CN111790277A - Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles - Google Patents
Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles Download PDFInfo
- Publication number
- CN111790277A CN111790277A CN202010652092.7A CN202010652092A CN111790277A CN 111790277 A CN111790277 A CN 111790277A CN 202010652092 A CN202010652092 A CN 202010652092A CN 111790277 A CN111790277 A CN 111790277A
- Authority
- CN
- China
- Prior art keywords
- membrane
- reverse osmosis
- polyamide
- phase solution
- osmosis membrane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D71/00—Semi-permeable membranes for separation processes or apparatus characterised by the material; Manufacturing processes specially adapted therefor
- B01D71/06—Organic material
- B01D71/58—Other polymers having nitrogen in the main chain, with or without oxygen or carbon only
- B01D71/62—Polycondensates having nitrogen-containing heterocyclic rings in the main chain
- B01D71/64—Polyimides; Polyamide-imides; Polyester-imides; Polyamide acids or similar polyimide precursors
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
- B01D61/025—Reverse osmosis; Hyperfiltration
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0002—Organic membrane manufacture
- B01D67/0006—Organic membrane manufacture by chemical reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D69/00—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor
- B01D69/02—Semi-permeable membranes for separation processes or apparatus characterised by their form, structure or properties; Manufacturing processes specially adapted therefor characterised by their properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2325/00—Details relating to properties of membranes
- B01D2325/36—Hydrophilic membranes
Abstract
The invention discloses a preparation method of a high-performance reverse osmosis membrane for promoting the growth of polyamide nano vesicles, which comprises the steps of selecting a polysulfone ultrafiltration membrane as a supporting base membrane, and carrying out interfacial polymerization reaction on a water-phase amine monomer and an oil-phase polybasic acyl chloride monomer on the surface of the supporting base membrane to compound a polyamide ultrathin layer to form the reverse osmosis membrane; and the osmotic selectivity of the reverse osmosis membrane is optimized by regulating and controlling parameter conditions in the interfacial polymerization process. On the basis, potassium perfluorobutyl sulfonate is introduced into the aqueous phase solution to promote the growth of polyamide nano vesicles on the surface of the supporting base membrane, increase the surface roughness of the membrane, further improve the permeation flux of the membrane and further optimize the performance of the reverse osmosis membrane. The reverse osmosis membrane prepared by the invention can obviously improve the permeation flux of the membrane without losing the salt rejection rate. The invention provides a new reference way for the development of the polyamide reverse osmosis membrane with high rejection rate and high flux.
Description
Technical Field
The invention relates to a preparation method of a high-performance reverse osmosis membrane for promoting the growth of polyamide nano vesicles.
Background
Water resources are abundant on earth, but water from low lying seas occupies 96.54%. The concentration of inorganic salts in seawater is as high as 3.5%, and there are also a large number of bacteria and microorganisms. Once people drink the high-concentration water for a long time, the high-concentration water can cause the extreme dehydration of human bodies and finally death. Fresh water resources which can be drunk by people on the earth account for only 2.53 percent of the total water amount, and the process of desalinating seawater into water which can be drunk by people is a great challenge. In addition, the current environmental water pollution problem is more and more serious, for example, waste liquid discharged from a chemical plant needs to be purified and discharged after reaching standards; concentration and recovery of useful substances for medicines and agricultural chemicals, and the like. Thus, the demand for an advanced water treatment technology is becoming more and more severe.
The reverse osmosis technology is the most advanced and energy-saving membrane separation water treatment technology which is newly developed in the 60 s. The working principle of the device is shown in figure 1: when separating two different salt concentration solutions with a reverse osmosis membrane, a certain pressure is applied to one side of high concentration of the reverse osmosis membrane, and the driving force overcomes the osmotic pressure of the solvent permeating from the low concentration salt solution to the high concentration salt solution, so that solvent molecules are driven to diffuse into the low concentration salt solution, the concentration of the low concentration salt solution is lower and lower, and the purpose of separating and purifying water resource is achieved. As early as 1953, c.e. reid, the university of florida, usa, found that cellulose acetate had excellent semi-permeability and was conceived to be applied to the field of seawater desalination. Subsequently, professor Sourirajan and Leob in the united states of 1960 developed a cellulose acetate asymmetric membrane, the water flux was more than 10 times of that of a homogeneous membrane prepared from the same material, which led to practical application of RO membranes from laboratories, and in addition, this phase inversion membrane-making process has attracted social interest. In the 70 s of the 20 th century, the wholly aromatic polyamide hollow fiber reverse osmosis device was invented by DuPont, U.S. DuPont for the first time, and subsequently, in 1978, Cadotte initiated a new era of membrane preparation of a thin film composite membrane by selecting trimesoyl chloride and m-phenylenediamine for an interfacial polymerization reaction on a polysulfone supporting base membrane. This is another important milestone in the development history of membrane science, and compared with the cellulose acetate membrane developed by the phase inversion method, the cellulose acetate membrane has a thinner desalination retention layer, and the thinner membrane structure can greatly reduce the resistance of the saline water transmission across the membrane, thereby significantly improving the osmotic selectivity of the membrane. Most of the current commercial reverse osmosis membranes are prepared by an interfacial polymerization method.
An interfacial polymerization membrane preparation method based on Cadotte is opened, and from the 80 s in the 20 th century, a great deal of research is conducted to adjust the micro-nano structure of a polyamide separation layer so as to optimize the performance of the membrane. The structure of a polyamide reverse osmosis membrane prepared by interfacial polymerization comprises three parts: a non-woven fabric (thickness of 100-150 μm) mainly used for supporting; a porous intermediate layer (e.g., polysulfone, polyacrylonitrile, etc., about 50 μm thick); an effective separating layer of polyamide (thickness 0.01-0.3 μm). Early in the 21 st century, Eric m.v. hoek, university of california, usa, proposed a method of preparation of nanoparticle mixed matrix reverse osmosis: the water phase or the oil phase is added with a proper amount of nano particles, and in the interfacial polymerization process, the nano particles participate in the polymerization reaction of water-oil phase reaction monomers, namely in-situ polymerization to form the nano particle mixed matrix reverse osmosis membrane. However, since most of the nanoparticles are inorganic materials, the polyamide layer is a high molecular organic material, the problem of poor compatibility between inorganic and organic materials exists when the nanoparticles are mixed into the reverse osmosis membrane, whether the nanoparticles are mixed into the polyamide membrane is a scientific problem worthy of further discussion, and then in order to solve the compatibility problem, some researchers modify the nanoparticles to enable the nanoparticles to be better dispersed in a reaction water phase or an oil phase, so that the nanoparticles can be more smoothly participated in the interfacial polymerization reaction together.
With the continuous exploration of scientific research and experimental research and the continuous improvement of modern material characterization technologies, people have more and more profound knowledge on the structure of polyamide, wherein the polyamide interception layer is a wave crest and trough-shaped structure containing cavities, the surface of the polyamide interception layer is covered with a leaf-shaped structure and a knot-shaped structure, and the back of the polyamide interception layer is a porous structure. And a large number of experimental researches suggest that the size and proportion of the leaf-shaped and knot-shaped structures on the surface of the polyamide can cause the difference of the roughness of the surface of the membrane, and the difference of the roughness can change the actual water permeable area of the membrane, so as to change the permeability of the membrane.
Disclosure of Invention
In view of the above technical problems in the prior art, the present application aims to provide a method for preparing a high-performance reverse osmosis membrane for promoting the growth of polyamide nanovesicles. The invention improves the osmotic selectivity of the membrane by optimizing the process conditions in the process of preparing the conventional polyamide reverse osmosis membrane (TFC-RO). On the basis, a proper amount of potassium perfluorobutyl sulfonate (YF-98) is introduced into the water phase, and the osmotic selectivity of the membrane is further improved under the condition of not losing the retention rate. The structural formula of the potassium perfluorobutyl sulfonate (YF-98) is shown in figure 3.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized by comprising the following steps of:
1) preparing an aqueous phase solution: adding an amine monomer with reaction activity into ultrapure water, then adding an organic weak acid with hydrophilic groups, adding an alkaline substance to adjust the pH value to 9-11, adding potassium perfluorobutyl sulfonate, and uniformly stirring and mixing to prepare an aqueous phase solution; wherein in the prepared aqueous phase solution, the addition concentration of an amine monomer is 1-10%, the addition concentration of the organic weak acid is 1-10%, and the addition concentration of the potassium perfluorobutyl sulfonate is 0.005-0.5%, preferably 0.01-0.2%;
2) preparation of oil phase solution: adding a polybasic acyl chloride monomer into an organic solvent, and fully performing ultrasonic dispersion to obtain a clear and transparent solution, namely preparing an oil phase solution; wherein the concentration of the polyacyl chloride in the oil phase solution is 0.05-0.15%;
3) and (3) interfacial polymerization process: soaking the surface of the porous supporting base membrane in the water phase solution prepared in the step 1) for 0.5-60min, then draining the water phase solution on the surface of the supporting base membrane, drying the surface of the supporting base membrane until no water drops or liquid drops appear on the surface of the supporting base membrane, soaking the surface of the supporting base membrane in the oil phase solution prepared in the step 2) for 0.5-60min so as to perform interfacial polymerization reaction on the surface of the supporting base membrane;
4) and (3) post-treatment process of the membrane: step 3), after the interfacial polymerization reaction is finished, pouring out the oil phase solution on the surface of the supporting base membrane, vertically placing and airing the supporting base membrane for a period of time, and then placing the supporting base membrane into an oven for drying to obtain the reverse osmosis membrane product; and finally, placing the prepared reverse osmosis membrane product in ultrapure water for storage.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 1), the amine monomer is m-phenylenediamine, p-phenylenediamine or o-phenylenediamine, preferably m-phenylenediamine; in the finally prepared aqueous phase solution, the concentration of the amine monomer is 2.2 percent; adding alkaline substances to adjust the pH value to 9.8-10.2 in the preparation process of the aqueous phase solution in the step 1).
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 1), the organic weak acid is citric acid, malic acid or camphorsulfonic acid, and preferably camphorsulfonic acid.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 1), the alkaline substance is sodium hydroxide, triethylamine or tetramethylammonium hydroxide, and triethylamine is preferred.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the oil phase solution prepared in the step 2), the organic solvent is Isopar-G, and the polyacyl chloride is terephthaloyl chloride or trimesoyl chloride, preferably trimesoyl chloride.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 3), the supporting base membrane is a polysulfone ultrafiltration membrane, the cutting molecular weight of the polysulfone ultrafiltration membrane is 35KDa, and the back surface and the surface of the supporting base membrane are washed clean with ultrapure water for later use.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 3), the soaking time of the surface of the supporting base membrane in the aqueous solution is 1-10 min; after the aqueous solution on the surface of the supporting base film is drained off, the surface of the supporting base film is dried by natural drying, fume drying in a fume hood, roller drying or air knife blowing drying, preferably nitrogen air knife blowing drying.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 3), the soaking time of the surface of the support basement membrane in the oil phase solution is 0.5-5 min; in the step 4), after the oil phase solution on the surface of the supporting basement membrane is poured off, the vertical draining is carried out for 0.5-2 min.
The preparation method of the high-performance reverse osmosis membrane for promoting the growth of the polyamide nano vesicles is characterized in that in the step 4), the drying temperature in an oven is 90-100 ℃, and preferably 95 ℃; the drying time in the oven is 5-10min, preferably 8 min.
It should be noted that the concentration% described in the present invention means the mass concentration wt%.
The reverse osmosis membrane prepared by the invention is composed of a supporting base membrane and a polyamide membrane layer formed by the reaction of the surface of the supporting base membrane, and the preparation conditions are optimized to regulate and optimize the micro-nano structure of the polyamide membrane layer, so that the reverse osmosis membrane composite membrane with high desalination rate and high flux is prepared.
The schematic cross-sectional structure of the polyamide membrane layer produced by the interfacial polymerization reaction of the aqueous phase amine monomer and the oil phase polybasic acyl chloride monomer on the surface of the supporting base membrane is shown in fig. 2. Referring to FIG. 2, when the interfacial polymerization reaction is performed, because the oil phase monomer trimesoyl chloride is very insoluble in water, and m-phenylenediamine can be dissolved in the oil phase solvent, the m-phenylenediamine monomer in the water phase diffuses upwards to cross the water-oil interface and reaches the oil phase to perform the polymerization reaction with trimesoyl chloride. The amine monomer and the polybasic acyl chloride monomer start to react at the water-oil phase interface, and the polyamide film layer generated by the reaction grows and grows towards the main body of the oil phase solution to form nano vesicles. The polyamide membrane formed in the water-oil phase interface and the oil phase contains a cavity nano vesicle structure with the size of 50-150nm, and the whole thickness of the membrane is about 100-200 nm.
In addition, if potassium perfluorobutylsulfonate (YF-98) is not added to the aqueous solution, the schematic diagram of the arrangement structure of the polyamide membrane layer nanovesicles formed by the interfacial polymerization reaction is shown in fig. 4, panel a. The arrangement structure schematic diagram of the polyamide membrane layer nano-vesicle generated by the interfacial polymerization reaction of adding perfluorobutyl potassium sulfonate (YF-98) into the aqueous phase solution for modification is shown as a partial diagram b in figure 4.
FIG. 4 is a schematic diagram showing the change of the cross-sectional structure of the polyamide membrane prepared by adding a proper amount of potassium perfluorobutylsulfonate to the aqueous solution for modification. From this figure, it can be seen that the nanocapsules within the polyamide membrane become significantly larger after modification. The enlargement of the nano vesicles can increase the water permeable area of the membrane, and further improve the permeation flux of the membrane.
The invention achieves the following beneficial effects:
1. the invention optimizes the process conditions of the interfacial polymerization reaction of the aqueous phase amine monomer and the oil phase polybasic acyl chloride monomer on the surface of the supporting basement membrane, such as: the category and the content of the organic weak acid and the alkaline substance added into the aqueous phase solution, and the optimal pH value of the aqueous phase solution is regulated and controlled. The invention adds acid into the aqueous phase solution, mainly considering that the prepared reverse osmosis membrane needs to enter an oven to be dried and heat-treated at a higher temperature of 90-100 ℃ in the subsequent process, the organic weak acid added in the invention has hydrophilic groups, which can endow the surface of the supporting base membrane with good wettability, thus avoiding the situation that the holes on the surface of the supporting base membrane are easy to shrink at the higher temperature of the drying and heat treatment, and further effectively avoiding weakening the permeability of the reverse osmosis membrane due to the shrinkage of the membrane holes. In addition, a proper amount of alkaline substances are added into the aqueous phase solution, the pH value of the aqueous phase solution is adjusted to a proper value, by-product hydrochloric acid is formed in the interfacial polymerization reaction of the aqueous phase amine monomer and the oil phase polybasic acyl chloride monomer on the surface of the supporting base film, and the added alkaline substances can neutralize the by-product hydrochloric acid generated in the interfacial polymerization reaction, so that the reaction is promoted to be more sufficient, and a more compact polyamide film is formed. In addition, the organic weak acid and the alkaline substance are added into the aqueous phase solution, and the alkaline substance can react with the organic weak acid in the aqueous phase solution to a certain extent without influencing hydrophilic groups carried by the organic weak acid.
2. The influence of the concentration of trimesoyl chloride on the osmotic selectivity of the reverse osmosis membrane is also discussed in the invention. Under the optimized process condition, the invention introduces the potassium perfluorobutyl sulfonate into the aqueous phase solution to further improve the performance of the polyamide reverse osmosis membrane. The added potassium perfluorobutyl sulfonate has extremely strong fluorine electronegativity, so that a carbon-fluorine bond is not easy to break and is very stable. The fluorine-containing compound has stronger anti-pollution performance, so that the pollution problem that some tiny particles are blocked in gaps of wave crest and wave trough-shaped structures with fluctuant surface of the film can be solved; on the other hand, the sulfonic acid group has excellent hydrophilicity, and when the substance is added into the aqueous phase solution, the sulfonic acid group can increase the loading amount of the amine monomer in the aqueous phase solution on the surface of the supporting base film and the uniformity of the loading, and can slow down the upward diffusion rate of the amine monomer in the aqueous phase solution on the surface of the supporting base film, so that the height of the polyamide film generated by the subsequent reaction in the vertical direction of the surface of the supporting base film is reduced, and then, the growth condition of the film in the horizontal direction is intensified, so that the cavity structure in the film is enlarged, the growth of the nano-vesicles of the polyamide film is promoted, and the leaf-shaped structure on the surface of the film is increased and enlarged, so that the roughness of the surface of. The experimental result shows that a proper amount of potassium perfluorobutyl sulfonate is introduced into the aqueous phase solution, and then the interfacial polymerization reaction is carried out, so that on the basis of the original blank membrane, the permeation flux of the membrane can be remarkably improved by adding the potassium perfluorobutyl sulfonate while the sodium chloride salt rejection rate is not lost. The invention provides a new reference way for the development of the polyamide reverse osmosis membrane with high rejection rate and high flux. The adoption of reverse osmosis membranes for brackish water desalination, seawater desalination and the like is still the core and hot spot technology of the current. If the membrane can further improve the permeation flux of the membrane and keep higher solute rejection rate under the same process operation conditions (operation pressure, temperature and the like), the operation cost of the reverse osmosis instrument can be greatly reduced, the working efficiency of the reverse osmosis instrument can be improved, and the production of enterprises can be brought with great benefit.
Drawings
FIG. 1 is a schematic diagram of the operation of a reverse osmosis process;
FIG. 2 is a schematic cross-sectional view of a polyamide film formed by interfacial polymerization of an aqueous amine monomer and an oil-phase polyacyl chloride monomer on the surface of a supporting base film;
FIG. 3 is a structural formula of potassium perfluorobutylsulfonate;
FIG. 4 is a schematic diagram showing the change principle of the membrane section structure after a proper amount of potassium perfluorobutylsulfonate is added to the water phase to modify the polyamide membrane;
FIG. 5 is a comparative surface SEM photograph of reverse osmosis membranes prepared in comparative example 1(C-1), example 1(M-0.01), example 2(M-0.05), example 3(M-0.1) and example 4(M-0.2), respectively.
Detailed Description
The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.
In the following examples and comparative examples, polysulfone ultrafiltration membranes from Huzhou research institute were used as the supporting base membrane, which had a cut molecular weight of 35kDa and whose back and surface were cleaned with ultrapure water before use.
In order to prepare the reverse osmosis membrane with high flux and high rejection rate, the invention develops a plurality of blank control experiments so as to optimize the process conditions in the interfacial polymerization process, and when the conditions reach the optimal effect, the potassium perfluorobutyl sulfonate is introduced into the aqueous phase solution so as to further optimize the membrane performance. Some of these comparative examples and examples will now be described.
A blank control group
1. Influence of buffer system formed by acid and alkali in aqueous solution
Comparative example 1
Dissolving 2.2 wt% of m-phenylenediamine in ultrapure water, adding 4 wt% of camphorsulfonic acid, adding a proper amount of triethylamine to adjust the pH value of the aqueous phase solution to 10.0 (the addition concentration of the triethylamine is 2.5 wt%), and uniformly dispersing solute molecules in the aqueous phase solution by using a magnetic stirrer to obtain a clear aqueous phase solution. 0.11 wt% of trimesoyl chloride is added into the Isopar-G oil phase solvent and is treated by ultrasonic treatment by an ultrasonic instrument to obtain clear and transparent oil phase solution.
Pouring the prepared aqueous phase solution on the surface of the polysulfone ultrafiltration membrane, standing for 2min, pouring the redundant aqueous phase on the surface of the polysulfone ultrafiltration membrane, and blowing the surface of the membrane by using a nitrogen air knife to remove water drops and liquid drops. And then pouring the prepared oil phase solution onto the surface of the membrane which is just soaked with the water phase solution, pouring off the redundant oil phase on the surface of the polysulfone ultrafiltration membrane after the duration time is 30s, vertically standing the membrane, draining for 20s, and drying in an oven with the temperature set to 95 ℃ for 8 min. Subsequently, the prepared membrane was taken out and stored in ultrapure water for 12 hours in order to prepare for the completion of the subsequent characterization of the membrane's permselectivity. The membrane was numbered as C-1.
Comparative example 2
Preparation steps of the membrane comparative example 1 was repeated except that "in the preparation of the aqueous phase solution, triethylamine added in comparative example 1 was replaced with NaOH to adjust the pH of the aqueous phase solution to 10.0", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-2.
Comparative example 3
Preparation steps of the membrane comparative example 1 was repeated except that "in the preparation of the aqueous phase solution, triethylamine added in comparative example 1 was replaced with tetramethylammonium hydroxide to adjust the pH of the aqueous phase solution to 10.0", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-3.
Comparative example 4
Preparation of membrane step comparative example 1 was repeated except that "4 wt% camphorsulfonic acid added in comparative example 1 was replaced with 4 wt% hydrochloric acid in the preparation of aqueous phase solution", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-4. Wherein, in the preparation process of the aqueous phase solution of the comparative example 4, the addition concentration of the triethylamine is required to be 6.5 wt%.
Comparative example 5
Preparation steps of the membrane comparative example 4 was repeated except that "in the preparation of the aqueous phase solution, triethylamine added in comparative example 4 was replaced with NaOH to adjust the pH of the aqueous phase solution to 10.0", and the remaining steps were the same as in comparative example 4, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-5.
Comparative example 6
Comparative example 4 was repeated except that "in the preparation of the aqueous phase solution, triethylamine added in comparative example 4 was replaced with tetramethylammonium hydroxide to adjust the pH of the aqueous phase solution to 10.0", and the remaining steps were the same as in comparative example 4, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-6.
2. Influence of the pH of the aqueous solution
Comparative example 7
Comparative example 1 was repeated except that "the pH of the aqueous solution was 3.50 by controlling the content of triethylamine (0.2 wt% added concentration of triethylamine) added during the preparation of the aqueous solution", and the remaining steps were the same as in comparative example 1, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-7.
Comparative example 8
Preparation of membrane comparative example 1 was repeated except that "the pH of the aqueous solution was 4.72 by controlling the content of triethylamine (0.5 wt% added triethylamine) added during the preparation of the aqueous solution", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-8.
Comparative example 9
Comparative example 1 was repeated except that "the pH of the aqueous solution was 5.08 by controlling the content of triethylamine (0.8 wt% added triethylamine) added during the preparation of the aqueous solution", and the remaining steps were the same as in comparative example 1, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-9.
Comparative example 10
Preparation of membrane comparative example 1 was repeated except that "the pH of the aqueous solution was 10.95 by controlling the content of triethylamine (added concentration of triethylamine was 3 wt%) added during the preparation of the aqueous solution", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-10.
Comparative example 11
Preparation steps of the membrane comparative example 1 was repeated except that "the pH of the aqueous solution was 12.25 by controlling the content of triethylamine added (the addition concentration of triethylamine was 5.5 wt%) in the preparation of the aqueous solution", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-11.
3. Effect of trimesoyl chloride concentration in oil phase solution
Comparative example 12
Preparation of membrane comparative example 1 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.07 wt%", and the remaining steps were the same as in comparative example 1, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-12.
Comparative example 13
Preparation of membrane comparative example 1 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.08 wt%", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-13.
Comparative example 14
Preparation of membrane comparative example 1 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.09 wt%", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-14.
Comparative example 15
Preparation of membrane comparative example 1 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.10% by weight", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-15.
Comparative example 16
Preparation of membrane comparative example 1 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.12 wt%", and the remaining steps were the same as in comparative example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered as C-16.
Second, group of embodiments
Based on the optimized interfacial polymerization process conditions, under the optimal conditions, a potassium perfluorobutyl sulfonate development experiment is introduced into the water phase, and the following specific examples are provided:
example 1
2.2 wt% of m-phenylenediamine was dissolved in ultrapure water, and 4 wt% of camphorsulfonic acid was added, and the pH of the aqueous phase solution was adjusted to 10.0 by adding an appropriate amount of triethylamine. After 0.01 wt% of potassium perfluorobutylsulfonate was added, solute molecules in the aqueous solution were dispersed uniformly with a magnetic stirrer to give a clear aqueous solution. 0.11 wt% of trimesoyl chloride is added into the Isopar-G oil phase solvent and is treated by ultrasonic treatment by an ultrasonic instrument to obtain clear and transparent oil phase solution.
Pouring the prepared aqueous phase solution on the surface of the polysulfone ultrafiltration membrane, standing for 2min, pouring the redundant aqueous phase on the surface of the polysulfone ultrafiltration membrane, and purging the surface of the polysulfone ultrafiltration membrane by using a nitrogen air knife to remove water drops and liquid drops. And pouring the prepared oil phase solution on the surface of the polysulfone ultrafiltration membrane which is just soaked with the water phase solution, pouring the redundant oil phase on the surface of the polysulfone ultrafiltration membrane after the duration of 30s, vertically standing the polysulfone ultrafiltration membrane, draining for 20s, and drying in an oven with the temperature set to 95 ℃ for 8 min. Subsequently, the prepared membrane was taken out and stored in ultrapure water for 12 hours in order to prepare for the completion of the subsequent characterization of the membrane's permselectivity. The membrane was numbered M-0.01.
Example 2
Membrane preparation procedure example 1 was repeated except that "the concentration of potassium perfluorobutylsulfonate added during the preparation of the aqueous solution was changed to 0.05% by weight", and the remaining procedure was the same as in example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered M-0.05.
Example 3
Membrane preparation procedure example 1 was repeated except that "the concentration of potassium perfluorobutylsulfonate added during the preparation of the aqueous solution was changed to 0.1% by weight", and the remaining procedure was the same as in example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered M-0.1.
Example 4
Membrane preparation procedure example 1 was repeated except that "the concentration of potassium perfluorobutylsulfonate added during the preparation of the aqueous solution was changed to 0.2% by weight", and the remaining procedure was the same as in example 1 to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered M-0.2.
Example 5
Membrane preparation procedure example 3 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.08% by weight", and the remaining procedure was the same as in example 3, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered O-0.08.
Example 6
Membrane preparation procedure example 3 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.09 wt%", and the remaining procedures were the same as in example 3, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered O-0.09.
Example 7
Membrane preparation procedure example 3 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.10% by weight", and the remaining procedure was the same as in example 3, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered O-0.10.
Example 8
Membrane preparation procedure example 3 was repeated except that "the concentration of trimesoyl chloride added during the preparation of the oil phase solution was changed to 0.12% by weight", and the remaining procedure was the same as in example 3, to finally prepare a polyamide reverse osmosis membrane. The membrane was numbered O-0.12.
The osmotic selectivity of the reverse osmosis membrane is evaluated by a cross-flow filtration system, high-concentration saline water of 32g/LNaCl is used as a feed liquid, and penetrating fluid is collected from the other side of the membrane under the driving of an external test pressure. The test conditions were set as: the temperature of the feed liquid was 25 ℃, the pH of the feed liquid was 7.5. + -. 0.5, and the test pressure was 5.5 MPa. After the membrane is pre-pressed for 1 hour, the permeation selectivity of the membrane is formally tested. The polyamide reverse osmosis membranes prepared in the comparative examples and examples of the present invention were tested by the above-described methods, and the test results are shown in tables 1, 2, 3 and 4, respectively.
Table 1 shows the flux and rejection of the reverse osmosis membranes prepared in the blank control group in different acid-base systems. Table 2 shows the flux and rejection of the reverse osmosis membranes prepared in the blank control under different pH conditions of the aqueous solution. Table 3 shows the flux and rejection of the reverse osmosis membranes prepared in the blank control under different concentrations of trimesoyl chloride monomer in the oil phase solution. Table 4 shows the flux and rejection performance of the reverse osmosis membranes prepared in the embodiment group after adding different amounts of potassium perfluorobutylsulfonate to the aqueous solution under the optimized process conditions.
TABLE 1
TABLE 2
TABLE 3
TABLE 4
The SEM photographs of the surfaces of the reverse osmosis membranes prepared in comparative example 1(C-1), example 1(M-0.01), example 2(M-0.05), example 3(M-0.1) and example 4(M-0.2) are shown in FIG. 5.
FIG. 5 is a SEM photograph showing a comparison of reverse osmosis membranes prepared in comparative example 1 and example groups in comparison with each other under the conditions of comparative example 1 and example group, after adding different amounts of potassium perfluorobutylsulfonate to the aqueous solution (example 1, example 2, example 3, and example 4). From the analysis of fig. 5, it can be seen that as the addition amount of the potassium perfluorobutyl sulfonate in the aqueous phase increases, the number of the leaf-like structures on the membrane surface increases, and from the cross-sectional structure of the membrane, the cavity nano vesicles in the polyamide membrane layer are correspondingly below the leaf-like structures, i.e. the large vesicles correspond to the large platelets, which explains the effect of the potassium perfluorobutyl sulfonate added in the aqueous phase solution on promoting the growth of the polyamide nano vesicles.
The description is given for illustrative purposes only and should not be construed to limit the scope of the invention to the particular forms set forth in the examples.
Claims (9)
1. A preparation method of a high-performance reverse osmosis membrane for promoting the growth of polyamide nano vesicles is characterized by comprising the following steps:
1) preparing an aqueous phase solution: adding an amine monomer with reaction activity into ultrapure water, then adding an organic weak acid with hydrophilic groups, adding an alkaline substance to adjust the pH value to 9-11, adding potassium perfluorobutyl sulfonate, and uniformly stirring and mixing to prepare an aqueous phase solution; wherein in the prepared aqueous phase solution, the addition concentration of an amine monomer is 1-10%, the addition concentration of the organic weak acid is 1-10%, and the addition concentration of the potassium perfluorobutyl sulfonate is 0.005-0.5%, preferably 0.01-0.2%;
2) preparation of oil phase solution: adding a polybasic acyl chloride monomer into an organic solvent, and fully performing ultrasonic dispersion to obtain a clear and transparent solution, namely preparing an oil phase solution; wherein the concentration of the polyacyl chloride in the oil phase solution is 0.05-0.15%;
3) and (3) interfacial polymerization process: soaking the surface of the porous supporting base membrane in the water phase solution prepared in the step 1) for 0.5-60min, then draining the water phase solution on the surface of the supporting base membrane, drying the surface of the supporting base membrane until no water drops or liquid drops appear on the surface of the supporting base membrane, soaking the surface of the supporting base membrane in the oil phase solution prepared in the step 2) for 0.5-60min so as to perform interfacial polymerization reaction on the surface of the supporting base membrane;
4) and (3) post-treatment process of the membrane: step 3), after the interfacial polymerization reaction is finished, pouring out the oil phase solution on the surface of the supporting base membrane, vertically placing and airing the supporting base membrane for a period of time, and then placing the supporting base membrane into an oven for drying to obtain the reverse osmosis membrane product; and finally, placing the prepared reverse osmosis membrane product in ultrapure water for storage.
2. The method for preparing a high-performance reverse osmosis membrane for promoting the growth of polyamide nanovesicles according to claim 1, wherein in the step 1), the amine monomer is m-phenylenediamine, p-phenylenediamine or o-phenylenediamine, preferably m-phenylenediamine; in the finally prepared aqueous phase solution, the concentration of the amine monomer is 2.2 percent; adding alkaline substances to adjust the pH value to 9.8-10.2 in the preparation process of the aqueous phase solution in the step 1).
3. The method for preparing a high-performance reverse osmosis membrane for promoting growth of polyamide nanovesicles according to claim 1, wherein in the step 1), the weak organic acid is citric acid, malic acid or camphorsulfonic acid, preferably camphorsulfonic acid.
4. The method for preparing a high-performance reverse osmosis membrane for promoting the growth of polyamide nanovesicles according to claim 1, wherein in the step 1), the basic substance is sodium hydroxide, triethylamine or tetramethylammonium hydroxide, preferably triethylamine.
5. The method for preparing a high-performance reverse osmosis membrane for promoting growth of polyamide nanovesicles according to claim 1, wherein in the oil phase solution prepared in the step 2), the organic solvent is Isopar-G, and the poly-acid chloride is terephthaloyl chloride or trimesoyl chloride, preferably trimesoyl chloride.
6. The method for preparing a high-performance reverse osmosis membrane for promoting growth of polyamide nanovesicles according to claim 1, wherein in the step 3), the supporting membrane is a polysulfone ultrafiltration membrane with a cut molecular weight of 35KDa, and the back and the surface of the supporting membrane are washed with ultrapure water before use for later use.
7. The method for preparing a high-performance reverse osmosis membrane for promoting the growth of polyamide nanovesicles according to claim 1, wherein in the step 3), the soaking time of the surface of the supporting base membrane in the aqueous solution is 1-10 min; after the aqueous solution on the surface of the supporting base film is drained off, the surface of the supporting base film is dried by natural drying, fume drying in a fume hood, roller drying or air knife blowing drying, preferably nitrogen air knife blowing drying.
8. The method for preparing a high performance reverse osmosis membrane for promoting growth of polyamide nanovesicles according to claim 1, wherein in the step 3), the soaking time of the surface of the supporting base membrane in the oil phase solution is 0.5-5 min; in the step 4), after the oil phase solution on the surface of the supporting basement membrane is poured off, the vertical draining is carried out for 0.5-2 min.
9. The method for preparing a high-performance reverse osmosis membrane for promoting the growth of polyamide nanovesicles according to claim 1, wherein in the step 4), the drying temperature in the oven is 90-100 ℃, preferably 95 ℃; the drying time in the oven is 5-10min, preferably 8 min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010652092.7A CN111790277B (en) | 2020-07-08 | 2020-07-08 | Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010652092.7A CN111790277B (en) | 2020-07-08 | 2020-07-08 | Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111790277A true CN111790277A (en) | 2020-10-20 |
| CN111790277B CN111790277B (en) | 2022-02-15 |
Family
ID=72810477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010652092.7A Active CN111790277B (en) | 2020-07-08 | 2020-07-08 | Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111790277B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112827369A (en) * | 2021-01-18 | 2021-05-25 | 蓝星（杭州）膜工业有限公司 | Preparation method of nano hybrid composite membrane |
| CN112957925A (en) * | 2021-03-11 | 2021-06-15 | 浙江工业大学 | Preparation method of high-permeability composite reverse osmosis membrane for reducing intrinsic thickness of polyamide layer |
| CN112973462A (en) * | 2021-03-24 | 2021-06-18 | 浙江工业大学 | Preparation method of high-selectivity reverse osmosis membrane by covering membrane surface defects |
| CN113318598A (en) * | 2021-05-17 | 2021-08-31 | 浙江工业大学 | Method for enhancing selective permeability of reverse osmosis membrane by adjusting pore diameter of base membrane |
| CN113877437A (en) * | 2021-09-16 | 2022-01-04 | 同济大学 | Nano-vesicle regulated nano-filtration membrane and preparation method and application thereof |
| CN114570216A (en) * | 2022-01-26 | 2022-06-03 | 同济大学 | Nano-ring-structured high-flux nanofiltration membrane and preparation method thereof |
| CN115105974A (en) * | 2022-08-03 | 2022-09-27 | 无锡恩捷新材料科技有限公司 | Reverse osmosis membrane and preparation method and application thereof |
| CN115368733A (en) * | 2022-08-26 | 2022-11-22 | 金发科技股份有限公司 | Polyamide composition and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104289117A (en) * | 2014-10-29 | 2015-01-21 | 天津工业大学 | Taurine modified hydrophilic complex film |
| CN107398189A (en) * | 2017-07-31 | 2017-11-28 | 宁波日新恒力科技有限公司 | The method that the reverse osmosis membrane containing aquaporin is prepared using secondary interface polymerization |
| US20190009207A1 (en) * | 2017-07-07 | 2019-01-10 | Saudi Arabian Oil Company | Multilayer aromatic polyamide thin-film composite membranes for separation of gas mixtures |
| CN111111448A (en) * | 2020-01-13 | 2020-05-08 | 天津工业大学 | Low-pressure composite nanofiltration membrane |
-
2020
- 2020-07-08 CN CN202010652092.7A patent/CN111790277B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104289117A (en) * | 2014-10-29 | 2015-01-21 | 天津工业大学 | Taurine modified hydrophilic complex film |
| US20190009207A1 (en) * | 2017-07-07 | 2019-01-10 | Saudi Arabian Oil Company | Multilayer aromatic polyamide thin-film composite membranes for separation of gas mixtures |
| CN107398189A (en) * | 2017-07-31 | 2017-11-28 | 宁波日新恒力科技有限公司 | The method that the reverse osmosis membrane containing aquaporin is prepared using secondary interface polymerization |
| CN111111448A (en) * | 2020-01-13 | 2020-05-08 | 天津工业大学 | Low-pressure composite nanofiltration membrane |
Non-Patent Citations (5)
| Title |
|---|
| CHUNLONG KONG等: "Controlled synthesis of high performance polyamide membrane with thin dense layer for water desalination", 《JOURNAL OF MEMBRANE SCIENCE》 * |
| LIN LIN等: "Investigating the void structure of the polyamide active layers of thin-film composite membranes", 《JOURNAL OF MEMBRANE SCIENCE》 * |
| XIAOXIAO SONG等: "Confined nanobubbles shape the surface roughness structures of thin film composite polyamide desalination membranes", 《JOURNAL OF MEMBRANE SCIENCE》 * |
| 杜娇等: "优化聚酰胺分离层制备高选择透过性反渗透膜", 《化工学报》 * |
| 王元: "水相添加剂对聚酰胺复合纳滤膜结构和性能的影响", 《中国优秀硕士学位论文全文数据库》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112827369A (en) * | 2021-01-18 | 2021-05-25 | 蓝星（杭州）膜工业有限公司 | Preparation method of nano hybrid composite membrane |
| CN112957925A (en) * | 2021-03-11 | 2021-06-15 | 浙江工业大学 | Preparation method of high-permeability composite reverse osmosis membrane for reducing intrinsic thickness of polyamide layer |
| CN112973462A (en) * | 2021-03-24 | 2021-06-18 | 浙江工业大学 | Preparation method of high-selectivity reverse osmosis membrane by covering membrane surface defects |
| CN113318598A (en) * | 2021-05-17 | 2021-08-31 | 浙江工业大学 | Method for enhancing selective permeability of reverse osmosis membrane by adjusting pore diameter of base membrane |
| CN113877437A (en) * | 2021-09-16 | 2022-01-04 | 同济大学 | Nano-vesicle regulated nano-filtration membrane and preparation method and application thereof |
| CN113877437B (en) * | 2021-09-16 | 2022-08-02 | 同济大学 | Nano-vesicle regulated nano-filtration membrane and preparation method and application thereof |
| CN114570216A (en) * | 2022-01-26 | 2022-06-03 | 同济大学 | Nano-ring-structured high-flux nanofiltration membrane and preparation method thereof |
| CN115105974A (en) * | 2022-08-03 | 2022-09-27 | 无锡恩捷新材料科技有限公司 | Reverse osmosis membrane and preparation method and application thereof |
| CN115368733A (en) * | 2022-08-26 | 2022-11-22 | 金发科技股份有限公司 | Polyamide composition and preparation method and application thereof |
| CN115368733B (en) * | 2022-08-26 | 2024-02-13 | 金发科技股份有限公司 | Polyamide composition and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111790277B (en) | 2022-02-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111790277B (en) | Preparation method of high-performance reverse osmosis membrane for promoting growth of polyamide nano vesicles | |
| CN111185103B (en) | Nanofiber-based organic/inorganic composite nanofiltration membrane and preparation method thereof | |
| KR100990168B1 (en) | Forward osmosis membranes and method for fabricating the same | |
| CN104248913B (en) | A kind of method of polyolefin hollow fiber ultrafiltration membrane hydrophilic modification | |
| CN106731841B (en) | A kind of supermolecule composite nanometer filtering film and its preparation method and application | |
| CN108295667B (en) | Forward osmosis composite membrane based on large-aperture base membrane and preparation method thereof | |
| CN106823854A (en) | A kind of preparation method of polymer-based metal organic backbone hybridized film | |
| CN110917907B (en) | High-flux reverse osmosis membrane and preparation method and application thereof | |
| CN108479395B (en) | Forward osmosis membrane and preparation method thereof | |
| CN107469650A (en) | A kind of preparation method of hydrophobic macropore polyimide nano-fiber forward osmosis membrane | |
| CN103785301B (en) | A kind of Cellulose acetate forward osmotic membrane material and preparation method thereof | |
| CN104128099A (en) | Composite nano-filtration membrane based on technologies of electrostatic spinning and self assembling and preparation method thereof | |
| Ravichandran et al. | A review on fabrication, characterization of membrane and the influence of various parameters on contaminant separation process | |
| TR201612129A2 (en) | ADVANCED OSMOS MEMBRANE OBTAINED BY USING SULPHONED POLYSULPHONE (sPSf) POLYMER AND THEIR PRODUCTION METHOD | |
| CN111203107B (en) | Polyphenol-iron nano film and preparation method and application thereof | |
| KR101869799B1 (en) | manufacturing method of forward osmosis filter using carbon nano-material | |
| CN105582816A (en) | Preparation method of forward osmosis membrane modified with oxidized graphene | |
| KR101517653B1 (en) | High Flux Reverse Osmosis Membrane Comprising Xanthene Compound And Manufacturing Method Thereof | |
| CN111888943B (en) | Preparation method of reverse osmosis membrane containing buffer layer free interface polymerization | |
| CN113600031A (en) | Composite nanofiltration membrane and preparation method thereof | |
| JPH078549B2 (en) | Polyvinylidene fluoride-based resin porous membrane and method for producing the same | |
| CN114432896A (en) | Preparation method of nanofiltration membrane | |
| CN115055061B (en) | Preparation method of polyamide composite nanofiltration membrane with high permeability selectivity | |
| CN116408054A (en) | Preparation of 3D Janus sponge for emulsion separation and dye adsorption | |
| CN109603577B (en) | Method for preparing forward osmosis membrane with reserved draw solute and double active layers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |