Nanoreactor, preparation method and application thereof

Abstract

The invention relates to the field of biology, and discloses a nanoreactor which comprises self-emulsifying orange peel essential oil, orange peel charcoal particles and tea polyphenol. The invention aims to solve the problem of lack of an effective method for degrading p-phenylenediamine in the prior art, and provides a nano reactor capable of degrading p-phenylenediamine, a preparation method and an application.

Description

Technical Field

[0001] The present invention relates to the field of biochemistry, and specifically relates to a nano-reactor, a preparation method thereof, and an application thereof. Background Art

[0002] p-Phenylenediamine (PPD) is an intermediate with a wide range of application fields. It can be used to prepare azo dyes and high molecular polymers, and can also be used in the production of fur dyes, rubber antioxidants, and photographic developers. However, it has significant hazards: for the human body, it has strong sensitization, and is prone to cause contact dermatitis or even systemic allergic reactions; acute exposure can cause skin burns and respiratory irritation, and accidental ingestion may cause hemolytic anemia or shock; long-term exposure may damage liver and kidney functions and has a potential carcinogenic risk (metabolites can induce DNA damage). In the environment, PPD is difficult to degrade and highly toxic to aquatic organisms, and it is easy to damage the ecological balance through water or soil pollution. In occupational exposure (such as hairdressers and rubber workers), its dust or vapor can be absorbed through the skin or respiratory tract, causing chronic health problems. Although international regulations limit its use concentration (such as ≤2% in cosmetics) and require mandatory labeling of warnings, its health and environmental risks still need to be strictly controlled. Given the widespread use of PPD in daily life and the lack of cost-effective alternatives on the market, it is extremely important to design a solution that can effectively degrade PPD residues. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem of the lack of effective methods for the existing degradation of p-phenylenediamine, and to provide a nano-reactor, a preparation method, and an application that can degrade p-phenylenediamine.

[0004] The present invention provides a basic technical solution: a nano-reactor, comprising self-emulsifying orange peel essential oil, orange peel biochar particles, and tea polyphenols.

[0005] Further, for the nano-reactor, the orange peel biochar particles are used as the core, and both the self-emulsifying orange peel essential oil and tea polyphenols are attached to the periphery and pore structure of the orange peel biochar particles.

[0006] Further, for the nano-reactor, the self-emulsifying orange peel essential oil and tea polyphenols are also attached to the internal pore structure of the orange peel biochar particles.

[0007] Further, for the nano-reactor, the mass ratio of the self-emulsifying orange peel essential oil, orange peel biochar particles, and tea polyphenols is 0.2:1:0.2.

[0008] Orange peel essential oil is an essential oil extracted from the peel of oranges, mainly distributed in the orange peel oil glands. Its volatile components account for 85–99%, mainly composed of terpene compounds (monoterpenes) and their derivatives (oxygenated monoterpenes and sesquiterpenes), among which limonene is the main component, accounting for more than 90% of the total essential oil.

[0009] Tea polyphenols are a class of natural organic compounds widely present in plants. Their molecular structure contains multiple phenolic hydroxyl groups (-OH) and aromatic rings. Current research has shown that tea polyphenols, as a powerful antioxidant and natural polyphenolic compound, have significant chemical reduction ability and free radical scavenging ability. However, there is currently no research demonstrating that tea polyphenols have the effect of directly degrading p-phenylenediamine.

[0010] In the research of the present inventors, the idea of using orange peel biochar loaded with self-emulsifying orange peel essential oil to degrade p-phenylenediamine was proposed and achieved good results. On this basis, considering that the presence of a large amount of limonene in orange peel essential oil can promote the generation of reactive oxygen species (ROS), and the generated ROS can degrade organic pollutants into non-toxic and harmless small molecules, such as water and carbon dioxide. However, although ROS can degrade PPD into small molecules, some intermediate products may be generated during the degradation process, such as aniline compounds and quinone compounds, and these intermediate products may still have strong toxicity and incomplete degradation.

[0011] Therefore, during the research process, the present inventors established a synergistic mechanism of tea polyphenols, orange peel essential oil, and biochar. Using the phenolic hydroxyl groups of tea polyphenols as strong reducing agents, through single electron transfer or dehydrogenation reactions, on the one hand, tea polyphenols can oxidize PPD into p-benzoquinone diimine; on the other hand, the p-benzoquinone diimine generated from the degradation of p-phenylenediamine by orange peel biochar loaded with self-emulsifying orange peel essential oil can also be further reduced by tea polyphenols into p-aminophenol, and then oxidized and ring-opened into small molecule carboxylic acids (oxalic acid, acetic acid); furthermore, the aromatic ring of tea polyphenols and the benzene ring of PPD form a complex through non-covalent interactions, reducing the stability of PPD, making each part of it vulnerable to subsequent attacks, and facilitating the degradation of PPD by attacks; fourthly, the hydroxyl groups of tea polyphenols can also form hydrogen bonds with the amino groups of PPD, changing the electron distribution of PPD, enhancing its reaction activity, and promoting the reaction of PPD degradation.

[0012] Based on this inventive concept, the present inventors designed a nano-reactor of orange peel biochar loaded with self-emulsifying orange peel essential oil and tea polyphenols for degrading p-phenylenediamine based on the regulation of the reaction microenvironment by the nano-reactor. On the one hand, the nano-reactor has a larger specific surface area and abundant active sites, which can degrade PPD to a greater extent, and the nano-reactor can also play a role in regulating the reaction microenvironment with higher stability.

[0013] Thus, the limonene in tea polyphenols and orange peel essential oil can achieve efficient degradation of PPD through physical and chemical synergistic effects and molecular-level joint reactions. Tea polyphenols and limonene jointly generate mixed free radicals, which can synergistically attack the amino group and benzene ring of PPD. Tea polyphenols act as electron donors, and limonene acts as an electron relay, forming an electron transfer chain of tea polyphenols → limonene → PPD, reducing the activation energy of the oxidation reaction. Moreover, tea polyphenols can also capture the electrons of p-phenylenediamine, making it in a more vulnerable oxidation state and accelerating the degradation reaction. During the degradation of p-phenylenediamine by limonene, some intermediates will be produced. These intermediates may have high activity and instability, and are prone to side reactions or recombination to form the original substances, thus hindering the degradation reaction. Tea polyphenols can stabilize the intermediates by forming hydrogen bonds, π-π stacking and other interactions with these intermediates, making them more inclined to further react to form degradation products, thus promoting the forward progress of the degradation reaction. Tea polyphenols can also change the microenvironment of the reaction system, such as pH value, polarity, etc. A suitable microenvironment is conducive to the interaction between limonene and p-phenylenediamine and the progress of the reaction. Therefore, the synergism of tea polyphenols and orange peel essential oil can greatly accelerate the degradation rate of PPD, completely degrade the vast majority of PPD into CO2 and H2O, and has a wide range of environmental adaptability.

[0014] Compared with the traditional mixed system composed of biochar, orange peel essential oil and tea polyphenols, limonene, tea polyphenols and PPD molecules are randomly distributed in the solution, and the probability of effective collision is relatively low. The incomplete degradation of PPD during the reaction may produce various side reactions and generate complex by-products, which will not only reduce the degradation efficiency of PPD, but also bring difficulties to the separation and subsequent treatment of the products. In the actual environment, PPD often coexists with dyes and heavy metal ions, and it is difficult to synchronously treat them by traditional methods. Biomass-derived carbon has the porous characteristics of nanomaterials, can effectively enrich PPD, increase the local concentration, accelerate the reaction kinetics, and limit and regulate the PPD degradation reaction at the nanoscale through the confinement effect and interface engineering, thus significantly improving the reaction efficiency and controllability. The nanoreactor constructed by self-emulsifying orange peel essential oil, tea polyphenols and biomass carbon regulates the electron transfer path through structural design and improves the catalytic activity. The loaded self-emulsifying orange peel essential oil and tea polyphenols can directly attack the amino group or benzene ring structure of PPD through the high activity of surface atoms. In addition, the nanoreactor constructed by using bio-based materials (self-emulsifying orange peel essential oil, tea polyphenols and biomass carbon) can degrade, reduce secondary pollution, reduce the environmental burden, and promote the greening and resource utilization in the PPD treatment project.

[0015] Thus, the present invention solves the problems of low degradation efficiency and incomplete degradation of p-phenylenediamine, and provides a technical solution capable of sustainable catalytic degradation of p-phenylenediamine. Moreover, orange peel essential oil, tea polyphenols, and biochar are all natural plant extracts, which are harmless to humans and the environment, and have a good synergistic degradation effect on PPD. Their application scenarios and prospects have obvious advantages, providing a new technical direction for environmental governance.

[0016] The present invention also provides another basic solution, a preparation method of a nano-reactor, including a preparation step of self-emulsified orange peel essential oil, a preparation step of orange peel biochar particles, and a fusion step.

[0017] Furthermore, in the preparation method of the nano-reactor, the preparation step of the orange peel biochar particles includes a biochar preparation step, and the biochar is prepared by an oxygen-limited pyrolysis method.

[0018] Furthermore, in the preparation method of the nano-reactor, in the fusion step, the mass ratio of the self-emulsified orange peel essential oil, the orange peel biochar particles, and the tea polyphenols is 0.2:1:0.2.

[0019] It can be seen from the experimental results that the nano-reactor of the present invention has an obvious composite layer of a mixture of tea polyphenols and self-emulsified orange peel essential oil. Compared with biochar, the pores are reduced. This indicates that through this preparation method, the orange peel biochar particles have successfully loaded the self-emulsified orange peel essential oil and tea polyphenols.

[0020] The present invention also provides another basic technical solution, an application of the above-mentioned nano-reactor in the preparation of a product for degrading p-phenylenediamine.

[0021] Furthermore, it includes daily necessities such as hair conditioners, shampoos, hair dyes, and skin care lotions containing p-phenylenediamine degrading agents.

[0022] Furthermore, it includes industrial treatment agents or environmental treatment agents such as wastewater treatment agents, industrial waste liquid treatment agents, and soil treatment agents containing p-phenylenediamine degrading agents.

[0023] Considering the high prevalence of current hair styling, both permanent waves and hair dyes contain p-phenylenediamine. Therefore, by using the nano-reactor of the present invention in the direction of daily necessities, it can degrade the p-phenylenediamine residues on hair and skin caused by permanent waves and hair dyes; making people healthier while enjoying beauty.

[0024] In addition, in other fields, such as wastewater treatment and industrial waste liquid treatment, the demand is more direct, and it can degrade p-phenylenediamine with higher efficiency. With the harm of waste liquid to the soil, the degradation of p-phenylenediamine in the soil becomes more important, solving the harm of p-phenylenediamine to human health from the source of health. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the nano-reactor of the present invention; Figure 2 (a) and (b) are SEM images of biochar; Figure 2 (c) and (d) are SEM images of the nano-reactor of the present invention; Figure 3 (a) and (b) are HRTEM images of biochar; Figure 3 (c) and (d) are HRTEM images of the nano-reactor of the present invention. Specific embodiments

[0026] The following is a further detailed description through specific embodiments: Example 1: The preparation method of the nano-reactor of the present invention is as follows: S1: Mix orange peel essential oil, surfactant and co-surfactant to obtain self-emulsifying orange peel essential oil SE-OPEO, with a total mass of 1 g. Subsequently, slowly drop 1 g of SE-OPEO into 100 mL of distilled water and perform self-emulsification with magnetic stirring at room temperature. The self-emulsification efficiency of SE-OPEO is classified according to the following visual classification criteria. The surfactant can be selected from one or any combination of Tween 20, Tween 80, Tween 85, and Triton X-100. In this example, Tween 20 is selected; the co-surfactant is one or any combination of absolute ethanol, isopropanol, and polyethylene glycol 400. In this example, absolute ethanol is selected.

[0027] The mass fraction ratios of orange peel essential oil, surfactant, and co-surfactant are as follows: the mass fractions of orange peel essential oil are set to 10%, 15%, 20%, 25%, and 30% respectively. Under the above orange peel essential oil mass fraction conditions, the surfactant and co-surfactant are mixed in the following mass ratios of 1 / 9, 2 / 8, 3 / 7, 4 / 6, 5 / 5, 6 / 4, 7 / 3, 8 / 2, 9 / 1 (w / w) to prepare 45 SE-OPEO combinations.

[0028] Grade A: The appearance of the emulsion is clear and transparent or slightly bluish, and it can be rapidly formed within 1 min; Grade B: The appearance of the emulsion is slightly turbid, bluish-white, and the formation time is the same as that of Grade A; Grade C: The emulsion is an opaque bright white liquid (similar to milk in appearance), and the formation time is about 2 min; Grade D: The appearance of the emulsion is grayish-white, slightly oily, and the formation time is greater than 2 min; Grade E: There are large oil droplets on the surface of the emulsion, and it is difficult to emulsify.

[0029] The self-emulsification efficiency is the time to form an emulsion. When the self-emulsification grade of SE-OPEO reaches Class A, it can be used for the next experiment. The oil phase is orange peel essential oil, the surfactant is Triton X-100, and the co-surfactant is isopropanol. The mass fractions of orange peel essential oil, Triton X-100, and isopropanol are determined to be 10.0–25.0%, 36.0–81.0%, and 7.5–54.0%, respectively.

[0030] S2: Wash the fresh orange peel successively with tap water and distilled water, cut it into small pieces of 1-2 cm, filter out a large amount of water, and place it in a forced-air oven at 60 °C for drying for 12 h. After crushing the dried orange peel small pieces into powder using a pulverizer, pass it through a 100-mesh sieve. Use the limited oxygen pyrolysis method to prepare orange peel biochar particles. The pyrolysis process is as follows: Take 10 g of orange peel powder and place it in a crucible, compact it, cover the lid, put it into a muffle furnace, and increase the pyrolysis temperature to the final temperature (900-1100 °C) at a heating rate of 10 °C / min, maintain for a period of time (2-4 h), and then cool to room temperature at 5 °C / min to obtain orange peel biochar particles.

[0031] S3: Grind the obtained orange peel biochar particles evenly, then wash them with distilled water until the pH of the filtrate is close to 7, and then place them in a forced-air oven at 80 °C for drying for 12 h. Finally, grind the dried orange peel biochar particles evenly, and pass them through a 100-mesh sieve again for standby.

[0032] S4. Fix the mass ratio of the self-emulsified orange peel essential oil, tea polyphenols, and orange peel biochar particles at 0.2:0.2:1 (w / w / w), and continuously stir to obtain the nano-reactor of the present invention with an appropriate greasy appearance and good fluidity. Its structure is approximately as Figure 1 shown. The orange peel biochar particles are the core, and both the self-emulsified orange peel essential oil and tea polyphenols are attached to the periphery of the orange peel biochar particles. The self-emulsified orange peel essential oil is also loaded in the pore structure of the biochar of the orange peel biochar particles, that is, BC / SE-OPEO powder.

[0033] Experiment 1: Observe the structure of the nano-reactor of the present invention under a scanning electron microscope and a high-resolution transmission electron microscope Observe the obtained nano-reactor of the present invention and orange peel biochar particles under a scanning electron microscope to obtain SEM images. As Figure 2 shown in (a) (b) (c) (d), by comparison, the surface of the orange peel biochar particles is rougher than that of the nano-reactor of the present invention, and there are many visible pores. This is because during the pyrolysis process, with the loss of volatile components, cellulose, and lignin, micropores are continuously formed, and then larger mesopores are generated, and finally visible macropores are formed.

[0034] The obtained nanoreactor of the present invention and orange peel biochar particles were observed under a high-resolution transmission electron microscope to obtain HRTEM images. As Figure 3 Comparing (a), (b), (c), and (d), it can be seen that the nanoreactor of the present invention has an obvious self-emulsifying orange peel essential oil and tea polyphenol composite layer, and compared with orange peel biochar particles, the pores are reduced. This can indirectly indicate that the orange peel biochar particles have successfully loaded self-emulsifying orange peel essential oil and tea polyphenols.

[0035] Experiment 2: Degradation effect experiment Experiment description: Tea polyphenols, self-emulsifying orange peel essential oil (SE-OPEO), and the nanoreactor of Example 1 of the present invention were used to verify their respective degradation efficiencies for PPD.

[0036] I. Preparation of tea polyphenols@BC The ratio of tea polyphenols to biochar was fixed at 0.4 / 1 (w / w). Briefly, 0.4 g of tea polyphenols was added to 1 g of biochar in small portions and stirred continuously after adding an appropriate amount of deionized water to obtain tea polyphenols@BC powder with certain fluidity.

[0037] II. Preparation of SE-OPEO@BC Orange peel essential oil, Triton X-100, and isopropanol were mixed in the optimal ratio to prepare SE-OPEO. The ratio of SE-OPEO to biochar was fixed at 0.4 / 1 (w / w). 0.4 g of SE-OPEO was added to 1 g of biochar in small portions and stirred continuously to obtain BC / SE-OPEO powder with an appropriate greasy appearance and good fluidity.

[0038] III. Experimental procedure: The pH of the PPD aqueous solution was adjusted using 0.1 M hydrochloric acid and sodium hydroxide. For tea polyphenols, self-emulsifying orange peel essential oil (SE-OPEO), and the nanoreactor of Example 1 of the present invention, 130 mg of each sample was taken and added to 5 mL of a 20 mg / L PPD aqueous solution (pH = 7). After shaking and reacting at a constant temperature in a shaker at 40°C for a gradient time (30 min, 70 min, 110 min, 150 min, and 190 min), 1 g / L ascorbic acid aqueous solution was added to stop the reaction. Parallel experiments were performed three times under the same reaction conditions. The concentration of PPD in the samples was detected using a high-performance liquid chromatograph. The chromatographic column was Agilent TC-C18 (250 mm × 4.6 mm × 5 µm), the flow rate was set at 0.6 mL / min, the column temperature was set at 30°C. The mobile phase was 0.002% ammonia water / methanol (95 / 5, v / v), the injection volume was set at 20 µL, and the ultraviolet detection wavelength was set at 290 nm. The data in Table 1 and Table 2 were obtained.

[0039] The nano-reactor of the first embodiment of the present invention was respectively applied to wastewater and dyed hair, and its degradation efficiency was measured. The description of the experimental process was also added to obtain the data in Table 3.

[0040] The wastewater was the wastewater remaining after the use of the dye. The dyed hair was provided by volunteers with ordinary black hair for dyeing for subsequent experiments. First, human hair was washed with tap water and distilled water to remove exogenous PPD and dried. 2 g of hair dye was applied to 0.4 g of human hair. After waiting for 30 min, the hair was washed clean with distilled water to obtain dye wastewater and dyed hair samples. 5 mg of ascorbic acid was added to 5 mL of dye wastewater (Sample 1); 50 mg of tea polyphenols / SE-OPEO@BC was added to 5 mL of dye wastewater and reacted at 40°C for 70 min. Then, ascorbic acid was added to the above solution to stop the reaction (Sample 2); 5 mL of distilled water was added to 0.2 g of the dyed hair sample and sonicated for 30 min to extract the residual PPD in the hair. 5 mg of ascorbic acid was added to the extract (Sample 3); 5 mL of distilled water and 50 mg of tea polyphenols / SE-OPEO@BC were added to 0.2 g of the dyed hair sample, reacted at 40°C for 70 min, sonicated for 30 min to extract the residual PPD in the hair, and 5 mg of ascorbic acid was added to the extract (Sample 4). Finally, the concentration of PPD in the above samples was detected using a high-performance liquid chromatograph, and the liquid phase program settings were the same as above.

[0041] IV. Experimental data Table 1. Degradation efficiency of various materials for PPD within gradient time (%) Reaction time Tea polyphenols@BC SE-OPEO@BC Tea polyphenols / SE-OPEO@BC of Example 1 of the present invention 30 min 56.73±0.31 60.81±0.76 75.78±1.93 70 min 81.97±0.11 88.20±1.37 98.76±0.75 110 min 85.80±1.04 94.76±0.15 98.85±0.30 150 min 89.56±0.57 96.75±0.02 98.87±0.51 190 min 92.45±0.72 98.05±0.11 98.89±0.21 Table 2. Degradation efficiency of various materials for PPD per unit time Material Degradation efficiency (%) Tea polyphenols@BC 81.97±0.11 SE-OPEO@BC 88.20±1.37 Tea polyphenols / SE-OPEO@BC of Example 1 of the present invention 98.76±0.75 Table 3. Degradation effect of tea polyphenols / SE-OPEO@BC on PPD in wastewater and dyed hair Actual sample Initial concentration of PPD Degradation efficiency (%) Sewage 23.17 mg / L 97.87±0.13 Dyed hair 162.58 μg / L 95.67±0.47 As can be seen from Table 1, with the increase of reaction time, the degradation efficiencies of tea polyphenols@BC, SE-OPEO@BC, and tea polyphenols / SE-OPEO@BC are all increasing. It is worth noting that tea polyphenols / SE-OPEO@BC reaches the limit of degradation efficiency at a reaction time of 70 min, about 98%, which is the sample with the shortest reaction time and the highest degradation efficiency among the three samples. As can be clearly seen from Table 2, at the same time (70 min), tea polyphenols / SE-OPEO@BC has a high degradation efficiency of 98.76% for PPD, higher than 81.97% and 88.20% of tea polyphenols@BC and SE-OPEO@BC. As can be seen from Table 3, tea polyphenols / SE-OPEO@BC has a good degradation effect on PPD in sewage. The concentration of PPD detected in the sewage sample is 23.17 mg / L. After treatment with tea polyphenols / SE-OPEO@BC, the PPD removal rate can reach 97.87%. The concentration of PPD in the dyed hair sample is 162.58 µg / g, and the PPD removal rate can reach 95.67%.

[0042] The present invention can be industrialized. As daily necessities such as hair conditioners, shampoos, hair dyes, and skin care lotions with the function of degrading p-phenylenediamine, or as industrial treatment agents or environmental treatment agents such as wastewater treatment agents, industrial waste liquid treatment agents, and soil treatment agents with the function of degrading p-phenylenediamine, they can all achieve a high efficiency of degrading PPD.

[0043] The above are only the embodiments of the present invention. Common knowledge such as specific structures and characteristics known in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can be made. These should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A nanoreactor, characterized in that: Includes self-emulsifying orange peel essential oil, orange peel biochar particles, and tea polyphenols.

2. The nanoreactor according to claim 1, characterized in that: The orange peel biochar particles are the inner core, and the self-emulsifying orange peel essential oil and tea polyphenols are attached to the outer periphery of the orange peel biochar particles.

3. The nanoreactor according to claim 2, characterized in that: The self-emulsifying orange peel essential oil and tea polyphenols are also attached to the internal pore structure of the orange peel biochar particles.

4. The nanoreactor according to claim 1, characterized in that: The mass ratio of the self-emulsifying orange peel essential oil, orange peel biochar particles and tea polyphenols is 0.2:1:0.

2.

5. The method for preparing a nanoreactor according to any one of claims 1 to 4, characterized in that: The method comprises a self-emulsifying orange peel essential oil preparation step, an orange peel biochar particle preparation step and a fusion step.

6. The method for preparing a nanoreactor according to claim 5, characterized in that: The orange peel biochar particle preparation step includes a biochar preparation step, and the biochar is prepared by oxygen-limited pyrolysis.

7. The method for preparing a nanoreactor according to claim 5, characterized in that: In the fusion step, the mass ratio of the self-emulsifying orange peel essential oil, orange peel biochar particles, and tea polyphenols is 0.2:1:0.

2.

8. Use of the nanoreactor according to any one of claims 1 to 4 as a method for preparing a product of degrading p-phenylenediamine.

9. The use according to claim 8, characterized in that: This includes daily necessities such as conditioners, shampoos, hair dyes, and skin care lotions that contain degradable p-phenylenediamine.

10. The use according to claim 8, characterized in that: The invention comprises an industrial treatment agent or an environmental treatment agent containing a wastewater treatment agent, an industrial waste liquid treatment agent, a soil treatment agent and the like for degrading p-phenylenediamine.

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