A purification paper (cloth) for removing indoor formaldehyde and a preparation method thereof

Abstract

The present application belongs to the technical field of indoor air purification, and particularly relates to a purification paper (cloth) for removing indoor formaldehyde and a preparation method thereof. Biomass is first calcined to prepare carbon powder, and then placed in a precursor solution containing a nitrogen source and a sulfur source to prepare nitrogen-sulfur doped carbon quantum dots through a hydrothermal reaction. Then, the obtained nitrogen-sulfur doped carbon quantum dots are compounded with an aldehyde removal aid, an adhesive, a humectant and a surfactant to form a composite aldehyde removal agent. Finally, a substrate is immersed in the composite aldehyde removal agent and dried to obtain the purification paper (cloth). The nitrogen-sulfur doped carbon quantum dots prepared by the method have high efficient capture capacity for formaldehyde. After being added to the aldehyde removal agent to prepare the purification paper (cloth), the purification paper (cloth) can significantly improve the formaldehyde removal effect. In addition, the purification paper (cloth) containing the nitrogen-sulfur doped carbon quantum dots has a simple preparation method, the raw materials are widely sourced and sustainable, and the purification paper (cloth) can be prepared on a large scale.

Description

Technical Field

[0001] This invention belongs to the field of indoor air purification technology, specifically relating to a purification paper (cloth) for removing indoor formaldehyde and its preparation method. Background Technology

[0002] With rapid societal development, people's lifestyles and living environments have undergone tremendous changes, leading to increasing attention to indoor air quality. Formaldehyde, as a major air pollutant, has attracted widespread concern. Common sources of formaldehyde include plywood, latex paint, and adhesives used in interior decoration. To remove formaldehyde gas released from plywood and furniture, the formaldehyde removal materials used must meet requirements such as rapid response to formaldehyde, sustainable reaction, and no additional pollution generation.

[0003] Currently known methods for indoor formaldehyde removal mainly include adsorption, chemical oxidation, and catalytic oxidation. Activated carbon has a certain adsorption effect on formaldehyde, but it suffers from the drawback of easy desorption, causing secondary pollution. Photocatalytic oxidation requires a light source and is ineffective in environments such as inside furniture and drawers. Chlorine dioxide can remove formaldehyde, but the concentration released by slow-release chlorine dioxide technology can easily cause health problems if too high, while too low a concentration cannot guarantee effective purification. Furthermore, while many commercially available formaldehyde-removing sprays offer rapid and targeted formaldehyde removal and are effective at removing free formaldehyde in open environments, their effectiveness in formaldehyde-releasing sources such as wooden furniture and drawers cannot be guaranteed.

[0004] Carbon quantum dots are generally defined as amorphous carbon particles with a size of less than 10 nm. Increasing research indicates that carbon quantum dots possess good dispersibility, low toxicity, and high biocompatibility. Furthermore, the performance of carbon quantum dots can be directionally controlled through elemental doping and functional group grafting, providing new ideas and methods for research in the field of air purification. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides nitrogen-sulfur-doped carbon quantum dots. The carbon quantum dots are prepared using biomass, and nitrogen-sulfur doping or surface modification improves the adsorption selectivity of the carbon quantum dots for formaldehyde. This method is green and environmentally friendly, and the prepared carbon quantum dots have good dispersibility and abundant surface functional groups. Furthermore, the nitrogen-sulfur-doped carbon quantum dots are combined with a formaldehyde removal agent to form purification paper (cloth). The resulting purification paper (cloth) has good formaldehyde removal effect, no secondary pollution, and long-term stability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The first aspect of this invention provides a method for preparing a clean paper (cloth), the method comprising the following steps:

[0008] S1. Biomass is calcined to produce biomass carbon powder, which is then dispersed in a precursor solution. After hydrothermal reaction, the reaction solution is centrifuged, filtered, and the pH of the filtrate is adjusted to neutral. After dialysis and freeze-drying, nitrogen-sulfur-doped carbon quantum dots are obtained. The precursor solution is a mixture of sulfuric acid and a dopant, and the dopant is one of diethylenetriamine, urea, thioacetamide, and thiourea.

[0009] S2. Nitrogen-sulfur-doped carbon quantum dots are compounded with formaldehyde removal additives, adhesives, humectants and surfactants to form a composite formaldehyde removal agent. The substrate material is then impregnated in the composite formaldehyde removal agent. After full absorption and drying, the purified paper (cloth) is obtained.

[0010] The nitrogen-sulfur-doped carbon quantum dots prepared by the method of this invention have a highly efficient formaldehyde capture ability. When added to formaldehyde removal agents to make purification paper (cloth), they can significantly improve the formaldehyde removal effect of the purification paper (cloth). At the same time, the purification paper (cloth) containing nitrogen-sulfur-doped carbon quantum dots provided by this invention has a simple preparation method, and the raw materials are widely available and sustainable, allowing for large-scale production.

[0011] Preferably, in the precursor solution, the concentration of sulfuric acid is 0.1-0.5 mol / L and the concentration of dopant is 0.05-0.3 mol / L.

[0012] The present invention does not specifically limit the type of biomass. In some preferred embodiments of the present invention, the biomass is one of Sargassum, kelp, and Gracilaria.

[0013] Preferably, the calcination is carried out under a nitrogen atmosphere at a temperature of 300-500℃ for 2-4 hours.

[0014] Preferably, the hydrothermal reaction is carried out at a temperature of 150-200°C for 4-12 hours.

[0015] Preferably, the formaldehyde removal agent includes one or more of amino acids, 2-imidazolidineone, and tea polyphenols.

[0016] More preferably, the amino acid includes one or more of arginine, lysine, methionine, histidine, and tyrosine.

[0017] Preferably, in the composite formaldehyde removal agent, the mass ratio of nitrogen-sulfur-doped carbon quantum dots to formaldehyde removal additive is 1:10-100, the mass fraction of adhesive is 0.5-5wt%, the mass fraction of humectant is 0.1-2wt%, and the concentration of surfactant is 30-500mg / L.

[0018] Preferably, the substrate material is selected from one of cellulose paper, polypropylene nonwoven fabric, and polyester nonwoven fabric.

[0019] In this invention, the substrate has almost no effect on removing formaldehyde. The formaldehyde removal agent coated on the purification paper (cloth) reacts chemically with the formaldehyde to form a non-toxic and harmless compound, thereby achieving the purpose of removing formaldehyde. The addition of nitrogen and sulfur doped carbon quantum dots enhances the formaldehyde removal agent's ability to remove formaldehyde.

[0020] Preferably, the ratio of biomass carbon powder to precursor solution is 0.15-0.90g:100mL.

[0021] Preferably, the adhesive comprises one or more of sodium carboxymethyl cellulose, polyvinyl alcohol, polyethylene glycol, polyvinylpyrrolidone, and xanthan gum.

[0022] Preferably, the humectant includes one or more of glycerin, sucrose, and glucose.

[0023] Preferably, the surfactant comprises one or more of alkyl glycoside APG0810, alkyl glycoside APG1214, dodecyl dimethyl benzyl ammonium chloride, hexadecyl trimethyl ammonium bromide, and octadecyl trimethyl ammonium chloride.

[0024] The second aspect of the present invention provides a clean paper (cloth) prepared by the preparation method described in the first aspect.

[0025] The third aspect of this invention provides the application of the purification paper (cloth) described in the second aspect in the removal of indoor formaldehyde.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention discloses a method for preparing purifying paper (cloth) for removing indoor formaldehyde. First, biomass is calcined to produce carbon powder, which is then placed in a precursor solution containing nitrogen and sulfur sources and subjected to a hydrothermal reaction to obtain nitrogen-sulfur-doped carbon quantum dots. These nitrogen-sulfur-doped carbon quantum dots are then compounded with formaldehyde-removing additives, adhesives, humectants, and surfactants to form a composite formaldehyde-removing agent. Finally, a substrate is impregnated with the composite formaldehyde-removing agent and dried to obtain the purifying paper (cloth). The nitrogen-sulfur-doped carbon quantum dots prepared using this method have formaldehyde-capturing capabilities, are stably dispersed in the composite formaldehyde-removing agent, and, when effectively combined with formaldehyde-removing additives, significantly enhance the formaldehyde removal capacity and long-lasting effect of the purifying paper (cloth). Furthermore, using biomass as the raw material for the nitrogen-sulfur-doped carbon quantum dots is widely available and renewable, contributing to sustainable development and mitigating the greenhouse effect. In addition, the purifying paper (cloth) provided by this invention has a simple preparation method, is suitable for large-scale production, and can efficiently remove formaldehyde in open environments. It is also suitable for small, relatively enclosed spaces such as wardrobes and drawers, filling a gap in existing air purification products. Attached Figure Description

[0028] Figure 1The fluorescence spectrum and fluorescence image of nitrogen-sulfur-doped carbon quantum dots in Example 1;

[0029] Figure 2 This is a photograph of the actual cleanroom paper (cloth) used in Example 3. Detailed Implementation

[0030] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0032] Example 1

[0033] This embodiment provides a method for preparing nitrogen-sulfur-doped carbon quantum dots, specifically including the following steps:

[0034] (1) After crushing the Sargassum, sieve it through a 40-mesh screen, then weigh an appropriate amount of Sargassum powder and place it in a tube furnace. Calcinate it at 400°C for 3 hours under nitrogen atmosphere and then cool it to obtain Sargassum carbon powder.

[0035] (2) 0.2 g of Sargassum carbon powder was dispersed in a precursor solution (solvent: water) with a sulfuric acid concentration of 0.1 mol / L and a urea concentration of 0.3 mol / L. After magnetic stirring for 2 h, the mixture was transferred to a 100 mL polytetrafluoroethylene-lined autoclave and reacted at 180 °C for 6 h to obtain a light brown suspension. The obtained light brown suspension was centrifuged, microfiltered at 0.22 μm, and the pH was adjusted to neutral with sodium hydroxide solution. After dialysis and freeze-drying, nitrogen-sulfur-doped carbon quantum dots were obtained.

[0036] from Figure 1 The optical characteristics of the carbon quantum dots show that the prepared sample is indeed carbon quantum dots, not ordinary carbon powder.

[0037] Example 2

[0038] This embodiment provides a method for preparing nitrogen-sulfur-doped carbon quantum dots, specifically including the following steps:

[0039] (1) After crushing the Gracilaria, sieve it through a 40-mesh screen, weigh an appropriate amount of Gracilaria powder and place it in a tube furnace. Calcinate it at 300℃ for 5 hours under nitrogen atmosphere and then cool it to obtain Gracilaria carbon powder.

[0040] (2) 0.5 g of Gracilaria carbon powder was dispersed in a precursor solution (solvent: water) with a sulfuric acid concentration of 0.3 mol / L and a thioacetamide concentration of 0.05 mol / L. After magnetic stirring for 2 h, the mixture was transferred to a 100 mL polytetrafluoroethylene-lined autoclave and reacted at 160 °C for 12 h to obtain a brown suspension. The obtained brown suspension was centrifuged, microfiltered at 0.22 μm, and the pH was adjusted to neutral with sodium hydroxide solution. After dialysis and freeze-drying, nitrogen-sulfur-doped carbon quantum dots were obtained.

[0041] Example 3

[0042] This embodiment provides a method for preparing clean paper (cloth), specifically including the following steps:

[0043] (1) Dissolve 2g of sodium hydroxymethyl cellulose in 150mL of water, and then add nitrogen-sulfur doped carbon quantum dots (100mg), methionine (3g), glycerol (1g) and alkyl glycoside APG1214 (50mg) from Example 1 in sequence. Stir well to obtain a composite formaldehyde remover.

[0044] (2) Impregnate a 12.5cm×12.5cm polypropylene nonwoven fabric in the composite formaldehyde removal agent of step (1) for 10-20 seconds, then dry the impregnated cellulose paper at 60℃ to obtain the purified paper (fabric). A photo of the actual product is shown below. Figure 2 As shown.

[0045] Example 4

[0046] This embodiment provides a method for preparing clean paper (cloth), specifically including the following steps:

[0047] (1) Dissolve 1.5g xanthan gum in 150mL of water, and then add nitrogen-sulfur doped carbon quantum dots (100mg), lysine (1.5g), tea polyphenols (0.5g), glucose (0.6g) and dodecyl dimethyl benzyl ammonium chloride (6mg) from Example 2 in sequence. Stir well to obtain a composite formaldehyde remover.

[0048] (2) Immerse a 12.5cm×12.5cm cellulose paper in the composite formaldehyde removal agent of step (1) for 10-20 seconds, and then dry the impregnated cellulose paper at 60℃ to obtain the purification paper (cloth).

[0049] Comparative Example 1

[0050] This comparative example was carried out using similar steps to Example 3, except that the nitrogen-sulfur-doped carbon quantum dots from Example 1 were not added to the formulation.

[0051] Comparative Example 2

[0052] This comparative example follows similar steps to Example 4, except that the nitrogen-sulfur-doped carbon quantum dots in the formulation are replaced with an equal amount of ordinary carbon powder.

[0053] Experimental Example

[0054] The following experiments demonstrate the formaldehyde removal effect of the purification paper (cloth) prepared according to the present invention.

[0055] (1) Changes in the quality of impregnated clean paper: The quality changes of clean paper before and after impregnation in step (2) of test examples 3 and 4 and comparative examples 1 and 2 are shown in Table 1.

[0056] (2) Formaldehyde adsorption capacity test: Referring to the QB / T2761-2006 standard, the purification paper (cloth) prepared in Examples 3 and 4 and Comparative Examples 1 and 2 were placed in a 0.12m³ volume container. 3 The tests were conducted inside a stainless steel glove box. Each group had the same formaldehyde concentration, with an initial formaldehyde concentration of 150 mg / m³. 3 The detection method was phenol reagent spectrophotometry, and the test results are shown in Table 2.

[0057] (3) Formaldehyde low-concentration cycling test: Referring to the QB / T2761-2006 standard, the purification paper (cloth) prepared in Example 3 was placed in a 0.12m³ volumetric immersion chamber. 3 The test was conducted inside a stainless steel glove box, with an initial formaldehyde concentration ten times the national standard. The test results are shown in Table 3.

[0058] As shown in Table 1, the active component loading of the purification paper (cloth) prepared by the present invention (Examples 3 and 4) under a certain concentration of composite formaldehyde removal agent is 0.2-0.3 g. Meanwhile, the formaldehyde adsorption capacity test results in Table 2 show that the purification paper (cloth) prepared by the present invention (Examples 3 and 4) has a large formaldehyde adsorption capacity. Compared with Comparative Examples 1 and 2, the addition of nitrogen-sulfur doped carbon quantum dots significantly improved the formaldehyde adsorption capacity of the purification paper (cloth), achieving a maximum formaldehyde adsorption capacity of 7.37 mg / g. Furthermore, the low-concentration cycling test results in Table 3 show that the purification paper (cloth) prepared by the present invention (Example 3) has a good low-concentration formaldehyde removal effect, which provides feasibility for its effective formaldehyde removal in practical applications.

[0059] Table 1 Quality of Clean Paper Before and After Impregnation

[0060] name Example 3 Example 4 Comparative Example 1 Comparative Example 2 Before soaking (g) 1.0431 1.0795 1.0399 1.0483 After soaking (g) 1.3414 1.3190 1.3408 1.3968 Load capacity (g) 0.2983 0.2395 0.3009 0.3485

[0061] Table 2. Test results of high-concentration formaldehyde adsorption capacity

[0062]

[0063] Table 3. Test results of formaldehyde removal paper (cloth) for low concentrations in Example 3.

[0064]

[0065] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for producing a purified paper / cloth, characterized by, The method comprises the following steps: S1, biomass is calcined to prepare biomass carbon powder, and then the biomass carbon powder is dispersed in a precursor solution, and after hydrothermal reaction, the reaction solution is centrifuged, filtered, and the pH of the filtrate is adjusted to neutral, and then dialysis and freeze-drying are performed to obtain nitrogen-sulfur doped carbon quantum dots; The precursor solution is a mixture of sulfuric acid and a dopant, the dopant is one of diethylene triamine, urea, thioacetamide and thiourea, and the biomass is one of sargassum, kelp and Gracilaria. S2, the nitrogen-sulfur doped carbon quantum dots are compounded with an aldehyde removal aid, an adhesive, a humectant and a surfactant to form a composite aldehyde removal agent, and then a base material is immersed in the composite aldehyde removal agent, and after sufficient absorption and drying, a purified paper / cloth is obtained; the aldehyde removal aid is selected from one or more of amino acids, 2-imidazolidinone and tea polyphenol.

2. A method of making a purified paper / cloth according to claim 1, characterized in that, In the precursor solution, the concentration of sulfuric acid is 0.1-0.5 mol / L, and the concentration of the dopant is 0.05-0.3 mol / L.

3. The method for preparing a cleanroom paper / cloth according to claim 1, characterized in that, The calcination is carried out in a nitrogen atmosphere, the temperature is 300-500℃, and the time is 2-4h.

4. The method for preparing a cleanroom paper / cloth according to claim 1, characterized in that, The temperature of the hydrothermal reaction is 150-200℃, and the time is 4-12h.

5. The method for preparing a cleanroom paper / cloth according to claim 1, characterized in that, In the composite aldehyde removal agent, the mass ratio of nitrogen-sulfur doped carbon quantum dots to aldehyde removal aid is 1:10-100, the mass fraction of the adhesive is 0.5-5wt%, the mass fraction of the humectant is 0.1-2wt%, and the concentration of the surfactant is 30-500mg / L.

6. The method for preparing a cleanroom paper / cloth according to claim 1, characterized in that, The base material is selected from one of cellulose paper, polypropylene non-woven fabric and polyester non-woven fabric.

7. The purified paper / cloth prepared by the preparation method of any one of claims 1-6.

8. The application of the purified paper / cloth of claim 7 in removing indoor formaldehyde.

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