CN104803700A - Preparation method of membranes for water treatment - Google Patents
Preparation method of membranes for water treatment Download PDFInfo
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- CN104803700A CN104803700A CN201510177547.3A CN201510177547A CN104803700A CN 104803700 A CN104803700 A CN 104803700A CN 201510177547 A CN201510177547 A CN 201510177547A CN 104803700 A CN104803700 A CN 104803700A
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Abstract
The invention relates to the field of membranes for water treatment, particularly to a preparation method of the membranes for water treatment. The method comprises steps as follows: alumina powder is used as aggregate, silicon carbide whiskers, a pore-forming agent, a sintering aid and water are added to be mixed with the alumina powder to form slurry, the slurry is ground, aged and dried, then a plasticizer and water are added, the mixture is ground again, press-molded, dried, sintered and cleaned, and a supporting body is obtained; ground aluminium isopropoxide is added to hot deionized water for magnetic stirring, nitric acid, a dispersing agent and a defoaming agent are added in batches, and sol is obtained through even stirring and aged; then coating, gelatinization, drying and sintering are performed. According to the method, the hydrolysis temperature and the consumption of the deionized water are controlled, and the relatively stable sol can be prepared; meanwhile, the proper dispersing agent and the proper defoaming agent are added to the sol, the wettability of the sol and the surface of the supporting body can be improved, the membrane forming quality can be improved, and cracks can be avoided; in addition, the even, transparent and crack-free dry gel membranes can be obtained with a graded drying method.
Description
Technical field
The present invention relates to water treatment film field, is a kind of preparation method of water treatment film specifically.
Background technology
Membrane technique is contemporary new and effective isolation technique, is the product of multi-crossed disciplines, compared with traditional isolation technique, it have efficient, energy-conservation, process is easy to control, easy to operate, environmental friendliness, easily and the advantage such as other technologies are integrated.Membrane technique extensively and is effectively applied to the fields such as the energy, electronics, petrochemical complex, medical and health, biochemistry, environment, food, defines emerging hi-tech industry.At present, being applied in membrane technique is mineral membrane more widely, and it has high temperature resistant, the advantage such as physical strength is high, chemical stability good, long service life relative to organic membrane.Mineral membrane generally adopts supporter to increase the physical strength of film, and separating layer is then the core of membrane technique.When separating layer adopts sol-gel method to prepare, colloidal sol is the key substance basis of separating layer.Existing colloidal sol preparation is hydrolyzing metallic salts, makes polycondensation between alcohol molecules of salt form cross-linking products; But prior art is good not owing to controlling amount of water and temperature, causes colloidal sol very unstable, causes film forming even not.
Summary of the invention
For above-mentioned technical problem, the invention provides that technique is simple, the uniform membrane for water treatment preparation method of film forming.
The technical scheme that the present invention solves the problems of the technologies described above employing is: a kind of preparation method of water treatment film, and it comprises the following steps:
(1) prepare supporter: be aggregate with aluminum oxide powder, add after silicon carbide whisker, pore-forming material, sintering agent and water are mixed into slurry and grind, then to slurry ageing, oven dry, then softening agent is added and water grinds again, then compression molding, oven dry, then sinter, clean, and be supported body;
(2) prepare colloidal sol: added by ground aluminum isopropylate in the deionized water of heat and carry out magnetic agitation, then add nitric acid in batches, be stirred to solution clear, then add dispersion agent and defoamer stirs, obtain colloidal sol, then ageing colloidal sol;
(3) apply: supporter is immersed in the colloidal sol of ageing, then supporter is upwards lifted out colloidal sol liquid level, make supporter to apply one deck liquid film;
(4) gelation: the supporter scribbling liquid film is positioned in the atmosphere containing water vapour and continues film forming, make liquid film be transformed into gel-film;
(5) dry: to adopt classification desiccating method dry to gel-film;
(6) sinter: the gel-film of drying is sintered.
As preferably, described silicon carbide whisker is by remix after pre-treatment, and preprocessing process is: first whisker is oxidized carbon removal treatment, then carries out acid treatment with the mixture of hydrofluoric acid and hydrochloric acid, then uses washed with de-ionized water, finally dries.
As preferably, described pore-forming material is starch, and sintering agent is kaolin; The mass ratio of aluminum oxide powder and silicon carbide whisker is 1:(0.5-0.7); Described starch accounts for the 8%--12% of aluminum oxide powder and silicon carbide whisker total mass; Described kaolin accounts for the 15%--25% of aluminum oxide powder and silicon carbide whisker total mass.
As preferably, ageing places 24h under field conditions (factors), then puts into baking oven and dry; Described softening agent is Vltra tears, and add-on accounts for the 1%--2% of aluminum oxide powder and silicon carbide whisker total mass.As preferably, forming pressure is 8MPa--12 MPa, first at 200 DEG C during sintering--carry out at the temperature of 800 DEG C, temperature rise rate is (6-7) DEG C/min; Then at 800 DEG C--carry out at the temperature of 1250 DEG C, temperature rise rate is (3-4) DEG C/min; Finally constant temperature 2h at 1250 DEG C.
As preferably, the mol ratio of aluminum isopropylate and deionized water is 1:(95--105), the temperature of deionized water is 80 DEG C--90 DEG C, concentration of nitric acid is 1.65mol/L, the mol ratio of itself and aluminum isopropylate is (0.15-0.3): 1, and nitric acid is divided equally three times and added, and each interval time is 1h.
As preferably, described dispersion agent is Disponer-W511, and add-on is the 0.15%--0.3% of solution quality; Described defoamer is DeformW-0506, and add-on is the 0.02%--0.04% of solution quality.
As preferably, pull rate during coating is 5-15cm/ min.
As preferably, first preliminarily dried 10min at 80 DEG C of temperature time dry, is then cooled to 50 DEG C of dry 20min, then is down to drying at room temperature 10min.
As preferably, during sintering, rise to 600 DEG C with the temperature rise rate of 2--3 DEG C/min, sintering time 3-4h.
From the above, have the advantages such as high strength, high rigidity, high-modulus due to silicon carbide whisker, it is added in the aggregate of aluminum oxide, not only can increase the toughness of supporter, and makes the pore size distribution of supporter more even, thus improves the performance of supporter; Present method passes through the consumption of controlled hydrolysis temperature and deionized water, can make to prepare comparatively stable colloidal sol; Meanwhile, in colloidal sol, add the wettability that suitable dispersion agent and defoamer contribute to improving colloidal sol and supporting body surface, improve quality of forming film, can avoid occurring crackle; In addition that adopt classification desiccating method can obtain homogeneous transparent and flawless xerogel film.
Embodiment
The preparation method of water treatment film of the present invention is introduced in detail below in conjunction with embodiment:
First, be aggregate with aluminum oxide powder, add after silicon carbide whisker, pore-forming material, sintering agent and water are mixed into slurry and grind; Silicon carbide whisker is by remix after pre-treatment, and its preprocessing process is: first whisker is oxidized carbon removal treatment, and prevent silicon carbide whisker to be oxidized in a large number, oxidizing temperature is generally at about 600 DEG C, and the time is about 5h, can remove carbon contained in whisker so completely; Due to the mainly silicon-dioxide of the impurity in oxidation and decarbonization after product, it belongs to acidic oxide, with general acids Fails To Respond, but can react with hydrofluoric acid, and hydrofluoric acid does not affect silicon carbide, also contain other metal oxides a small amount of in whisker in addition, therefore acid treatment is carried out with the mixture of hydrofluoric acid and hydrochloric acid, the volume ratio of hydrofluoric acid and hydrochloric acid should adopt 3:1, can leave standstill 24 hours, and period repeatedly stirs with sticking plaster to make reaction carry out completely; Owing to adopting hydrofluoric acid and hydrochloric acid mixture to soak, so carry out filtering with funnel and filter paper or the method for natural sedimentation carries out being separated of whisker and water, and repeatedly clean with deionized water, until the pH value of rinse water is close to neutral; Whisker after process should add in aluminum oxide powder after drying in oven again.
In implementation process, the mass ratio of aluminum oxide powder and silicon carbide whisker should adopt 1:(0.5-0.7), wherein pore-forming material is starch, sintering agent is kaolin, starch accounts for the 8%--12% of aluminum oxide powder and silicon carbide whisker total mass, and kaolin accounts for the 15%--25% of aluminum oxide powder and silicon carbide whisker total mass.Ageing places 24h under field conditions (factors), then puts into baking oven and dry, and adds softening agent subsequently and water grinds again, and softening agent is Vltra tears, and add-on accounts for the 1%--2% of aluminum oxide powder and silicon carbide whisker total mass.
Compression molding simple to operate, forming pressure is advisable with 8MPa--12 MPa, shaping rear electricity consumption oven drying, and its advantage to arrange drying temperature, heats up evenly, effective.Employing retort furnace sinters, the too fast issuable cracking of moisture removal and distortion during in order to prevent low temperature calcination, makes base substrate inside that physical-chemical reaction occurs simultaneously, should at 200 DEG C--and carry out at the temperature of 800 DEG C, temperature rise rate adopts (6-7) DEG C/min; Too fast and ftracture in order to prevent from shrinking, thereafter should at 800 DEG C--carry out at the temperature of 1250 DEG C, temperature rise rate is (3-4) DEG C/min, then at 1250 DEG C, constant temperature is about 2h, then powered-down, takes out supporter after making its naturally cooling.Because sintering process can produce some flours on surface, must clean it, normally adopt pickling to carry out chemical treatment to its surface, then dry.
Then, by levigate for aluminum isopropylate shredder, then aluminum isopropylate is added heat deionized water in carry out magnetic agitation; The mol ratio of aluminum isopropylate and deionized water is 1:(95-105); The temperature of deionized water is 80 DEG C--90 DEG C, the method for heating in water bath can be utilized to maintain the temperature of deionized water then, and with nitric acid as peptizing agent, add nitric acid all in three batches, each interval time is about 1h, then is stirred to solution clear.The colloidal sol transparency generated when making peptizing agent with nitric acid is high, and not easily separates out precipitation.Because the add-on of nitric acid is different, by causing, the pH value of solution is different, thus has an impact to Sol-Gel process and the final alumina sol formed.The add-on of nitric acid is too low or too high, can cause the precipitation of particle, cause particle aggregation.The concentration of nitric acid that present method adopts is 1.65mol/L, and its mol ratio with aluminum isopropylate be (0.15-0.3): 1, and the alumina sol of generation is like this stablized, transparent; Add the Disponer-W511 dispersion agent of 0.15%--0.3% and the DeformW-0506 defoamer of 0.02%--0.04% again, and stir, stand-by.Only have supporting body surface and colloidal sol to have good wettability, just can guarantee the homogeneity of film and the stability of drying process.Otherwise colloidal sol is difficult to sprawl in supporting body surface, or form local defect in the drying process of gel-film.Therefore, in colloidal sol, add the wettability that suitable dispersion agent contributes to improving colloidal sol and supporting body surface.Meanwhile, because stirring and refluxing can produce a lot of bubble, when film, bubble hinders the moistening of colloidal sol and supporter, suppresses the generation of bubble by adding defoamer.The colloidal sol of preparation through the burin-in process of 2-3 months, must be easy to film forming on supporter.Weathering process makes the physicochemical property of colloidal sol more uniform and stable, thus improves quality of forming film.
Supporter is immersed in above-mentioned colloidal sol, then supporter is upwards lifted out colloidal sol liquid level with the speed of 5-15cm/min, at this moment supporter will cover the uniform liquid film of one deck.The supporter scribbling liquid film is positioned in the atmosphere containing water vapour, proceeds hydrolysis in film process and polyreaction thus be transformed into gel-film.
Then classification is dry.Drying process is exactly residual water-content, organic group and organic solvent in removing wet gel.The final structure of xerogel film depends on that colloidal sol starts to be formed the structure of wet gel film, and xerogel film essence is contracted or the wet gel film of alteration of form.And first preliminarily dried 10min at 80 DEG C of temperature, be then cooled to 50 DEG C of dry 20min, the drier rule of the classification of being down to drying at room temperature 10min can obtain homogeneous transparent and flawless xerogel film.As carried out drying 80 DEG C or 50 DEG C always, generate although avoid large crystallisate, because drying is too fast, film surface will produce ununiform shrinkage with inside, easily makes film peeling.
Finally, the gel-film of drying is sintered, during sintering, rises to 600 DEG C with the temperature rise rate of 2--3 DEG C/min, sintering time 3-4h.
Embodiment 1
Aluminum oxide powder and pretreated silicon carbide whisker is got with the mass ratio of 1:0.5, add after the starch of the above two quality 8%, 15% kaolin and appropriate water are mixed into slurry and grind, place 24h post-drying under field conditions (factors), the Vltra tears and the appropriate water that add 1% grind again; Then molded with the pressure mould of 8MPa, shaping rear electricity consumption oven drying, then adopt retort furnace with 7 DEG C/min temperature rise rate to 800 DEG C sintering at the temperature of 200 DEG C, then 4 DEG C/min temperature rise rate rises to 1250 DEG C, then after at 1250 DEG C, constant temperature is about 2h, cooling is taken out, and be supported body.
Get the levigate aluminum isopropylate of 1mol to add in the deionized water of the 95mol of 80 DEG C and carry out magnetic agitation, maintain the temperature of deionized water with heating in water bath; The nitric acid 1/33L adding 1.65 mol/L again stirs, the above-mentioned nitric acid adding 1/33L after about 1h again stirs, after about 1h, third time adds the above-mentioned nitric acid stirring of 1/33L, adds 0.15% Disponer-W511 dispersion agent and 0.02% DeformW-0506 defoamer, namely obtain colloidal sol after about 30min; The supporter prepared is placed in aging through 2 months after above-mentioned colloidal sol, lift out liquid level with the speed of 5cm/min, then be placed in steam atmosphere film forming, finally preliminarily dried 10min at 80 DEG C of temperature, then be cooled to 50 DEG C of dry 20min, then be down to drying at room temperature 10min; Finally rise to 600 DEG C with the temperature rise rate of 2 DEG C/min, sintering time 3h, obtains composite membrane.This film unit weight is about 1.5, and acid and alkali corrosion rate of weight loss is all less than 1%, and about 0.6 μm, film average diameter aperture, bending strength is 14MPa/m
2, ultimate compression strength is 12MPa.
Embodiment 2
Aluminum oxide powder and pretreated silicon carbide whisker is got with the mass ratio of 1:0.6, add after the starch of the above two quality 10%, 20% kaolin and appropriate water are mixed into slurry and grind, place 24h post-drying under field conditions (factors), the Vltra tears and the appropriate water that add 1% grind again; Then molded with the pressure mould of 10MPa, shaping rear electricity consumption oven drying, then adopt retort furnace with 6 DEG C/min temperature rise rate to 800 DEG C sintering at the temperature of 200 DEG C, then 4 DEG C/min temperature rise rate rises to 1250 DEG C, then after at 1250 DEG C, constant temperature is about 2h, cooling is taken out, and be supported body.
Get the levigate aluminum isopropylate of 1mol to add in the deionized water of the 100mol of 85 DEG C and carry out magnetic agitation, maintain the temperature of deionized water with heating in water bath; The nitric acid 0.05L adding 1.65 mol/L again stirs, the above-mentioned nitric acid adding 0.05L after about 1h again stirs, after about 1h, third time adds the above-mentioned nitric acid stirring of 0.05L, adds 0.25% Disponer-W511 dispersion agent and 0.03% DeformW-0506 defoamer, namely obtain colloidal sol after about 30min; The supporter prepared is placed in aging through 2 months after above-mentioned colloidal sol, lift out liquid level with the speed of 10cm/min, then be placed in steam atmosphere film forming, finally preliminarily dried 10min at 80 DEG C of temperature, then be cooled to 50 DEG C of dry 20min, then be down to drying at room temperature 10min; Finally rise to 600 DEG C with the temperature rise rate of 2 DEG C/min, sintering time 4h, obtains composite membrane.This film unit weight is about 1.5, and acid and alkali corrosion rate of weight loss is all less than 1%, and about 0.4 μm, film average diameter aperture, bending strength is 16MPa/m
2, ultimate compression strength is 14MPa.
Embodiment 3
Get the levigate aluminum isopropylate of 1mol to add in the deionized water of the 105mol of 90 DEG C and carry out magnetic agitation, maintain the temperature of deionized water with heating in water bath; The nitric acid 2/33L adding 1.65 mol/L again stirs, the above-mentioned nitric acid adding 2/33L after about 1h again stirs, after about 1h, third time adds the above-mentioned nitric acid stirring of 2/33L, adds 0.3% Disponer-W511 dispersion agent and 0.04% DeformW-0506 defoamer, namely obtain colloidal sol after about 30min; The supporter prepared is placed in aging through 3 months after above-mentioned colloidal sol, lift out liquid level with the speed of 15cm/min, then be placed in steam atmosphere film forming, finally preliminarily dried 10min at 80 DEG C of temperature, then be cooled to 50 DEG C of dry 20min, then be down to drying at room temperature 10min; Finally rise to 600 DEG C with the temperature rise rate of 3 DEG C/min, sintering time 3h, obtains composite membrane.This film unit weight is about 1.5, and acid and alkali corrosion rate of weight loss is all less than 1%, and about 0.5 μm, film average diameter aperture, bending strength is 15MPa/m
2, ultimate compression strength is 13MPa.
Above-mentioned embodiment is used for illustrative purposes only, and be not limitation of the present invention, the those of ordinary skill of relevant technical field, without departing from the spirit and scope of the present invention, can also make various change and modification, therefore all equivalent technical schemes also should belong to category of the present invention.
Claims (10)
1. a preparation method for water treatment film, it comprises the following steps:
(1) prepare supporter: be aggregate with aluminum oxide powder, add after silicon carbide whisker, pore-forming material, sintering agent and water are mixed into slurry and grind, then to slurry ageing, oven dry, then softening agent is added and water grinds again, then compression molding, oven dry, then sinter, clean, and be supported body;
(2) prepare colloidal sol: added by ground aluminum isopropylate in the deionized water of heat and carry out magnetic agitation, then add nitric acid in batches, be stirred to solution clear, then add dispersion agent and defoamer stirs, obtain colloidal sol, then ageing colloidal sol;
(3) apply: supporter is immersed in the colloidal sol of ageing, then supporter is upwards lifted out colloidal sol liquid level, make supporter to apply one deck liquid film;
(4) gelation: the supporter scribbling liquid film is positioned in the atmosphere containing water vapour and continues film forming, make liquid film be transformed into gel-film;
(5) dry: to adopt classification desiccating method dry to gel-film;
(6) sinter: the gel-film of drying is sintered.
2. method according to claim 1, it is characterized in that: described silicon carbide whisker is by remix after pre-treatment, and preprocessing process is: first whisker is oxidized carbon removal treatment, then carries out acid treatment with the mixture of hydrofluoric acid and hydrochloric acid, then use washed with de-ionized water, finally dry.
3. method according to claim 1, it is characterized in that: described pore-forming material is starch, sintering agent is kaolin; The mass ratio of aluminum oxide powder and silicon carbide whisker is 1:(0.5-0.7); Described starch accounts for the 8%--12% of aluminum oxide powder and silicon carbide whisker total mass; Described kaolin accounts for the 15%--25% of aluminum oxide powder and silicon carbide whisker total mass.
4. method according to claim 1, is characterized in that: ageing places 24h under field conditions (factors), then puts into baking oven and dry; Described softening agent is Vltra tears, and add-on accounts for the 1%--2% of aluminum oxide powder and silicon carbide whisker total mass.
5. method according to claim 1, is characterized in that: forming pressure is 8MPa--12 MPa, first at 200 DEG C during sintering--carry out at the temperature of 800 DEG C, temperature rise rate is (6-7) DEG C/min; Then at 800 DEG C--carry out at the temperature of 1250 DEG C, temperature rise rate is (3-4) DEG C/min; Finally constant temperature 2h at 1250 DEG C.
6. method according to claim 2, it is characterized in that: the mol ratio of aluminum isopropylate and deionized water is 1:(95--105), the temperature of deionized water is 80 DEG C--90 DEG C, concentration of nitric acid is 1.65mol/L, the mol ratio of itself and aluminum isopropylate is (0.15-0.3): 1, nitric acid is divided equally three times and is added, and each interval time is 1h.
7. method according to claim 1, it is characterized in that: described dispersion agent is Disponer-W511, add-on is the 0.15%--0.3% of solution quality; Described defoamer is DeformW-0506, and add-on is the 0.02%--0.04% of solution quality.
8. method according to claim 1, is characterized in that: pull rate during coating is 5-15cm/ min.
9. method according to claim 1, is characterized in that: first preliminarily dried 10min at 80 DEG C of temperature time dry, is then cooled to 50 DEG C of dry 20min, then is down to drying at room temperature 10min.
10. method according to claim 1, is characterized in that: rise to 600 DEG C with the temperature rise rate of 2--3 DEG C/min during sintering, sintering time 3-4h.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114262214A (en) * | 2022-01-17 | 2022-04-01 | 铜陵华兴精细化工有限公司 | High-weather-resistance ceramic diaphragm pipe and preparation method thereof |
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| CN102380321A (en) * | 2011-09-07 | 2012-03-21 | 三达膜科技（厦门）有限公司 | Method for preparing coating of alumina ceramic membrane |
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- 2015-04-16 CN CN201510177547.3A patent/CN104803700A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102380321A (en) * | 2011-09-07 | 2012-03-21 | 三达膜科技（厦门）有限公司 | Method for preparing coating of alumina ceramic membrane |
Non-Patent Citations (1)
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| 李祥锋: "《"用于水处理陶瓷膜材料的制备研究"》", 2 July 2007 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114262214A (en) * | 2022-01-17 | 2022-04-01 | 铜陵华兴精细化工有限公司 | High-weather-resistance ceramic diaphragm pipe and preparation method thereof |
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Application publication date: 20150729 |