It is a kind of to have both high flux and high retention ratio fragrance polyamides using the preparation of tannic acid modified basement membrane
The method of amine complex reverse osmosis membrane
Technical field
Using the preparation of tannic acid modified basement membrane, to have both high flux and high retention ratio aromatic polyamides compound the present invention relates to a kind of
The method of reverse osmosis membrane belongs to complex reverse osmosis membrane preparation field.
Background technique
Interfacial polymerization aromatic polyamide composite reverse osmosis membrane is the reverse osmosis membrane of current main-stream.Preparation have both it is high-throughput and
High rejection aromatic polyamide composite reverse osmosis membrane is expected to that reverse osmosis membrane process energy consumption and cost is greatly reduced.
In general, flux can be increased with the reduction of separating layer thickness.Therefore, many researchers are dedicated to exploitation tool
There is the complex reverse osmosis membrane of ultra-thin separating layer.Zhu etc. has prepared the separation that thickness only has 12nm using extremely low monomer concentration
Layer (Y. Zhu, W.Xie, S.Gao, F.Zhang, W.Zhang, Z.Liu, J.Jin, Single-walled carbon
nanotube film supported nanofiltration membrane with a nearly 10nm thick
polyamide selective layer for high-flux and high-rejection desalination,
Small,12(2016)5034-5041.).There is very high flux (32L m due to being film-made with ultra-thin separating layer-2h-1bar-1).(B.Khorshidi, T.Thundat, B.A. Fleck, M.Sadrzadeh, the A Novel such as Khorshidi
Approach Toward Fabrication of High Performance Thin Film Composite Polyamide
Membranes, Scientific Reports, 6 (2016) 22069.) it is successfully thinned point by reducing organic phase temperature
Absciss layer thickness, so that complex reverse osmosis membrane flux increases.However, although above two method makes membrane flux increase,
But lower monomer concentration and lower organic phase temperature are unfavorable for forming the separating layer of high-compactness, so can not be simultaneously
Ensure film rejection with higher.In fact, the be film-made sodium chloride rejection of the studies above is lower (being lower than 95%).It mentions
The conventional method of high rejection is to increase complex reverse osmosis membrane separating layer compactness extent, but increase the meeting of separating layer compactness extent simply
Flux is caused to reduce.It follows that merely increasing separating layer compactness extent or reducing the equal Shortcomings of separating layer thickness.If
The two can be combined, that is, increase separating layer compactness extent while separating layer is thinned, then be expected to prepare have both it is high-throughput and high
Rejection aromatic polyamide composite reverse osmosis membrane.
Summary of the invention
High flux and high retention ratio is had both using the preparation of tannic acid blending and modifying basement membrane the purpose of the present invention is to provide a kind of
The method of aromatic polyamide composite reverse osmosis membrane.This method is simple, easy to operate.While this method can realize thinned separating layer
Increase separating layer compactness extent, made complex reverse osmosis membrane is made to have both high-throughput and high rejection.The present invention is by following skills
Art scheme is realized.
Tannic acid is a kind of natural material, is mainly originated in the insect gall of certain trees, and a large amount of phenol hydroxyls are contained in molecular structure
Base, typical tannic acid structural formula are as follows:
It is compound anti-that utilization tannic acid blending and modifying basement membrane preparation of the invention has both high flux and high retention ratio aromatic polyamides
The method of permeable membrane, including following procedure:
1) mixed solution with preparing tannic acid, N-N dimethyl acetamide and polysulfones;Above-mentioned mixed solution is scratched in polyester
On non-woven fabrics, it is then immersed in water and solidifies the obtained basement membrane containing tannic acid;
2) basement membrane containing tannic acid made from step 1) is infiltrated on 25~35s in aqueous phase solution;Then, film is infiltrated
Cause interfacial polymerization in the n-heptane solution that the temperature containing pyromellitic trimethylsilyl chloride is 28~32 DEG C to form aromatic polyamides
Separating layer;Then, film is placed in 4~6min of heat treatment at 70~90 DEG C, aromatic polyamide composite reverse osmosis membrane is made.
The aromatic polyamide composite reverse osmosis membrane is sufficiently cleaned with deionized water.
The mixed solution of tannic acid, N-N dimethyl acetamide and polysulfones in the step 1) is preferably to be containing concentration
The mixing of 0.05~0.45% tannic acid, 81.55~81.95% N-N dimethyl acetamide and 18.00% polysulfones is molten
Liquid.Above-mentioned concentration is respectively concentration of three kinds of substances in mixed liquor.
It is 0.02~0.06% that the n-heptane solution of pyromellitic trimethylsilyl chloride in the step 2), which is preferably containing concentration,
Pyromellitic trimethylsilyl chloride and 99.94~99.98% normal heptane solution.Above-mentioned concentration is the concentration of two kinds of substances in the solution.
Heat treatment temperature in the step 2) is preferably 70~90 DEG C.
Due to the high-hydrophilic of tannic acid, during basement membrane freezing film, tannic acid spontaneous can segregate to membrane surface,
Make membrane surface rich in tannic acid.Strong interaction, on the one hand makes water phase between the tannic acid and aqueous phase monomers of membrane surface
Monomer can more and more uniformly be adsorbed in membrane surface, on the other hand aqueous phase monomers can be hindered to spread, above-mentioned both sides
Influence make everywhere aromatic polyamide polymer grown in entire interfacial polymerization film forming procedure relatively sufficiently, can finally be formed relatively cause
Close polymer architecture.Further, since tannic acid hinders aqueous phase monomers diffusion, so that in entire interfacial polymerization film forming procedure,
Aqueous phase monomers diffusion length is shorter, and then causes finally formed separating layer relatively thin.To sum up, made due to the effect of tannic acid
Aromatic polyamide composite reverse osmosis membrane has thinner and finer and close separating layer.
Advantages of the present invention: preparation process is simple, easy to implement, at low cost etc..In addition, the aromatic polyamides of preparation are compound
Reverse osmosis membrane has both high-throughput and high salt rejection rate: material liquid be 2000ppm sodium-chloride water solution, pressure be 1.55MPa and
Under the test condition that temperature is 25 DEG C, water flux and salt rejection rate can reach 50L/ (m respectively2And 99.24% h).The present invention is not only
It is limited to the preparation to aromatic polyamide composite reverse osmosis membrane, and is also applied for preparing other high selection through performance performance interfaces
It polymerize seperation film.
Detailed description of the invention
Fig. 1 is the membrane surface structural scan electron microscope containing tannic acid made from embodiment 1.
Fig. 2 is aromatic polyamide composite reverse osmosis membrane separating layer section structure transmission electron microscope picture made from embodiment 2.
Specific embodiment
Embodiment 1
Configure the good casting solution containing 0.05% tannic acid, 81.95% N-N dimethyl acetamide and 18% polysulfones;
Before use, casting solution is stood deaeration in 24 hours.By casting solution blade coating on non-woven fabrics after rapidly immerse coagulating bath (go from
Sub- water) in, so that casting solution curing of coatings is formed a film.In blade coating step environment temperature and humidity be controlled as 25 ± 1 DEG C and 30 ±
2%.
The prepared membrane surface containing tannic acid is infiltrated on 25s in aqueous phase solution.Then, solution is outwelled.It connects
, after ensuring that film surface does not have visible liquid, film surface is infiltrated on containing 0.02% equal chlorobenzoyl chloride and 99.98% just
Cause interfacial polymerization in the solution that the temperature of heptane is 28 DEG C.It is heat-treated 4min finally, film is placed at 70 DEG C, fragrance is made
Polyamide composite reverse osmosis membrane.
Filtered at 1.55MPa, 25 DEG C 2000ppm sodium-chloride water solution test to obtain the complex reverse osmosis membrane flux and
Rejection is respectively 69L/ (m2And 29.38% h).
Embodiment 2
Configure the good casting solution containing 0.25% tannic acid, 81.75% N-N dimethyl acetamide and 18% polysulfones;
Before use, casting solution is stood deaeration in 24 hours.By casting solution blade coating on non-woven fabrics after rapidly immerse coagulating bath (go from
Sub- water) in, so that casting solution curing of coatings is formed a film.In blade coating step environment temperature and humidity be controlled as 25 ± 1 DEG C and 30 ±
2%.The membrane surface structure is as shown in Figure 1.It can be seen that membrane surface is in porous pattern, aperture is about 11nm, surface
Porosity is about 2.06%.
The prepared membrane surface containing tannic acid is infiltrated on 30s in aqueous phase solution.Then, solution is outwelled.It connects
, after ensuring that film surface does not have visible liquid, film surface is infiltrated on containing 0.04% equal chlorobenzoyl chloride and 99.96% just
Cause interfacial polymerization in the solution that the temperature of heptane is 30 DEG C.It is heat-treated 5min finally, film is placed at 80 DEG C, fragrance is made
Polyamide composite reverse osmosis membrane.The complex reverse osmosis membrane separating layer section structure is as shown in Figure 2.As shown, the separating layer is in
Typical peak and valley structure, including tight section and two, hole part.Wherein, tight section thickness is about 48nm.
Filtered at 1.55MPa, 25 DEG C 2000ppm sodium-chloride water solution test to obtain the complex reverse osmosis membrane flux and
Rejection is respectively 50L/ (m2And 99.24% h).
Embodiment 3
Configure the good casting solution containing 0.45% tannic acid, 81.55% N-N dimethyl acetamide and 18% polysulfones;
Before use, casting solution is stood deaeration in 24 hours.By casting solution blade coating on non-woven fabrics after rapidly immerse coagulating bath (go from
Sub- water) in, so that casting solution curing of coatings is formed a film.In blade coating step environment temperature and humidity be controlled as 25 ± 1 DEG C and 30 ±
2%.
The prepared membrane surface containing tannic acid is infiltrated on 35s in aqueous phase solution.Then, solution is outwelled.It connects
, after ensuring that film surface does not have visible liquid, film surface is infiltrated on containing 0.06% equal chlorobenzoyl chloride and 99.94% just
Cause interfacial polymerization in the solution that the temperature of heptane is 32 DEG C.It is heat-treated 6min finally, film is placed at 90 DEG C, fragrance is made
Polyamide composite reverse osmosis membrane.
Filtered at 1.55MPa, 25 DEG C 2000ppm sodium-chloride water solution test to obtain the complex reverse osmosis membrane flux and
Rejection is respectively 37L/ (m2And 99.41% h).
Comparative example
By the extremely low monomer concentration method of existing thinned utilization and reduces organic phase concentration method and utilize tannic acid modified base
Film method compares, and as a result it is as shown in the table.1,2 and 3 respectively represent utilization tannic acid modified basement membrane method preparation in table
Film, the film with the preparation of extremely low monomer concentration method and the film using reduction organic phase concentration method preparation.It uses as seen from table
The film of extremely low monomer concentration method preparation is low with using the rejection of film for reducing the preparation of organic phase concentration method.Relative to it
His two methods significantly improve rejection while keeping high-throughput using tannic acid modified basement membrane method: rejection
Increase rate is respectively 76.74% and 3.54%.It is excellent using tannic acid modified basement membrane method from the comprehensive performance of film
In other two methods.
Film |
Flux (L/ (m2·h)) |
Sodium chloride rejection (%) |
1 |
50 |
99.24 |
2 |
240 |
22.50 |
3 |
77 |
95.70 |
The tannic acid modified basement membrane of a kind of utilization that the present invention is disclosed and proposed prepares the compound reverse osmosis of high-performance aromatic polyamides
The method of permeable membrane, those skilled in the art can be by using for reference present disclosure, and the appropriate links such as condition route that change are realized, although
Method and technology of preparing of the invention is described by preferred embodiment, and related technical personnel can obviously not take off
Methods and techniques described herein route is modified or is reconfigured from the content of present invention, spirit and scope, Lai Shixian
Final technology of preparing.In particular, it should be pointed out that all similar replacements and change are for a person skilled in the art
It will be apparent that they are considered as being included in spirit of that invention, range and content.