Cement hydration reaction regulating device and experimental method based on microfluidic technology

Abstract

The application provides a cement hydration reaction regulation device and experimental method based on microfluidic technology, and relates to the technical field of cement hydration test and analysis. The cement clinker and gypsum are taken as a whole, the solid-liquid interface of the former and water is taken as an observation object, microscopic observation is carried out through a microscope, and the input efficiency of water and modified substances is regulated through microfluidic technology, so that the dynamic process of the hydration reaction can be obtained. The application can well solve the problems that the single experiment consumes a long time in the cement hydration experiment process, only the properties of the formed cement can be compared, and the experimental flexibility is poor.

Description

Technical Field

[0001] This invention relates to the field of cement hydration testing and analysis technology, specifically to a cement hydration reaction control device and experimental method based on microfluidic technology. Background Technology

[0002] Cement, with its excellent binding properties, compatibility, economy, and durability, has become the most widely used and cost-effective core basic material in the modern construction field. The core essence of cement forming is the cement hydration reaction: cement clinker reacts with gypsum and water to produce cementitious hydration products. These cementitious hydration products gradually aggregate and fill the pores of the paste, eventually hardening to form dense cement with high strength.

[0003] Therefore, the hydration reaction of cement is an important factor affecting the properties of cement. Researchers have been able to obtain cement of better quality by adjusting the types and proportions of materials used in the hydration reaction and the environmental conditions of the hydration reaction.

[0004] However, most current modifications of cement-based materials are based on comparisons of the properties of the molded cement, which has the following drawbacks:

[0005] (1) Each experiment takes a long time and can only be compared by the properties of the cement after molding, resulting in poor experimental flexibility.

[0006] (2) The properties of cement are related to the hydration reaction, as well as its molding process and curing conditions. In many experiments, it is difficult to control these external factors outside the hydration process, which affects the accuracy of the experimental results of the hydration process.

[0007] (3) There are differences in the size of clinker and gypsum particles during the cement hydration process. Therefore, the comparison mainly relies on the macroscopic properties of the formed cement. However, there are no obvious external characteristics in the macroscopic state during the hydration process.

[0008] (4) Cement hydration actually occurs at the microscopic level, and experiments cannot be designed based on the actual reaction phenomena. Summary of the Invention

[0009] Therefore, this invention provides a cement hydration reaction control device and experimental method based on microfluidic technology to solve the above-mentioned problems. Taking cement clinker and gypsum as a whole, the solid-liquid interface between the former and water is observed. Microscopic observation is performed using a microscope, and the dynamic process of the hydration reaction can be obtained by controlling the input efficiency of water and modifying substances through microfluidic technology. This invention effectively solves the problems of traditional cement modification experiments.

[0010] This invention provides a cement hydration reaction control device based on microfluidic technology, comprising a reaction plate with a reaction channel on its upper surface; the reaction channel has an inlet end and an outlet end at both ends, with the inlet end connected to a liquid injection device. The liquid injection device includes a housing, within which a syringe is disposed, and a flexible tube is connected to the output end of the syringe, extending into the inlet end of the reaction channel.

[0011] Furthermore, the syringe includes a syringe barrel with an internal cavity. A sealing plate is slidably connected inside the cavity, and an injection rod is provided on the side of the sealing plate away from the syringe output end. The side of the sealing plate is slidably connected to the inner surface of the cavity to realize the piston function. A sealing ring may also be provided on the side of the sealing plate to ensure the possibility of sliding.

[0012] Furthermore, the end of the injection rod away from the injection cylinder is connected to a push rod, which passes through one end of the housing and is connected to a fixing plate at one end of the fixing frame; a threaded hole is provided on the fixing plate at the other end of the fixing frame, and a screw is threaded into the threaded hole; one end of the screw extends into the fixing frame, and the other end is connected to the motor output shaft.

[0013] Furthermore, a limiting plate is provided on the lower surface of the fixed frame, and the limiting plate is connected to the housing; the limiting plate contacts the surface of the fixed frame, which can limit the fixed frame and prevent it from rotating, without hindering the movement of the fixed frame relative to the surface of the limiting plate.

[0014] Furthermore, the reaction channel is S-shaped, which can extend the length of the reaction channel.

[0015] Furthermore, the syringes are arranged in three groups side by side inside the housing, with the output end of each group of syringes connected to the inlet end of the reaction channel, thereby improving injection efficiency.

[0016] Furthermore, the upper surface of the reaction plate is covered with a glass plate to facilitate observation of the reaction channel.

[0017] The present invention also provides a cement hydration experimental method based on the above-mentioned cement hydration reaction control device based on microfluidic technology, comprising the following steps:

[0018] Step 1: Grind the cement clinker and gypsum into powder and press them into a plate with an area of ​​150mm × 120mm; carve reaction channels with a width of 2mm and a depth of 2mm on the plate surface. The length and shape of the channels can be adjusted according to actual needs; install liquid bolts at the inlet and outlet ends of the reaction channels on the edge of the plate; cover the reaction plate with a glass plate.

[0019] Step 2: After adding the required modified solution and water to the syringe, insert the syringe body into the limiting groove opened in the shell, connect the connecting hose to the output end of the syringe head, and adjust the hose to keep the whole hose in a horizontal state so that it is connected to the inlet end of the reaction channel. Start the motor to push the push rod until the push rod slightly touches the surface of the syringe rod tail.

[0020] Step 3: During the experiment, start the servo motor to inject a small amount of liquid into the reaction channel; focus the microscope on the interface between the reaction plate and the liquid and observe the reaction at this point; the liquid will flow further into the channel as it is actually moved. By moving the microscope, the cement hydration reaction phenomenon at different reaction times can be captured.

[0021] Furthermore, in step three, before the experiment, the entire device is placed on the microscope platform for easy observation.

[0022] The present invention has the following advantages over the prior art:

[0023] 1. This invention addresses the problems of long single-experiment time and poor experimental flexibility in traditional cement hydration experiments. By using microfluidic technology, only a single high-concentration solution needs to be prepared. The flow rate can be controlled by this device to achieve gradient experiments with multiple concentrations. Furthermore, it can be combined with a microscope to achieve real-time microscopic observation of the cement hydration reaction. The scheme can be adjusted in time when the experimental results deviate from the expectations, effectively shortening the experimental time and improving the experimental flexibility.

[0024] 2. This invention addresses the problem that external factors outside the hydration process, such as cement molding process and curing conditions, are difficult to control and can easily affect the accuracy of experimental results. It directly observes the hydration reaction process, avoiding interference from molding and curing processes. Furthermore, the device has a small overall size, making it easy to precisely control external environmental conditions such as temperature and humidity, significantly reducing the impact of external factors on experimental results and improving the accuracy of experimental results.

[0025] 3. This invention addresses the issue that cement hydration is a microscopic reaction—the macroscopic state of the hydration process has no obvious external characteristics. Traditional experiments can only rely on comparisons of the macroscopic properties of the formed cement, lacking direct reference. Therefore, experiments cannot be designed based on actual reaction phenomena. This invention takes the solid-liquid interface between cement clinker and water as the object of observation. Through a microscope, the cement hydration reaction phenomena at different reaction times can be captured, obtaining the dynamic process of the hydration reaction. It can link the modified solution with the microscopic phenomena of the hydration reaction, making it easier for researchers to discover experimental laws, design and optimize experimental schemes based on actual reaction phenomena. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0029] Figure 3 This is a schematic diagram of the fixed frame structure of the present invention.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Reaction plate; 2. Reaction channel; 3. Inlet end; 4. Outlet end; 5. Shell; 6. Syringe; 7. Injector; 8. Sealing plate; 9. Injection rod; 10. Push rod; 11. Fixing frame; 12. Fixing plate; 13. Screw; 14. Motor; 15. Limiting plate; 16. Glass plate; 17. Tube. Detailed Implementation

[0032] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1

[0034] Reference Figures 1 to 3This invention provides a cement hydration reaction control device based on microfluidic technology, comprising a reaction plate 1, with a reaction channel 2 disposed on the upper surface of the reaction plate 1; the reaction channel 2 has an inlet end 3 and an outlet end 4 at both ends, and the inlet end 3 is connected to a liquid injection device. The liquid injection device includes a housing 5, and a syringe 6 is disposed inside the housing 5. A flexible tube 17 is connected to the output end of the syringe 6, and the flexible tube 17 extends into the inlet end 3 of the reaction channel 2. The syringe 6 includes an injection cylinder 7 with an internal cavity, and a sealing plate 8 is slidably connected inside the cavity. An injection rod 9 is disposed on the side of the sealing plate 8 away from the output end of the syringe 6; the side of the sealing plate 8 is slidably connected to the inner surface of the cavity to achieve a piston function; a sealing ring can also be disposed on the side of the sealing plate 8 to ensure the possibility of sliding. The injection rod 9 is connected to a push rod 10 at the end away from the injection cylinder 7. The push rod 10 passes through one end of the housing 5 and connects to a fixing plate 12 at one end of the fixing frame 11. A threaded hole is provided on the fixing plate 12 at the other end of the fixing frame 11, and a screw 13 is threaded into the threaded hole. One end of the screw 13 extends into the fixing frame 11, and the other end is connected to the output shaft of the motor 14. A limit plate 15 is provided on the lower surface of the fixing frame 11 and is connected to the housing 5. The limit plate 15 contacts the surface of the fixing frame 11, which can limit the fixing frame 11 and prevent it from rotating, without hindering the movement of the fixing frame 11 relative to the surface of the limit plate 15. The reaction channel 2 is S-shaped, which can extend the length of the reaction channel 2.

[0035] The syringes 6 are arranged in three groups side by side inside the housing 5. The output end of each group of syringes 6 is connected to the inlet end 3 of the reaction channel 2 to improve injection efficiency. The upper surface of the reaction plate 1 is covered with a glass plate 16 to facilitate observation of the reaction channel 2.

[0036] The motor 14 can be adjusted and controlled in terms of speed and direction using existing technology. The screw 13 is coaxially fixed to the drive shaft of the motor 14. A cuboid is positioned with a threaded hole of the same size as the screw 13 at the center of its left side. Limiting plates 15 can be installed on both the top and bottom surfaces to prevent the frame from rotating, thus allowing the fixed frame 11 to move forward and backward. The fixed frame 11 is connected to the push rod 10, whose diameter is the same as the diameter of the opening on the side of the housing 5, allowing it to pass through the housing 5 and rest against the tail plane of the injection rod 9. When the servo motor 14 drives the threaded rod to rotate, the fixed frame 11 is driven by the thread and, due to its limitation, can only move forward and backward, thus advancing the push rod 10 and ultimately placing the injection rod 9 inside the syringe 7. The housing 5 has a columnar limiting groove in the middle to restrict the position of the main body of the syringe 6. Small holes are provided on the left and right sides of the housing 5. The small hole on the left allows the push rod 10 to extend and rest against the tail of the injection rod 9 of the syringe 6. The small hole on the right allows the connecting hose 17 to pass through and connect to the syringe 6. The reaction plate is composed of a mixture of cement clinker and gypsum, and has reaction channels 2. Liquid bolts are installed at each inlet and outlet for easy connection to the output end of the syringe 6 via hoses 17. The internal area of ​​the reaction plate frame is 150mm × 120mm. The cement clinker and gypsum are ground and pressed into a plate with an area of ​​150mm × 120mm. Reaction channels 2, 2mm wide and 2mm deep, are engraved on the plate surface; the length and shape of the channels can be adjusted according to actual needs. Liquid bolts are installed at the inlet and outlet ports on the edge of the plate. A high-transparency quartz plate is then placed over the reaction plate.

[0037] Example 2

[0038] This embodiment provides a cement hydration experimental method based on the above-mentioned microfluidic technology-based cement hydration reaction control device, including the following steps:

[0039] Step 1: Grind the cement clinker and gypsum into powder and press them into a plate with an area of ​​150mm×120mm; carve reaction channels 2 with a width of 2mm and a depth of 2mm on the plate surface. The length and shape of the channels can be adjusted according to actual needs; install liquid bolts at the inlet end 3 and outlet end 4 of the reaction channels 2 on the edge of the plate; cover the reaction plate with glass plate 16.

[0040] Step 2: After adding the required modified solution and water to the syringe 6, insert the main body of the syringe 6 into the limiting groove opened in the housing 5, connect the output end of the syringe 6 to the connecting hose 17, and adjust the hose 17 to keep the whole horizontal so that it is connected to the inlet end 3 of the reaction channel 2. Start the motor 14 to push the push rod 10 until the push rod 10 slightly touches the tail surface of the syringe rod 9 of the syringe 6.

[0041] Step 3: During the experiment, start the servo motor 14 to inject a small amount of liquid into the reaction channel 2; focus the microscope on the interface between the reaction plate and the liquid and observe the reaction at this point; the liquid will flow further into the channel as it actually flows. By moving the microscope, the cement hydration reaction phenomenon at different reaction times can be captured.

[0042] In step three, before the experiment, the entire apparatus is placed on the microscope platform for easy observation. Before placing it, a sheet material can be placed on the microscope platform to prevent it from widening, which facilitates the overall placement of the apparatus.

[0043] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A cement hydration reaction control device based on microfluidic technology, characterized in that, The reaction plate (1) is provided with a reaction channel (2) on its upper surface; the reaction channel (2) has an inlet end (3) and an outlet end (4) at both ends, and the inlet end (3) is connected to a liquid injection device.

2. The cement hydration reaction control device based on microfluidic technology according to claim 1, characterized in that, The liquid injection device includes a housing (5), a syringe (6) is provided inside the housing (5), and a hose (17) is connected to the output end of the syringe (6). The hose (17) extends into the inlet end (3) of the reaction channel (2).

3. The cement hydration reaction control device based on microfluidic technology according to claim 2, characterized in that, The syringe (6) includes a syringe barrel (7) with an internal cavity. A sealing plate (8) is slidably connected inside the cavity. An injection rod (9) is provided on the side of the sealing plate (8) away from the output end of the syringe (6).

4. The cement hydration reaction control device based on microfluidic technology according to claim 3, characterized in that, The injection rod (9) is connected to a push rod (10) at the end away from the injection cylinder (7). The push rod (10) passes through the housing (5) and is connected to the fixing plate (12) at one end of the fixing frame (11). The fixing plate (12) at the other end of the fixing frame (11) has a threaded hole, and a screw (13) is threaded into the threaded hole. One end of the screw (13) extends into the fixing frame (11), and the other end is connected to the output shaft of the motor (14).

5. The cement hydration reaction control device based on microfluidic technology according to claim 4, characterized in that, A limiting plate (15) is provided on the lower surface of the fixed frame (11), and the limiting plate (15) is connected to the shell (5).

6. The cement hydration reaction control device based on microfluidic technology according to claim 5, characterized in that, The reaction channel (2) is S-shaped.

7. The cement hydration reaction control device based on microfluidic technology according to claim 6, characterized in that, The syringes (6) are arranged in three groups side by side inside the housing (5), and the output end of each group of syringes (6) is connected to the inlet end (3) of the reaction channel (2).

8. The cement hydration reaction control device based on microfluidic technology according to claim 7, characterized in that, The upper surface of the reaction plate (1) is covered with a glass plate (16).

9. A cement hydration experimental method based on the cement hydration reaction control device based on microfluidic technology as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Grind the cement clinker and gypsum and press them into a plate; carve reaction channels (2) on the plate surface, and adjust the length and shape of the channels according to actual needs; install liquid bolts on the inlet (3) and outlet (4) of the reaction channels (2) on the edge of the plate; cover the reaction plate with a glass plate (16); Step 2: After adding the required modified solution and water to the syringe (6), insert the main body of the syringe (6) into the limiting groove opened in the housing (5), connect the output end of the syringe (6) to the connecting hose (17), and adjust the hose (17) to keep the whole horizontal state so that it is connected to the inlet end (3) of the reaction channel (2). Start the motor (14) to push the push rod (10) until the push rod (10) slightly touches the tail surface of the syringe (6) injection rod (9); Step 3: During the experiment, start the servo motor (14) to inject a small amount of liquid into the reaction channel (2); focus the microscope on the interface between the reaction plate and the liquid and observe the reaction situation there; the liquid will flow to the far end of the channel as it actually flows. By moving the microscope, the cement hydration reaction phenomenon at different reaction times can be captured.

10. The method according to claim 9, characterized in that, In step three, before the experiment, the entire device is placed on the microscope platform.

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