CN102961891B - Sublimating crystallizing device - Google Patents

Abstract

The invention discloses a sublimation crystallization device, which comprises a constant temperature tube, a heating layer, a temperature controller and an air release tube. The movable material loading tube is placed in the sublimation area of the constant temperature tube, and the inner wall of the material loading tube is fixedly provided with a temperature measuring tube. The thermocouple connected to the temperature controller is placed in the temperature measuring tube. The crystallization area of the constant temperature tube is provided with a crystallization tube. The upper part of the crystallization tube is a planar structure, and a constant temperature circulating liquid medium is used to control the temperature of the outer surface of the crystallization tube. The invention can realize the three processes of sublimation crystallization with carrier gas flow, vacuum sublimation crystallization and target impurity intervention sublimation crystallization, easy to operate, accurate temperature measurement and temperature control, can precisely adjust the supersaturation of crystallization, and the obtained product is easy to pipet and analyze , which is conducive to the development of new polymorphic products and the study of crystallization nucleation and growth mechanisms.

Description

A kind of sublimation crystallization device

technical field

The invention relates to a sublimation crystallization device, belonging to the technical field of chemical equipment.

Background technique

Sublimation crystallization is different from solution crystallization. The crystallization process is less affected by other molecules, and can directly change from gaseous state to solid crystal. Some substances can be purified by sublimation crystallization or converted into polymorphic products that cannot be obtained by other crystallization methods.

The sublimation device in the current experiment has the following deficiencies: (1) The design of the device is simple, only the temperature of the sublimation zone is properly controlled, and the fine temperature adjustment of the crystallization zone is lacking; (2) The effect of supersaturation on the sublimation crystal morphology and (3) It is inconvenient to pipette the crystalline product, and the pipetting process can easily cause damage to the crystal morphology, which is not conducive to further analysis and testing of the product.

With the extensive research on polymorphism, more and more attention has been paid to the influence of foreign target impurity molecules or crystallization matrix on crystal habit and crystal form in sublimation crystallization. Foreign impurity molecules can be selectively adsorbed on some specific crystal faces, thereby changing the crystal growth rate, and finally causing changes in the crystal habit; impurity molecules can also be selectively adsorbed on certain specific crystal forms, inhibiting the growth of the crystal form. Growth, ultimately changing the quantitative ratio of different crystalline forms in the product. At present, the research on the influence of impurity molecules on the crystallization process is mainly concentrated in the field of solution crystallization, and the sublimation crystallization process has received less attention. Effect of crystallized settling matrix on crystallized product.

Contents of the invention

The purpose of the present invention is to provide a sublimation crystallization device with fine temperature control, convenient product transfer and scientific experiment, so as to solve the existing problems in the existing crystallization device, such as imprecise temperature control in the crystallization area, inconvenient transfer of crystallized products, and inability to introduce Target impurity molecules and alter crystal matrix deficiencies.

The realization process of the present invention is as follows:

A sublimation crystallization device, including a constant temperature tube, a heating layer, a temperature controller and an air release tube. The movable loading tube (7) is placed in the sublimation zone of the constant temperature tube (14), and the inner wall of the loading tube (7) is fixed with a measuring The temperature tube (5), the thermocouple is placed in the temperature measuring tube (5), and the thermocouple is connected to the temperature controller (4); the crystallization area of the thermostat tube (14) is provided with a crystallization tube (15), and the crystallization tube (15) The upper part is a planar structure, and a constant temperature circulating liquid medium is passed inside the crystallization tube (15) to control the temperature of the outer surface of the crystallization tube (15).

The first implementation mode of the present invention is: the opening end of the sublimation zone of the thermostatic tube (14) is provided with a sealing rubber plug (13).

The second implementation mode of the present invention is: the carrier gas cylinder (8) is connected to the sublimation zone of the thermostatic tube (14) through a conduit.

The third implementation mode of the present invention is: the material storage (2) is connected to the sublimation zone of the thermostatic tube (14) through a conduit, and the material storage (2) is placed in the thermostatic bath (1).

The constant temperature circulating liquid medium in the circulating constant temperature tank (10) of the present invention is passed into the crystallization tube (15) through the liquid inlet (11), and flows back into the circulating constant temperature tank (10) from the liquid outlet (12).

The upper part of the crystallization tube (15) of the present invention is a planar structure, and a glass sheet, a metal sheet, a silicon sheet or a plastic sheet is placed thereon.

Advantages and positive effects of the present invention: 1. The present invention can conveniently realize three processes of carrier gas sublimation crystallization, vacuum sublimation crystallization and target impurity intervention sublimation crystallization by changing the connection mode. 2. The use of movable loading tube can easily add or remove materials, measure the quality change of materials, calculate the sublimation rate, and facilitate cleaning after the experiment. 3. The inner wall of the loading tube is fixed with a temperature measuring tube, and the thermocouple is placed in the temperature measuring tube. This connection method realizes the close-range and rapid measurement of the material temperature, and the measured temperature is closer to the real temperature value of the material. 4. Using the constant temperature circulating liquid medium to precisely control the temperature of the crystallization tube realizes the control of the supersaturation of sublimation crystallization, and thus obtains crystallization products at different supersaturations, which is conducive to the development of new polymorphic products and is convenient for Conduct scientific research on crystallization nucleation and growth mechanism. 5. The planar structure design of the upper part of the crystallization tube can meet the needs of placing thin-sheet crystal substrates of different materials to study the influence of different substrates on the crystallization process. Direct microscope observation of the sublimation crystal products on the thin slices avoids the tedious and troublesome process of transferring products again. This results in damage to the shape.

Description of drawings

Figure 1 is a schematic diagram of the structure of a vacuum sublimation crystallization device. In the figure, 4-temperature controller, 5-temperature measuring tube, 6-heating layer, 7-loading tube, 9-venting tube, 10-circulating constant temperature tank, 11-liquid inlet, 12-liquid outlet, 13- Rubber stopper, 14-thermostatic tube, 15-crystallization tube;

Fig. 2 is a schematic diagram of the structure of a carrier gas sublimation crystallization device. In the figure 4-temperature controller, 5-temperature measuring tube, 6-heating layer, 7-loading tube, 8-carrier gas cylinder, 9-release tube, 10-circulating constant temperature tank, 11-liquid inlet, 12- Liquid outlet, 13-rubber plug, 14-thermostatic tube, 15-crystallization tube;

Fig. 3 is a schematic structural diagram of a sublimation crystallization device intervened by target impurities. In the figure 1-constant temperature tank, 2-material storage, 4-temperature controller, 5-temperature measuring tube, 6-heating layer, 7-loading tube, 9-venting tube, 10-circulating constant temperature tank, 11-inlet Liquid port, 12-liquid outlet, 13-rubber plug, 14-thermostatic tube, 15-crystallization tube;

Figure 4 is a photo of succinic acid vacuum sublimation crystallization (sublimation 180 degrees, crystallization area 95 degrees);

Figure 5 shows the crystallization of pyrene on glass under nitrogen carrier gas purging (sublimation zone 140 degrees, crystallization zone 35 degrees);

Figure 6 shows the crystallization of pyrene on aluminum foil under nitrogen carrier gas purging (sublimation zone 140 degrees, crystallization zone 35 degrees);

Figure 7 in the presence of isopropanol molecules in the crystallization sublimation zone 180 degrees, crystallization zone 95 degrees).

Detailed ways

In order to make the content of the present invention more clearly understood, the present invention will be further described in detail below according to specific embodiments of the present invention and in conjunction with the accompanying drawings.

Sublimation crystallization device, the movable loading tube 7 is placed in the sublimation zone of the constant temperature tube 14, the inner wall of the loading tube 7 is fixed with a temperature measuring tube 5, the thermocouple is placed in the temperature measuring tube 5, and the thermocouple is connected to the temperature controller 4 The crystallization zone of the thermostatic tube 14 is provided with a crystallization tube 15, and the upper part of the crystallization tube 15 is a planar structure, and the inside of the crystallization tube 15 has a constant temperature circulating liquid medium for controlling the temperature of the crystallization tube 15 outer surfaces.

Specifically, the present invention has the following three implementations:

1. The thermostatic tube 14 of the present invention can be directly connected to the rubber stopper in an airtight manner, and not connected to the material storage 2. At this time, the air release pipe 9 is connected to a vacuum pump to form a vacuum sublimation crystallization device.

2. The thermostatic tube 14 of the present invention can be connected with the carrier gas cylinder 8, the carrier gas cylinder 8 is an inert gas cylinder, and the gas release pipe 9 communicates with the atmosphere to form a carrier gas sublimation crystallization device.

3. The material storage container 2 of the present invention is a cylindrical container containing a liquid target impurity solvent (keep the cross-sectional size unchanged up and down). At this time, the air release pipe 9 is connected to the vacuum pump, and the temperature and flow rate are controlled by the constant temperature tank 1. The regulator realizes the introduction of target impurity molecules into the crystallization system at a uniform speed, constituting a sublimation crystallization device intervened by target impurities.

The outer diameter of the loading tube 7 is slightly smaller than the inner diameter of the thermostatic tube 14, so that the loading tube 7 is placed in the thermostatic tube 14 and ensure that all air flows through the loading tube 7.

Example 1: Vacuum sublimation crystallization

As shown in Figure 1, put about 1g of β-succinic acid crystal powder into the loading tube 7, weigh the total weight as m0, put the thermocouple into the temperature measuring tube 5, and move the loading tube 7 to the thermostatic tube 14 In the middle of the sublimation zone, cover the rubber stopper 13, place the glass sheet above the crystallization tube 15, adjust the temperature controller 4, set the heating temperature to 180°C, turn on the vacuum pump connected to the vent pipe 9, and turn on the circulation constant temperature tank 10, Keeping the set temperature at 95°C, the material in the loading tube 7 is heated and sublimated into a gas under reduced pressure. When the hot air flows through the glass sheet above the crystallization tube 15, the temperature of the hot air drops, and the formed supersaturated steam slowly Crystal nuclei are precipitated on the glass flakes, and the crystal nuclei grow gradually. After sublimation for a period of time t, turn off the vacuum pump, the circulation constant temperature tank 10, and the temperature controller 4. The thin glass slice placed above the crystallization tube 15 was taken out and observed under a microscope, the obtained crystal was needle-shaped ( FIG. 4 ), and the crystal form was α crystal form by XRD analysis, and the crystal form changed. Take out the loading tube 7 and weigh it as m1, and the sublimation rate = (m0-m1)/t can be obtained.

Example 2: Carrier gas flow sublimation crystallization

As shown in Figure 2, put about 1g of pyrene crystal powder into the loading tube 7, weigh the total weight as m0, put the thermocouple into the temperature measuring tube 5, and move the loading tube 7 to the sublimation zone of the thermostatic tube 14 Cover the middle part with the rubber stopper 13, connect the carrier gas cylinder 8 (nitrogen), and fix the nitrogen flow rate at 20 ml/min. Place the glass flake or aluminum foil above the crystallization tube 15, adjust the temperature controller 4, set the heating temperature to 140°C, connect the air release pipe 9 to the atmosphere, open the circulation constant temperature tank 10, keep the set temperature at 35°C, and adjust the flow regulator The material in the loading tube 7 is heated and sublimated into a gas under a nitrogen flow, and when the steam flows through the glass sheet or aluminum foil above the crystallization tube 15, the temperature of the hot air flow drops, and the formed supersaturated steam slowly precipitates crystal nuclei on the glass sheet, and the crystallization The nucleus grows gradually. After sublimation for a period of time t, the circulation constant temperature tank 10 and the temperature controller 4 are closed. Take out the glass flake or aluminum foil placed above the crystallization tube 15, place it under a microscope for observation, and get diamond-shaped flaky crystals on the glass flake (Figure 5), and spherical agglomerates on the aluminum foil (Figure 6). XRD analysis shows that the crystal form is not change. Take out the loading tube 7 and weigh it as m1, and the sublimation rate = (m0-m1)/t can be obtained.

Example 3: Sublimation crystallization intervened by target impurities

As shown in Figure 3, put about 1g of β-succinic acid crystal powder into the loading tube 7, weigh the total weight as m0, put the thermocouple into the temperature measuring tube 5, and move the loading tube 7 to the thermostatic tube 14 In the middle part of the sublimation zone, cover the rubber stopper 13, connect the material storage 2 (the target impurity is isopropanol solvent), open the constant temperature tank 1 to maintain a certain temperature to ensure that the evaporation pressure of isopropanol remains constant, and place the glass sheet Place it above the crystallization tube 15, adjust the temperature controller 4, set the heating temperature to 180°C, turn on the vacuum pump connected to the air release pipe 9, maintain a certain degree of vacuum, and ensure that the flow rate of the flow regulator is fixed. Open the circulating constant temperature tank 10, keep the set temperature at 95°C, adjust the flow regulator, the material in the loading tube 7 is heated and sublimated into a gas under the nitrogen flow, and when the steam flows through the glass sheet above the crystallization tube 15, the temperature of the hot air flow drops , the formed supersaturated steam slowly precipitates crystal nuclei on the glass sheet, and the crystal nuclei grow up gradually. After sublimation for a period of time t, turn off the vacuum pump, the circulation constant temperature tank 10, and the temperature controller 4. The thin glass slice placed above the crystallization tube 15 was taken out and observed under a microscope to obtain needle-shaped crystals ( FIG. 7 ). XRD analysis showed that the crystal form had not changed. Take out the loading tube 7 and weigh it as m1, and the sublimation rate = (m0-m1)/t can be obtained.

Claims (6)

1. a distillation crystallization apparatus, comprise constant warm tube, zone of heating, temperature controller and bleeder pipe, it is characterized in that: movable material containing pipe (7) is placed in the distillation district of constant warm tube (14), material containing pipe (7) inwall is fixedly installed temperature tube (5), the thermocouple be connected with temperature controller (4) is placed in temperature tube (5), the crystal region of constant warm tube (14) is provided with crystallizer (15), crystallizer (15) top is planar structure, and inside is connected with constant temperature circulating liquid medium for crystallization control pipe (15) hull-skin temperature; Material storage storage (2) is communicated to the distillation district of constant warm tube (14) by conduit, and the material storage storage (2) for storing liquid target impurity solvent is placed in thermostat (1).

2. distillation crystallization apparatus according to claim 1, is characterized in that: described material containing pipe (7) external diameter is slightly less than constant warm tube (14) internal diameter, to be placed in constant warm tube (14) and to ensure air-flow all through material containing pipe (7) to make material containing pipe (7).

3. distillation crystallization apparatus according to claim 1, is characterized in that: the openend in constant warm tube (14) distillation district is provided with sealing rubber plug (13).

4. distillation crystallization apparatus according to claim 1, is characterized in that: material storage storage (2) is hydrostatic column.

5. according to one of any described distillation crystallization apparatus of Claims 1-4, it is characterized in that: the constant temperature circulating liquid medium in circulation thermostat (10) passes into crystallizer (15) by inlet (11), flows back to circulation thermostat (10) from liquid outlet (12).

6. distillation crystallization apparatus according to claim 5, is characterized in that: crystallizer (15) top is planar structure, is placed with sheet glass, sheet metal, silicon chip or plastic sheet.