JPS63277240A - Uranium adsorbent - Google Patents

Abstract

PURPOSE:To obtain a readily handleable uranium adsorbent, consisting of a polyethyleneimine having a specific calix[n]arene derivative residue in the side chain and having excellent affinity and selectivity for uranyl ions. CONSTITUTION:For example, a calix[n]arene is added to concentrated sulfuric acid and thermally reacted to provide p-toluenesulfonic acid calix[n]arene, which is then reacted with an alkylating agent to afford calixarene-p-sulfonic acid derivative. The resultant derivative is subsequently reacted with thionyl chloride to provide a calixarene-p-sulfonyl chloride, which is then dissolved in tetrahydrofuran, slowly dripped into an aqueous solution of polyethyleneimine and reacted to afford the aimed polyethyleneimine having a calix[n]arene derivative expressed by the formula (n is preferably 6-8; R is H, CH2OH, etc.; x and y are H, alkyl, etc.) in the side chain.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a novel uranium adsorbent.

(Conventional technology) Nuclear power, hydropower, wind power, tidal power, and other energy sources are being considered as alternatives to oil, but none are superior to nuclear power in terms of technological perfection, cost, output, etc. do not have.

On the other hand, uranium, which is the fuel for nuclear energy, is buried on land.
The amount of a is estimated to be 5 million tons, but this is not enough to meet future demand. However, a huge amount of uranium, totaling 4.2 billion tons of N, exists in seawater, albeit at an extremely dilute concentration of a few ppb. The technology for recovering uranium from seawater is an extremely important technology that is being intensively studied, but a sufficient adsorbent has not yet been found.

Requirements for a uranium adsorbent include a large association constant with uranium and excellent selective adsorption of uranium with respect to other metal ions.

Many uranium adsorbents have been proposed so far, and the representative ones include potassium titanate, amidoxime resin, and crown ether compounds, but they do not satisfy the above-mentioned requirements and are expensive. , Regeneration of adsorbent material
There were problems in terms of reusability, handling, etc. Also, a report by Zinke et al. in 1941 (Ber, dtsc
h.

Chem, Ges, 7th Sat., 1729 (1941))
Cornforth et al. (Brit.

J, Pharmacol, ±0.73 (1955)
).

Kammer et al.
.

Chem, 162, 179 (1972)).

Munch (Makromo 1. Chem.

178.69 (1977)) and Gutsche et al.
(J, Am, Chem, Soc,
103°3782 (1981)) etc., various calixalene i, which are cylindrical compounds consisting of benzene rings.
21) Body synthesis is shown. However, none of the resulting calixarene derivatives is water soluble, but there is a problem in that the water solubility is poor (of course, there is no description of a uranium adsorbent from seawater).

The present inventors have thoroughly examined the shortcomings of the prior art and conducted a thorough analysis of the existing form of uranium in seawater. The uranyl ion uoH has a quasi-planar hexacoordination structure, which is significantly different from the planar four-coordination structure and tetrahedral structure of other metal ions. be. It was discovered that by utilizing this fact, it was possible to produce a uranium adsorbent with excellent selectivity and association constant for uranium, and first fixed a calixarene derivative with a specific ring structure and chemical structure to a resin. A uranium adsorbent was proposed.

However, when immobilizing the resin, the immobilization is limited to only the surface portion of the resin, and in order to improve the immobilization rate, it is necessary to use an extremely microporous resin.

(Problems to be Solved by the Invention) An object of the present invention is to propose a water-swellable uranium adsorbent in which a calixsalene derivative having excellent selective adsorption of uranium is immobilized extremely uniformly and at a high rate. .

(Means for Solving the Problems) The present invention is a uranium adsorbent made of polyethyleneimine having a calix[n]arene derivative residue 1) represented by the following general formula in its side chain.

R: hydrogen, lower alkyl group, lower alkyl alcohol, thiol, amine or carboxylic acid derivative, unsaturated alkyl group or aromatic hydrocarbon x, 'y: hydrogen, alkyl group, aromatic hydrocarbon Uranium adsorption of the present invention In materials, uranyl ions (u
It is important to have just the right cavity to capture oH゛゛>, and n is in the range of 4 to 10, preferably 6 to 10.
It is 8. If n is 3 or less, it is extremely difficult to synthesize and the uranium adsorption property is poor, making it unusable.
If the u
A decrease in adsorption selectivity for "oH" occurs.

In terms of selective adsorption of uranyl ions, R is preferably H, a lower alkyl alcohol, a thiol, an amine, or a carboxylic acid derivative; 1).

More preferred are CHzOH, CHas H, and CHtNHz.

x and y are not particularly limited as long as they do not adversely affect the uranium adsorption properties of the general formula.

In the calix[n]arene derivative represented by the above formula (1), as n becomes larger, the ring structure becomes larger, and rotation at -CI□- becomes easier. Therefore, the calisox(n)
Changes in the configuration of the arene derivatives can also be observed, but when n is less than 6 and R-1), hydrogen bonding by OH acts strongly, and OR (or s o , M) is oriented in a fixed direction. The probability of a structure (“cone” structure) is high. In addition, if R is not hydrogen or r1≧6, the solvent and the Kalinox (
n) It is necessary to consider the interaction with allene derivatives, but it is not necessary to take a co n e $ 1 structure, but to create a structure in which the orientation of OR (or SO3M) is alternated (“alte
nata''' structure) can also be taken.

Host of uoH゛ and calysox(n) arene derivative-
In the guest-type complex formation reaction, when R is a carboxylic acid having a lower alkyl group, it is sufficient to coordinate three carboxylates of kalinox(n)arene, and D-preference is achieved regardless of the double conformation. However, in the case of other substituted W, it is preferable to have a cone structure.

The polyethyleneimine may be any ordinary polyethyleneimine and is not particularly limited.The degree of polymerization of polyethyleneimine is usually 10 or more, preferably 100 to 10,000.If the degree of polymerization is less than 10, it can be used as a uranium adsorbent. Strong yy and lack of durability are not desirable. Also 1ooo
If it exceeds 0, water swelling property or calix[n]a1
The rate of non-introduction will decline. Polyethyleneimine is preferably -→CI (□-GHz -NH←) without side chains, but -←CH, -CH, -N with some side chains
The introduction rate of calix[n]arene into the H←polyethyleneimine chain is preferably calix(n)arene/ethyleneimine unit-1) 5 (molar ratio) or more, more preferably 1/10 to 1/1000. be. Calix (n)
The fixation of allene to the polyethyleneimine chain is carried out by the calix (
n) It is sufficient that it is bound to at least one binding site of the a1/one structure, but it may be bound to two or more binding sites, or it can be bound to other polyethyleneimine chains. It's okay.

The uranium adsorbent of the present invention is highly hydrophilic because it has polyethyleneimine in its main chain, but it is not water-soluble and only swells in water because it has immobilized califux[n]arene.

Next, an example of the method for manufacturing the uranium adsorbent of the present invention is shown. The calixox(n)arene derivative portion of the general formula can be made from calix(n)arene and sulfuric acid.

Calix (n) arenes are, for example, C, D.

Gutsche (Accounts of Che
mical Research, 1983(16)1
It can be produced by debutylating p-tert~butylcalix(n)arene produced by the method of 61-170) in toluene using a dealkylating agent such as anhydrous aluminum chloride.

In a flask equipped with a reflux condenser, 1 to 20 g, preferably 5 to 15 g of calisox(0)alene are mixed with 10 to 1 of concentrated sulfuric acid of 90% or more, preferably 95% or more, more preferably 98% or more 50rnI! , preferably 40-100m
1, heated (preferably above SO'C) and dissolved, usually for at least 1 hour, preferably for at least 2 hours, more preferably for 3 to 5 hours, at 60 to 100°C, preferably at 70°C.
React at ~90°C. After the reaction is completed, the contents are cooled,
By separating and washing the precipitated p-sulfonic acid calinx (n) arene, R=H, M in the above formula (I)
=H compound can be obtained.

In addition, when R is a lower alkyl group, p-sulfonate kalinox (n) arene and an appropriate alkylating agent, such as an alkyl halide, are mixed in a solvent that dissolves the alkylating agent, such as water, methanol, ethanol, It can be dissolved in THF etc. and substituted with an alkyl group at the OH site.

Further, when R is a lower alkyl carboxylic acid, the lower alkyl carboxylic acid can be substituted at the OH position in the above general formula by using a halogenated alkyl carboxylic acid. Compounds in which M is other than H can be obtained by ion exchange with various ions.

The resulting calixacin-p-sulfonic acid derivative was immobilized on polyethyleneimine by reacting calixacin-p-sulfonate sodium with thionyl chloride to form calixacin-p-sulfonyl chloride, and then reacting calixacin-p-sulfonyl chloride with calixacin-p-sulfonyl chloride. The reaction product, which is dissolved in tetrahydrofuran and gradually dropped into an aqueous polyethyleneimine solution for reaction, precipitates out in the form of a gel.

The feature of this production method is that the immobilization of the calixsalene derivative to polyethyleneimine only takes one step, and a crosslinked structure is formed simultaneously with the immobilization, so that a water-insoluble gel-like resin can be obtained.

(Effects of the Invention) The uranium adsorbent of the present invention has a side chain of a calixsalene derivative that selectively adsorbs uranyl ions, and is composed of a main chain of polyethyleneimine that is highly hydrophilic and water-swellable. It has extremely good affinity and selectivity with uranyl ions even in wastewater and seawater containing uranyl ions, and since it is in the form of a resin, it is very easy to handle.

The side chain calixsalene derivative can be used to freely design a cavity as a host to form a coordination compound with the target uranyl ion and introduce a functional group, and its skeleton can be used to form a coordination compound with other uranyl ions such as crown ether. Since it does not have the flexibility of cyclic ligands, it exhibits high selectivity for uranyl ions and has a characteristic of having low adsorption properties for other metal ions. Therefore, it has extremely good selectivity and large adsorption power for adsorbing uranium present in seawater. Further, the uranium adsorbent of the present invention is neither highly toxic nor expensive like crown ether. Therefore, if the uranium adsorbent of the present invention is used, uranium in seawater or wastewater can be adsorbed extremely efficiently, and the purity of the adsorbed uranium is high in order to suppress the adsorption of other metals, making it possible to greatly reduce the purification process. It can be shortened to . Furthermore, it is of great industrial significance as it can be efficiently recovered and reused.

(Example) The present invention will be explained in more detail below with reference to Examples.

In a flask equipped with a stirrer and a cooling tube, 78 g of Calisox [6] Alene 7 was added with 98% concentrated sulfur fa 50 m j!
and continued stirring at 80°C for 3 hours with stirring.
The end point of the reaction is defined as the point at which no water-insoluble substances are present.

Next, it was cooled to room temperature, the precipitated crystals were separated in a furnace, and 98%
This was washed with concentrated sulfuric acid to obtain crystals of p-sulfonic acid calix[6]arene. The obtained crystals are dissolved in water and neutralized with barium carbonate, and the resulting barium sulfate precipitate is separated by furnace. Sodium carbonate is added to the solution to obtain a sodium p-sulfonate caulifux[6]alene aqueous solution.

Add sodium carbonate until the pH of the fgi solution becomes 8-9.

After treating the aqueous solution with activated carbon, it is dried under reduced pressure. Dissolve the residue in water and separate the insoluble matter by furnace. The added liquid is treated with activated carbon again, and after removing the activated carbon, the remaining liquid is concentrated. The reaction product obtained by adding ethanol to the concentrate and then fractionating and crystallizing the product was confirmed to be sodium p-sulfonate calinx[6]arene based on the analysis results shown in Table 1 below.

In addition, the starting material Calinx [6] arene is Gutsc
The method of He et al.
p-tert-butylcalix[6]arene obtained by the method of 1982)) was A1) CIts in toluene.
It was obtained by debutylation with a dealkylating agent such as.

Example 1 The calix[6]arene derivative of the above formula (1) was heated under reflux in thionyl chloride for 6 hours, then poured into Kumiki water, and then stirred at room temperature for one day to obtain S Ox Na (
D Partially chlorosulfonylated (-3Q, C1). Excess thionyl chloride was distilled off under reduced pressure.

Kalinox[6]arene-p-chlorosulfonyl derivative was dissolved in tetrahydrofuran. Separately, a 30% water/8 solution of polyethyleneimine (degree of polymerization 1900) was prepared, and the above tetrahydrofuran solution was gradually added dropwise to this polyethyleneimine aqueous solution at room temperature. - After stirring day and night, the resulting gel was filtered, washed with water, and dried at room temperature to obtain a white powder.

The results of elemental analysis were H6, 50%, C42, 34%.

It can be seen that the N content was 10.24%, 310.01%, and 030.91%, and that 5.2×10 −' moles of calinx[6]arene units were contained per gram of resin. That is, Kalinox (nl arene/ethyleneimine units = 1/22 (molar ratio)).

Next, the above white I5) powder resin was added to an aqueous solution containing 31.5 ppm of uranyl nitrate to give 1 to 40%
During this period, a uranyl ion adsorption test was conducted. Adsorption reached saturation in about one day, and it was found that 1) 1 had an extremely high adsorption rate. Table 1 shows the adsorption amount in terms of uranium after 4 days.

Table 1 *: Data published in Pressure et al. 1 Journal of the Chemical Society of Japan 1769 (1980) **: Data published in Pressure et al. 2 Journal of the Chemical Society of Japan 958 (1979)

Claims (1)

[Claims] (1) A uranium adsorbent made of polyethyleneimine having a calix[n]arene derivative residue (I) represented by the following general formula in its side chain. ▲There are mathematical formulas, chemical formulas, tables, etc.▼・・・・・・( I
) However, n: 4 to 10 R: hydrogen, lower alkyl group, lower alkyl alcohol, thiol, amine or carboxylic acid derivative, unsaturated alkyl group or aromatic hydrocarbon x, y: hydrogen, alkyl group, aromatic hydrocarbon