CN101735417A - Method for preparing surface imprinted material for rare-earth ion identification and separation - Google Patents

Abstract

The invention relates to a method for preparing a surface imprinted material, in particular to a method for preparing a surface imprinted material for rare-earth ion identification and separation. The method solves the problem that the surface imprinted material suitable for separating rare-earth ions is unavailable at present. The method comprises the following steps: grafting and polymerizing acrylonitrile to the surface of surface modified silica gel particles, and then converting the grafted acrylonitrile into polyamidoxime so as to obtain grafted particles; secondly, saturating and adsorbing the rare-earth ions by means of the interaction between the polyamidoxime on the surface of the grafted particles and the rare-earth ions; thirdly, crosslinking molecules of the polyamidoxime by using glutaric dialdehyde as a cross linker, and meanwhile imprinting the rare-earth ions; and finally, removing the rare-earth ions to leave a large amount of imprinted cavity in a polyamidoxime thin layer on the surface of the silica gel particles so as to obtain the surface imprinted material for the rare-earth ion identification and separation. The process for introducing the surface imprinted material prepared by the method into the separation of the rare-earth ions greatly promotes the separation efficiency of the rare-earth metal ions.

Description

Be used for rare earth ion and discern the preparation method of isolating surface imprinted material

Technical field

The present invention relates to ion surface imprinted preparation methods, be specially and be used for the preparation method that rare earth ion is discerned isolating surface imprinted material.

Background technology

Rare earth element has unique optics, electricity, magnetics and mechanical property, occupies important status in modern science and technology.Because the atomic structure of rare earth element is similar, physicochemical property are approaching, and their gathering appearance again usually in the earth's crust, symbiosis is among mineral, and these all make sepn process very difficult, and the separation of single-element is a very complicated process.At present, solvent extration is still the main method that Rare Earth Separation adopts, and this method is not only loaded down with trivial details, and separation efficiency is lower, needs repeatedly circulation, but also produces environmental problem.Solvent extration has been obtained significant progress and development in recent years, and especially in China, the foundation of cascade extraction theory has been played very big pushing effect to Rare Earth Separation.But however, the shortcoming of liquid-liquid extraction method does not have substantial change.

China's rare earth resources is very abundant, develops the new technology of Rare Earth Separation more efficiently, for the development of Chinese national economy and the lifting of scientific and technological level, all has crucial meaning.Solvent extration is to utilize rare earth ion to have different partition characteristics in immiscible two-phase and realize being separated from each other; And chemical vapor conveying method is based on different rare earth chlorides and the formed gaseous state title complex of other muriate, has different decomposition heat mechanical behaviors, thereby realize being separated from each other.

The class functional polymer material that ion (molecule) imprinted material is tailored meticulously, its inside is distributed with the trace hole of a large amount of template ions (molecule), these holes and template ion (molecule) are complementary to heavens at aspects such as size, space structure, binding sites, make molecular engram material have special identification selection and good binding affinity, be called artificial antibody or artificial susceptor by people to template ion.Because ion (molecule) imprinted material can carry out selectivity identification to template ion (molecule) on ion (molecule) level, at present, various high-tech areas have been widely used in, especially in separation, purifying and the enrichment method field of material, with ion (molecule) imprinted material is that ion (molecule) the trace solid phase extraction (MISPE) of solid adsorbent arises at the historic moment, and has obtained using widely.The traditional method of preparation ion (molecule) imprinted material is an entrapping method, and this method shortcoming has: dark or tension are crossed in embedding to template ion (molecule), and not only wash-out difficulty, and trace hole number is limited, and trace efficient is not high; Because the duct is dark, template ion (molecule) diffusional resistance is big, and mass transfer velocity is slow, is difficult for combining with recognition site; Pulverize process of lapping the abundant traces hole is wrecked, the bonding properties of material is reduced.For overcoming above-mentioned shortcoming effectively, investigators have proposed the preparation method of the surface imprinted material of ion (molecule), attempt ion (molecule) trace hole is placed the solid particles surface with good accessibility, thereby help removing and combination again of template ion (molecule), improve the efficient of molecular imprinting.When the surface imprinted material of this ion of preparation (molecule), adopt " being grafted to " method (" grafting to " method) or " picking out " method (" grafting from " method) respectively, earlier will and template ion (molecule) between have secondary valence bond power and (comprise electrostatic interaction, hydrogen bond action, hydrophobic interaction and coordination sequestering action etc.) the function macromolecular material, be grafted to micron order inorganic particles (aerosil particles, titanium dioxide fine particles, aluminium sesquioxide) or organic polymer (cross-linking polyvinyl alcohol, poly hydroxy ethyl acrylate, poly (glycidyl methacrylate), polystyrene, polyacrylamide) microsphere surface makes grafting particulate (ball); Rely on the function macromole on grafting particulate (ball) surface and the interaction between the template ion (molecule) then, saturated absorption template ion (molecule) or other group ion; Re-use special linking agent (having the double reactive end group), it is crosslinked that the function macromole is able to, and realizes the trace of template ion (molecule) simultaneously; After removing (flush away) template ion (molecule) then; in the function macromolecular material thin layer on inorganic particles or polymer microballoon surface; stay a large amount of trace holes, obtained the surface imprinted material of high-performance (to template ion (molecule) in conjunction with speed is fast, identification selection is strong, binding capacity is high).In addition, the preparation method of this surface imprinted material has exempted troublesome operation such as grinding and screening fully, also the granular size of may command imprinted material.The preparation method's of the surface imprinted material of ion (molecule) ultimate principle is seen Fig. 1.

Be grafted to the macromole functional materials of micron order inorganic particles or organic polymer microsphere surface, isolating ion (molecule) is closely related with wanting.Separate different ions (molecule), need to select different macromole functional materialss, adopt different linking agents.At present, owing to be not applicable to rare-earth separating ionic surface imprinted material, therefore, do not see that at present to adopt surface imprinted material to carry out rare earth ion isolating, do not see relevant bibliographical information yet.

Summary of the invention

The present invention provides a kind of preparation method that rare earth ion is discerned isolating surface imprinted material that is used in order to solve the problem that is not applicable to rare-earth separating ionic surface imprinted material at present.

The present invention adopts following technical scheme to realize: be used for the preparation method that rare earth ion is discerned isolating surface imprinted material, with the silica particle surface of acrylonitrile grafting polymerization in surface modification, then the grafted polyacrylonitrile is converted into poly-amidoxim (PAO), thereby makes the grafting particulate (PAO/SiO that surface grafting has poly-amidoxim ₂); Rely on the poly-amidoxim (PAO) of grafting microparticle surfaces and the interaction between the rare earth ion, saturated absorption rare earth ion then; Again with glutaraldehyde as cross linker, what make poly-amidoxim (PAO) intermolecularly is able to crosslinkedly, realizes the trace of rare earth ion simultaneously; Remove rare earth ion then, in poly-amidoxim (PAO) thin layer of silica particle surface, stay a large amount of trace holes, discern isolating surface imprinted material thereby obtain to be used for rare earth ion.

The present invention as the function macromolecular material that grafts on particulate or microsphere surface, selects glutaraldehyde as cross linker with poly-amidoxim, made to rare earth ion in conjunction with speed soon, identification selection is strong, binding capacity is high surface imprinted material.Simultaneously, owing to used silica matrix, greatly improved the physical strength of imprinted material.The surface imprinted material of the method for the invention preparation is suitable for industrial production requirement, the material use efficiency height, and cost is low, and rare earth ion is had selectivity well, and rare earth ion is had very strong identification and associativity, and has good ion desorption performance.Described rare earth ion can be group of the lanthanides and actinide ion.

Select three kinds of adjacent in lanthanon element S m for use ³⁺, Eu ³⁺, Gd ³⁺Three kinds of ions are discerned separation, to rare earth gadolinium ion Gd ³⁺Implemented surface imprintedly, prepared gadolinium ion surface imprinted material IIP-PAO/SiO ₂Investigated described gadolinium ion surface imprinted material IIP-PAO/SiO ₂To three kinds of adjacent rare earth ion samarium (Sm ³⁺), europium (Eu ³⁺), gadolinium (Gd ³⁺) identification and the separation performance of ion (ionic radius differs 1-3pm).The result shows: described imprinted material IIP-PAO/SiO ₂To gadolinium ion have height in conjunction with selectivity, to the then basic nonrecognition of samarium, europium ion, debond, thereby realized on the micromicron yardstick separation to adjacent three kinds of rare earth ions.The surface imprinted material that this method is made is introduced the sepn process of rare earth ion, greatly promotes the efficient of Rare Earth Separation.

One, gadolinium ion surface imprinted material IIP-PAO/SiO ₂To adjacent rare-earth Sm ³⁺, Eu ³⁺, Gd ³⁺The experiment of three kinds of ionic bond characteristics:

Select three kinds of adjacent in lanthanon element S m ³⁺, Eu ³⁺, Gd ³⁺Three kinds of ions are discerned separation, and above-mentioned three kinds of ionic electronic configurations are similar; Physicochemical property are similar; Ionic radius is close, and is subjected to the influence of lanthanide contraction, and three kinds of ionic radiuses are very near (differing 1～3pm).The structural performance of three kinds of rare earth ions is listed in table 1, and obviously, separating analogous in the mutual separation of isotropic substance between them is very difficult.Adopt ion surface imprinted material that three kinds of adjacent rare earth ions are separated from each other, specifically implement as follows:

The structured data of three kinds of rare earth ions of table 1

Rare earth ion	??Sm 3+	??Eu 3+	??Gd 3+
				Ordination number electronic configuration ionic radius/pm	??62??4f 5??96.4	??63??4f 6??95.0	??64??4f 7??93.8

(1) Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂Preparation process

Will be to Gd ³⁺Ionic adsorption has reached saturated grafting particulate PAO/SiO ₂, place the aqueous solution that adds the linking agent glutaraldehyde, by means of the schiff base reaction between the primary amine group in aldehyde radical on the linking agent and the PAO macromole, the PAO macromole is crosslinked, Gd ³⁺Ion then is wrapped in the cross-linked network, thereby has realized Gd ³⁺The ionic ion blotting; Flush away template ion Gd ³⁺Behind the ion, a large amount of Gd in the polymer foil on silica gel surface, have been stayed ³⁺The ionic hole has formed Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂

(2) IIP-PAO/SiO ₂To Gd ³⁺, Eu ³⁺, Sm ³⁺Three kinds of ionic binding characteristics

Adopt static (batch method) and dynamic (column method) two kinds of methods, use grafting microparticle material PAO/SiO ₂With Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂, respectively to the Gd in the water medium ³⁺, Eu ³⁺, Sm ³⁺Three kinds of ions have carried out the isothermal adsorption experiment.Concrete steps are as follows:

Adopt static and dynamic two kinds of methods respectively, measure Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺The ionic bonding properties.Measure IIP-PAO/SiO equally, earlier ₂To Gd ³⁺The behavior of ionic binding kinetics determines that in conjunction with reaching balance time be 4h, on this basis, carries out the mensuration of bonding properties.

1. stationary method: under 35 ℃ steady temperature, the Gd that the 25mL concentration series is changed ³⁺Place some tool plug Erlenmeyer flasks in the solion respectively, add the Gd of about 0.05g of accurate weighing ³⁺Ion surface imprinted microparticle material IIP-PAO/SiO ₂, the 4h that vibrates in vibrator makes in conjunction with reaching balance, and Gd in the EDTA complexometric titration supernatant liquor is adopted in centrifugation ³⁺The ionic equilibrium concentration according to formula (1), is calculated IIP-PAO/SiO ₂To Gd ³⁺Ionic junction at equilibrium resultant Q _e(g/100g), and draw the junction at equilibrium resultant, i.e. isothermal joint line (seeing accompanying drawing 2) to the equilibrium concentration relation curve.

$Q=\frac{V(C_0-C_e)\×M}{m\×10}---\left(1\right)$

C in the formula (1) ₀(mol/L), C _e(mol/L) be respectively Gd in the solution of absorption front and back ³⁺Concentration; V (mL) is the adsorption liquid volume; M is Gd ³⁺The relative molar mass of ionic (157.3g/mol); M (g) is ion surface imprinted material IIP-PAO/SiO ₂Quality.

According to above-mentioned static method, measure Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Sm ³⁺With Eu ³⁺Ionic isothermal joint line (seeing accompanying drawing 2).

Measure grafting microparticle material PAO/SiO according to above-mentioned static method ₂To Gd ³⁺, Sm ³⁺, Eu ³⁺Ionic adsorption isothermal line (seeing accompanying drawing 3).

Accompanying drawing 3 demonstrates grafting microparticle material PAO/SiO ₂To the adsorption isothermal line of three kinds of rare earth ions, 2 in accompanying drawing demonstrates Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To three kinds of rare earth ions in conjunction with thermoisopleth.

Static Adsorption result shows: as shown in Figure 3, and grafting microparticle material PAO/SiO ₂Three kinds of rare earth ions are all had high, identical loading capacity, do not show adsorption selectivity.As can be seen from Figure 2, through Gd ³⁺Ion blotting and the surface imprinted material IIP-PAO/SiO that forms ₂, to Eu ³⁺With Sm ³⁺Two kinds of ionic binding capacities but reduce (high adsorption capacity drops to 1.1g/100g by 7.8g/100g) greatly; And for Gd ³⁺Ion has not only kept original high binding capacity, but also increase (high adsorption capacity is increased to 8.3g/100g by 7.8g/100g) shown Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺Special identification selection that ion has and binding affinity highly.Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂In the polymer foil on surface, be distributed with a large amount of Gd ³⁺Ionic trace hole, these holes are at aspect and Gd such as size and action sites ³⁺Ion is matched (Gd ³⁺Ionic radius is 93.8pm, sees above-mentioned table 1), with Eu ³⁺And Sm ³⁺Ion then is unmatched (both radiuses is respectively 95.0pm and 96.4pm).Obviously, Eu ³⁺And Sm ³⁺Ionic radius ratio Gd ³⁺Ion is wanted big 1-3pm, therefore, and Gd ³⁺Ionic trace hole can not hold Eu ³⁺And Sm ³⁺Ion, Eu in other words ³⁺And Sm ³⁺Ion can not enter among these trace holes.Therefore, the hole in the polymer foil is to template ion Gd ³⁺Ion has produced special recognition capability, has very strong keying action, causes very high binding capacity, demonstrates imprinted material IIP-PAO/SiO ₂To Gd ³⁺The ion identification characteristic of ion excellence.

2. dynamic method: under the room temperature condition, with the Gd of 1.1g ³⁺Ion surface imprinted material IIP-PAO/SiO ₂Be contained in after the swelling in water in the Glass tubing that internal diameter is 10mm, (Bed Volume BV) is 2mL to make the bed volume of packed column.Making concentration is the Gd of 0.01mol/L ³⁺Solion is with 4BVh ^-1The flow velocity adverse current by packed column, collect effluent liquid with the interval of 2BV, measure Gd in the effluent liquid ³⁺Ionic concentration is drawn dynamic binding curve (seeing accompanying drawing 4,5), and utilizes the concentration and the bed volume number of effluent liquid, calculates IIP-PAO/SiO ₂To Gd ³⁺Ionic leaks binding capacity and saturated binding capacity.

Adopt above-mentioned dynamic approach, measure Gd respectively ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Sm ³⁺And Eu ³⁺The dynamic binding curve of ionic (seeing accompanying drawing 4,5).

Measure grafting microparticle material PAO/SiO according to above-mentioned dynamic approach ₂To Gd ³⁺, Sm ³⁺, Eu ³⁺Ionic dynamic adsorption curve (seeing accompanying drawing 6,7).

Fig. 6 has provided grafting microparticle material PAO/SiO ₂To Gd ³⁺And Eu ³⁺Two kinds of ionic dynamic adsorption curves, Fig. 4 demonstrates Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺And Eu ³⁺Two kinds of dynamic binding curves of ionic; Fig. 7 has then provided grafting microparticle material PAO/SiO ₂To Gd ³⁺And Sm ³⁺Two kinds of ionic dynamic adsorption curves, Fig. 5 then demonstrates Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺And Sm ³⁺Two kinds of dynamic binding curves of ionic.

Dynamic adsorption is the result show: as shown in Figure 6, and for PAO/SiO ₂Packed column, when rare-earth ion solution passes through packed column with the flow velocity adverse current of 4BV/h, Gd ³⁺Ion and Eu ³⁺Solion all begins to leak at 22BV, and dynamic adsorption is the result show again, grafting microparticle material PAO/SiO ₂To Gd ³⁺With Eu ³⁺Two kinds of ionic absorption non-selectivities.From Fig. 4, but see, for Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂Packed column, Gd ³⁺The leakage curve of solion obviously is different from Eu ³⁺The leakage curve of solion.Eu ³⁺The leakage volume of solion reduces (only being 2BV) greatly, and Gd ³⁺The leakage volume of solion still keeps high numerical value (24BV), and the latter is much larger than the former.Obviously, Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Eu ³⁺Ion is not selected substantially, nonrecognition, debond; And for Gd ³⁺Ion has but shown special identification selection and excellent combination affinity.As calculated, Eu ³⁺Ionic is revealed adsorptive capacity and saturated extent of adsorption only is 0.28g/100g and 1.41g/100g, and Gd ³⁺Ionic leakage adsorptive capacity and saturated extent of adsorption are then up to 6.29g/100g and 8.71g/100g.

Equally, as seen from Figure 7, grafting microparticle material PAO/SiO ₂To Gd ³⁺With Sm ³⁺Two kinds of ionic absorption non-selectivities; As can see from Figure 5, for Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂Packed column, Gd ³⁺The leakage curve of solion obviously is different from Sm ³⁺The leakage curve of solion, Sm ³⁺The leakage volume of solion also only is 2BV, as calculated, and Sm ³⁺Ionic is revealed adsorptive capacity and saturated extent of adsorption only is 0.27g/100g and 1.31g/100g, and Gd ³⁺The ionic adsorptive capacity is but very high.Obviously, Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Sm ³⁺Ion also be do not select substantially, nonrecognition, debond.

Two, gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd in the mixed solution ³⁺Ion and Eu ³⁺Ion, Gd ³⁺Ion and Sm ³⁺The experiment of ionic competitive adsorption:

Compound concentration is the Gd of 0.01mol/L ³⁺And Eu ³⁺Binary ion mixed solution, get the 25mL mixed solution in tool plug Erlenmeyer flask, add the gadolinium ion surface imprinted material IIP-PAO/SiO of 0.1g ₂, the 4h that vibrates in warm vibrator makes absorption reach balance, and Gd in the supernatant liquor is measured in centrifugation ³⁺Ion and Eu ³⁺Ionic equilibrium concentration: Gd ³⁺Ionic concn is directly calculated (pre-rendered typical curve) by the strength detection of its characteristic fluorescence emission (304nm); Eu ³⁺The mensuration of ionic concn then is to carry out after adding fluorescent color-developing agent γ-thenoyltrifluoroacetone, thereby measures the fluorescent emission intensity calculating concentration (pre-rendered typical curve) at λ=618nm place.Then by formula (2) calculate two kinds of ionic partition ratios.

Adopt identical above-mentioned steps to carry out gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺Ion and Sm ³The experiment of+ionic competitive adsorption is measured two kinds of ionic partition ratios of calculating by (2) formula.For this binary ion mixed solution, Gd in the supernatant liquor after the adsorption equilibrium ³⁺Ion and Sm ³⁺The mensuration of ionic equilibrium concentration: Gd ³⁺Ionic concn is still directly calculated by the strength detection of its characteristic fluorescence emission, and Sm ³⁺The mensuration of ionic concn also is to carry out after adding fluorescent color-developing agent γ-thenoyltrifluoroacetone, by the fluorescent emission intensity calculating concentration (pre-rendered typical curve) at λ=563nm place.

$K_d=\frac{Q_e}{C_e}---\left(2\right)$

In the formula, K _d(mLg ^-1) be the partition ratio of certain material; C _e(mgmL ^-1) be the equilibrium concentration of this material in the supernatant liquor; Q _e(mgg ^-1) be the junction at equilibrium resultant of this material.

By the partition ratio data of two kinds of materials in two groups of solution,, calculate gadolinium ion surface imprinted material IIP-PAO/SiO according to formula (3) ₂To Gd ³⁺Ionic selectivity coefficient (with respect to the contrast ion).

$k=\frac{K_d\left({\mathrm{<figure-callout\; id="3"\; label="Gd"\; filenames="H2009102278735E00021.png,H2009102278735E00022.png"\; state="\{\{state\}\}">Gd</figure-callout>}}^{3+}\right)}{K_d\left(M^{3+}\right)}---\left(3\right)$

In the formula, k is with respect to contrast ion M ³⁺(Sm ³⁺Or Eu ³⁺), gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺The ionic selectivity coefficient, the size of k value numerical value indicates gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺Ionic is in conjunction with selectivity.

To above-mentioned preparation Gd ³⁺/ Eu ³⁺And Gd ³⁺/ Sm ³⁺Binary ion mixing solutions uses gadolinium ion surface imprinted material IIP-PAO/SiO ₂, carried out the competitive adsorption experiment.Table 2 has been listed Gd ³⁺/ Eu ³⁺System and Gd ³⁺/ Sm ³⁺Two kinds of ionic partition ratio K in the system _d, selectivity coefficient k.

Table 2 Gd ³⁺/ Eu ³⁺System, Gd ³⁺/ Sm ³⁺System partition ratio and selectivity coefficient data

From the data of above-mentioned table 2 as can be seen: Gd ³⁺Ion and adjacent Eu ³⁺The only poor 1.2pm of ion, ionic radius (seeing above-mentioned table 1) is with respect to Eu ³⁺Ion, gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺Ionic selectivity coefficient very high (7.490), gadolinium ion surface imprinted material IIP-PAO/SiO ₂Can make a Gd ³⁺Ion well separates from mixed solution; Equally as can be seen, Gd ³⁺Ion and Sm ³⁺Ion, ionic radius differ 2.6pm (seeing above-mentioned table 1), with respect to Sm ³⁺Ion, gadolinium ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺The ionic selectivity coefficient can make the two be able to effective separation up to 7.930.

Three, gadolinium ion surface imprinted material IIP-PAO/SiO ₂Middle Gd ³⁺The experiment of ion desorption performance:

With saturated absorption Gd ³⁺Ionic gadolinium ion surface imprinted material IIP-PAO/SiO ₂Filling the dress post, at ambient temperature, is that the hydrochloric acid of 0.1mol/L is as elutriant, with 2BVh with concentration ^-1The flow velocity adverse current by packed column, carry out desorption experiment, experimental result shows: desorption efficiencies reach that desorption efficiency can reach 99.54% in 97.82%, 29 bed volume in 25 bed volumes.Above-mentioned experimental data proves absolutely and is bonded to imprinted material IIP-PAO/SiO ₂On Gd ³⁺Ion has good desorption performance, and this regeneration for column extractor in the rare earth ion sepn process is very favorable with recycling.

Description of drawings

Fig. 1 is the preparation method's of surface imprinted material a basic principle schematic;

Fig. 2 is Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To three kinds of rare earth ions in conjunction with thermoisopleth;

Fig. 3 is grafting particulate PAO/SiO ₂Adsorption isothermal line to three kinds of rare earth ions;

Fig. 4 is Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺And Eu ³⁺The dynamic binding curve of ionic;

Fig. 5 is Gd ³⁺Ion surface imprinted material IIP-PAO/SiO ₂To Gd ³⁺And Sm ³⁺The dynamic binding curve of ionic;

Fig. 6 is grafting particulate PAO/SiO ₂To Gd ³⁺And Eu ³⁺Ionic dynamic adsorption curve;

Fig. 7 is grafting particulate PAO/SiO ₂To Gd ³⁺And Sm ³⁺Ionic dynamic adsorption curve;

Fig. 8 is the ion surface imprinted material IIP-PAO/SiO of preparation ₂Chemical reaction process;

Embodiment

Be used for rare earth ion and discern the preparation method of isolating surface imprinted material, with the silica particle surface of acrylonitrile grafting polymerization in surface modification, then the grafted polyacrylonitrile is converted into poly-amidoxim (PAO), thereby makes the grafting particulate (PAO/SiO that surface grafting has poly-amidoxim ₂); Rely on the poly-amidoxim (PAO) of grafting microparticle surfaces and the interaction between the rare earth ion then, saturated absorption rare earth ion, again with glutaraldehyde as cross linker, what make poly-amidoxim (PAO) intermolecularly is able to crosslinkedly, realizes the trace of rare earth ion simultaneously; Remove rare earth ion then, in poly-amidoxim (PAO) thin layer of silica particle surface, stay a large amount of trace holes, discern isolating surface imprinted material thereby obtain to be used for rare earth ion.

During concrete enforcement, the acrylonitrile grafting polymerization is converted into poly-amidoxim (PAO), realizes that with glutaraldehyde the crosslinked those skilled in the art of being realizes on the basis of existing technology easily in silica particle surface, the polyacrylonitrile of surface modification.Just the technical parameter selection is improper, can make graft(ing) degree, cyano group transformation efficiency etc. lower, and the performance of final material is influenced to some extent.Provide a kind of concrete preparation method below, this method has higher graft(ing) degree, cyano group transformation efficiency.

Be used for rare earth ion and discern the preparation method of isolating surface imprinted material,

(1) at the silica particle surface graft polymerization vinyl cyanide of surface modification

The aerosil particles MPS-SiO that in the four-hole boiling flask that electric mixer, reflux condensing tube and thermometer are housed, adds the 1.23g surface modification successively ₂(double bond content that adopts Potassium Bromide-potassium bromate method to record the surface is 2.11mmol/g), 100mL N, the solution that is dissolved with the 11.79mL vinyl cyanide in the dinethylformamide (DMF) adds respectively in the flask, stirs down logical N ₂Gas excluding air 30min is warming up to 75 ℃ then, adds the Diisopropyl azodicarboxylate of 0.143g, and constant temperature also carries out graft polymerization reaction 5h under agitation condition, and suction filtration obtains the particulate PAN/SiO that surface grafting polymerization has vinyl cyanide ₂, prepared surface grafting polymerization has the particulate PAN/SiO of vinyl cyanide ₂Have higher graft(ing) degree, its graft(ing) degree is 13.70g/100g.

(2) surface grafting polymerization has the particulate PAN/SiO of vinyl cyanide ₂The amidoxim conversion

In four-hole bottle with the oxammonium hydrochloride solution of 1.0mol/L and the Na of 1.0mol/L ₂CO ₃Solution mixes, and its pH of mixed value is 6.0-7.0, adds grafting particulate PAN/SiO again ₂, feed N ₂, system is heated to 70 ℃, react 4h down in constant temperature and agitation condition, filter, use the distilled water repetitive scrubbing, be neutral to washings, vacuum-drying then promptly gets grafting particulate PAO/SiO ₂Adopt weighting method to measure and calculate the cyano group transformation efficiency (mol%) of the vinyl cyanide of graft polymerization.Prepared grafting particulate PAO/SiO ₂The cyano group transformation efficiency be 78%.

(3) ion surface imprinted material IIP-PAO/SiO ₂Preparation

With grafting particulate PAO/SiO ₂Place ion---the M of group of the lanthanides or actinide elements arbitrary element ³⁺In the deionized water solution (M3+ represents the ion of arbitrary element in group of the lanthanides and the actinide elements), the pH value with the diluted sodium hydroxide solution regulation system makes pH=5, mixed solution is placed constant temperature oscillator, the constant temperature vibration makes grafted gather fully swelling of amidoxim (PAO), makes the grafting particulate to M ³⁺Ionic absorption reaches capacity, and leaches microballoon, vacuum-drying.With the saturated absorption of 1.1g M ³⁺Ionic grafting particulate PAO/SiO ₂Place the M of 0.01mol/L ³⁺In the solution, the pH value with the dilute NaOH solution regulation system makes pH=5, and the concentration that adds 1mL is 50% glutaraldehyde water solution, stirs 12h down at 35 ℃, and reaction is used 0.1molL after finishing ^-1The hydrochloric acid soln repetitive scrubbing is removed template ion M ³⁺, suction filtration, vacuum-drying promptly gets M ³⁺Ion surface imprinted material IIP-PAO/SiO ₂

Above-mentioned preparation process chemical reaction as shown in Figure 8.

Claims (2)

1. one kind is used for the preparation method that rare earth ion is discerned isolating surface imprinted material, it is characterized by: with the silica particle surface of acrylonitrile grafting polymerization in surface modification, then the grafted polyacrylonitrile is converted into poly-amidoxim, thereby makes the grafting particulate that surface grafting has poly-amidoxim; Rely on the poly-amidoxim of grafting microparticle surfaces and the interaction between the rare earth ion, saturated absorption rare earth ion then; Again with glutaraldehyde as cross linker, what make poly-amidoxim intermolecularly is able to crosslinkedly, realizes the trace of rare earth ion simultaneously; Remove rare earth ion then, in the poly-amidoxim thin layer of silica particle surface, stay a large amount of trace holes, discern isolating surface imprinted material thereby obtain to be used for rare earth ion.

2. according to claim 1ly be used for the preparation method that rare earth ion is discerned isolating surface imprinted material, it is characterized by:

(1) at the silica particle surface graft polymerization vinyl cyanide of surface modification

The aerosil particles that in the four-hole boiling flask that electric mixer, reflux condensing tube and thermometer are housed, adds the 1.23g surface modification successively, 100mL N, the solution that is dissolved with the 11.79mL vinyl cyanide in the dinethylformamide adds respectively in the flask, stirs down logical N ₂Gas excluding air 30min is warming up to 75 ℃ then, adds the Diisopropyl azodicarboxylate of 0.143g, and constant temperature also carries out graft polymerization reaction 5h under agitation condition, and suction filtration obtains the particulate that surface grafting polymerization has vinyl cyanide;

(2) surface grafting polymerization has the amidoxim conversion of the particulate of vinyl cyanide

In four-hole bottle with the oxammonium hydrochloride solution of 1.0mol/L and the Na of 1.0mol/L ₂CO ₃Solution mixes, and its pH of mixed value is 6.0-7.0, adds the grafting particulate again, feeds N ₂, system is heated to 70 ℃, react 4h down in constant temperature and agitation condition, filter, use the distilled water repetitive scrubbing, be neutral to washings, vacuum-drying then promptly gets the grafting particulate;

(3) preparation of ion surface imprinted material

The grafting particulate is placed the ion of group of the lanthanides or actinide elements arbitrary element---M ³⁺In the deionized water solution, the pH value with the diluted sodium hydroxide solution regulation system makes pH=5, and mixed solution is placed constant temperature oscillator, and the constant temperature vibration makes grafted gather the abundant swelling of amidoxim, makes the grafting particulate to M ³⁺Ionic absorption reaches capacity, and leaches microballoon, and vacuum-drying is with the saturated absorption of 1.1g M ³⁺Ionic grafting particulate places the M of 0.01mol/L ³⁺In the solution, the pH value with the dilute NaOH solution regulation system makes pH=5, and the concentration that adds 1mL is 50% glutaraldehyde water solution, stirs 12h down at 35 ℃, and reaction is used 0.1molL after finishing ^-1The hydrochloric acid soln repetitive scrubbing is removed template ion M ³⁺, suction filtration, vacuum-drying promptly gets M ³⁺Ion surface imprinted material IIP-PAO/SiO ₂

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