A kind of composite fiber membrane with chiral molecular imprint and its production and application
Technical field
The present invention relates to a kind of preparation method of molecular engram composite membrane, specifically, the present invention relates to a kind of preparation method of chiral molecular imprinting composite membrane.
Background technology
Molecular imprinting (Molecular Imprinting Technique) is a kind of technology that " memory " function of utilizing molecularly imprinted polymer that microsphere stereochemical structure and shape are had is carried out specific molecular identification, therefore have precordainment and identity, from Mosbach in 1993 etc. delivering on " Nature " relevant can separate theophylline molecularly imprinted polymer report since, obtained developing rapidly, become chemistry, biology, macromolecular material, the crossing domain of subjects such as medical science is in the chromatographic stationary phase, SPE, film separates, immunoassay, the antibody simulation, bionical thing sensor, aspect such as catalyst and synzyme shows good prospects for application.
Is the important branch of MIT with chipal compounds as the molecular imprinting of microsphere, be called the chiral molecular imprinting technology, it utilizes the chiral molecular imprinting polymer that " memory " function of chirality microsphere is carried out chiral Recognition, is that the chiral separation field has a kind of new technology of using and developing value in recent years.
Can obtain the membrane material of different separating properties by the method for grafting of polymer membrane surface chemistry or modification.As supporter, molecularly imprinted polymer is grafted to the surface of film with micro-filtration or milipore filter, can obtains specific microsphere is had the asymmetric composite membrane of recognition reaction.Nidal etc. are grafted to polyvinylidene fluoride (PVDF) ultrafiltration membrane surface with 3 ', 5 '-cyclic adenosine monophosphate molecularly imprinted polymer by photopolymerisable method in solvent, prepared 3 ', and 5 '-cyclic adenosine monophosphate molecule has the molecular engram composite membrane of evident characteristics.
Usually, the preparation process of molecular engram composite membrane can be divided into for three steps: at first microsphere and an amount of function monomer are dissolved in the solvent, make the abundant combination of microsphere and function monomer; Secondly be fixed in membrane surface by certain method, polymerization forms surface imprinted polymer under uniform temperature or ultraviolet lighting condition again; Last wash-out microsphere forms the surperficial chirality imprinted polymer film with basement membrane support.
The composite membrane of preparations such as Nidal is to be the molecular engram composite membrane of microsphere preparation with the non-chiral compound, prepare the chiral molecular imprinting composite membrane if use chipal compounds instead as microsphere, then be a kind of new preparation method, the mild condition of membrane separation technique, chiral Recognition performance simple to operate, that be easy to characteristics such as serialization and chiral molecular imprinting technology can be combined, realize fast, the separation of chipal compounds easily.
Generally speaking, obtain desirable having that basement membrane supports and film with chiral selectivity is the comparison difficulty, mainly contain the influence of following factor: the 1) selection of basal lamina material; 2) preparation of molecularly imprinted polymer; 3) compound condition determines.
At present, chiral separation method is limited to analysis mostly, and it is few to be used for industrial method, and has significant limitation.In general, a kind of specific chiral separation method is only effective to the fractionation of certain chipal compounds, and it is invalid to the fractionation of other chipal compounds, sharing is poor, be difficult to continuous operation, cost is higher relatively, and often there is very big blindness (as the selection to the chiral resolution ligand reagent) in split process.
Characteristics combine but the chiral molecular imprinting composite membrane is will be to continuous operation, the flux of identity, specificity and the film of chiral molecules big etc., the composite membrane that preparation has chiral separation performance, be a kind of potential, efficiently, novel chiral resolution means, can reduce the blindness when selecting chiral ligand, make the chiral resolution continuous operation.In addition, because " cavity structure " that the composite bed of chiral molecular imprinting composite membrane has the specific identification performance, so its separating property is different fully with the resulting composite membrane of other surface modification, selectivity is higher.
Therefore, research and develop a kind of preparation method of composite fiber membrane with chiral molecular imprint, will have crucial meaning.
Summary of the invention
The technical issues that need to address of the present invention are to disclose a kind of composite fiber membrane with chiral molecular imprint and its production and application, to satisfy the needs of the parties concerned.
Method of the present invention comprises the steps:
(1) film surface-coated thermal initiator:
The macromolecular fibre film is contacted with the solution that contains initator, dry then, obtain the macromolecular fibre film that the film surface-coated has thermal initiator;
Said macromolecular fibre film is hollow-fibre membrane or dull and stereotyped ultrafiltration tunica fibrosa, membrane material be selected from polysulfones (PSF), polyether sulfone (PES), Kynoar (PVDF), polyvinyl chloride (PVC), polyamide or cellulose or and derivative etc. in a kind of;
Said doughnut basement membrane preferably has following performance parameter:
External diameter (μ m) | 1000~1400 |
Wall thickness (μ m) | 200~300 |
Porosity, % | 80~90 |
Pure water flux, L/m
2.h
| 200~300 |
In the said solution that contains initator, the mass percentage content of initator is 0.05~10%;
Said initator comprises azodiisobutyronitrile, benzoyl peroxide, benzyl dimethyl acetal, azo methyl pentane nitrile, 4, a kind of in 4-azo (4-itrile group valeric acid) or the ammonium persulfate etc.;
Said solvent comprises a kind of or its mixture in acetonitrile or the cyclohexane etc.;
(2) preparation of chiral molecular imprinting composite membrane:
Coating liquid is coated on the macromolecular fibre film surface that the resulting film surface-coated of step (1) has thermal initiator, drains, vacuum drying obtains chiral molecular imprinting composite membrane precursor;
Vacuum is-0.09~-0.005MPa, temperature is 0~90 ℃, the time is 4~72 hours.
In the coating liquid, component and mass percentage content are:
Chipal compounds 0.25~10%
Function monomer 1%~15%
Crosslinking agent 5%~75%
Solvent 10%~85%.
Said chipal compounds is selected from a kind of in dibenzoyl-L-tartaric acid, D-tryptophan, lefofloxacin, dextrorotation Ofloxacin or other chiral compound enantiomer;
Said function monomer is selected from ethyl acrylate, methyl methacrylate, acrylic acid, acrylamide, methacrylic acid, 4-vinylpyridine or styrene etc.;
Said crosslinking agent is selected from ethylene glycol dimethacrylate, tetramethylene dimethylacrylate, 1,4-phenylate diacrylamine, N, N-1,3-penylene two (2-methyl-2-acrylamide or trimethyl propane trimethyl acrylic esters etc.
Said crosslinking agent all can adopt the commercially available prod;
Said solvent is selected from acetonitrile, cyclohexane etc. or its mixture;
(3) wash-out of template molecule:
Place eluant, eluent to wash the chiral molecular imprinting composite membrane precursor of step (2), till chipal compounds is washed off, obtain the chiral Recognition molecular engram composite membrane that has of the present invention;
Said eluant, eluent is the acetic acid/methanol solution of percent by volume 0.05~15%.
In above-mentioned preparation method, membrane surface applies the sequencing of initator and coating coating liquid and can change.Basement membrane is the polymer polymeric membrane, best cleaning treatment in advance before carrying out the surface heat polymerization, and oven dry is handled.
Adopt the chiral molecular imprinting composite membrane that said method obtained, bigger variation has taken place in the membrane surface form before and after surface aggregate, and is fine and close and smooth without the membrane surface of surface aggregate, and through behind the surface aggregate, stacked crosslinked shape layer occurs; Basement membrane cortex without surface aggregate is very thin, and through after the surface aggregate, cortex obviously thickens.Utilize SEM can measure the about 3.0 μ m of chiral molecular imprinting composite membrane skin thickness.The hole of many sizes below 200nm obviously appears in the film configuration of surface behind the wash-out, and also has the hole within the hole as can be seen, has three-dimensional three-dimensional hole network structure.The maximum void diameter is also below 200nm.Porosity is about 7 * 10
6Individual/m
2
Utilization the invention provides system initiator solution and coating liquid proportioning and filming technology, by changing template molecule, can prepare the molecular engram composite membrane of varied recognition performance, can be used for splitting multiple racemic compound.
The chiral molecular imprinting composite membrane that utilizes said method to obtain has good identification selection, as being template molecule with L-DBTA, only, less to the identification selection of other compound to L-DBTA, to racemic L, D-DBTA solution, its separation factor can reach 2.7.
Description of drawings
Fig. 1 is surface aggregate anterior basal membrane outer surface form SEM Electronic Speculum figure.
Fig. 2 is surface aggregate anterior basal membrane section S EM Electronic Speculum figure.
Fig. 3 is the configuration of surface SEM Electronic Speculum figure of chiral molecular imprinting composite membrane precursor.
Fig. 4 is the section S EM Electronic Speculum figure of chiral molecular imprinting composite membrane precursor.
Fig. 5 is surface aggregate anterior basal membrane epidermis SEM Electronic Speculum figure.
Fig. 6 is the epidermis SEM Electronic Speculum figure of chiral molecular imprinting composite membrane precursor.
Fig. 7 is chiral molecular imprinting composite membrane configuration of surface SEM Electronic Speculum figure.
Fig. 8 is a chiral molecular imprinting composite membrane testing arrangement schematic diagram.
The specific embodiment
Below for example the technology of the present invention is described, give an actual example but patented technology is not limited in institute.
Embodiment 1
Take by weighing raw material at first by mass percentage, azodiisobutyronitrile: 6%, acetonitrile: 94%, be mixed with initiator solution, its process is: AIBN is joined in the acetonitrile, and jog makes the AIBN dissolving.Then solution evenly is applied to preprepared PSF doughnut outer surface, dries.
Take by weighing raw material then by mass percentage, chipal compounds dibenzoyl-L-tartaric acid: 2%; Acetonitrile: 60%; Methyl methacrylate: 5%; Ethylene glycol dimethacrylate: 32% is mixed with coating liquid, and its process is: earlier L-DBTA is joined in the acetonitrile, jog makes its dissolving, placed 2 hours, 25 ℃ of temperature add methyl methacrylate, ethylene glycol dimethacrylate again, shake up, be coating liquid.Then coating liquid evenly being applied to the PSF doughnut film outer surface that scribbles initator, placing after 3 hours, the PSF hollow-fibre membrane is placed 60 ℃ vacuum drying chamber, vacuum is-0.09~-0.005MPa, 48 hours.
At last the PSF film of handling well is placed 10% acetic acid/methyl alcohol (volume ratio) solution wash-out template molecule, wash-out repeatedly is till template molecule is washed off.Use washed with methanol then, dry, promptly make the chiral molecular imprinting composite membrane.Can when dry state, be assembled into chiral molecular imprinting composite membrane assembly, can reach 2.8 the separation factor of racemic dibenzoyl tartaric acid solution.
PSF doughnut basement membrane has following performance parameter:
External diameter (μ m) | 1200 |
Wall thickness (μ m) | 234 |
Porosity, % | 87.8 |
Pure water flux, L/m
2.h
| 267 |
Surface aggregate anterior basal membrane outer surface form is seen Fig. 1, and Fig. 2 is seen in surface aggregate anterior basal membrane cross section.Chiral molecular imprinting composite membrane precursor is seen Fig. 3.Fig. 4 is seen in the cross section of chiral molecular imprinting composite membrane precursor.Surface aggregate anterior basal membrane epidermis is seen Fig. 5.The epidermis of chiral molecular imprinting composite membrane precursor is seen Fig. 6.Fig. 7 is seen on chiral molecular imprinting composite membrane surface.
Embodiment 2
Press embodiment 1 described preparation condition and process, the employing material is that the hollow fiber ultrafiltration membrane of polyether sulfone (PES) is as supporter, other is with to execute example 1 identical, repeat to execute the process system of example 1, also can make the chiral molecular imprinting composite membrane, and be assembled into membrane module, to racemic L, the separation factor of D-DBTA solution can reach 2.0.
Embodiment 3
Press embodiment 1 described preparation condition and process, adopt lefofloxacin as template molecule, other is with to execute example 1 identical, the process that repeats to execute example 1 makes lefofloxacin chiral molecular imprinting composite membrane, and be assembled into membrane module, can reach 1.7 to the separation factor of racemic Ofloxacin solution.
Embodiment 4
Pressing embodiment 1 described preparation condition, material and process, change the coating order, is template molecule with the chipal compounds earlier, adds function monomer, and ultrasonic dissolution leaves standstill it is fully acted on, and adds solvent and crosslinking agent and shakes up and be mixed with coating liquid.
Wherein the mass percentage content of chipal compounds is 5.5%, and the mass percentage content of function monomer is 10%, crosslinking agent 42.5%, and the mass percentage content of solvent is 42%.
Above-mentioned coating liquid is coated on the surface of first step film, dries in the shade.Then initator is dissolved in the solvent in proportion, the mass percentage content that is mixed with initator is 5% solution, and the film that will dry is process therefrom, dries then.At last film is placed vacuum drying chamber, heat treatment under-0.07MPa vacuum, heat treatment temperature is 60 ℃, the processing time is 72 hours.Other can make the chiral molecular imprinting composite membrane, and be assembled into membrane module with to execute example 1 identical, and to racemic L, the separation factor of D-DBTA solution can reach 2.2.
Embodiment 5
Press embodiment 1 described preparation condition and process, take by weighing raw material at first by mass percentage, azodiisobutyronitrile: 2%, acetonitrile: 98%, be mixed with initiator solution, other is with to execute example 1 identical, and the process that repeats to execute example 1 makes the chiral molecular imprinting composite membrane, and be assembled into membrane module, can reach 1.7 to the separation factor of racemic dibenzoyl tartaric acid solution.
Embodiment 6
Press embodiment 1 described preparation condition and process, chipal compounds dibenzoyl-L-tartaric acid addition: 4%; Acetonitrile: 58%; Methyl methacrylate: 5%; Ethylene glycol dimethacrylate: 32% is mixed with coating liquid, and other is with to execute example 1 identical, and the process that repeats to execute example 1 makes the chiral molecular imprinting composite membrane, and is assembled into membrane module, and to racemic L, the separation factor of D-DBTA solution can reach 2.0.
Embodiment 7
Press embodiment 1 described preparation condition and process, with the hollow-fibre membrane that coats in 50 ℃ vacuum drying chamber, heat treatment under-0.09MPa vacuum, heat treatment 48 hours.Other is with to execute example 1 identical, and the process that repeats to execute example 1 makes the chiral molecular imprinting composite membrane, and is assembled into membrane module, can reach 1.4 to the separation factor of racemic dibenzoyl tartaric acid solution.
Embodiment 8
Press embodiment 1 described preparation condition and process, with the hollow-fibre membrane that coats in 60 ℃ vacuum drying chamber, heat treatment under-0.09MPa vacuum, heat treatment 12 hours.Other is with to execute example 1 identical, and the process that repeats to execute example 1 makes the chiral molecular imprinting composite membrane, and is assembled into membrane module, can reach 1.5 to the separation factor of racemic dibenzoyl tartaric acid solution.
Embodiment 9
Press embodiment 1 described preparation condition and process, then coating liquid evenly is applied to the PSF doughnut film outer surface that scribbles initator, only place and dried in the shade 1 hour, other is with to execute example 1 identical, the process that repeats to execute example 1 makes the chiral molecular imprinting composite membrane, and be assembled into membrane module, can reach 1.4 to the separation factor of racemic dibenzoyl tartaric acid solution.
Embodiment 10
5 of the chiral molecular imprinting composite membranes that embodiment 1~9 is made are packed in φ 6 * 230mm stainless steel tube, and two ends seal with epoxide-resin glue, are assembled into small-sized membrane module respectively, measure its separation factor on device device shown in Figure 8.Concrete grammar is: respectively the chipal compounds solution that revolves about certain density is put into former liquid bath 1, be delivered to membrane module 6 with pump 5, utilize flowmeter 4 and Pressure gauge 3 control chipal compounds liquid inventory and pressure, after the composite fiber membrane with chiral molecular imprint separation, concentrate enters former liquid bath 1 circulation through circulating slot 2, sees through liquid and analyzes.Distribution coefficient and separation factor adopt formula (1) and formula (2) to calculate.
The assay method of separation factor is as follows:
Distribution coefficient (K
L):
Separation factor (α): α=K
L/ K
D(2)
In the formula: K
LExpression chiral molecular imprinting composite membrane is to the distribution coefficient of left-handed chipal compounds, and C represents to see through the concentration of liquid, C
0Expression substrate initial concentration, K
DExpression chipal compounds chiral molecular imprinting composite membrane is to the distribution coefficient of dextro-compound.Separation factor alpha is represented the selectivity of chiral molecular imprinting film to template molecule.