Aryl pinene formaldehyde adsorbent and preparation method thereof

Abstract

The invention relates to an aryl pinene formaldehyde adsorbent and a preparation method thereof. Aryl pinene is subjected to amido modification, a plurality of amido groups are introduced to a ring structure, then the aryl pinene is loaded to a matrix material, and efficient adsorption of formaldehyde is realized by 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 present invention belongs to the field of adsorption, and relates to an aromatic pinene formaldehyde adsorbent and a preparation method thereof. Background Art

[0002] Formaldehyde, also known as formic aldehyde, has a strong pungent odor and is an air pollutant that harms people's physical 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 begin to pay attention to the indoor environment, especially the air quality. Studying the formaldehyde purification technology in indoor air and improving the indoor air quality is of great significance.

[0003] Currently, the methods for removing formaldehyde from air include adsorption method, catalytic oxidation method, biodegradation method, plasma technology, etc. These methods have their own advantages and disadvantages, and the most commonly used one is the adsorption method. Currently, 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, while the adsorption capacity for strongly polar formaldehyde is very small, and it is easily released secondarily when the adsorption is saturated, i.e., at a relatively high temperature. Therefore, there is an urgent need to develop a purification material with low cost, harmless to the human body, and high formaldehyde removal efficiency.

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

[0005] In order to overcome the above-mentioned disadvantages of the prior art, the present invention provides an aromatic pinene formaldehyde adsorbent, which conducts amino modification on aromatic pinene, introduces multiple amino groups on the ring structure, and then loads the aromatic pinene onto the matrix material to achieve efficient adsorption of formaldehyde by utilizing the interaction between the amino group and formaldehyde, especially enabling the adsorbent to still have high adsorption activity for formaldehyde under high relative humidity conditions.

[0006] In one embodiment, the aromatic pinene specifically refers to pinene-based diphenylamine, and its preparation principle and steps are as follows:

[0007]

[0008] Step 1: Add a certain amount of CCl 4 to α-pinene, stir at 0 °C, dropwise add a certain amount of liquid bromine, and react for a certain time; after the reaction is completed, wash with water to remove the residual bromine; rotary evaporate to remove CCl 42,6-dibromocamphane is obtained.

[0009] Step 2: Stir 2,6-dibromocamphane at a certain temperature, dropwise add a certain amount of aniline. After the addition is complete, continue the reaction for a certain period of time. After the reaction is completed, a pinene-based diphenylamine compound is obtained.

[0010] Step 3: Load the pinene-based diphenylamine compound onto a substrate material to obtain the target product, a pinene-based diphenylamine formaldehyde adsorbent.

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

[0012] In Step 2, the reaction temperature is 28 - 32 °C, and the dropwise addition amount of aniline is n 苯胺 :n 2,6-二溴莰烷 = 2:1, and the reaction time is 2 - 4 h.

[0013] The substrate material in Step 3 is not limited. Suitable substrate materials are activated carbon, titanium oxide, manganese oxide, silicon oxide, N-doped TiO 2 , Zn-doped TiO 2 , calcium titanate, expanded graphite, etc. The loading method is also not limited, as long as the amino pinene can be successfully loaded onto the substrate material. Suitable loading methods include the impregnation method, spraying method, spin coating method, etc. The loading amount of diamino pinene is 5 - 8 wt% of the adsorbent material.

[0014] In another embodiment, the aromatic pinene specifically refers to pinene-based polyaniline, and its preparation principle and steps are as follows:

[0015]

[0016] Step 1': Add a certain amount of CCl 4 to α-pinene, stir at 0 °C, dropwise add liquid bromine, and react for a certain period of time; after the reaction is completed, wash with water to remove the residual bromine; rotary evaporate to remove CCl 4 to obtain 2,6-dibromocamphane.

[0017] 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 addition is complete, continue stirring until the solution color changes to light yellow, stop the reaction, wash with water to remove the residual bromine, and obtain a polybrominated pinene-based substituent.

[0018] Step 3': Stir the polybrominated pinene-based substituent at a certain temperature, dropwise add a certain amount of aniline. After the addition is complete, continue the reaction for a certain period of time. After the reaction is completed, a pinene-based polyaniline compound is obtained.

[0019] Step 4': Load the pinene-based polyaniline compound onto the matrix material to obtain the target product, the pinene-based polyaniline formaldehyde adsorbent.

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

[0021] In step 2', the reaction temperature is 40 - 60 °C, and the amount of liquid bromine used 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 dropping amount of aniline is n 苯胺 : n 2,6-二溴莰烷 = 4:1, and the reaction time is 2 - 4 h.

[0023] The matrix material in step 4' is not limited. Suitable matrix materials are activated carbon, titanium oxide, manganese oxide, silicon oxide, N-doped TiO 2 , Zn-doped TiO 2 , calcium titanate, expanded graphite, etc. The loading method is also not limited, as long as the amino pinene can be successfully loaded onto the matrix material. Suitable loading methods include the impregnation method, spraying method, spin coating method, etc. The loading amount of polyamino pinene is 5 - 8 wt% 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 this as a medium to introduce aniline into the pinene ring structure, the pinene is converted into an active component with high formaldehyde adsorption activity through amino modification of the pinene surface.

[0026] 2. Aryl pinene is slightly soluble in water. Although the amino groups introduced on its surface have hydrophilicity, the amino pinene as a whole still shows hydrophobicity, which makes the amino pinene adsorbent unexpectedly exhibit excellent formaldehyde adsorption effects in high-temperature environments, high relative humidity environments, and acid-base environments. Specific Embodiments

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

[0028] Example 1

[0029] Preparation of pinene-based diphenylamine adsorbent AC-2An:

[0030] Step 1: Add a certain amount of CCl 4 to α-pinene, stir at 0 °C, and drop a certain amount of liquid bromine, n α-蒎烯 : n液溴 = 1:1, react for 10 h; after the reaction is completed, wash with water to remove residual bromine; rotary evaporate to remove CCl 4 to obtain 2,6-dibromocamphane.

[0031] Step 2: Stir 2,6-dibromocamphane at 30 °C, add a certain amount of aniline dropwise, and the dropwise addition amount of aniline is n 苯胺 :n 2,6-二溴莰烷 = 2:1. After the dropwise addition is completed, continue the reaction for 2 h. After the reaction is completed, obtain the pinene-based diphenylamine compound.

[0032] Step 3: Load the pinene-based diphenylamine compound onto activated carbon, and the loading amount is 5 wt% of the mass of the adsorbent to obtain the target product, pinene-based diphenylamine AC-2An formaldehyde adsorbent.

[0033] Example 2

[0034] Preparation of pinene-based polyaniline adsorbent AC-nAn:

[0035] Step 1': Add a certain amount of CCl to α-pinene 4 , stir at 0 °C, add liquid bromine dropwise, n α-蒎烯 :n 液溴 = 1:1, react for 10 h; after the reaction is completed, wash with water to remove residual bromine; rotary evaporate to remove CCl 4 to obtain 2,6-dibromocamphane.

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

[0037] Step 3': Stir the polybrominated pinene-based substituent at 30 °C, add a certain amount of aniline dropwise, n 苯胺 :n 2,6-二溴莰烷 = 4:1. After the dropwise addition is completed, continue the reaction for 2 h. After the reaction is completed, obtain the pinene-based polyaniline compound.

[0038] Step 4': Load the pinene-based polyaniline compound onto the matrix material (the same as in Example 1), and the loading amount is 5 wt% of the mass of the adsorbent to obtain the target product, pinene-based polyaniline formaldehyde adsorbent.

[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 assist the gas circulation inside the box. Formaldehyde gas was injected into the box by a micro syringe with formalin solution. The initial concentration of formaldehyde could be adjusted by changing the injection volume. Usually, the evaporation of 30μL formalin solution made the formaldehyde concentration in the box reach 150ppm. The formaldehyde concentration could be measured by the phenol spectrophotometry method. 10mL of the gas containing trace formaldehyde was adsorbed by 10mL of phenol reagent solution (1*10 -4 wt%) for 5min. Then 1.2mL (1wt%) ammonium ferric sulfate solution was added as a colorant. Subsequently, it was oscillated and waited for 15min in the dark environment. The absorbance at 630nm was measured by a spectrophotometer (Hitachi U-3010 UV-vis spectrophotometer) to obtain the formaldehyde concentration, and further calculate the adsorption capacity of the adsorbent.

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

[0042]

[0043] In the prior art, the adsorption capacities of conventional formaldehyde adsorbents are significantly lower than those of this application. For example, for 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), at 25℃ and a relative humidity of 30%, the adsorption capacity of formaldehyde is 0.08mg·g -1 , and for MOF-5 in Document 2 (Gu, Z.Y., Wang, G., Yan, X.P., 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), at 20℃ and a relative humidity of 45%, the adsorption capacity of formaldehyde is 0.11mg·g -1 .

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

[0045] The above is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A method for preparing an aromatic pinene formaldehyde adsorbent, characterized in that: The aromatic pinene formaldehyde adsorbent is a pinene diphenylamine formaldehyde adsorbent or a pinene polyaniline formaldehyde adsorbent. The preparation steps of the pinenyl diphenylamine 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: Stir 2,6-dibromocamphane at a certain temperature, dropwise add a certain amount of aniline, and after the dropwise addition is completed, continue the reaction for a certain time to obtain a pinenyl diphenylamine compound after the reaction is completed; Step 3: loading the pinenyl diphenylamine compound onto a base material to obtain the target product, pinenyl diphenylamine formaldehyde adsorbent; The preparation steps of the pinene-based polyaniline 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': stirring the polybrominated pinenyl substituent at a certain temperature, adding a certain amount of aniline dropwise, and continuing the reaction for a certain time after the addition is complete; After the reaction is completed, a pinenyl polyaniline compound is obtained; Step 4': loading the pinenyl polyaniline compound onto a base material to obtain the target product, pinenyl polyaniline formaldehyde adsorbent.

2. The method for preparing the aromatic pinene 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 aromatic pinene formaldehyde adsorbent according to claim 1, characterized in that: In step 2, the reaction temperature is 28-32°C, and the amount of aniline added is n 苯胺 :n 2,6-二溴莰烷 =2:1, reaction time is 2-4h.

4. The method for preparing the aromatic pinene 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.

5. The method for preparing the aromatic pinene 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.

6. The method for preparing the aromatic pinene formaldehyde adsorbent according to claim 1, characterized in that: In step 3', the reaction temperature is 28-32°C, and the amount of aniline added is n 苯胺 :n 2,6-二溴莰烷 =4:1, reaction time is 2-4h.

7. The method for preparing the aromatic pinene 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 loading amount of the pinenyl diphenylamine compound or the pinenyl polyaniline compound is 5-8wt% of the adsorbent material.

8. An aromatic pinene formaldehyde adsorbent prepared by the preparation method according to any one of claims 1 to 7.

9. An application of an aromatic pinene formaldehyde adsorbent for adsorbing formaldehyde in a high relative humidity environment, characterized in that: The aromatic pinene formaldehyde adsorbent used is the aromatic pinene formaldehyde adsorbent described in claim 8.

Images