Amino pinene formaldehyde adsorbent and preparation method thereof

Abstract

According to the amido pinene formaldehyde adsorbent and the preparation method thereof, amido modification is carried out on pinene, a plurality of amido groups are introduced to a ring structure, then amido pinene is loaded to a base material, and efficient adsorption of formaldehyde is achieved through the action of the amido groups and formaldehyde. Particularly, the adsorbent still has high adsorption activity on formaldehyde under the condition of high relative humidity.

Description

Technical Field

[0001] The invention belongs to the field of adsorption and relates to an aminopinene formaldehyde adsorbent and a preparation method thereof. Background Art

[0002] Formaldehyde, also known as formic aldehyde, has a strong irritating odor and is an air pollutant that harms people's health. With the progress of society and the improvement of material living standards, people's requirements for the environment have also increased. More and more people have begun to pay attention to the indoor environment, especially the air quality. It is of great significance to study the formaldehyde purification technology in indoor air and improve the indoor air quality.

[0003] At present, the methods used to remove formaldehyde from the air include adsorption, catalytic oxidation, biodegradation, plasma technology, etc. These methods have their own advantages and disadvantages, and the most commonly used one is adsorption. At present, solid adsorbents mainly composed of various activated carbons and their products only have a relatively strong adsorption effect on non-polar or weakly polar substances, but the adsorption capacity for strongly polar formaldehyde is very small, and it is easy to be released secondary when the adsorption is saturated, that is, when the temperature is high. Therefore, it is urgent to develop a low-cost, harmless to the human body, and high-efficiency purification material for removing formaldehyde.

[0004] Pinene is an organic compound with the chemical formula C 10 H 16 It is a colorless transparent liquid, slightly soluble in water, insoluble in propylene glycol and glycerin, soluble in most organic solvents such as ethanol, ether, chloroform, glacial acetic acid, etc., and is mostly used to synthesize other fragrances, but it itself is also a VOC and has low toxicity. How to utilize the properties of pinene and use it for formaldehyde adsorption has not been reported in the prior art. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides an aminopinene formaldehyde adsorbent, which is obtained by amino-modifying pinene, introducing multiple amine groups on the ring structure, and then loading the aminopinene onto a matrix material. The effect of the amine groups and formaldehyde is utilized to achieve efficient adsorption of formaldehyde, especially enabling the adsorbent to still have high adsorption activity for formaldehyde under high relative humidity conditions.

[0006] In one embodiment, the amino pinene specifically refers to diamino pinene, and the preparation principle and steps thereof are as follows:

[0007]

[0008] Step 1: Add a certain amount of CCl4 to α-pinene, stir at 0°C, drop a certain amount of liquid bromine, and react for a certain time; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane.

[0009] Step 2: Add a small amount of polyethylene glycol to 2,6-dibromocamphane, stir evenly, then introduce ammonia gas, and maintain a certain temperature. After the introduction of ammonia gas, continue the reaction for a certain time. Remove the polyethylene glycol and unreacted products by rotary evaporation to obtain a diaminopinene product.

[0010] Step 3: Load diaminopinene onto a base material to obtain the target product, aminopinene formaldehyde adsorbent.

[0011] In step 1, the amount of liquid bromine used is n α-蒎烯 :n 液溴 =1:1, reaction time is 8-12h.

[0012] In step 2, the reaction temperature is 28-32°C, and the amount of ammonia introduced is n 氨气 :n 2,6-二溴莰烷 =2:1, react for 1-3h after the ammonia gas is introduced.

[0013] The matrix material in step 3 is not limited, and suitable matrix materials are activated carbon, titanium oxide, manganese oxide, silicon oxide, N-doped TiO2, Zn-doped TiO2, calcium titanate, expanded graphite, etc. The loading method is also not limited, as long as the aminopinene can be successfully loaded on the matrix material, and suitable loading methods include impregnation, spraying, spin coating, etc. The loading amount of diaminopinene is 2-5wt% of the adsorbent material.

[0014] In another embodiment, the amino pinene specifically refers to polyamino pinene, and the preparation principle and steps thereof are as follows:

[0015]

[0016] Step 1': Add a certain amount of CCl4 to α-pinene, stir at 0°C, drop liquid bromine, and react for a certain time; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane.

[0017] Step 2': Stir and heat 2,6-dibromocamphane to a certain temperature, drop a certain amount of liquid bromine, and irradiate with ultraviolet light. After the dropwise addition is completed, continue stirring until the color of the solution changes to light yellow, stop the reaction, wash with water to remove residual bromine, and obtain a polybrominated pinenyl substituted product.

[0018] Step 3': Add a small amount of polyethylene glycol to the polybrominated pinene substituted product, stir evenly, then introduce ammonia gas, and maintain a certain temperature. After the introduction of ammonia gas, react for a certain time. Remove the polyethylene glycol and unreacted products by rotary evaporation to obtain a polyamino pinene product.

[0019] Step 4': Loading polyaminopinene onto a base material to obtain the target product, polyaminopinene formaldehyde adsorbent.

[0020] In step 1', the amount of liquid bromine used is n α-蒎烯 :n 液溴 =1:1, reaction time is 8-12h.

[0021] In step 2', the reaction temperature is 40-60°C, and the amount of liquid bromine is n 2,6-二溴莰烷 :n 液溴 =1:1.5.

[0022] In step 3', the reaction temperature is 28-32°C, and the amount of ammonia introduced is n 氨气 :n 多溴蒎烯基取代物 =5:1, react for 1-3h after the ammonia gas is introduced.

[0023] The matrix material in step 4' is not limited, and suitable matrix materials are activated carbon, titanium oxide, manganese oxide, silicon oxide, N-doped TiO2, Zn-doped TiO2, calcium titanate, expanded graphite, etc. The loading method is also not limited, as long as the amino pinene can be successfully loaded on the matrix material, and suitable loading methods include impregnation, spraying, spin coating, etc. The loading amount of polyamino pinene is 2-5wt% of the adsorbent material.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. By introducing Br into the pinene ring structure, and then cleverly using it as a medium to introduce amine groups into the pinene ring structure, the pinene surface is modified with amine groups to convert pinene into an active component with high formaldehyde adsorption activity.

[0026] 2. Pinene is slightly soluble in water. Although the amino groups introduced on its surface are hydrophilic, aminopinene is still hydrophobic as a whole. This makes the aminopinene adsorbent unexpectedly able to exhibit excellent formaldehyde adsorption effects in high temperature environments, high relative humidity environments, and acid-base environments. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments.

[0028] Example 1

[0029] Preparation of diaminopinene adsorbent AC-2NH2:

[0030] Step 1: Add a certain amount of CCl4 to α-pinene, stir at 0℃, and drop a certain amount of liquid bromine. α-蒎烯 :n 液溴 =1:1, react for 10 hours; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane.

[0031] Step 2: Add a small amount of polyethylene glycol to 2,6-dibromocamphane, stir evenly, and then introduce ammonia gas. The amount of ammonia gas introduced is n 氨气 :n 2,6-二溴莰烷 =2:1, maintain the temperature at 30°C. After the ammonia gas is introduced, continue the reaction for 2 hours. Remove the polyethylene glycol and unreacted products by rotary evaporation to obtain the diaminopinene product.

[0032] Step 3: Load diaminopinene onto activated carbon, with the loading amount being 3 wt% of the adsorbent mass, to obtain aminopinene formaldehyde adsorbent AC-2NH2.

[0033] Example 2

[0034] Preparation of polyamine-based pinene adsorbent AC-nNH2:

[0035] Step 1': Add a certain amount of CCl4 to α-pinene, stir at 0℃, add liquid bromine dropwise, α-蒎烯 :n 液溴 =1:1, react for 10 hours; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane.

[0036] Step 2': Stir 2,6-dibromocamphane and heat to 50°C, add liquid bromine dropwise, 2,6-二溴莰烷 :n 液溴 =1:1.5, and irradiate with ultraviolet light. After the addition is completed, continue stirring until the color of the solution changes to light yellow, stop the reaction, wash with water to remove residual bromine, and obtain a polybrominated pinenyl substituted product.

[0037] Step 3': Add a small amount of polyethylene glycol to the polybrominated pinenyl substituted product, stir evenly, and then introduce ammonia gas, maintaining the temperature at 30°C. The amount of ammonia gas introduced is n 氨气 :n 多溴蒎烯基取代物 =5:1. After the ammonia gas is introduced, the mixture is reacted for a certain period of time. The polyethylene glycol and unreacted products are removed by rotary evaporation to obtain a polyaminopinene product.

[0038] Step 4': Load polyaminopinene onto activated carbon (same as in Example 1) with a loading amount of 3 wt% of the mass of the adsorbent to obtain polyaminopinene formaldehyde adsorbent AC-nNH2.

[0039] Example 3

[0040] The formaldehyde adsorption experiment was carried out in a 60L plexiglass box. During the adsorption experiment, a 5W electric fan was placed at the bottom of the box to help circulate the gas in the box. Formaldehyde gas was injected into the box with formalin solution through a micro-syringe. The initial concentration of formaldehyde can be adjusted by changing the injection volume. Usually, the volatilization of 30μL formalin solution makes the formaldehyde concentration in the box 150ppm. The concentration of formaldehyde can be measured by phenol spectrophotometry. 10mL of gas containing trace formaldehyde is diluted with 10mL of phenol reagent solution (1*10 -4 wt%) was adsorbed for 5 min. Then 1.2 mL (1 wt%) of ammonium ferric sulfate solution was added as a colorant. After shaking, the mixture was allowed to stand for 15 min in a dark environment, and the absorbance at 630 nm was measured using a spectrophotometer (Hitachi U-3010 UV-vis spectrophotometer) to obtain the formaldehyde concentration, and the adsorption capacity of the adsorbent was further calculated.

[0041] Table 1. Adsorption capacity of adsorbents at room temperature and different relative humidity conditions (mg formaldehyde g -1 Adsorbent

[0042]

[0043] The adsorption capacity of conventional formaldehyde adsorbents in the prior art is significantly lower than that of the present application. For example, in the activated carbon in document 1 (Ma, C., Li, X., Zhu, T., 2011. Removal of low-concentration formaldehyde in air by adsorption on activated carbon modified by hexamethylene diamine. Carbon 49 (8), 2873-2875), the adsorption capacity of formaldehyde is 0.08 mg g at 25 ° C and relative humidity of 30%. -1 Reference 2 (Gu, ZY, Wang, G., Yan, XP, 2010. MOF-5 metal-organic framework as sorbent for in-field sampling and preconcentration in combination with thermal desorption GC / MS for determination of atmospheric formaldehyde. Anal. Chem. 82 (4), 1365-1370) MOF-5, at 20°C and relative humidity of 45%, has a formaldehyde adsorption capacity of 0.11 mg g -1 .

[0044] From the comparison with the above-mentioned prior art, it can be seen that the adsorption capacity of the aminopinene formaldehyde adsorbent prepared by the present invention is much higher than that of conventional activated carbon and MOF-5 adsorbents, and as the relative humidity changes, the adsorbent prepared by the present invention unexpectedly maintains a very high adsorption capacity, which fully demonstrates the excellent formaldehyde adsorption performance of the aminopinene formaldehyde adsorbent.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an aminopinene formaldehyde adsorbent, characterized in that: The amino pinene formaldehyde adsorbent is a diamino pinene formaldehyde adsorbent or a polyamino pinene formaldehyde adsorbent. The preparation steps of the diaminopinene formaldehyde adsorbent are as follows: Step 1: Add a certain amount of CCl4 to α-pinene, stir at 0°C, drop a certain amount of liquid bromine, and react for a certain time; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane; Step 2: adding a small amount of polyethylene glycol to 2,6-dibromocamphane, stirring evenly, introducing ammonia gas, maintaining a certain temperature, and continuing the reaction for a certain time after the introduction of ammonia gas is completed; removing the polyethylene glycol and unreacted products by rotary evaporation to obtain a diaminopinene product; Step 3: loading diaminopinene onto a base material to obtain a diaminopinene formaldehyde adsorbent; The preparation steps of the polyamino pinene formaldehyde adsorbent are as follows: Step 1': Add a certain amount of CCl4 to α-pinene, stir at 0°C, drop liquid bromine, and react for a certain time; after the reaction is completed, wash with water to remove residual bromine; remove CCl4 by rotary evaporation to obtain 2,6-dibromocamphane; Step 2': Stir and heat 2,6-dibromocamphane to a certain temperature, dropwise add a certain amount of liquid bromine, and irradiate with ultraviolet light. After the dropwise addition is completed, continue stirring until the color of the solution changes to light yellow, stop the reaction, wash with water to remove residual bromine, and obtain a polybrominated pinenyl substituted product; Step 3': adding a small amount of polyethylene glycol to the polybrominated pinene substituted product, stirring evenly, introducing ammonia gas, and maintaining a certain temperature; after the introduction of ammonia gas is completed, reacting for a certain time, and removing the polyethylene glycol and unreacted products by rotary evaporation to obtain a polyamino pinene product; Step 4': Loading polyaminopinene onto a base material to obtain a polyaminopinene formaldehyde adsorbent.

2. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 1, the amount of liquid bromine used is n α-蒎烯 :n 液溴 =1:1, reaction time is 8-12h.

3. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 2, the reaction temperature is 28-32°C.

4. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 2, the amount of ammonia introduced is n 氨气 :n 2,6-二溴莰烷 =2:1, react for 1-3h after the ammonia gas is introduced.

5. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 1', the amount of liquid bromine used is n α-蒎烯 :n 液溴 =1:1, reaction time is 8-12h.

6. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 2', the reaction temperature is 40-60°C, and the amount of liquid bromine is n 2,6-二溴莰烷 :n 液溴 =1:1.

5.

7. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In step 3', the reaction temperature is 28-32°C, and the amount of ammonia introduced is n 氨气 :n 多溴蒎烯基取代物 =5:1, react for 1-3h after the ammonia gas is introduced.

8. The method for preparing the aminopinene formaldehyde adsorbent according to claim 1, characterized in that: In steps 3 and 4', the matrix material is activated carbon, titanium oxide, manganese oxide, silicon oxide, N-doped TiO2, Zn-doped TiO2, calcium titanate or expanded graphite, and suitable loading methods include impregnation, spraying, and spin coating. The aminopinene loading amount is 2-5wt% of the adsorbent material.

9. An aminopinene formaldehyde adsorbent prepared by the preparation method according to any one of claims 1 to 8.

10. An application of an aminopinene formaldehyde adsorbent for adsorbing formaldehyde in a high relative humidity environment, characterized in that: The aminopinene formaldehyde adsorbent used is the aminopinene formaldehyde adsorbent described in claim 9.

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