Purification paper (cloth) for removing indoor formaldehyde and preparation method thereof

Abstract

The invention belongs to the technical field of indoor air purification, and particularly relates to purification paper (cloth) for removing indoor formaldehyde and a preparation method of the purification paper (cloth). The preparation method comprises the following steps: calcining biomass to prepare carbon powder, placing the carbon powder in a precursor solution containing a nitrogen source and a sulfur source, carrying out a hydrothermal reaction to prepare nitrogen-sulfur-doped carbon quantum dots, and compounding the obtained nitrogen-sulfur-doped carbon quantum dots with an aldehyde removal auxiliary agent, an adhesive, a humectant and a surfactant to form the composite aldehyde removal agent. And finally, dipping the substrate into the composite formaldehyde removal agent, and drying to obtain the purification paper (cloth). The nitrogen-sulfur-doped carbon quantum dots prepared by the method provided by the invention have efficient formaldehyde capturing ability, and after the nitrogen-sulfur-doped carbon quantum dots are added into a formaldehyde removal agent to prepare purification paper (cloth), the formaldehyde removal effect of the purification paper (cloth) can be remarkably improved. In addition, the purification paper (cloth) containing the nitrogen and sulfur doped carbon quantum dots is simple in preparation method, wide in raw material source, sustainable and capable of being prepared on a large scale.

Description

Technical Field

[0001] The invention belongs to the technical field of indoor air purification, and in particular relates to purification paper (cloth) for removing indoor formaldehyde and a preparation method thereof. Background Art

[0002] With the rapid development of society, people's lifestyles and living environments have undergone tremendous changes, and indoor air quality has received more and more attention. Among them, formaldehyde as a major air pollutant has attracted widespread attention. Plywood, latex paint, adhesives, etc. commonly used in interior decoration are common sources of formaldehyde. In order to remove the formaldehyde gas released from plywood and furniture, the formaldehyde removal materials used need to meet the requirements of fast response speed to formaldehyde, sustainable reaction, and no additional pollution.

[0003] Currently known indoor formaldehyde removal methods mainly include adsorption, chemical oxidation, catalytic oxidation, etc. Among them, activated carbon has a certain adsorption effect on formaldehyde, but it has the disadvantage of easy desorption and causing secondary pollution. Photocatalytic oxidation requires a light source, and it is difficult to work inside furniture, drawers and other environments. Chlorine dioxide can remove formaldehyde, but the chlorine dioxide concentration released by chlorine dioxide slow-release technology is too high to easily cause health problems, and too low a concentration makes it difficult to ensure effective purification efficiency. In addition, although many formaldehyde removal spray products sold on the market have the characteristics of rapid and targeted removal of formaldehyde, and have a good effect on removing free formaldehyde in open environments, their formaldehyde removal effects cannot be guaranteed in formaldehyde release sources such as wooden furniture and drawers.

[0004] Carbon quantum dots are usually defined as amorphous carbon particles with a size less than 10nm. More and more studies have shown that carbon quantum dots have good dispersibility, low toxicity and high biocompatibility. In addition, the performance of carbon quantum dots can be directional controlled by element doping and functional group grafting, providing new ideas and methods for research in the field of air purification. Summary of the invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a nitrogen-sulfur doped carbon quantum dots, which are prepared from biomass, and the adsorption selectivity of the carbon quantum dots to formaldehyde is improved by nitrogen-sulfur doping or surface modification. The method is green and environmentally friendly, and the prepared carbon quantum dots have good dispersibility and rich surface functional groups. At the same time, the nitrogen-sulfur doped carbon quantum dots and the formaldehyde removal agent are made into purification paper (cloth), and the obtained purification paper (cloth) has good formaldehyde removal effect, no secondary pollution, and has long-term stability.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

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

[0008] S1. calcining biomass to prepare biomass carbon powder, and then dispersing the biomass carbon powder in a precursor solution, centrifuging and filtering the reaction solution after hydrothermal reaction, adjusting the pH of the filtrate to neutral, and then dialyzing and freeze-drying to obtain nitrogen-sulfur doped carbon quantum dots; 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. Compounding nitrogen and sulfur-doped carbon quantum dots with formaldehyde removal aids, adhesives, moisturizers and surfactants to form a composite formaldehyde removal agent, and then immersing the base material in the composite formaldehyde removal agent. After full absorption, the base material is dried to obtain purification paper (cloth).

[0010] The nitrogen-sulfur doped carbon quantum dots prepared by the method of the present invention have a high efficiency in capturing formaldehyde. After being added to a formaldehyde removal agent to make purification paper (cloth), the formaldehyde removal effect of the purification paper (cloth) can be significantly improved. At the same time, the purification paper (cloth) containing nitrogen-sulfur doped carbon quantum dots provided by the present invention has a simple preparation method, a wide and sustainable source of raw materials, and can be prepared on a large scale.

[0011] Preferably, 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.

[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, Laminaria japonica, and Gracilaria truncatula.

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

[0014] Preferably, the temperature of the hydrothermal reaction is 150-200° C. and the time is 4-12 h.

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

[0016] More preferably, the amino acids include 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 auxiliary agent is 1:10-100, the mass fraction of adhesive is 0.5-5wt%, the mass fraction of moisturizer is 0.1-2wt%, and the concentration of surfactant is 30-500mg / L.

[0018] Preferably, the base material is selected from one of cellulose paper, polypropylene non-woven fabric and polyester non-woven fabric.

[0019] In the present invention, the substrate has almost no effect on removing formaldehyde. The purpose of removing formaldehyde is achieved by utilizing the chemical reaction of the formaldehyde removal agent coated on the purification paper (cloth) with formaldehyde to form non-toxic and harmless compounds. The addition of nitrogen-sulfur doped carbon quantum dots enhances the formaldehyde removal ability of the formaldehyde removal agent.

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

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

[0022] Preferably, the humectant comprises one or more of glycerol, sucrose and glucose.

[0023] Preferably, the surfactant includes one or more of alkyl polyglycoside APG0810, alkyl polyglycoside APG1214, dodecyldimethylbenzyl ammonium chloride, hexadecyltrimethylammonium bromide, and octadecyltrimethylammonium chloride.

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

[0025] The third aspect of the present invention provides the use of the purification paper (cloth) described in the second aspect in removing indoor formaldehyde.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The invention discloses a preparation method of purification paper (cloth) for removing indoor formaldehyde, wherein the biomass is first calcined to form carbon powder, and then placed in a precursor solution containing a nitrogen source and a sulfur source to obtain nitrogen-sulfur-doped carbon quantum dots through hydrothermal reaction, and then the obtained nitrogen-sulfur-doped carbon quantum dots are compounded with a formaldehyde removal auxiliary agent, an adhesive, a moisturizer and a surfactant to form a composite formaldehyde removal agent, and finally the substrate is impregnated into the composite formaldehyde removal agent and dried to obtain the purification paper (cloth). The nitrogen-sulfur-doped carbon quantum dots prepared by the method of the invention have a capture function for formaldehyde, are stably dispersed in the composite formaldehyde removal agent, and can significantly improve the formaldehyde removal ability and long-term performance of the purification paper (cloth) after being effectively combined with the formaldehyde removal auxiliary agent. At the same time, biomass is used as the raw material of nitrogen-sulfur-doped carbon quantum dots, and its source is widely distributed and renewable, which is conducive to sustainable development and reduces the greenhouse effect. In addition, the purification paper (cloth) provided by the present invention has a simple preparation method and has the conditions for large-scale production. It can not only efficiently remove formaldehyde in an open environment, but also is suitable for small spaces such as wardrobes and drawers, and relatively closed environments, making up for the vacancy of existing air purification products. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 2 This is a real photo of the purification paper (cloth) of Example 3. DETAILED DESCRIPTION

[0030] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0032] Example 1

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

[0034] (1) The Sargassum is crushed and sieved with a 40-mesh sieve. An appropriate amount of Sargassum powder is weighed and placed in a tubular furnace. The powder is calcined at 400°C for 3 h in a nitrogen environment and then cooled 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, 0.22 μm microfiltered, and the pH was adjusted to neutral with sodium hydroxide solution, and then dialyzed and freeze-dried to obtain nitrogen-sulfur doped carbon quantum dots.

[0036] from Figure 1 The optical characteristics of carbon quantum dots show that the prepared samples are 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, which specifically includes the following steps:

[0039] (1) After the Gracilaria was crushed, it was sieved with a 40-mesh sieve. An appropriate amount of Gracilaria powder was weighed and placed in a tubular furnace. It was calcined at 300°C for 5 h in a nitrogen environment and then cooled 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, and then dialyzed and freeze-dried to obtain nitrogen-sulfur doped carbon quantum dots.

[0041] Example 3

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

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

[0044] (2) A 12.5 cm × 12.5 cm polypropylene nonwoven fabric is impregnated into the composite formaldehyde removal agent of step (1) for 10-20 seconds, and then the impregnated cellulose paper is placed at 60° C. and dried to obtain a purification paper (cloth). The actual photo is shown in FIG. Figure 2 shown.

[0045] Example 4

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

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

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

[0049] Comparative Example 1

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

[0051] Comparative Example 2

[0052] This comparative example was carried out using steps similar to those of Example 4, except that the nitrogen-sulfur-doped carbon quantum dots in the formula were 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 by the present invention.

[0055] (1) Changes in the quality of purification paper after impregnation: The quality changes of the purification paper before and after impregnation in step (2) of Examples 3 and 4 and Comparative Examples 1 and 2 were tested. The test results are shown in Table 1.

[0056] (2) Formaldehyde adsorption test: Referring to QB / T2761-2006 standard, the purification paper (cloth) prepared in Examples 3 and 4 and Comparative Examples 1 and 2 was placed in a 0.12 m 3 The test was carried out in a stainless steel glove box. The formaldehyde concentration in each group was the same, and the initial concentration of formaldehyde was 150 mg / m 3 The above detection method is phenol reagent spectrophotometry, and the test results are shown in Table 2.

[0057] (3) Formaldehyde low concentration cycle test: Referring to the QB / T2761-2006 standard, the purification paper (cloth) prepared in Example 3 was placed in a 0.12 m 3 The test was carried out in a stainless steel glove box, and the initial concentration was ten times the national standard formaldehyde concentration. The test results are shown in Table 3.

[0058] According to 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 0.2-0.3g. At the same time, the formaldehyde adsorption test results of 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 increases the formaldehyde adsorption of the purification paper (cloth), so that its maximum formaldehyde adsorption can reach 7.37mg / g. In addition, the low-concentration cycle test results of 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 removal of formaldehyde in practical applications.

[0059] Table 1 Quality table of purification paper before and after impregnation

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

[0061] Table 2 High concentration formaldehyde adsorption test results

[0062]

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

[0064]

[0065] The embodiments of the present invention are 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 of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.

Claims

1. A method for preparing purification paper (cloth), characterized in that: The following steps are involved: S1. calcining biomass to prepare biomass carbon powder, then dispersing the biomass carbon powder in a precursor solution, centrifuging and filtering the reaction solution after a hydrothermal reaction, adjusting the pH of the filtrate to neutral, and then dialyzing and freeze-drying to obtain nitrogen-sulfur doped carbon quantum dots; The precursor solution is a mixture of sulfuric acid and a dopant, and the dopant is one of diethylenetriamine, urea, thioacetamide, and thiourea; S2. Compounding nitrogen and sulfur-doped carbon quantum dots with formaldehyde removal aids, adhesives, moisturizers and surfactants to form a composite formaldehyde removal agent, and then immersing the base material in the composite formaldehyde removal agent. After full absorption, the base material is dried to obtain purification paper (cloth).

2. The method for preparing a purification 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 purification paper (cloth) according to claim 1, characterized in that: The biomass is one of Sargassum, Laminaria japonica and Gracilaria truncatula.

4. The method for preparing a purification paper (cloth) according to claim 1, characterized in that: The calcination is carried out in a nitrogen atmosphere at a temperature of 300-500° C. for 2-4 hours.

5. The method for preparing a purification paper (cloth) according to claim 1, characterized in that: The temperature of the hydrothermal reaction is 150-200° C. and the time is 4-12 hours.

6. The method for preparing a purification paper (cloth) according to claim 1, characterized in that: The formaldehyde removal auxiliary agent includes one or more of amino acids, 2-imidazolidinone and tea polyphenols.

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

8. The method for preparing a purification paper (cloth) according to claim 1, characterized in that: The base material is selected from cellulose paper, polypropylene non-woven fabric, and polyester non-woven fabric.

9. Purification paper (cloth) prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the purification paper (cloth) according to claim 9 in removing indoor formaldehyde.

Images