A hollow microtube-based biomimetic tree evaporator and application thereof

Abstract

The application discloses a hollow microtube-based biomimetic tree-shaped evaporator and application thereof, and relates to the technical field of solar water treatment, and comprises the following steps: taking bacterial cellulose hybrid spinning liquid as a shell fluid, taking anhydrous ethanol as a core fluid, and extruding the two to an ethanol coagulation bath, solidifying, washing with ethanol and deionized water in sequence until neutral, and drying to obtain a hollow hybrid microtube; arranging and fixing a plurality of hollow hybrid microtubes according to a tree-shaped branch structure on a support to obtain the biomimetic tree-shaped evaporator. The prepared biomimetic tree-shaped evaporator has excellent mechanical flexibility, salt resistance and purification efficiency, and provides a new material and a new scheme for efficient and sustainable solar seawater desalination and wastewater treatment.

Description

Technical Field

[0001] This invention relates to the field of solar water treatment technology, specifically a biomimetic tree-shaped evaporator based on hollow microtubes and its application. Background Technology

[0002] As traditional water resource management methods struggle to meet ever-increasing water demand, freshwater scarcity has become an increasingly serious problem. Interfacial evaporation technology offers a potential solution to this problem, utilizing solar energy to promote a phase change in water vapor, achieving an efficient transformation from liquid to gaseous water. However, traditional interfacial solar evaporators face a challenge in balancing water delivery and heat management; excessive water delivery leads to significant heat loss, limiting evaporation efficiency. Furthermore, while existing three-dimensional evaporators expand the evaporation area, they still lack precise control over water flux, making it difficult to achieve efficient heat localization.

[0003] In addition, interfacial evaporators made from fiber materials have attracted much attention due to their high cost-effectiveness and flexible structural design. Although fiber materials have good hydrophilicity and biocompatibility, which can significantly improve the evaporation efficiency of interfacial evaporators, their water transport is mostly passive and lacks space-constrained water path design.

[0004] Therefore, it is of great significance to develop a new type of evaporator that combines high performance, recyclability, and biodegradability. Summary of the Invention

[0005] The purpose of this invention is to provide a biomimetic tree-shaped evaporator based on hollow microtubes and its application, so as to solve the problems raised in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A biomimetic dendritic evaporator based on hollow microtubes includes the following steps: S1: Using bacterial cellulose hybrid spinning solution as the shell fluid and anhydrous ethanol as the core fluid, they are extruded together into an ethanol coagulation bath, solidified, washed with ethanol and deionized water until neutral, and dried to obtain hollow hybrid microtubes. S2: Multiple hollow hybrid microtubes are arranged in a tree-like branching structure and fixed on a support to obtain a biomimetic tree-like evaporator.

[0007] Further, in step S1, the preparation method of the bacterial cellulose hybrid spinning solution is as follows: 3,4-ethylenedioxythiophene is added to the bacterial cellulose solution, heated and stirred to obtain the bacterial cellulose hybrid spinning solution; In the preparation of the bacterial cellulose hybrid spinning solution, the mass ratio of 3,4-ethylenedioxythiophene to bacterial cellulose is (1-5):1.

[0008] Further, the bacterial cellulose solution is prepared as follows: the purified bacterial cellulose hydrogel is added to a 60-70 wt% zinc chloride aqueous solution, heated and stirred until completely dissolved, so that the solution concentration is 1-1.5 wt%, to obtain the bacterial cellulose solution.

[0009] Further, the preparation method of the purified bacterial cellulose hydrogel is as follows: the bacterial cellulose hydrogel is added to an aqueous sodium hydroxide solution, heated to remove impurities, and washed with deionized water until neutral to obtain the purified bacterial cellulose hydrogel; In the preparation of purified bacterial cellulose hydrogel, the mass ratio of bacterial cellulose hydrogel to sodium hydroxide is 1:(10-15).

[0010] Furthermore, in step S1, during the co-extrusion process, the shell flow rate is 90-110 mL / h and the core flow rate is 45-55 mL / h.

[0011] Application of a biomimetic tree-shaped evaporator based on hollow microtubes in solar steam generation.

[0012] Furthermore, the water evaporation rate of the tree-shaped evaporator under sunlight is 3-4 kg·m³. -2 ·h -1 .

[0013] Furthermore, the tree-shaped evaporator produces an average of 1-2 kg·m³ of water per day under natural outdoor conditions. -2 .

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention introduces 3,4-ethylenedioxythiophene into a bacterial cellulose hybrid spinning solution, endowing hollow hybrid microtubes with a full-spectrum absorption capability of 250-2500 nm, improving heat conversion efficiency, and exhibiting significant thermal localization effects, thereby effectively enhancing solar energy utilization efficiency. Simultaneously, this invention uses bacterial cellulose as the main raw material, reducing dependence on petroleum-based polymers. The overall structure is biodegradable, reducing the potential environmental pollution from electronic waste and aligning with the concept of green development. Furthermore, bacterial cellulose and 3,4-ethylenedioxythiophene can construct a dual-network structure, resulting in hollow hybrid microtubes with a Young's modulus of 2.5 GPa in the dry state and maintaining good flexibility and mechanical stability in the wet state, making them suitable for complex application scenarios.

[0015] This invention employs a coaxial spinning process to fabricate hollow hybrid microtubes. On one hand, the fabrication process is continuous, controllable, and easily scaled up, enabling large-scale production of hollow hybrid microtubes. The assembled tree-like structure exhibits excellent modularity and scalability, making it suitable for practical engineering applications. On the other hand, this invention achieves space-constrained capillary water transport through the hollow microtube structure, effectively isolating the water passage from the bulk hydrothermal phase. This resolves the contradiction between water supply and heat localization in traditional evaporators, significantly reducing heat loss.

[0016] The tree-shaped evaporator assembled in this invention has good modularity and scalability, making it suitable for practical engineering applications. Under sunlight (1 kW / m²), 2 Under these conditions, the evaporation rate of the tree-shaped evaporator can reach 3.57 kg·m³. -2 ·h -1 Under natural outdoor conditions, the average daily water yield reaches 1.5 kg·m³. -2 Furthermore, it exhibits no performance degradation after 96 hours of continuous operation, demonstrating excellent salt tolerance and environmental adaptability. Simultaneously, the dendritic evaporator prepared by this invention possesses highly efficient removal capabilities for various ions and organic pollutants, and the resulting condensate meets drinking water standards, making it suitable for various water treatment applications such as seawater desalination and dye wastewater purification. Attached Figure Description

[0017] Figure 1 This is a schematic diagram illustrating the macroscopic structure of the hollow hybrid microtube BCP50-HHT of the present invention. Figure 2 This is a schematic diagram illustrating the microstructure of a hollow hybrid microtube BCP50-HHT according to the present invention. Figure 3 The mechanical properties (a: stress-strain curve, b: Young's modulus) and water management properties (c: swelling change of microfiber in water over time) of a hollow hybrid microtube of the present invention are shown in the figure. Figure 4 The following are images illustrating the evaporation performance and thermal localization effect of a biomimetic tree-shaped evaporator of the present invention: (a: Infrared thermal images of each sample under one sun; b: Temperature change of sample surface with illumination time; c: Water evaporation on sample surface over time under one sun). Figure 5 This is an outdoor application diagram of a biomimetic tree-shaped evaporator of the present invention (a: changes in surface temperature, evaporation rate and irradiance of BCP50-HHT sample over time under real outdoor conditions; b: changes in water evaporation mass of BCP50-HHT sample under various weather conditions). Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0019] Example 1: A biomimetic tree-like evaporator based on hollow microtubes and its application: Step 1: Preparation of bacterial cellulose hybrid spinning solution: S1: Add the bacterial cellulose hydrogel to a 0.1 mol / L sodium hydroxide aqueous solution, heat to 80℃ for 2 h to remove impurities, wash with deionized water until neutral, and obtain purified bacterial cellulose hydrogel; S2: Add the purified bacterial cellulose hydrogel to a 65wt% zinc chloride aqueous solution and stir at 80℃ for 2 hours until completely dissolved, so that the solution concentration is 1.5wt% to obtain a bacterial cellulose solution; S3: Add 7.5g of 3,4-ethylenedioxythiophene to 1L of bacterial cellulose solution and stir at 70℃ for 2h to obtain bacterial cellulose hybrid spinning solution; Step 2: Fabrication of a biomimetic tree-shaped evaporator: S1: Using bacterial cellulose hybrid spinning solution as the shell fluid and anhydrous ethanol as the core fluid, the solution was squeezed into an ethanol coagulation bath through a coaxial needle at a shell flow rate of 100 mL / h and a core flow rate of 50 mL / h. After solidification for 30 min, the solution was washed with ethanol and deionized water until neutral and then air-dried to obtain BCP50-HHT hollow hybrid microtubes. S2: Multiple BCP50-HHT hollow hybrid microtubes are arranged in a tree-like branching structure and fixed on a support to obtain a biomimetic tree-like evaporator; S3: Under sunlight (1 kW / m 2 Under these conditions, the biomimetic tree-shaped evaporator was placed in an aqueous solution containing sodium chloride and magnesium chloride, and the evaporation rate and water production were tested.

[0020] Comparative Example 1: A biomimetic dendritic evaporator based on hollow microtubes and its application: Step 1: Preparation of bacterial cellulose hybrid spinning solution: S1: Add the bacterial cellulose hydrogel to a 0.1 mol / L sodium hydroxide aqueous solution, heat to 80℃ for 2 h to remove impurities, and wash with deionized water until neutral. The purified bacterial cellulose hydrogel is obtained. S2: Add the purified bacterial cellulose hydrogel to a 65wt% zinc chloride aqueous solution and stir at 80℃ for 2 hours until completely dissolved, so that the solution concentration is 1.5wt% to obtain a bacterial cellulose solution; Step 2: Fabrication of a biomimetic tree-shaped evaporator: S1: Using bacterial cellulose solution as the shell fluid and anhydrous ethanol as the core fluid, the solution was squeezed into an ethanol coagulation bath through a coaxial needle at a shell flow rate of 100 mL / h and a core flow rate of 50 mL / h. After solidification for 30 min, the solution was washed with ethanol and deionized water until neutral and then air-dried to obtain BC bacterial cellulose microtubules. S2: Multiple BC bacterial cellulose microtubules are arranged in a tree-like branching structure and fixed on a support to obtain a biomimetic tree-like evaporator; S3: Under sunlight (1 kW / m 2 Under these conditions, the biomimetic tree-shaped evaporator was placed in an aqueous solution containing sodium chloride and magnesium chloride, and the evaporation rate and water production were tested.

[0021] Comparative Example 2: A biomimetic tree-like evaporator based on hollow microtubes and its application: Step 1: Preparation of bacterial cellulose hybrid spinning solution: S1: Add the bacterial cellulose hydrogel to a 0.1 mol / L sodium hydroxide aqueous solution, heat to 80℃ for 2 h to remove impurities, and wash with deionized water until neutral. The purified bacterial cellulose hydrogel is obtained. S2: Add the purified bacterial cellulose hydrogel to a 65wt% zinc chloride aqueous solution and stir at 80℃ for 2 hours until completely dissolved, so that the solution concentration is 1.5wt% to obtain a bacterial cellulose solution; S3: Add 7.5g of 3,4-ethylenedioxythiophene to 1L of bacterial cellulose solution and stir at 70℃ for 2h to obtain bacterial cellulose hybrid spinning solution; Step 2: Fabrication of a biomimetic tree-shaped evaporator: S1: Using bacterial cellulose hybrid spinning solution as the shell fluid and bacterial cellulose solution as the core fluid, the solution was squeezed into an ethanol coagulation bath through a coaxial needle at a shell flow rate of 100 mL / h and a core flow rate of 50 mL / h. After solidification for 30 min, the solution was washed with ethanol and deionized water until neutral and then air-dried to obtain BCP50-BC solid microtubes. S2: Arrange multiple BCP50-BC solid microtubes in a tree-like branching structure and fix them on a support to obtain a biomimetic tree-like evaporator; S3: Under sunlight (1 kW / m 2 Under these conditions, the biomimetic tree-shaped evaporator was placed in an aqueous solution containing sodium chloride and magnesium chloride, and the evaporation rate and water production were tested.

[0022] Performance testing: The biomimetic tree-shaped evaporators prepared in Example 1 and Comparative Examples 1-2 were subjected to system performance testing to evaluate their mechanical properties, water management performance, heat localization effect and outdoor purification effect.

[0023] Mechanical property testing: Tensile tests were performed on the hollow hybrid microtubes using a universal testing machine at room temperature (25℃) and relative humidity (50%). Dry samples were tested in a dry environment, while wet samples were tested after being immersed in deionized water for 24 hours.

[0024] Water management performance testing: The biomimetic tree-shaped evaporator was placed in an aqueous solution containing 1.5 wt% sodium chloride, and water transport behavior was observed at room temperature. Water management performance was evaluated through capillary rise experiments and evaporation rate tests.

[0025] Thermal localization detection: using a solar simulator (1 kW / m²) 2 Under ambient temperature of 25℃ and relative humidity of 50%, the surface temperature distribution of the biomimetic tree-shaped evaporator was measured using an infrared thermal imager.

[0026] Outdoor purification effect test: under natural outdoor conditions (average solar irradiance 0.8-1.0 kW / m²) 2 (At an ambient temperature of 20-30℃), the biomimetic tree-shaped evaporator was placed in simulated seawater containing 3.5wt% sodium chloride and wastewater containing 10mg / L crystal violet and rhodamine B dye, and operated continuously for 7 days to test the water production and purification efficiency of the biomimetic tree-shaped evaporator.

[0027] Test results are as follows Figures 3-5 As shown.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A biomimetic tree-like evaporator based on hollow microtubes, characterized in that: The biomimetic tree-shaped evaporator is prepared by the following method, which includes the following steps: S1: Using bacterial cellulose hybrid spinning solution as the shell fluid and anhydrous ethanol as the core fluid, they are extruded together into an ethanol coagulation bath, solidified, washed with ethanol and deionized water until neutral, and dried to obtain hollow hybrid microtubes. S2: Multiple hollow hybrid microtubes are arranged in a tree-like branching structure and fixed on a support to obtain a biomimetic tree-like evaporator; The preparation method of the bacterial cellulose hybrid spinning solution is as follows: 3,4-ethylenedioxythiophene is added to the bacterial cellulose solution, heated and stirred to obtain the bacterial cellulose hybrid spinning solution; In the preparation of the bacterial cellulose hybrid spinning solution, the mass ratio of 3,4-ethylenedioxythiophene to bacterial cellulose is (1-5):

1. The bacterial cellulose solution is prepared as follows: the purified bacterial cellulose hydrogel is added to a 60-70 wt% zinc chloride aqueous solution, heated and stirred until completely dissolved, so that the concentration of the purified bacterial cellulose hydrogel in the solution is 1-1.5 wt%, thus obtaining the bacterial cellulose solution; The method for preparing the purified bacterial cellulose hydrogel is as follows: the bacterial cellulose hydrogel is added to an aqueous sodium hydroxide solution, heated to remove impurities, and washed with deionized water until neutral to obtain the purified bacterial cellulose hydrogel. In the preparation of purified bacterial cellulose hydrogel, the mass ratio of bacterial cellulose hydrogel to sodium hydroxide is 1:(10-15). In step S1, during the co-extrusion process, the shell flow rate is 90-110 mL / h and the core flow rate is 45-55 mL / h.

2. The application of the biomimetic tree-shaped evaporator based on hollow microtubes according to claim 1, characterized in that: Applications in solar steam generation.

3. The application of the biomimetic tree-shaped evaporator based on hollow microtubes according to claim 2, characterized in that: The water evaporation rate of the tree-shaped evaporator under sunlight is 3-4 kg·m³. -2 ·h -1 .

4. The application of the biomimetic tree-shaped evaporator based on hollow microtubes according to claim 2, characterized in that: The average daily water production of the tree-shaped evaporator under outdoor natural conditions is 1-2 kg·m³. -2 .

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