CN114891517B - Rosin-based CO 2 /N 2 Responsive microemulsion, and preparation method and application thereof - Google Patents

Abstract

The invention discloses a rosin-based CO ₂ /N ₂ The responsive microemulsion comprises the following substances in parts by mass: 1-9 parts of surfactant compound system (ME), 1-15 parts of n-butanol (cosurfactant) and 1-9 parts of oil phase; wherein ME is derived from rosin-based CO ₂ /N ₂ The responsive surfactant MPANGG, sodium dodecyl sulfate and water are mixed. The microemulsion can be alternately introduced with CO ₂ /N ₂ The process can be repeated many times with no change in emulsion particle size before and after the response. The invention also discloses a method for preparing silver nano particles by using the microemulsion, which utilizes tertiary amine groups contained in MPANGG in the microemulsion to cause the tertiary amine groups to have oxidation-reduction reaction with silver ions to prepare the silver nano particles, thereby realizing the rapid separation of the nano particles from a system and having simple operation.

Description

A kind of rosin-based CO2/N2 responsive microemulsion and its preparation method and application

technical field

The invention belongs to the technical field of green surfactants, and in particular relates to a rosin-based CO ₂ /N ₂ responsive microemulsion and a preparation method and application thereof.

Background technique

As one of the noble metal nanomaterials, silver nanoparticles are widely used in many fields, for example, they can be used in antibacterial materials, antistatic materials, low temperature superconducting materials and biosensor materials. Nano-silver composite fibers with permanent antibacterial activity can be prepared by adding nano-silver to ordinary synthetic textiles; spun fibers coated with nano-silver have better antibacterial activity; as a catalytic material, nano-silver has catalytic activity.

Microemulsions can be used as novel reaction media for the synthesis of nanoparticles. The W/O microemulsion contains monodisperse nano-scale water droplets, which can be used as a micro-reaction pool for the synthesis of nanoparticles. When two or more precursor microemulsions for synthesizing nanoparticles are mixed, due to the random Brownian motion of the nanoscale dispersed phase (small water droplets) in the microemulsion, material exchange occurs in the small water droplets and becomes a microreactor. , and finally generate nanoparticles. At the same time, the small water droplets are wrapped with surfactants and co-surfactants, which can effectively prevent the agglomeration of the prepared nanoparticles. The microemulsion method is a versatile preparation technique that can control particle properties such as size, geometry, morphology, uniformity, and surface area. One of its main advantages is that it can prepare nanoscale metals with high surface area and high catalytic activity. base catalyst. The microemulsion method also has some disadvantages. For example, a large amount of surfactants and organic solvents are added to the system, which are difficult to separate and remove from the final product, so the demulsification of the emulsion is also very important, because the demulsification is usually from (micro ) is an important step in the acquisition/separation of products in emulsions. For ordinary emulsions, demulsification can generally be achieved by adjusting the temperature and adding electrolytes; more complex methods include adding demulsifiers and centrifugation, pulse voltage centrifugation, applying uneven electric fields, magnetic fluidized bed technology, and applying electric and magnetic fields at the same time , Apply strong electric field and microwave. Since the microemulsion is a thermodynamically stable system, it is more difficult to demulsify its stability or demulsification. In addition, in the subsequent treatment, if a large amount of surfactants/co-surfactants, oil phase or additives contained in the system are directly discharged It will not only cause environmental pollution but also cause waste of resources. Therefore, the development of stimuli-responsive microemulsions to realize the recycling and reuse of microemulsions is attracting more and more interest of scientific researchers. Common stimuli-responsive triggering factors include light, heat, magnetic field, redox agent, pH, etc. These triggering factors consume a lot of energy or irreversibly change the composition of the system, affecting the recycling and reuse of microemulsions. CO ₂ as An environmentally friendly, non-toxic, low-cost and easy-to-remove stimulant has attracted widespread attention.

At present, the research on the use of stimuli-responsive surfactants in the preparation of emulsions is mainly limited to ordinary emulsions, and there are relatively few reports on the preparation of microemulsions. The application of stimuli-responsive microemulsions is a potential way to realize the recycling and reuse of microemulsions. The stimuli-responsive energy sources prepared by these microemulsions use stimuli-responsive surfactants, but in contrast to stimuli-responsive surfactants, There are still relatively few reports on their preparation of microemulsions, and the current reported stimulus-responsive surfactants are still based on long-chain alkanes, so the present invention provides a kind of rosin-based surfactant prepared from natural resource rosin as raw material , a CO ₂ /N ₂ responsive microemulsion was prepared based on the surfactant, and the application of the CO ₂ /N ₂ responsive microemulsion in the preparation of nanoparticles was studied.

Contents of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a rosin-based CO ₂ /N ₂ responsive microemulsion and its preparation method and application.

To achieve the above object, the technical solution adopted in the present invention is:

A rosin-based CO ₂ /N ₂ responsive microemulsion, consisting of the following substances in parts by mass:

Surfactant compound system (ME) 1-9 parts,

1-15 parts of n-butanol (cosurfactant),

1-9 parts of oil phase;

Wherein, the surfactant compound system (ME) is composed of rosin-based CO ₂ /N ₂ responsive surfactant MPANGG, sodium dodecyl sulfate (SDS) and water in mass ratio (2-10): (1 -5): (6-30) composition.

As a preferred technical solution, the oil phase is alkane liquid compounds such as n-hexane, n-heptane, and liquid paraffin; more preferably, the oil phase is n-hexane.

The structural formula of the rosin-based CO ₂ /N ₂ responsive surfactant MPANGG (hereinafter referred to as MPANGG) is as follows:

The preparation method of MPANGG is: firstly add maleopimaric acid to rosin and maleic anhydride to obtain maleopimaric acid; then imidize maleopimaric acid and N,N-dimethyl-1,3-propylenediamine The reaction generates MPAN; finally, MPAN is esterified with glycidyl alcohol in absolute ethanol solvent to obtain the target product.

Another object of the present invention is to provide a method for preparing the above-mentioned rosin-based CO ₂ /N ₂ responsive microemulsion, comprising the following steps:

(1) Dissolving rosin-based CO ₂ /N ₂ responsive surfactants MPANGG and sodium lauryl sulfate in water to prepare a surfactant compound system;

(2) After mixing the surfactant complex system with n-hexane, n-butanol was added dropwise while stirring to prepare a CO ₂ /N ₂ responsive microemulsion. Use a capillary to slowly pass CO ₂ from the condenser tube into the microemulsion, the system will first become turbid, continue to pass CO ₂ , the system will have white precipitates, and the microemulsion will break; then pass N ₂ into the breaker in the same way In the system, the microemulsion needs to be ultrasonicated intermittently during the period, and the demulsified system becomes a clear and transparent microemulsion again, and this process can be repeated many times.

The third object of the present invention is to provide a method for preparing Ag nanoparticles using the above-mentioned rosin-based CO ₂ /N ₂ responsive microemulsion, comprising the following steps:

(1) Add the _AgNO3 aqueous solution to the rosin-based _CO2 / _N2 responsive microemulsion, stir and mix to obtain a uniform, colorless and transparent microemulsion, and react in a light-proof environment to form a microemulsion containing Ag nanoparticles; as a preferred According to the scheme, the temperature of the reaction in the dark environment is room temperature, and the time is 3-4 days, preferably 4 days;

(2) Introduce CO ₂ into the microemulsion containing Ag nanoparticles to cause demulsification, white precipitates are precipitated, and Ag nanoparticles are obtained by separating the white precipitates.

Reaction mechanism of the present invention is:

The rosin-based CO ₂ /N ₂ responsive surfactant MPANGG is a nonionic surfactant. When CO ₂ is passed into the microemulsion, MPANGG will be protonated into a cationic surfactant MPANGGH ⁺ ; the cationic MPANGGH ⁺ will react with the anion Sodium lauryl sulfate is combined into salt through electrostatic interaction and loses surface activity to demulsify the microemulsion; then _N2 is passed into the aqueous solution of MPANGGH ⁺ to deprotonate it and change it back to the nonionic surfactant MPANGG, the system It returns to the state of microemulsion again, and this process can be repeated many times; the response process and schematic diagram of the system to CO ₂ /N ₂ are as follows:

The formation of Ag nanoparticles is a redox reaction between the tertiary amine groups in MPANGG and _AgNO3 , and the reaction mechanism is as follows:

Compared with the prior art, the present invention has the following beneficial effects:

(1) The raw material of surfactant MPANGG described in the present invention is natural resource rosin, meets the concept of green sustainable development, and microemulsion, preparation method is simple, and raw material is green pollution-free; The microemulsion obtained after preparation responds repeatedly The particle size of the emulsion basically does not change, and it can be recycled many times.

(2) The present invention utilizes the tertiary amine group in MPANGG to _CO Responsiveness, by interacting with sodium lauryl sulfate, prepares a kind of responsive microemulsion; The stimuli responsiveness of this microemulsion The trigger factor is CO ₂ /N ₂ , CO ₂ /N ₂ is easy to remove from the system and will not pollute the microemulsion system, so that the microemulsion can be recycled, significantly reducing input costs; and CO ₂ /N ₂ is environmentally friendly , non-toxic, low price, easy for industrial application.

(3) Utilize the tertiary amine group that MPANGG contains in the microemulsion of the present invention, make it redox reaction with silver ion, prepare silver nanoparticles, and can realize the rapid separation of nanoparticles from the system, simple operation, improve production efficiency.

Description of drawings

Fig. 1 is the ¹ H NMR spectrogram of MPANGG;

Figure 2 is the appearance diagram of the CO ₂ /N ₂ responsive microemulsion response process;

Fig. 3 is the analysis diagram of the emulsion particle size after microemulsion repeated response 3 times;

Figure 4 is a comparison of the appearance before and after the AgNO ₃ aqueous solution was added to the microemulsion and left to stand for 4 days.

Detailed ways

Below in conjunction with embodiment the present invention will be further described. Apparently, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The preparation of embodiment 1MPANGG

100g (0.33mol, the total amount of abietic acid, neoabietic acid and palustric acid is calculated as 80%, 0.265mol) masson pine rosin, 35g (0.357mol) maleic anhydride, 40g acetic acid, react at 140°C for 4h, add after cooling 100g of glacial acetic acid was crystallized by cooling, and suction filtered to obtain maleopimaric acid.

Add 10g of maleopimaric acid into the reactor and dissolve it in ethanol, and stir at 85°C for 0.5h. Dissolve 2.55g of N,N-dimethyl-1,3-propanediamine in ethanol solvent, add it dropwise into the reactor, continue stirring for 5h after the dropwise addition, after cooling, white crystals precipitate, filter and dry to obtain MPAN

Add 10g MPAN into the reactor and dissolve it in ethanol. After stirring at 85°C for 0.5h, dissolve 2.36g of glycidyl alcohol in the solvent ethanol and add it into the reactor dropwise. After the dropwise addition, add triethyl alcohol Amine (the amount of triethylamine is 1wt% of the total mass of reactants), continue to stir for 8h, distill off the solvent, the crude product is purified by chromatography (methanol:dichloromethane volume ratio is 2:8) to obtain the product MPANGG.

^{The 1} H NMR spectrum of MPANGG is shown in Figure 1, and it can be seen from the ¹ H NMR spectrum of Figure 1 that the prepared product is the target product. Its structural formula is as follows:

Example 2CO ₂ /N ₂ Preparation of Responsive Microemulsion

Earlier 2.345g MPANGG, 1g sodium dodecyl sulfate (SDS) are dissolved in 6.06g water (the amount of the material of strict control MPANGG and SDS is the same), prepare surfactant complex system (ME); Get 0.4gME and After mixing 0.6 g of n-hexane, 1 g of n-butanol was added dropwise with stirring to obtain a clear and transparent microemulsion. Take the prepared microemulsion and drop them into water and n-hexane respectively. If it is dispersed in water and not dispersed in n-hexane, it is an O/W microemulsion. If it is not dispersed in water but dispersed in n-hexane, then It is a W/O microemulsion, and if it is dispersed in both water and n-hexane, it is a bicontinuous microemulsion. Through experiments, what the present invention prepares is W/O type microemulsion. It is verified by experiments that when ME: n-butanol: the mass ratio of n-hexane is (1-9): (1-15): (1-9), and MPANGG in ME: SDS: the mass ratio of water is (2 -10): (1-5): (6-30) can prepare CO ₂ /N ₂ responsive microemulsions; in addition, besides n-hexane, alkanes such as n-heptane and liquid paraffin can also be used It can be used as the oil phase to achieve the same experimental purpose.

Example 3

In order to make the experimental phenomenon more obvious, the microemulsion was placed in a stoppered scale test tube. In order to reduce the volatilization of n-hexane and n-butanol, the condenser tube was placed above the test tube, and _CO2 was slowly passed from the condenser tube into the microemulsion with a capillary tube. In the same way, the system becomes turbid first, and CO ₂ continues to be introduced, and the system has white precipitates, and the microemulsion breaks; then N ₂ is passed into the demulsification system in the same way, and the microemulsion needs to be ultrasonically intermittently during this period. The demulsified system becomes a clear and transparent microemulsion again, and this process can be repeated many times. The change of microemulsion appearance with CO ₂ /N ₂ is shown in Fig. 2 . Figure 3 is an analysis diagram of the particle size of the emulsion after the microemulsion responded three times. It can be seen from the figure that after several repetitions, the particle size of the emulsion basically does not change.

Example 4

After mixing 0.4 g of ME and 0.6 g of n-hexane, 1 g of n-butanol was added dropwise with stirring to obtain a clear and transparent microemulsion. Add 0.01g of _AgNO3 aqueous solution with a mass concentration of 2% to the microemulsion, mix it in the dark to obtain a uniform, colorless and transparent microemulsion, keep it in the dark at room temperature for 4 days, and take samples at regular intervals to measure its ultraviolet light. Near-infrared is visible, and with the prolongation of the standing time in the dark, the microemulsion gradually changes from uniform, colorless and transparent to reddish brown. ₃ is reduced to Ag nanoparticles, and due to the small size effect, the plasmonic excitation of the electrons on the surface of Ag nanoparticles will cause it to absorb ultraviolet and visible light. With the prolongation of the standing time, the absorbance increases, indicating that the silver ion Ag ⁺ is gradually reduced into metallic silver Ag.

Although this description is described according to implementation modes, not each implementation mode only includes an independent technical solution, and this description in the description is only for the sake of clarity, and those skilled in the art should take the description as a whole, and each embodiment The technical solutions can also be properly combined to form other implementations that can be understood by those skilled in the art. Therefore, the above descriptions are only preferred embodiments of the present application, and are not intended to limit the scope of implementation of the present application; that is, all equivalent transformations made according to the scope of the claims of the present application are within the protection scope of the claims of the present application. .

Claims (6)

1. A rosin-based CO ₂ /N ₂ responsive microemulsion, characterized in that: it is composed of the following materials in parts by mass: Surfactant compound system 1-9 parts, 1-15 parts of n-butanol, 1-9 parts of oil phase; Wherein, the surfactant compound system consists of rosin-based CO ₂ /N ₂ responsive surfactant MPANGG, sodium lauryl sulfate and water in mass ratio (2-10): (1-5): (6 -30) composition; The structural formula of the rosin-based CO ₂ /N ₂ responsive surfactant MPANGG is as follows:

. 2 . The rosin-based CO ₂ /N ₂ responsive microemulsion according to claim 1 , wherein the oil phase comprises at least one of n-hexane, n-heptane and liquid paraffin. 3. The preparation method of rosin-based _CO2 / _N2 responsive microemulsion as claimed in claim 1, characterized in that: comprising the following steps: (1) Disperse the rosin-based CO ₂ /N ₂ responsive surfactant MPANGG and sodium lauryl sulfate in water to prepare the surfactant compound system, denoted as ME; (2) Mix ME with the oil phase, and add n-butanol under agitation to prepare a CO ₂ /N ₂ responsive microemulsion; use a capillary to slowly pass CO ₂ into the microemulsion, and the microemulsion breaks; then N ₂ Into the demulsification system in the same way, the microemulsion needs to be ultrasonically intermittently during the period, and the demulsification system becomes a clear and transparent microemulsion again, and this process can be repeated many times. 4. A preparation method of Ag nanoparticles, characterized in that: comprise the steps: (1) Add the AgNO ₃ aqueous solution to the rosin-based CO ₂ /N ₂ responsive microemulsion as described in any one of claims 1 to 3, mix evenly to obtain a colorless and transparent microemulsion, and react in a light-proof environment Generate microemulsions containing Ag nanoparticles; (2) Introduce CO ₂ into the microemulsion containing Ag nanoparticles to cause demulsification, precipitate white precipitates, and separate the white precipitates to obtain Ag nanoparticles. 5 . The method for preparing Ag nanoparticles according to claim 4 , characterized in that: in step (1), the temperature of the reaction in the dark environment is room temperature, and the reaction time is 3-4 days. 6. The method according to claim 4, characterized in that: in step (1), the mass concentration of the solute in the AgNO ₃ aqueous solution is 1-3%.

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