Micro liquid crystallization device based on electric field enhancement

Abstract

The utility model relates to a crystallization process and crystallization equipment in a chemical process, in particular to a micro liquid crystallization device based on electric field enhancement, and belongs to the field of novel chemical equipment. According to the utility model, the mixing and homogenization of solutions are realized by utilizing the simple micro-channel fluid conveying disturbance and the self-circulation mixing effect of micro-liquid. A uniform electric field capable of being continuously adjusted is introduced into the crystallizer to realize crystallization process strengthening and crystal form screening. And efficient regulation and control and preparation of a micro liquid crystal product are realized by utilizing the action of series or parallel coupling electric fields of the multi-stage microchannels, and the key problem that a traditional crystallizer cannot regulate and control the micro liquid crystallization process is solved.

Description

Technical Field

[0001] The utility model relates to a crystallization process and crystallization equipment in a chemical process, in particular to a trace liquid crystallization device based on electric field enhancement, belonging to the field of new chemical equipment. Background Art

[0002] Crystallization is a key step in the chemical process for the purification and preparation of substances. In the traditional crystallization process, crystal growth is affected by many factors such as solution saturation, temperature, solvent type, etc. However, the morphological characteristics of the crystals, including particle size, crystal form and purity, are difficult to control, especially in the field of pharmaceutical products involving small liquid production processes and specific crystal form screening. As an external control method, the potential of electric field to influence the crystallization process has been preliminarily verified.

[0003] The existing crystallization equipment of various sizes all use kettle crystallizers, such as: CN201410307, ​​CN203653265U, CN108371828A, etc. The kettle crystallizer must be equipped with macroscopic stirring equipment such as stirring rods, mechanical stirring paddles, and magnetic stirring rods, which limits the minimum amount of liquid used. For the crystallization process of trace liquids, traditional kettle crystallizers cannot be used for regulation. In addition, the electric field has an enrichment effect on the interface of micro-droplet solutes. This makes it difficult to introduce electric fields as a means of regulation in kettle crystallizers, and it is impossible to achieve the screening of directional crystal forms.

[0004] At present, there is no solution that can provide an effective method to achieve efficient regulation and crystal form screening of tiny liquid amounts of crystals, which seriously limits its application in high-end crystal preparation and other fields. Utility Model Content

[0005] In order to solve the deficiencies of the prior art, the utility model provides a new crystallization device, which is a trace liquid crystallization control device based on electric field enhancement. The solution is mixed and homogenized by using simple microchannel fluid transport disturbance and the self-circulating mixing effect of trace liquid. The crystallization process is enhanced and the crystal type screening is achieved by introducing a continuously adjustable uniform electric field inside the crystallizer. The series or parallel coupled electric field effect of multi-stage microchannels is used to achieve efficient control and preparation of trace liquid crystal products, solving the key problem that traditional crystallizers cannot control the trace liquid crystallization process.

[0006] In order to realize the above utility model, the following specific technical solutions are provided:

[0007] A trace liquid crystallization device based on electric field enhancement comprises a voltage regulator, two electrode plates, a bottom member and a top member; the bottom member is a trough structure, in which one or more crystallization pools with independent channels are arranged, and one or more inlets and outlets are arranged on both sides of the bottom member, corresponding to the channels of the crystallization pool one by one and communicating with the corresponding channels; notches are arranged around the upper part of the bottom member for liquid evaporation; the top member is fixed on the top of the bottom member and serves as a cover of the bottom member; the top member and the bottom member are both provided with grooves for placing the electrode plates, wherein the groove of the bottom member is located below the crystallization pool so that the crystallization pool is located between the upper and lower electrode plates; the two electrode plates are both connected to an external voltage regulator, and the voltage between the two electrode plates is adjusted by the voltage regulator to change the electric field strength in the crystallization pool.

[0008] The bottom component and the top component are made of polyacrylic resin.

[0009] The electrode plate is made of metal material, such as copper or silver.

[0010] The depth of the channel of the crystallization pool does not exceed 20 mm, and the length and width of the channel of a single crystallization pool are less than 10 times of its depth.

[0011] The bottom area of ​​the crystallization pool is smaller than the bottom area of ​​the groove for placing the electrode plate.

[0012] The four sides of the crystallization pool are rounded.

[0013] When there are multiple channels in the crystallization pool, the multiple channels can be used in parallel to improve the production efficiency of the product per unit time. The multiple channels can also be connected in series in sequence to be used as a continuous multi-stage crystallization pool to improve the purity and control efficiency of the crystal product.

[0014] The above-mentioned trace liquid crystallization device based on electric field enhancement is used to perform crystallization control, including the following steps:

[0015] (1) Solution preparation: Determine the solution and its concentration based on the crystal type.

[0016] (2) Solution injection: The solution is injected into each independent channel of the crystallization pool, and the channels are connected in parallel or in series.

[0017] (3) Electric field application and regulation: Start the voltage regulator and adjust the voltage between the electrode plates to control the electric field strength in the crystallization pool; by adjusting the electric field, the growth direction, rate and morphology of the crystal can be affected.

[0018] (4) Crystal growth and collection: Under the action of the electric field, the crystals grow in the crystallization pool. When the desired crystal size and quality are reached, the electric field application is stopped and the crystals are collected.

[0019] Beneficial effects of the utility model:

[0020] The multi-channel circulation crystallizer proposed in the utility model includes a bottom and a top member, both of which are designed with grooves for embedding electrode plates. This design not only solves the shielding effect of the crystallizer on the external electric field, but also further simplifies the structure, so that the electrode plates can be independently disassembled without affecting the operation of the crystallization pool.

[0021] By adjusting the voltage between the top and bottom electrode plates, a uniform electric field is introduced into the microfluid environment. The strengthening effect of the electric field not only promotes the uniform growth of crystals, but also selectively controls the formation of different crystal forms by changing the electric field parameters, thereby meeting the needs of specific chemical products.

[0022] The crystallization pool includes several independent microfluid channels. By means of the fluid transport disturbance in the microchannel and the self-circulating mixing effect of the micro liquid, the mixing and homogenization of the micro liquid is achieved without an external stirring device.

[0023] Each channel can be independently affected by the electric field generated by the electrode plate, allowing both parallel production of multiple crystals and series connection to improve crystal production efficiency and product quality.

[0024] Through the above-mentioned design and functions, the utility model can not only regulate the crystal growth process of trace fluids and realize high-efficiency and high-quality production of high-end crystal products, but also expand the application scope of crystallization technology in the fields of materials science and chemical industry. It is an innovative new chemical equipment method suitable for the preparation of high-end materials and fine chemical products.

[0025] Compared with the traditional crystallization control scheme, the utility model adopts a microchannel design, does not require macroscopic stirring equipment, and has no minimum liquid usage, which significantly expands the scene of crystal production. At the same time, the introduction of an adjustable internal electric field as a means of controlling the crystallization process solves the key problem that the traditional crystallizer cannot achieve trace liquid crystal type screening. In addition, the utility model adopts a multi-channel design, and the control and preparation efficiency of crystal products is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of a single-channel circulation crystallizer.

[0027] Figure 2 Schematic diagram of a multi-channel circulation crystallizer.

[0028] In the figure: 1 groove of the upper electrode plate, 2 crystallization pool, 3 groove of the lower electrode plate. DETAILED DESCRIPTION

[0029] The specific implementation of the utility model is further described below in conjunction with the accompanying drawings and technical solutions.

[0030] The micro-liquid crystallization device based on electric field enhancement of the utility model has a single-channel structure as follows Figure 1 As shown, the multi-channel structure is as follows Figure 2 As shown, they all include a voltage regulator, two electrode plates, a bottom member, and a top member. The bottom member is a trough structure, in which one or more crystallization pools 2 with independent channels are arranged, and one or more inlets and outlets are arranged on both sides of the bottom member, corresponding to the channels of the crystallization pools 2 one by one, and connected to the corresponding channels; the top member is fixed on the top of the bottom member, serving as a cover of the bottom member; the top member is provided with a groove 1 for placing the upper electrode plate, and the bottom member is provided with a groove 3 for placing the lower electrode plate, wherein the groove of the bottom member is located below the crystallization pool, so that the crystallization pool is located between the upper and lower electrode plates; both electrode plates are connected to an external voltage regulator.

[0031] (1) Structure and layout of crystallizer:

[0032] Crystallizer body: The crystallizer of the utility model includes a bottom member and a top member, both of which are made of high temperature resistant polyacrylic resin material. Each member is designed with a groove for embedding the electrode plate to ensure the stability of the electrode plate and facilitate maintenance and replacement.

[0033] Multi-channel crystallization pool: A microfluidic crystallization pool with multiple independent channels in the bottom member. Each channel can be operated independently and can independently receive the electric field generated by the electrode plate, which is suitable for different experimental settings and production needs. The design of these channels allows different crystal growth environments to be carried out in one device at the same time, increasing experimental flexibility and high throughput of production.

[0034] (2) Generation and regulation of electric field:

[0035] Configuration of electrode plates: Electrode plates are respectively embedded in the grooves of the top and bottom components, and the electrode plates are made of metal materials with good conductivity, such as copper or silver. The design of the electrode plates ensures that a uniform electric field can be generated in the entire crystallization pool to regulate the crystallization environment in the crystallization pool.

[0036] Voltage regulation mechanism: The crystallizer is equipped with a voltage regulator that can accurately control the voltage difference between the electrode plates. High-throughput preparation of crystals is achieved by adjusting the electric field strength. Users can adjust the voltage as needed to change the electric field strength in the crystallization pool and achieve precise control of the crystal growth rate and crystal form.

[0037] (3) Preparation of crystals:

[0038] Solution preparation: First, prepare a solution containing the desired crystals. The solution should be prepared with a suitable solvent and concentration based on the specific crystal type.

[0039] Solution injection: Inject the prepared solution into each independent channel of the multi-channel crystallization pool.

[0040] Electric field application and regulation: Start the voltage regulator and adjust the voltage between the electrode plates according to the experimental requirements to control the electric field strength in the crystallization pool. By adjusting the electric field, the growth direction, rate and morphology of the crystal can be affected.

[0041] Crystal growth and collection: Under the action of an appropriate electric field, crystals grow in the crystallization pool. After reaching the desired crystal size and quality, the electric field application is stopped and the crystals are collected.

[0042] In this embodiment, the size of the groove 1 of the upper electrode plate and the groove 3 of the lower electrode plate is 78mm×30mm×3.5mm, which is specially used to install the electrode plate. In addition, a rectangular crystallization pool 2 with a size of 70mm×22mm×7.5mm is designed in the bottom component, and all the tip interfaces of the crystallization pool 2 are rounded with a radius of 0.5mm to reduce the influence of the tip heterogeneous interface on crystal nucleation and growth. The model is printed using a high-precision 3D printer with a resolution of 10μm. The two parts of the component are assembled and integrated by bolts, and an electrode plate with a size of 75mm×28mm×2.0mm is installed in the groove 1 of the upper electrode plate and the groove 3 of the lower electrode plate, and connected to the positive and negative high-voltage DC power supplies respectively. At this time, the distance between the two electrode plates is 25mm, and the crystallization pool 2 is located between the two electrode plates.

[0043] In the current production process, it is difficult to directly produce paracetamol crystals of pharmaceutical grade purity by crystallization. However, based on the utility model, paracetamol crystal screening and preparation of pharmaceutical grade high-purity crystal products are realized. The specific process is as follows:

[0044] First, prepare 200 mL of saturated paracetamol ethanol solution and inject it into the crystallization pool. Turn off the power supply connected to the electrode and control the electric field strength in the crystallization pool to 0 V mm -1 , paracetamol crystal product of form I (monoclinic system) was prepared. At this time, the average particle size of the crystal was 0.28 mm and the purity was 86.7%. Subsequently, 200 mL of saturated paracetamol ethanol solution was re-prepared and injected into the crystallization pool. The power supply connected to the electrode was turned on, the voltage between the two plates was adjusted, and the electric field strength in the crystallization pool was controlled to be 600 V mm -1 , a paracetamol crystal product of crystal form II (orthorhombic system) was prepared. At this time, the average particle size of the crystal was 0.79 mm and the purity was 98.8%.

[0045] Through the above experiments, the utility model has proved its significant advantages in improving the efficiency and quality of crystal preparation, and is particularly suitable for high-tech fields and industrial production that require precise control of the crystal growth environment.

Claims

1. A micro-liquid crystallization device based on electric field enhancement, characterized in that: The trace liquid crystallization device based on electric field enhancement includes a voltage regulator, two electrode plates, a bottom member and a top member; the bottom member is a trough structure, in which one or more crystallization pools with independent channels are arranged, and one or more entrances and exits are arranged on both sides of the bottom member, corresponding to the channels of the crystallization pool one by one and connected to the corresponding channels; notches are arranged around the upper part of the bottom member for liquid evaporation; the top member is fixed on the top of the bottom member and serves as a cover of the bottom member; the top member and the bottom member are both provided with grooves for placing electrode plates, wherein the groove of the bottom member is located below the crystallization pool so that the crystallization pool is located between the upper and lower electrode plates; the two electrode plates are both connected to an external voltage regulator, and the voltage between the two electrode plates is adjusted by the voltage regulator to change the electric field strength in the crystallization pool.

2. The trace liquid crystallization device based on electric field enhancement according to claim 1, characterized in that: The bottom component and the top component are made of polyacrylic resin.

3. A micro-liquid crystallization device based on electric field enhancement according to claim 1 or 2, characterized in that: The electrode plate is made of metal material.

4. A micro-liquid crystallization device based on electric field enhancement according to claim 1 or 2, characterized in that: The depth of the channel of the crystallization pool does not exceed 20 mm, and the length and width of the channel of a single crystallization pool are less than 10 times of its depth.

5. A trace liquid crystallization device based on electric field enhancement according to claim 1 or 2, characterized in that: The bottom area of ​​the crystallization pool is smaller than the bottom area of ​​the groove for placing the electrode plate.

6. A micro-liquid crystallization device based on electric field enhancement according to claim 1 or 2, characterized in that: The four sides of the crystallization pool are rounded.

7. A trace liquid crystallization device based on electric field enhancement according to claim 1 or 2, characterized in that: When there are multiple channels in the crystallization pool, the multiple channels are used in parallel, or the multiple channels are connected in series in sequence to be used as a continuous multi-stage crystallization pool.

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