the effective concentration (EC) of the three bacteria 50 ).

[0105] In addition, CO-LCE, Blank-LCE, and CAR were simply sprayed on fabrics (cotton, silk), e.g. Figure 4 As shown in (d), no colonies appeared where the sample or fabric came into contact with the culture medium, indicating that simply spraying CO-LCE on the fabric surface can have an antibacterial effect.

[0106] Test Example V

[0107] The sustained-release performance and long-term antibacterial effect of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 were evaluated by the release of CO and the long-term antibacterial effect on bacteria.

[0108] Using 50% ethanol aqueous solution as the sustained release medium, the release curves of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 and CO were compared (see Figure 5 (a) shows the half-release time (t) of CO in CO-LCE. 1 / 2 =59.2h) is much longer than the half release time of unencapsulated CO (t1 / 2 =6.6h), indicating that CO-LCE has a longer sustained release period than CO and can extend the half-release time of CO by about 8 times.

[0109] Kinetic fitting was performed on the sustained release curve. Figure 5 (b) are all in accordance with the first-order kinetic model. Release experiments show that the CO-LCE with "pomegranate seed type" and "nesting doll type" structures can achieve slow release of CO in 50% ethanol aqueous solution.

[0110] Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans) were selected as the test bacteria, CO-LCE and CO were sprayed on the fabric respectively, and the fabric sprayed with CO-LCE and CO was placed on the culture medium after streaking with bacterial liquid according to AATCC 147-2011. After incubation for different time, photos were taken. The results are shown in Figure 2. Figure 5 (c) As shown. It can be seen that after 22 hours of co-incubation, CO-LCE can still inhibit the growth of Candida albicans (C.albicans), but CO can no longer inhibit the growth of Candida albicans. After 17 hours of co-incubation, CO-LCE can still inhibit Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli), while CO can no longer inhibit the growth of both. The above results show that CO-LCE can prolong the release cycle and antibacterial duration of CO.

[0111] Test Example VI

[0112] The standard CCK-8 method was used to evaluate the in vitro cytotoxicity of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4, the blank liquid crystal emulsion (Blank-LCE) obtained in the comparative example, and the commercial antibacterial agents CAR-1 and CAR-2 on human immortalized keratinocytes (HaCaT).

[0113] like Figure 6 As shown in (a), after CO, Blank-LCE and CO-LCE obtained in Example 4 were mixed and incubated with cells, the cell viability of the CO group was the lowest, and the cell viability of Blank-LCE was the highest. However, at the same CO concentration, the cell viability of the CO-LCE group was higher than that of the CO group, indicating that CO-LCE reduced the cytotoxicity of CO. Figure 6 (b) It can be seen that when the dosage of antimicrobial agents was the same, the cell viability of the CO-LCE group was higher than that of the commercial antimicrobial agents CAR-1 and CAR-2.

[0114] Example 5

[0115] A method for preparing a citronella oil multiple liquid crystal emulsion for fabric antibacterial properties comprises the following steps:

[0116] S1. Add 3 g of lecithin liquid crystal emulsifier, 0.15 g of Tween-80, and 0.15 g of docusate sodium (DOSS) to 6 g of coconut oil, and heat in a water bath at 75° C. to dissolve the lecithin liquid crystal emulsifier, Tween-80, and docusate sodium in the coconut oil to obtain an oil phase.

[0117] S2. Slowly add 0.5 g of activated chitosan quaternary ammonium salt into 89.2 g of deionized water while stirring, and keep stirring to form a uniform solution. Then put it into a water bath and heat it to 75° C. to obtain an aqueous phase.

[0118] The activation of chitosan quaternary ammonium salt adopts the following specific steps: adding 2g of chitosan quaternary ammonium salt to 35g of 1mol / L acetic acid aqueous solution and stirring evenly to obtain a chitosan solution; adding 1.5g of 2.0-generation amino-terminated polyamidoamine to 15g of 0.5mol / L hydrochloric acid and stirring evenly, then adding the chitosan solution and stirring evenly, adding 0.05g of glutaraldehyde thereto under stirring, stirring at 50°C for 4h, stirring at a speed of 1500r / min, cooling to room temperature, washing with anhydrous ethanol, and vacuum drying.

[0119] S3. Pour the oil phase into the water phase rapidly at a water bath temperature of 75°C, and homogenize at a speed of 6500 r / min for 5 minutes to make it uniformly mixed.

[0120] S4. The homogenized emulsion was mechanically stirred at 650 r / min for 15 min under the condition of an external water bath temperature of 28° C. to cool it down. After cooling and stirring for 2 min, 1 g of citronella oil was added to obtain 100 g of citronella oil multiple liquid crystal emulsion, that is, a 1% citronella oil multiple liquid crystal emulsion with a pH of 7 was obtained.

[0121] Test Example VII

[0122] The stability of the citronella oil multiple liquid crystal emulsion obtained in Example 5 was evaluated by observing the microstructure of the samples after being diluted to different multiples, the long-term room temperature storage of the emulsion, and the stabilization mechanism.

[0123] The citronella oil multiple liquid crystal emulsion obtained in Example 5 was diluted with deionized water by 10 and 10 2 , 10 3 After the experiment was performed, the polarized light microscope was used to observe the results. Figure 7 As shown in (a), dilution 10 3 After the mixture was diluted to 400 μg / ml, the lamellar liquid crystal structure and the multiple emulsion structure still existed, indicating that the citronella oil multiple liquid crystal emulsion obtained in Example 5 has dilution stability.

[0124] The photo of the citronella oil multiple liquid crystal emulsion obtained in Example 5 after being stored at room temperature for several days (as shown in FIG. Figure 7(b) shows that it is still stable after long-term storage at room temperature. The activated chitosan quaternary ammonium salt can act on the interface between the two phases and promote the formation of a stable emulsion structure between different phases. There is a large interface area between each phase, which significantly enhances the stability of the emulsion. The zeta potential value of the emulsion is also relatively stable at +30.6mV, indicating that the citronella oil multiple liquid crystal emulsion is in a stable state under this state.

[0125] Test Example VIII

[0126] With reference to GB / T 20944.3-2008 and AATCC 147-2011, Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Candida albicans (C. albicans) were selected as test strains to evaluate the antibacterial effects of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 and the citronella oil multiple liquid crystal emulsion obtained in Example 5 at a concentration of 1.25 mg / mL.

[0127] like Figure 8 As shown, the citronella oil multiple liquid crystal emulsion obtained in Example 5 still has a better antibacterial effect on Candida albicans (C.albicans) and Staphylococcus aureus (S.aureus) at a low concentration.

[0128] Test Example IX

[0129] The standard CCK-8 method was used to evaluate the in vitro cytotoxicity of the citronella oil multiple liquid crystal emulsion (CO-LCE) obtained in Example 4 and the citronella oil multiple liquid crystal emulsion obtained in Example 5 at concentrations of 2 mg / mL and 4 mg / mL on human immortalized keratinocytes (HaCaT).

[0130] like Fig. 9 As shown, at the same concentration, the in vitro cytotoxicity of the citronella oil multiple liquid crystal emulsion obtained in Example 5 was similar to that of Example 4 (P>0.05), that is, the use of activated chitosan quaternary ammonium salt did not enhance the in vitro cytotoxicity of the emulsion.

[0131] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A fragrant plant essential oil emulsion for antibacterial fabric, characterized in that: The raw materials include, by mass fraction, 0.1-1% of aromatic plant essential oil, 1-6% of liquid crystal emulsifier, 0.1-1% of nonionic surfactant, 0.1-1% of anionic surfactant, 0.1-0.5% of thickener, 3-10% of liquid oil, and the balance of water.

2. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The aromatic plant essential oil emulsion has a layered structure of oil / liquid crystal / water and a multiple emulsion structure of water / oil / water.

3. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The aromatic plant essential oil is at least one of citronella essential oil, clove essential oil, sage essential oil, bamboo leaf essential oil, cyperus rotundus essential oil, oregano essential oil and tsaoko essential oil.

4. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The liquid crystal emulsifier is at least one of an alkyl glycoside liquid crystal emulsifier, a phosphate liquid crystal emulsifier, a lecithin liquid crystal emulsifier, a sucrose ester liquid crystal emulsifier, a stearoyl liquid crystal emulsifier, and an olive ester liquid crystal emulsifier.

5. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The nonionic surfactant is sorbitan fatty acid ester and / or polyoxyethylene sorbitan fatty acid ester; Preferably, the anionic surfactant is at least one of dodecylbenzenesulfonic acid, sodium fatty alcohol ether sulfate, sodium ethoxylated fatty acid methyl ester sulfonate, sodium secondary alkyl sulfonate, and dioctyl sodium succinate sulfonate.

6. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The thickener is at least one of gelatin, xanthan gum, carboxymethyl cellulose, hydroxyethyl cellulose, gum arabic, guar gum, chitosan quaternary ammonium salt, and activated chitosan quaternary ammonium salt.

7. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 6, characterized in that: The activation of chitosan quaternary ammonium salt adopts the following specific steps: adding chitosan quaternary ammonium salt to acetic acid aqueous solution and stirring evenly to obtain chitosan solution; adding amino-terminated polyamidoamine to hydrochloric acid and stirring evenly, then adding chitosan solution and stirring evenly, adding glutaraldehyde thereto under stirring, stirring at 40-60° C. for 2-6 hours, cooling to room temperature, washing, and vacuum drying.

8. The aromatic plant essential oil emulsion for antibacterial fabric according to claim 1, characterized in that: The liquid oil is at least one of vegetable oil, animal oil, and synthetic oil; Preferably, the vegetable oil is at least one of coconut oil, peanut oil, soybean oil, linseed oil, castor oil, rapeseed oil, avocado oil, corn oil and palm oil; Preferably, the animal fat is squalane and / or squalene; Preferably, the synthetic oil is at least one of caprylic capric triglyceride, isooctyl palmitate, isopropyl myristate, isooctyl stearate, isononyl isononanoate, dicaprylyl carbonate, and diisostearyl malate.

9. A method for preparing an aromatic plant essential oil emulsion for antibacterial fabrics as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1. Mix the liquid crystal emulsifier, nonionic surfactant, anionic surfactant and liquid oil, heat in a water bath at 60-90° C. and mix well to obtain an oil phase; S2, mix the thickener and water evenly, heat in a water bath at 60-90°C to obtain an aqueous phase; S3, adjusting the water bath temperature to 60-90°C, pouring the oil phase into the water phase, high-speed shearing homogenization mixing for 1-5 minutes, the shear speed is 4000-10000r / min, to obtain a mixture; S4. Place the mixture in a 25-35°C water bath, stir at a speed of 300-800r / min for 1-3min, add aromatic plant essential oil and continue stirring for 10-20min.

10. Use of the aromatic plant essential oil emulsion for antibacterial fabric according to any one of claims 1 to 8 for improving the antibacterial effect of fabric.

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