An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials
By designing an integrated microfluidic chip, the problems of poor solution mixing and agglomeration in the preparation of noble metal nanoparticles were solved, enabling continuous synthesis and protection of nanoparticles, improving mixing efficiency and yield, and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HAINAN UNIV
- Filing Date
- 2025-07-02
- Publication Date
- 2026-06-16
AI Technical Summary
Traditional methods for preparing precious metal nanoparticles suffer from problems such as poor solution mixing, significant batch-to-batch variations, easy agglomeration of nanoparticles, and high loss rates during centrifugation, leading to increased application difficulty and reduced yield.
An integrated microfluidic chip is used, which includes a wave-shaped reaction zone, a spiral protection zone, and a separation zone. Mixing is promoted through periodic bending structures and random obstacles. Combined with the principle of deterministic lateral displacement, continuous synthesis and protection of nanoparticles are achieved, reducing the need for centrifugation separation steps.
It improves the size uniformity and controllability of nanoparticles, reduces batch-to-batch variability, increases mixing efficiency and yield, and reduces the cumbersome steps and costs of traditional methods.
Smart Images
Figure CN224358470U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to an integrated microfluidic chip for the preparation, protection, and concentration of precious metal nanoparticles. Background Technology
[0002] Traditional methods for preparing precious metal nanoparticles typically employ a one-pot process, which suffers from poor solution mixing and significant batch-to-batch variations in nanoparticle size. Furthermore, the prepared nanoparticles, lacking special protection, are prone to aggregation, leading to damage to their original nanomaterial properties (such as optical properties and catalytic activity), making them unsuitable for long-term storage and requiring immediate preparation and use, significantly increasing the difficulty of applying precious metal nanoparticles. If additional protective agents are needed, multiple high-speed centrifugations are required to separate the nanomaterials from other components (such as reducing agents, precursor compounds, and excess protective agents). Centrifugation results in nanomaterial loss and a low final yield. Utility Model Content
[0003] The main objective of this invention is to provide an integrated microfluidic chip for the preparation, protection, and concentration of precious metal nanoparticles.
[0004] The technical solution adopted by this utility model to solve its technical problem is:
[0005] An integrated microfluidic chip for the preparation, protection, and concentration of noble metal nanoparticles includes a first wavy reaction zone, a second wavy reaction zone, a helical protection zone, and a separation zone connected in sequence. The first wavy reaction zone has a first inlet and a second inlet for injecting a first reducing agent and a first precursor compound, respectively. The first and second inlets converge and enter the wavy region. The outlet of the first wavy reaction zone and the inlet of the second wavy reaction zone are connected by a first connecting pipe, which has a third inlet and a fourth inlet for injecting a second reducing agent and a second precursor compound, respectively. The outlet of the second wavy reaction zone is connected to the helical protection zone by a second connecting pipe, which has a fifth inlet for injecting a protective agent. The separation zone has a sixth inlet at its inlet end for injecting a separation liquid. The outlet end has a first outlet and a second outlet spaced apart. The separation zone contains a micropillar array following the deterministic lateral displacement principle (DLD). Random obstacles are provided at the top of both the wavy reaction zone and the helical protection zone. The height and width of the random obstacles are 1 / 5 to 1 / 2 of the height and width of the wavy reaction zone and the helical protection zone, respectively.
[0006] Furthermore, the random obstacles are fishbone-shaped structures or roadblock structures.
[0007] Furthermore, the first and second wave-shaped reaction zones are each formed by connecting multiple rows of parallel wave-shaped pipes; the tails of the first and second rows are connected, the heads of the second and third rows are connected, and so on, connecting all rows of wave-shaped pipes together.
[0008] Furthermore, the S-shaped flow channel of the wavy area has a width of 50-1000 micrometers and a flow channel height of 10-1000 micrometers; a single row of wavy areas contains repeating units of no less than 2 S-shaped flow channels, with a total of no less than 2 rows.
[0009] Furthermore, the top of the S-shaped flow channel in the wave-shaped region is provided with a fishbone-shaped structure, which is 5-500 micrometers high and 10-1000 micrometers wide, and there is no less than one fishbone-shaped structure in each repeating unit of the S-shaped flow channel.
[0010] Furthermore, the spiral protection zone is shaped like a double-coil mosquito coil, with the ends of the double-coil mosquito coils connected.
[0011] Furthermore, the parameters of the spiral protection zone are a channel width of 50-1000 micrometers and a channel height of 10-1000 micrometers.
[0012] Furthermore, a barrier structure is provided at the top of the spiral flow channel, with a height of 5-800 micrometers and a width of 10-800 micrometers.
[0013] Furthermore, the separation zone is elongated, with its four corners extending outward along the edges of the strip to form four protrusions; one of the protrusions is connected to the outlet of the spiral protection zone via a third connecting pipe, and the other protrusion at the same end as the first protrusion is provided with a sixth inlet; the two protrusions at the other end are respectively provided with a first outlet and a second outlet.
[0014] Compared with the prior art, this technical solution has the following advantages:
[0015] 1. This invention features two wavy reaction zones and one spiral reaction zone. The periodically curved structure of the wavy reaction zones promotes mixing (especially at low Reynolds numbers) by disturbing the laminar flow of the fluid, making it more efficient than straight channels, centrifuge tubes, or round-bottom flasks, and suitable for the generation of nanoparticle seeds and mature nanoparticles. The periodically changing fluid velocity in the wavy channels and the wavy, directional flow reduce particle deposition, making it suitable for processing fluids containing microparticles.
[0016] The secondary flow (such as Dean vortex) generated by the helical structure of the helical reaction zone enhances the mixing of fluids, making it particularly suitable for microfluidic scenarios with low Reynolds numbers (low flow rates) and reducing reliance on external mixers. Within a limited space, the helical design increases the channel length, allowing for more thorough mixing of the added protective agent and nanoparticles. The helical shape of the double-disc mosquito coil maximizes the use of planar space on the chip; the helical shape is also more suitable for high-viscosity fluids. Therefore, this invention incorporates a helical reaction zone for mixing the protective agent and nanoparticles.
[0017] The tops of the wave-shaped reaction zone and the spiral protection zone are equipped with random obstacles, which can change the direction of the particles and promote mixing.
[0018] 2. The separation liquid is injected from the sixth inlet. Due to their different sizes, the nanoparticles, driven by the DLD principle, eventually flow out from one of the two outlets in the separation zone, thereby significantly reducing the concentration of interfering components such as reducing agents, precursor compounds and protective agents in the nanoparticle solution without the need for centrifugation.
[0019] 3. This invention enables continuous production by continuously injecting the corresponding components from each inlet, whereas existing technologies can only produce in batches. This invention achieves integrated operation of nanoparticle seed generation, nanoparticle synthesis, and protection, reducing the cumbersome steps in traditional nanoparticle manufacturing processes and improving nanomaterial yield; it enables continuous nanoparticle synthesis, thereby reducing batch-to-batch variations unavoidable in traditional methods, optimizing the size uniformity and controllability of nanoparticles; and it improves the mixing efficiency of reactants, thus increasing the utilization rate of expensive precious metal precursor compounds and reducing costs. Attached Figure Description
[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0021] Figure 1 Example 1 shows a schematic diagram of the structure of an integrated microfluidic chip for the preparation, protection, and concentration of noble metal nanoparticles, and a partially enlarged schematic diagram thereof.
[0022] Figure 2 This is a schematic diagram of the structure after removing random obstacles.
[0023] Figure 3 for Figure 2 A schematic diagram of the local structure of the wavy reaction zone.
[0024] Figure 4 for Figure 2 A schematic diagram of the local structure of the helical reaction zone.
[0025] Figure 5 for Figure 2 A schematic diagram of the partial structure of the separation zone.
[0026] Figure 6 This is a schematic diagram of the distribution structure of random obstacles.
[0027] Figures 1 to 6 In the middle, 1-First Entrance, 2-Second Entrance, 3-Third Entrance, 4-Fourth Entrance, 5-Fifth Entrance, 6-Sixth Entrance, 7-First Exit, 8-Second Exit
[0028] 100 - First wave-shaped reaction zone; 110 - Collection pipe; 120 - Wave-shaped pipe; 130 - Fishbone-shaped column
[0029] 200 - Second wave-shaped reaction zone; 210 - First connecting pipe
[0030] 300 - Spiral Reaction Zone; 310 - Second Connecting Pipe; 320 - Spiral Pipe; 330 - Prism Column
[0031] 400 - Separation Zone; 410 - Third Connecting Pipe; 420 - Small Cylinder
[0032] 500-chip Detailed Implementation
[0033] Example 1
[0034] Please refer to Figures 1 to 6 An integrated microfluidic chip 500 for the preparation, protection and concentration of precious metal nanoparticles includes a first wave-shaped reaction zone 100, a second wave-shaped reaction zone 200, a spiral reaction zone 300 and a separation zone 400 connected in sequence on the chip.
[0035] The first wavy reaction zone 100 has a first inlet 1 and a second inlet 2, which converge and enter the wavy zone. See also Figure 2 The wavy area is formed by connecting multiple rows of parallel wavy pipes 120. The first inlet 1 and the second inlet 2 are located in the top row, and the outlet is located in the bottom row. The tails of the first and second rows are connected, the heads of the second and third rows are connected, and so on, connecting all rows of wavy pipes together.
[0036] The cross-section of pipe 120 can be square or circular.
[0037] In the square case, the width of the S-shaped flow channel is 50-1000 micrometers (e.g., 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers. Preferably 100-500 micrometers), and the flow channel height is 10-1000 micrometers (e.g., 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers). Micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers. Preferably 100 micrometers-500 micrometers); a single row of wavy areas contains at least two repeating units of S-shaped flow channels, with a total of no less than two rows; a fishbone-shaped structure is provided at the top of the S-shaped flow channel, with a height of 5-500 micrometers and a width of 5-500 micrometers, and no less than one fishbone-shaped structure in each repeating unit of the S-shaped flow channel.
[0038] In the case of a circular pipe, the diameter of pipe 120 ranges from 50 to 1000 micrometers. Examples include 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, and 1000 micrometers. Preferably, the diameter is between 100 and 500 micrometers.
[0039] Amplitude (A): The vertical distance between the crest and trough of a wave, ranging from 100 to 2000 micrometers. Examples include 100 micrometers, 200 micrometers, 300 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers, 1100 micrometers, 1200 micrometers, 1300 micrometers, 1400 micrometers, 1500 micrometers, 1600 micrometers, 1700 micrometers, 1800 micrometers, 1900 micrometers, and 2000 micrometers. Preferably, it is between 500 and 2000 micrometers.
[0040] Wavelength (λ): The horizontal distance between adjacent wave crests or troughs, ranging from 100 to 2000 micrometers. Examples include 100 micrometers, 200 micrometers, 300 micrometers, 400 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, 1000 micrometers, 1100 micrometers, 1200 micrometers, 1300 micrometers, 1400 micrometers, 1500 micrometers, 1600 micrometers, 1700 micrometers, 1800 micrometers, 1900 micrometers, and 2000 micrometers. Preferably, it is between 500 and 2000 micrometers.
[0041] Wave height ratio: The ratio of amplitude to wavelength, ranging from 0.05 to 20.
[0042] Radius of curvature: The radius of curvature at the crest / trough, ranging from 50 to 1000 micrometers. Examples include 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, and 1000 micrometers. Preferably, it is between 100 and 500 micrometers.
[0043] Obstacles are further randomly placed at the top of the flow channel. In this embodiment, a fishbone-shaped column is provided at the top of the chip inside the corrugated pipe 120. Furthermore, two fishbone-shaped columns 130 are provided in the pipe between each crest and trough, wherein the tips of the fishbone-shaped columns (as shown by fishbone-shaped columns 131 and 132) all face the same side. Figure 1 (The middle is the top side) to increase the random probability.
[0044] The second wave-shaped reaction zone 200 has the same structure as the first wave-shaped reaction zone 100. The outlet of the first wave-shaped reaction zone 100 and the inlet of the second wave-shaped reaction zone 200 are connected by a first connecting pipe 210. The first connecting pipe 210 is also provided with a third inlet 3 and a fourth inlet 4. The pipes of the third inlet 3 and the fourth inlet 4 and the first connecting pipe 210 form a cross shape, with the third inlet 3 and the fourth inlet 4 located at the two ends of the vertical lines of the cross.
[0045] The outlet of the second wave-shaped reaction zone 200 is connected to the spiral zone 300 via a second connecting pipe 310, and a fifth inlet 5 is provided on the second connecting pipe 310. The spiral protection zone 300 is a double-coil rotating structure, except that the two ends of the two mosquito coils inside are connected.
[0046] The total length L of a single mosquito coil spiral is 100-500 mm.
[0047] Inner and outer diameter:
[0048] Inner diameter (initial radius): The initial radius of the helix, r = 100-1000 micrometers.
[0049] Outer diameter (maximum radius): The maximum radius of the helix is R = 5000-10000 micrometers.
[0050] The diameter range of the spiral pipe 320 is 50-1000 micrometers. For example, 50 micrometers, 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 600 micrometers, 700 micrometers, 800 micrometers, 900 micrometers, and 1000 micrometers. Preferably, it is 100-500 micrometers.
[0051] At the top of the spiral pipe 320, roadblock structures are randomly distributed. In this embodiment, the roadblock structures are prismatic prisms 330, spaced at intervals of 50-200 micrometers to increase mixing efficiency. The height and width of the prismatic prisms 330 can be 1 / 5 to 1 / 3 of the pipe diameter, respectively.
[0052] The separation zone 400 is elongated, with four protrusions extending outward from its four corners along the edges. One of these protrusions connects to the outlet of the spiral zone 300 via a third connecting pipe 410. This end (i.e. Figure 1 The other protrusion at the right end of the middle section is provided with a sixth entrance 6. The other end (i.e....) Figure 1 The two protruding parts at the left end of the middle are respectively provided with a first outlet 7 and a second outlet 8.
[0053] The separation zone 400 contains multiple small cylinders 410. These small cylinders 410 constitute a micropillar array following the Deterministic Lateral Displacement (DLD) principle. Deterministic lateral displacement is a particle separation method based on microfluidics technology. By designing a specific micropillar array structure, it utilizes laminar flow and microscale effects to achieve precise separation of particles of different sizes, shapes, or deformability. The DLD chip consists of periodically arranged micropillars (such as circular, triangular, or square ones) forming an inclined flow channel network. The arrangement direction of the micropillars forms a certain angle with the main flow direction.
[0054] The working principle of this utility model is as follows:
[0055] The chip body is divided into two parts: a reaction zone and a separation zone. The reaction zone includes two wavy reaction zones and a spiral flow channel reaction zone, with randomly placed obstacles (fishbone-shaped pillars 130 and prismatic pillars 330) at the top of the flow channel to promote fluid mixing within the flow channel. In one embodiment, the first wavy reaction zone 100 is a nanoparticle seed generation zone. A first reducing agent and a first precursor compound are injected from two inlets (first inlet 1 and second inlet 2) of the first reaction zone 100, respectively. After thorough mixing within the wavy flow channel, nanoparticle seeds are generated and subsequently flow into the second wavy reaction zone 200. The third inlet 3 and the fourth inlet 4 are used to inject the second reducing agent and the second precursor compound, respectively, to form mature nanoparticles based on the seed particles. The mature nanoparticle solution then flows into the spiral reaction zone 300, and the fifth inlet 5 is used to inject a protective agent. After the protective agent and mature nanoparticles are thoroughly mixed in the spiral reaction zone 300, a protective layer is formed on the surface of the nanoparticles, protecting their optical and catalytic activity from environmental factors. The protected nanoparticles then flow into the separation zone. A series of micropillar arrays following the deterministic lateral displacement (DLD) principle are arranged within the separation zone, with the separation liquid injected through the sixth inlet. Due to their different sizes, the nanoparticles, driven by the DLD principle, eventually flow out from one of the two outlets of the separation zone, thereby significantly reducing the concentration of interfering components such as reducing agents, precursor compounds, and protective agents in the nanoparticle solution without the need for centrifugation.
[0056] The above description is only a preferred embodiment of the present utility model, and therefore cannot be used to limit the scope of the present utility model. All equivalent changes and modifications made in accordance with the scope of the present utility model patent and the contents of the specification should still fall within the scope of the present utility model.
Claims
1. An integrated microfluidic chip for the continuous synthesis of noble metal nanomaterials, characterized in that: The chip includes a first wavy reaction zone, a second wavy reaction zone, a spiral protection zone, and a separation zone connected in sequence. The first wavy reaction zone has a first inlet and a second inlet for injecting a first reducing agent and a first precursor compound, respectively. The first and second inlets converge and enter the wavy region. The outlet of the first wavy reaction zone and the inlet of the second wavy reaction zone are connected by a first connecting pipe, which has a third inlet and a fourth inlet for injecting a second reducing agent and a second precursor compound, respectively. The outlet of the second wavy reaction zone is connected to the spiral protection zone by a second connecting pipe, which has a fifth inlet for injecting a protective agent. The inlet end of the separation zone has a sixth inlet for injecting a separation liquid. The outlet end has a first outlet and a second outlet spaced apart. The separation zone contains a micropillar array following a deterministic lateral displacement principle. Random obstacles are provided at the top of both the wavy reaction zone and the spiral protection zone. The height and width of the random obstacles are 1 / 5 to 1 / 2 of the height and width of the wavy reaction zone and the spiral protection zone, respectively.
2. The integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: The random obstacles are fishbone-shaped structures or roadblock structures.
3. The integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: The first and second wave-shaped reaction zones are each formed by connecting multiple rows of parallel wave-shaped pipes; the tails of the first and second rows are connected, the heads of the second and third rows are connected, and so on, connecting all rows of wave-shaped pipes together.
4. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 3, characterized in that: The width of the S-shaped flow channel in the wavy area is 50-1000 micrometers, and the height of the flow channel is 10-1000 micrometers; a single row of wavy areas contains at least two repeating units of S-shaped flow channels, with a total of no less than two rows.
5. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 3, characterized in that: The top of the S-shaped flow channel is provided with a fishbone-shaped structure, which is 5-500 micrometers high and 10-500 micrometers wide. Each repeating unit of the S-shaped flow channel has at least one fishbone-shaped structure.
6. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: The spiral protection zone is shaped like a double-coil mosquito coil, with the ends of the two coils connected inside.
7. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: The spiral protection zone has a flow channel width of 50-1000 micrometers and a flow channel height of 10-1000 micrometers.
8. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: A roadblock structure is installed at the top of the spiral flow channel, with a height of 5-800 micrometers and a width of 10-800 micrometers.
9. An integrated microfluidic chip for continuous synthesis of noble metal nanomaterials according to claim 1, characterized in that: The separation zone is elongated, with four protrusions extending outward from its four corners along the edges of the strip. One of the protrusions is connected to the outlet of the spiral protection zone via a third connecting pipe, and another protrusion at the same end as this protrusion has a sixth inlet. The two protrusions at the other end have a first outlet and a second outlet, respectively.