Preparation method and application of biomass quantum dot coating inclined tube
The biomass sub-dots are prepared by rubber bark as raw material, combined with microwave pyrolysis and ultrasonic treatment, and applied to the inclined tube of the sedimentation tank, which solves the problems of environmental pollution and insufficient application of traditional methods and achieves efficient water quality treatment effects.
Patent Information
- Application Number
- CN202510772126.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-11
- Publication Date
- 2025-08-22
AI Technical Summary
The existing biomass sub-domain is rarely used in the field of water treatment. The traditional quantum dot preparation methods have problems with environmental pollution and biotoxicity, and lack efficient green preparation methods.
The biomass sub-dots are prepared by using rubber bark as raw material, combined with microwave pyrolysis and ultrasonic treatment, and biomass sub-dot coated inclined tubes are prepared by chitosan and glutaraldehyde treatment. They are applied in precipitation tanks and the surface effect of quantum dots and the adsorption catalytic action are used to treat wastewater.
The prepared biomass sub-dots have uniform size, excellent optical performance, high fluorescence quantum yield and luminescence stability, which can improve the precipitation efficiency of the precipitation tank and improve the water quality treatment effect. The process is simple and suitable for large-scale production.
Smart Images
Figure SMS_6 
Figure SMS_7
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of application of biomass quantum dots, and in particular to a preparation method and application of a biomass quantum dot-coated oblique tube. Background Art
[0002] Biomass quantum dots are a class of nanomaterials derived from natural biomass. Due to their excellent optical properties, biocompatibility and environmental friendliness, they have received widespread attention in recent years in the fields of fluorescence imaging, sensors, drug delivery, etc.
[0003] Traditional methods for preparing quantum dots often rely on toxic metal precursors, which pose environmental and biotoxicity challenges. Therefore, developing green, sustainable methods has become a hot topic. Using natural biomass as a feedstock for preparing quantum dots not only avoids the use of hazardous substances but also effectively utilizes agricultural waste, offering significant environmental and economic benefits.
[0004] Currently, various biomasses have been used to prepare quantum dots. For example, spinach leaves are ground into a paste, then added to a mixture of ethanol and acetone. After filtering and heating, natural biomass quantum dots have been successfully prepared. These quantum dots have excellent photoluminescence properties.
[0005] However, there are many studies on biomass quantum dots as fluorescent materials, but there are few reports on their application in water treatment. Summary of the Invention
[0006] In view of this, the present invention proposes a preparation method and application of a biomass quantum dot-coated oblique tube, aiming to provide a new use or application field of biomass quantum dots.
[0007] In one aspect, the present invention provides a method for preparing a biomass quantum dot, comprising the following steps:
[0008] S1: taking the bark of a 6-10 year old rubber tree, rinsing it with water, cutting it into pieces, drying it, and crushing it to obtain rubber tree powder;
[0009] S2: adding the rubber tree powder to 68%-70% concentrated nitric acid and stirring for 6-9 hours, performing solid-liquid separation by vacuum filtration and repeatedly washing the solid phase with deionized water until the filtrate is neutral to obtain a solid phase powder, and drying the solid phase powder;
[0010] S3: The dried solid phase powder is subjected to the following steps: microwave pyrolysis at 2.45 Hz and 600 W for 10-15 minutes in an inert environment; ultrasonication at 40 kHz for 30-40 minutes in pure water; centrifugation at 5000 rpm for 10-15 minutes, and filtration to remove solid components with a particle size greater than 5 nm to obtain a biomass quantum dot solution.
[0011] Preferably, in step S1, the rubber bark is crushed to a particle size of less than 100 μm;
[0012] The drying in steps S1 and S2 is performed by heating and drying at 60° C. for 12 hours.
[0013] Preferably, in step S2, the added amount of rubber tree powder and concentrated nitric acid is 1 g:4 mL.
[0014] Preferably, the excitation wavelength of the biomass quantum dot solution is 320-400 nm, and the emission wavelength is 400-550 nm.
[0015] On the other hand, the present invention also provides an application of a biological quality quantum dot solution, the application comprising:
[0016] 1) Applying biomass quantum dot solutions to the field of fluorescent materials;
[0017] 2) Apply the biomass quantum dot solution to the inclined tube of the sedimentation tank;
[0018] Wherein, the biomass quantum dot solution is prepared according to the above-mentioned biomass quantum dot preparation method.
[0019] In another aspect, the present invention provides a method for preparing a biomass quantum dot-coated oblique tube, comprising the following steps:
[0020] Add 0.1-0.5 mg / mL of ammonia water to the biomass quantum dot solution according to any one of claims 1-4 to adjust the alkalinity to pH = 10.0, and let it stand for 20-30 minutes;
[0021] A 0.5% chitosan solution was prepared, and the chitosan solution was mixed with the alkaline-adjusted biomass quantum dot solution. After magnetic stirring for 2 hours, the mixture was allowed to stand for 24 hours and centrifuged to remove unadsorbed chitosan to obtain a dispersion.
[0022] Immerse the inclined tube in the dispersion or apply the dispersion to the surface of the inclined tube and let it stand for 6 hours;
[0023] 1% glutaraldehyde solution was sprayed onto the inclined tube, allowed to stand for 1 hour, and the inclined tube was dried at low temperature twice to obtain a biomass quantum dot-coated inclined tube.
[0024] Preferably, the chitosan solution and the alkaline-adjusted biomass quantum dot solution are mixed in a volume ratio of 1:1.
[0025] Preferably, when preparing a 0.5% chitosan solution, acetic acid is added to the 0.5% chitosan solution, and the amount of acetic acid added is 0.1% of the volume of the chitosan solution.
[0026] Preferably, the two low-temperature drying steps are as follows: after spraying the glutaraldehyde solution and letting it stand, the first low-temperature drying step is performed, the surface of the inclined tube is repeatedly rinsed with deionized water, and the second low-temperature drying step is performed;
[0027] The temperature of the two low-temperature dryings was 60°C, and the drying time was 5-6 hours.
[0028] Preferably, when centrifugation is performed to remove non-adsorbed chitosan, the centrifugation is performed at 5000 rpm for 10 min.
[0029] Compared with the prior art, the present invention has the following beneficial effects:
[0030] Using rubber tree bark as raw material, a method combining microwave pyrolysis and ultrasonic-assisted processing has successfully produced biomass quantum dots with uniform size and excellent optical properties. By controlling the reaction conditions, the resulting biomass quantum dots exhibit high fluorescence quantum yield and strong luminescence stability.
[0031] Using rubber bark as raw material not only avoids the use of toxic metals and chemical reagents, but also reduces environmental pollution.
[0032] Biomass quantum dots are applied to inclined tubes in sedimentation tanks based on their surface effects and adsorption-catalytic principles. Quantum dots have a large specific surface area and abundant surface active sites, enabling them to interact with suspended particles and pollutants in wastewater through physical and chemical adsorption. Quantum dots can act as flocculation cores, promoting the aggregation and precipitation of suspended particles. The active sites on their surfaces may also have catalytic effects, accelerating the decomposition and transformation of certain pollutants in wastewater, thereby increasing the sedimentation efficiency of the sedimentation tank and improving water quality treatment.
[0033] The preparation method proposed in this invention is not only simple and highly controllable, but also suitable for large-scale production. With the growing demand for environmentally friendly biomass quantum dots, this green and sustainable preparation method can meet the market demand for highly efficient, environmentally friendly materials and has broad prospects for industrial production and market application. DETAILED DESCRIPTION
[0034] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0035] Example 1
[0036] Take the bark of a six-year-old rubber tree, rinse it with clean water, and remove any surface impurities. Cut the bark into small pieces approximately 1 cm x 1 cm and dry them at 60°C for 12 hours to obtain dried rubber bark blocks.
[0037] Crush dried rubber bark to a particle size of <100 μm to obtain rubber tree powder. Add 4 mL of concentrated nitric acid (68%-70%) to 1 g of rubber tree powder and stir at room temperature for 8 hours. Maintain uniform stirring during the reaction.
[0038] After stirring, vacuum filtration was used to separate the solid and liquid phases, and the solid phase was collected and repeatedly rinsed with deionized water until the filtrate was neutral. The resulting solid phase powder was then dried at 60°C for 12 hours.
[0039] The dried solid powder was subjected to microwave pyrolysis in an inert atmosphere (nitrogen) using a microwave frequency of 2.45 GHz and a power of 600 W for 12 minutes.
[0040] After microwave pyrolysis, the pyrolysis product was placed in pure water and cleaned using 40kHz ultrasonic waves for 30 minutes. The solution was then centrifuged at 5000 rpm for 10 minutes to filter out solid particles larger than 5nm, ultimately obtaining a biomass quantum dot solution.
[0041] Example 2
[0042] The bark of an 8-year-old rubber tree was rinsed with clean water and cut into blocks approximately 2 cm x 2 cm. The blocks were then dried at 60°C for 12 hours.
[0043] The dried bark pieces were crushed to obtain rubber tree powder with a particle size of <100 μm. To 2 g of rubber tree powder, 8 mL of concentrated nitric acid (68%-70%) was added and stirred for 7 hours for acidification.
[0044] After the reaction is complete, vacuum filtration is used to separate the solid and liquid phases, and the solid phase is washed several times with deionized water until the filtrate is neutral. The solid phase powder is dried and heated at 60°C for 12 hours.
[0045] The obtained dry powder was placed in an inert atmosphere and subjected to microwave heating at a microwave frequency of 2.45 GHz and a power of 600 W for 15 minutes.
[0046] Pure water was added to the treated product and the product was cleaned with 40 kHz ultrasonic waves for 40 minutes. The product was then centrifuged at 5000 rpm for 10 minutes and filtered to remove particles larger than 5 nm to obtain a transparent biomass quantum dot solution.
[0047] Example 3
[0048] Take the bark of a 10-year-old rubber tree, rinse it with clean water, and cut it into 5 cm x 5 cm blocks. Dry the blocks at 60°C for 12 hours to ensure they are completely dry.
[0049] The dried bark pieces were crushed to a particle size of <100 μm to obtain rubber tree powder. To 1.5 g of rubber tree powder, 6 mL of concentrated nitric acid (68%-70%) was added and stirred for 7 hours to allow the bark powder and nitric acid to fully react.
[0050] After the reaction, the solid and liquid were separated by vacuum filtration, and the solid phase was washed with deionized water until the filtrate was neutral. The solid phase powder was heated and dried at 60°C for 12 hours.
[0051] The dried powder was placed in an inert environment and subjected to microwave pyrolysis using a 2.45 GHz microwave oven with a power of 600 W for 10 min.
[0052] After microwave pyrolysis, the product was added to pure water and ultrasonically cleaned for 35 minutes at 40kHz. Then, it was centrifuged at 5000 rpm for 10 minutes and filtered to remove particles larger than 5 nm, ultimately obtaining a biomass quantum dot solution.
[0053] The biological quality quantum dot solutions obtained in Examples 1-3 were tested, and the test items were as follows:
[0054] 1. Particle size distribution
[0055] Experimental method: Dynamic light scattering (DLS)
[0056] Principle: The DLS method uses laser to irradiate the sample solution and measures the change in scattered light intensity caused by the Brownian motion of the particles. By calculating the diffusion coefficient of the particles, the size distribution of the particles is obtained.
[0057] step:
[0058] Take an appropriate amount of biomass quantum dot solution and dilute it appropriately.
[0059] The solution was injected into the DLS sample cell.
[0060] Start the DLS instrument and set the appropriate temperature and test parameters.
[0061] Measure the scattered light signal of the sample and analyze the particle size distribution.
[0062] Equipment: Zetasizer, Malvern, Horiba LA-950.
[0063] 2. Fluorescence quantum yield
[0064] Experimental method: fluorescence spectrometer measurement
[0065] Principle: Fluorescence quantum yield refers to the ratio of the number of fluorescent photons to the number of excitation photons, reflecting the light emission efficiency of the material. Its calculation formula is:
[0066] ;
[0067] in, is the intensity of fluorescence emission from the sample, is the intensity of the excitation light, is the quantum yield of the standard substance, is the ratio of the number of fluorescence photons of the sample to that of the standard substance.
[0068] Steps: Dilute the biomass quantum dot solution to an appropriate concentration.
[0069] Select an appropriate excitation wavelength and measure the fluorescence intensity of the sample using a fluorescence spectrometer.
[0070] The quantum yield of the sample is calculated using a standard sample (molecular fluorescent dye) with a known fluorescence quantum yield as a reference.
[0071] Equipment: Horiba Scientific, Edinburgh Instruments.
[0072] 3. Optical properties (excitation wavelength and emission wavelength)
[0073] Experimental method: fluorescence spectroscopy measurement
[0074] Principle: By irradiating the sample with excitation light and measuring its emission spectrum, the excitation and emission wavelength ranges of the biomass quantum dots can be obtained and their optical properties can be evaluated.
[0075] step:
[0076] Inject the sample solution into the fluorescence sample cell.
[0077] Set the appropriate excitation wavelength range (usually 320-400 nm).
[0078] Measure the emission spectrum of the sample and record the fluorescence intensity at different emission wavelengths.
[0079] Analyze the results and determine the range of excitation and emission wavelengths.
[0080] Equipment: Horiba Scientific, Perkin Elmer, Horiba FL-4500.
[0081] 4. Surface chemical properties (surface functional groups)
[0082] Experimental method: Fourier transform infrared spectroscopy (FTIR)
[0083] Principle: FTIR analyzes the surface functional groups and chemical composition of a material by measuring the wavelength of infrared light absorbed by the material.
[0084] step:
[0085] The biomass quantum dot solution was pelleted with KBr or the sample was dried directly.
[0086] Use FTIR instrument to scan and obtain the absorption spectrum.
[0087] The type of surface functional groups can be determined by comparing with existing functional group spectra.
[0088] Equipment: Thermo Fisher Nicolet 6700, Bruker Vertex 70, Jasco FTIR 4600.
[0089] 5. Sedimentation efficiency and water quality improvement ability
[0090] Experimental method: sedimentation experiment and water quality analysis
[0091] Principle: Apply the biological quality point to sewage, observe the particle settling effect through the sedimentation tank, and analyze the changes of pollutants (COD, BOD, suspended particulate matter, etc.) in the water through water quality testing.
[0092] Procedure: Prepare a solution of biomass titer of known concentration.
[0093] Add the biomass quantum dot solution to the sewage and stir evenly.
[0094] Let it stand and observe the sedimentation of suspended particles.
[0095] Measure the COD index in the water sample after sedimentation.
[0096] Equipment: COD analysis: A chemical oxygen demand tester (Thermo Scientific Orion) was used.
[0097] BOD test: Use BOD analyzer (YSI ProDSS).
[0098] Suspended particle test: Use a suspended particle analyzer (Turbidimeter).
[0099] The test results of the biological quality quantum dot solutions of Examples 1-3 are shown in Table 1.
[0100] Table 1
[0101]
[0102] Example 4
[0103] A 0.1 mg / mL solution of the biomass quantum dots was prepared, adjusted to pH 10.0 with ammonia, and allowed to stand for 20 minutes. Next, a 0.5% chitosan solution was prepared and 0.1% acetic acid was added, resulting in a 1:1 volume ratio. The chitosan solution and the alkaline-adjusted biomass quantum dot solution were mixed, magnetically stirred for 2 hours, and allowed to stand for 24 hours. Next, the solution was centrifuged to remove unadsorbed chitosan, resulting in a dispersion. A bevel tube was immersed in the dispersion and allowed to stand for 6 hours. Subsequently, a 1% glutaraldehyde solution was sprayed onto the surface of the bevel tube and allowed to stand for 1 hour. Finally, the tube was dried twice at 60°C for 5 hours each time to obtain a biomass quantum dot-coated bevel tube.
[0104] Example 5
[0105] A 0.3 mg / mL solution of the biomass quantum dots was prepared, adjusted to pH 10.0 with ammonia, and allowed to stand for 30 minutes. Next, a 0.5% chitosan solution was prepared and 0.1% acetic acid was added, resulting in a 1:1 volume ratio. The chitosan solution and the alkaline-adjusted biomass quantum dots solution were mixed, magnetically stirred for 2 hours, and allowed to stand for 24 hours. Next, the solution was centrifuged to remove unadsorbed chitosan, resulting in a dispersion. A bevel tube was coated with the dispersion and allowed to stand for 6 hours. Subsequently, a 1% glutaraldehyde solution was sprayed onto the surface of the bevel tube and allowed to stand for 1 hour. Finally, the tube was dried twice at 60°C for 6 hours each to obtain the biomass quantum dots-coated bevel tube.
[0106] Example 6
[0107] A 0.5 mg / mL solution of the biomass quantum dots was prepared, adjusted to pH 10.0 with ammonia, and allowed to stand for 25 minutes. Next, a 0.5% chitosan solution was prepared and 0.1% acetic acid was added, resulting in a 1:1 volume ratio. The chitosan solution and the alkaline-adjusted biomass quantum dots solution were mixed, magnetically stirred for 2 hours, and allowed to stand for 24 hours. Next, the solution was centrifuged to remove unadsorbed chitosan to obtain a dispersion. A bevel tube was coated with the dispersion and allowed to stand for 6 hours. Subsequently, a 1% glutaraldehyde solution was sprayed onto the surface of the bevel tube and allowed to stand for 1 hour. Finally, the tube was dried twice at 60°C for 5 hours each time to obtain the biomass quantum dots-coated bevel tube.
[0108] Examples 4-6 were tested, and the test items were as follows:
[0109] Specific test methods and estimated test results for the performance of the coated inclined pipe and sewage treatment efficiency of Examples 4-6:
[0110] 1. Test item: coating uniformity
[0111] Inspection method: Scanning electron microscopy (SEM) was used to observe the uniformity and coverage of the coating.
[0112] Take a sample of the coated oblique tube and use SEM to observe the coating surface at high magnification to check the distribution, thickness uniformity and coverage of the coating.
[0113] Observe the surface of the inclined tube for uneven coating or peeling.
[0114] 2. Test item: coating adhesion
[0115] Test method: Adhesion test was performed using a cross scratch test.
[0116] A cross scratch was made on the surface coating of the inclined tube and the test was performed using a standard force (500 g weight).
[0117] Adhesion was assessed by visually inspecting the scratched area for any coating loss or by examining the scratched area using a scanning electron microscope (SEM).
[0118] 3. Test item: pollutant removal efficiency
[0119] Detection method:
[0120] Immerse the coated inclined tube in simulated sewage (standard solution of suspended particles or heavy metal ions).
[0121] The removal efficiency before and after treatment was calculated by detecting the concentration of pollutants in the sewage (heavy metal concentration was determined by atomic absorption spectrometry).
[0122] Heavy metal concentrations were analyzed by comparing the concentration changes in water samples before and after treatment, and suspended particles were measured using a turbidity meter.
[0123] 4. Test items: catalytic degradation performance
[0124] Detection method:
[0125] Catalytic degradation experiments were carried out using simulated polluted water (water containing specific organic pollutants).
[0126] The degradation rate and removal efficiency of pollutants were measured within a fixed time, and the changes in pollutant concentrations were monitored using ultraviolet-visible spectrophotometry (UV-Vis).
[0127] By calculating the degradation rate at different time points, it is determined whether the quantum dot coating has a catalytic effect.
[0128] The test results of the above test items are shown in Table 2.
[0129] Table 2
[0130]
[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.
Claims
1. A method for preparing biological quality quantum dots, characterized in that: The following steps are involved: S1: taking the bark of a 6-10 year old rubber tree, rinsing it with water, cutting it into pieces, drying it, and crushing it to obtain rubber tree powder; S2: adding the rubber tree powder to 68%-70% concentrated nitric acid and stirring for 6-9 hours, performing solid-liquid separation by vacuum filtration and repeatedly washing the solid phase with deionized water until the filtrate is neutral to obtain a solid phase powder, and drying the solid phase powder; S3: The dried solid phase powder is subjected to the following steps: microwave pyrolysis at 2.45 Hz and 600 W for 10-15 minutes in an inert environment; ultrasonication at 40 kHz for 30-40 minutes in pure water; centrifugation at 5000 rpm for 10-15 minutes, and filtration to remove solid components with a particle size greater than 5 nm to obtain a biomass quantum dot solution.
2. The method for preparing biological quality quantum dots according to claim 1, characterized in that: In step S1, the rubber bark is crushed to a particle size of less than 100 μm; The drying in steps S1 and S2 is performed by heating and drying at 60° C. for 12 hours.
3. The method for preparing biological quality quantum dots according to claim 1, characterized in that: In step S2, the added amount of rubber tree powder and concentrated nitric acid is 1 g:4 mL.
4. The method for preparing biological quality quantum dots according to claim 1, characterized in that: The excitation wavelength of the biomass quantum dot solution is 320-400 nm, and the emission wavelength is 400-550 nm.
5. An application of a biological quality quantum dot, characterized in that: The applications include: 1) Applying biomass quantum dot solutions to the field of fluorescent materials; 2) Apply the biomass quantum dot solution to the inclined tube of the sedimentation tank; Wherein, the biological quality quantum dot solution is prepared according to the preparation method according to any one of claims 1-4.
6. A method for preparing a biomass quantum dot coated oblique tube, characterized in that: The following steps are involved: Add 0.1-0.5 mg / mL of ammonia water to the biomass quantum dot solution according to any one of claims 1-4 to adjust the alkalinity to pH = 10.0, and let it stand for 20-30 minutes; A 0.5% chitosan solution was prepared, and the chitosan solution was mixed with the alkaline-adjusted biomass quantum dot solution. After magnetic stirring for 2 hours, the mixture was allowed to stand for 24 hours and centrifuged to remove unadsorbed chitosan to obtain a dispersion. Immerse the inclined tube in the dispersion or apply the dispersion to the surface of the inclined tube and let it stand for 6 hours; 1% glutaraldehyde solution was sprayed onto the inclined tube, allowed to stand for 1 hour, and the inclined tube was dried at low temperature twice to obtain a biomass quantum dot-coated inclined tube.
7. The method for preparing a biomass quantum dot coated oblique tube according to claim 6, characterized in that: The chitosan solution and the alkaline-adjusted biomass quantum dot solution are mixed in a volume ratio of 1:
1.
8. The method for preparing a biomass quantum dot coated oblique tube according to claim 6, characterized in that: When preparing a 0.5% chitosan solution, acetic acid is added to the 0.5% chitosan solution, and the amount of acetic acid added is 0.1% of the volume of the chitosan solution.
9. The method for preparing a biomass quantum dot coated oblique tube according to claim 6, characterized in that: The two low-temperature drying steps are as follows: after spraying the glutaraldehyde solution and letting it stand, the first low-temperature drying is performed, the surface of the inclined tube is repeatedly rinsed with deionized water, and the second low-temperature drying is performed; The temperature of the two low-temperature dryings was 60°C, and the drying time was 5-6 hours.
10. The method for preparing a biomass quantum dot coated oblique tube according to claim 6, characterized in that: When centrifugation was performed to remove unadsorbed chitosan, the mixture was centrifuged at 5000 rpm for 10 min.