CN103736407B - A kind of PVDF microfiltration membranes hydrophilic modification method - Google Patents
A kind of PVDF microfiltration membranes hydrophilic modification method Download PDFInfo
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- CN103736407B CN103736407B CN201410033087.2A CN201410033087A CN103736407B CN 103736407 B CN103736407 B CN 103736407B CN 201410033087 A CN201410033087 A CN 201410033087A CN 103736407 B CN103736407 B CN 103736407B
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Abstract
A kind of PVDF microfiltration membranes hydrophilic modification method, belongs to field of material technology.Described method of modifying comprises the steps: the pretreatment of PVDF microfiltration membranes, dehydrofluorination, washing, free radical, grafting.The PVDF microfiltration membranes hydrophilic effect of modification of the present invention improves significantly, and modified PVDF microfiltration membranes water flux improves more than 50%; The PVDF micro-filtration hydrophilic film reliable in quality that the present invention makes, and adopt chemical method to carry out modification, make reaction evenly, simple to operate, process stabilizing, is easy for suitability for industrialized production; Material modified and the medicine used in product of the present invention is domestic technical grade product, cheap, is applicable to large-scale industrial production.
Description
Technical field
The invention belongs to field of material technology, relate to a kind of membrane materials for water filtration and gather inclined fluorine polyethylene (PVDF) hydrophilic modification method.
Background technology
Kynoar (PVDF) material due to containing the C-F key of higher bond energy, make the C-C key of lower bond energy surround by C-F key, therefore there is excellent chemical stability, heat endurance, mechanical stability, radiation resistance.It is widely used in the various water treatment such as sanitary sewage disposal, Industrial Wastewater Treatment mainly as a kind of micro-filtration and ultrafiltration membrane material.But, the C-F key on pvdf membrane surface and c h bond determine again its slightly water-wet, PVDF and hydrone is made to be difficult to produce the effect of hydrogen bond, wettable poor performance, hydrophobic effect are strong, hydrone is more difficult is attached to pvdf membrane surface, cause water flux lower, the requirement for water flux in actual production can not be met.So PVDF is when oil-water separation system, because its hydrophobic effect is strong, surface energy is low, and oiliness pollutant is easy to be adsorbed on film surface, and causes the blocking of fenestra.Along with the water flux of the increase film of water filtration membrane service time declines gradually, water filtration membrane is finally caused to use.Stronger hydrophobicity acts as the key factor in order to limit PVDF flux, limits the further genralrlization application of PVDF in actual production life.
Summary of the invention
The object of the invention is the slightly water-wet that C-F key and c h bond in order to overcome existing PVDF water filtration membrane surface cause, the have difficult labour effect of raw hydrogen bond of PVDF and hydrone causes that the wettable poor performance of PVDF, hydrophobic effect are strong, water flux is lower, and the defect that can not meet for the requirement of water flux in actual production, a kind of method of PVDF water filtration membrane hydrophilic modifying is provided, PVDF hydrophily is improved, and water flux is improved.
The object of the invention is to be achieved by following technical proposals:
The pretreatment of A, PVDF microfiltration membranes
PVDF microfiltration membranes is positioned in clear water and soaks 12 ~ 24h, to remove the additive, solvent and other material that add in production process contained in PVDF microfiltration membranes;
B, dehydrofluorination
Temperature 40 ~ 60 DEG C with under the condition stirred, NaOH and potassium permanganate mixed aqueous solution process 10 ~ 20min will be placed in the pretreated PVDF microfiltration membranes of steps A, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond;
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10 ~ 20min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate;
D, free radical
PVDF microfiltration membranes after the washing of step C clear water is added in the ethanolic solution containing initator and promoter, under the condition of room temperature, process 5 ~ 10min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical;
E, grafting
The mixed aqueous solution containing maleic anhydride, the concentrated sulfuric acid and ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 70 ~ 85 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 3 ~ 6h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Described PVDF microfiltration membranes is immersed in 2 ~ 3h in 10 ~ 20% glycerine water solutions (mass fraction) after washing 10 ~ 30min under being placed on pure water, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
A preferred embodiment of the invention, in described NaOH and potassium permanganate mixed aqueous solution, the concentration equivalent of potassium permanganate is 0.15 ~ 0.2mol/L,
A preferred embodiment of the invention, in described NaOH and potassium permanganate mixed aqueous solution, the concentration equivalent of NaOH is 1.5 ~ 2.5mol/L.
A preferred embodiment of the invention, is respectively 20 ~ 30% maleic anhydrides, 3 ~ 5% concentrated sulfuric acids and 3 ~ 8% ethyl orthosilicates containing mass fraction in described mixed aqueous solution.
A preferred embodiment of the invention, described maleic anhydride monomer is 20 ~ 25% in the mass concentration of mixed aqueous solution.
A preferred embodiment of the invention, the temperature of described dehydrofluorination is 50 ~ 55 DEG C.
A preferred embodiment of the invention, the consumption of the described concentrated sulfuric acid is 10 ~ 20% of maleic anhydride quality.
A preferred embodiment of the invention, in described ethanolic solution containing mass fraction be 3 ~ 4% initator and mass fraction be the promoter of 0.5 ~ 0.8%.
A preferred embodiment of the invention, described initator is dibenzoyl peroxide, and promoter is cobalt naphthenate or naphthoic acid cobalt.
A preferred embodiment of the invention, described graft reaction temperature is 77 ~ 82 DEG C.
A preferred embodiment of the invention, the consumption of described cobalt naphthenate promoter is 1.0 ~ 2.0% of described maleic anhydride monomer quality.
A preferred embodiment of the invention, the consumption of described ethyl orthosilicate is 10 ~ 30% of described maleic anhydride monomer quality.
A preferred embodiment of the invention, the consumption of described ethyl orthosilicate is 20 ~ 25% of described maleic anhydride monomer quality.
The present invention has following beneficial effect:
1, the PVDF microfiltration membranes hydrophilic effect of modification of the present invention improves significantly, and as can be seen from Figure 2, modified PVDF microfiltration membranes water flux improves more than 50%.
2, the PVDF micro-filtration hydrophilic film reliable in quality of the present invention's making, and adopt chemical method to carry out modification, make reaction evenly, simple to operate, process stabilizing, is easy for suitability for industrialized production.
3, the material modified and medicine used in product of the present invention is domestic technical grade product, cheap, is applicable to large-scale industrial production.
Accompanying drawing explanation
Fig. 1 is modified PVDF microfiltration membranes infared spectrum analysis;
Fig. 2 be before modified after water flux value.
Detailed description of the invention
Below in conjunction with embodiment, technical scheme of the present invention is further described; but do not limit to so; everyly technical solution of the present invention modified or equivalent to replace, and not departing from the spirit and scope of technical solution of the present invention, all should be encompassed in protection scope of the present invention.
embodiment 1:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
PVDF microfiltration membranes is positioned in clear water and soaks 12 ~ 24h, to remove the additive, solvent and other material that add in production process contained in PVDF microfiltration membranes.
The PVDF microfiltration membranes that the present invention uses is the finished product that market is sold, as by clear water source, Beijing company the PVDF microfiltration membranes of producing.The PVDF microfiltration membranes product that the present invention uses has following performance characteristics usually: have higher intensity; Water flux reaches certain value; May be used for sewage disposal.
In this step, the additive that remove normally lithium chloride, silica etc.The solvent removed is DMF etc. normally.Other material removed is polyethylene glycol etc. normally.
B, dehydrofluorination
Temperature be 40 ~ 60 DEG C with stir condition under, NaOH and potassium permanganate mixed aqueous solution process 10 ~ 20min will be placed in the pretreated PVDF microfiltration membranes of steps A, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
In this step, in the NaOH of use and potassium permanganate mixed aqueous solution, the concentration equivalent of potassium permanganate is 0.15 ~ 0.2mol/L, and the concentration equivalent of NaOH is 1.5 ~ 2.5mol/L.The amount of NaOH should be strict controlled in certain limit, if amount of sodium hydroxide is very few, then the double bond content formed is less, is unfavorable for next step modification; Sodium hydrate content is too much, then in PVDF, double bond content is more, and film strength can be made greatly to reduce.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10 ~ 20min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
According to the present invention, the NaOH on the PVDF microfiltration membranes surface after described dehydrofluorination is not removed clean, then can produce adverse influence to PVDF microfiltration membranes subsequent processing steps.If NaOH does not remove completely, then can participate in next step material reacted and react, affect reaction and carry out.
D, free radical
The PVDF microfiltration membranes after the washing of step C clear water, to be added to mass fraction be 3 ~ 4% dibenzoyl peroxide initators and mass fraction is in the ethanolic solution of 0.5 ~ 0.8% cobalt naphthenate promoter, under the condition of room temperature, process 5 ~ 10min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20 ~ 30% maleic anhydrides, 3 ~ 5% concentrated sulfuric acids and 3% ~ 8% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 70 ~ 85 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.It is 2 ~ 3h in the glycerine water solution of 10 ~ 20% that described PVDF microfiltration membranes is immersed in mass fraction after washing 10 ~ 30min under being placed on pure water, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
As shown in Figure 1, at 800cm
-1and 1080cm
-1place can see that two peaks prove there is silicon oxygen bond.
In this step, each material concentration in mixed aqueous solution for grafting hydrophilic modifying reaction extremely important, if ethyl orthosilicate concentration lower than 3% time, then the grafted chain formed is shorter, hydrophilic modifying weak effect; If ethyl orthosilicate concentration higher than 8% time, then the grafting segment formed is long, causes PVDF water filtration membrane micro-filtration hole to be blocked by segment; Therefore, the concentration of ethyl orthosilicate is 3 ~ 8% is suitable.
embodiment 2:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 12h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 60 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.15mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 3:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 60 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.15mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 4:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 24h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 60 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.15mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
The method adopting this description to describe have detected that the PVDF microfiltration membranes with hydrophilic layer prepared by this embodiment contains hydrophilic radical, water flux increases, and have detected this embodiment simultaneously and uses that the hydrophily of PVDF microfiltration membranes strengthens, water flux increases.Above-described embodiment clearly illustrates that this embodiment can be successful, and has better effects at A step immersion 12 ~ 24h.
embodiment 5:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.15mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 6:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 50 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.15mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
The method adopting this description to describe have detected that the PVDF microfiltration membranes with hydrophilic layer prepared by this embodiment contains hydrophilic radical, water flux increases, and have detected this embodiment simultaneously and uses that the hydrophily of PVDF microfiltration membranes strengthens, water flux increases.Above-described embodiment clearly illustrates that this embodiment can be successful, and it is higher to walk 55 DEG C of reaction efficiencies at B.
embodiment 7:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 1.5mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 8:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 20min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 9:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 15min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 10:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 20min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 3% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
The method adopting this description to describe have detected that the PVDF microfiltration membranes with hydrophilic layer prepared by this embodiment contains hydrophilic radical, water flux increases, and have detected this embodiment simultaneously and uses that the hydrophily of PVDF microfiltration membranes strengthens, water flux increases.Above-described embodiment clearly illustrates that
Along with the increase of wash time in step C, though Modified Membrane sample effect has part to promote, consider industry preparation washing 10min.
embodiment 11:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 12:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.8% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 5min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 13:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 14:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 5% concentrated sulfuric acid and 3% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 15:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 6% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 16:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 8% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 17:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 6% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 70 C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 18:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 6% ethyl orthosilicate is added in the solution that step D obtains, then, under the condition of temperature 70 C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 5h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 10min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
embodiment 19:
The implementation step of polyvinylidene fluoride microporous filtering film hydrophilic modifying is as follows:
The pretreatment of A, PVDF microfiltration membranes
The PVDF microfiltration membranes that clear water source, Beijing company produces is positioned in clear water and soaks 18h, to remove the additive lithium chloride, the silica that add in production process contained in PVDF microfiltration membranes, DMF solvent and polyethylene glycol etc.
B, dehydrofluorination
Temperature be 55 DEG C with under 50 revs/min of conditions stirred, to be placed in the pretreated PVDF microfiltration membranes of steps A and process 10min containing 0.2mol/L NaOH and 2.0mol/L potassium permanganate mixed aqueous solution, with the HF of removing on steps A pretreated PVDF microfiltration membranes surface, form C=C double bond.
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10min, with remove remain in described dehydrofluorination PVDF microfiltration membranes surface on NaOH and potassium permanganate.
D, free radical
It is 4% dibenzoyl peroxide initator and mass fraction is in the ethanolic solution of 0.6% cobalt naphthenate promoter that PVDF microfiltration membranes after the washing of step C clear water is added to containing mass fraction, under the condition of room temperature, process 40min, to make described initator, the C=C double bond on described water washing PVDF microfiltration membranes surface is caused generation free radical.
E, grafting
The mixed aqueous solution that mass fraction is 20% maleic anhydride, 3% concentrated sulfuric acid and 6% ethyl orthosilicate is added in the solution that step D obtains, then in temperature: under the condition of 80 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 4h.Reaction terminates described PVDF microfiltration membranes surface and can obtain one deck hydrophilic layer.Being immersed in mass fraction after washing 15min under described PVDF microfiltration membranes is placed on pure water is 2h in the glycerine water solution of 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
Claims (7)
1. a PVDF microfiltration membranes hydrophilic modification method, is characterized in that described modification method is as follows:
The pretreatment of A, PVDF microfiltration membranes
PVDF microfiltration membranes is positioned in clear water and soaks 12 ~ 24h;
B, dehydrofluorination
Temperature 40 ~ 60 DEG C with under the condition stirred, NaOH and potassium permanganate mixed aqueous solution process 10 ~ 20min will be placed in the pretreated PVDF microfiltration membranes of steps A, in described NaOH and potassium permanganate mixed aqueous solution, the concentration equivalent of NaOH is 1.5 ~ 2.5mol/L;
C, washing
PVDF microfiltration membranes after step B dehydrofluorination is placed in clear water and carries out cyclic washing 10 ~ 20min;
D, free radical
PVDF microfiltration membranes after the washing of step C clear water is added in the ethanolic solution containing initator and promoter, process 5 ~ 10min under the condition of room temperature, described initator is dibenzoyl peroxide, and promoter is cobalt naphthenate or naphthoic acid cobalt;
E, grafting
The mixed aqueous solution containing maleic anhydride, the concentrated sulfuric acid and ethyl orthosilicate is added in the solution that step D obtains, then under the condition of temperature 70 ~ 85 DEG C, the free radical on described PVDF microfiltration membranes surface and maleic anhydride is made to carry out graft reaction 3 ~ 6h, being immersed in mass fraction after washing 10 ~ 30min under PVDF microfiltration membranes being placed on after reaction terminates pure water is 2 ~ 3h in the glycerine water solution of 10 ~ 20%, finally at room temperature dries and can obtain the PVDF microfiltration membranes that there is hydrophilic layer on surface.
2. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1, is characterized in that being respectively 20 ~ 30% maleic anhydrides, 3 ~ 5% concentrated sulfuric acids and 3 ~ 8% ethyl orthosilicates containing mass fraction in described mixed aqueous solution.
3. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1 and 2, is characterized in that described maleic anhydride monomer is 20 ~ 25% in the mass concentration of mixed aqueous solution.
4. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1, is characterized in that the temperature of described dehydrofluorination is 50 ~ 55 DEG C.
5. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1, it is characterized in that in described ethanolic solution containing mass fraction be 3 ~ 4% initator and mass fraction be the promoter of 0.5 ~ 0.8%.
6. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1, is characterized in that described graft reaction temperature is 77 ~ 82 DEG C.
7. a kind of PVDF microfiltration membranes hydrophilic modification method according to claim 1, is characterized in that the mass fraction of glycerine in described glycerine water solution is 20%.
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| CN105214503A (en) * | 2015-10-14 | 2016-01-06 | 江南大学 | The hydrophilic method of repair membrane after Chemical cleaning |
| CN106621842B (en) * | 2017-01-16 | 2019-03-22 | 南京大学 | A kind of preparation method, regeneration method and application chelating microfiltration membranes |
| CN107200848B (en) * | 2017-05-08 | 2020-01-14 | 苏州科技大学 | Modified nano-silica and PVDF (polyvinylidene fluoride) microfiltration membrane and application thereof |
| CN108514818A (en) * | 2018-05-02 | 2018-09-11 | 熊振 | A kind of hydrophilic PVDF film and preparation method thereof |
| CN108927007A (en) * | 2018-07-25 | 2018-12-04 | 哈尔滨工业大学（威海） | The modified PVDF filter membrane of method of modifying, gained of PVDF filter membrane and its application |
| CN111100300B (en) * | 2018-10-25 | 2022-09-06 | 中国石油化工股份有限公司 | Polymerizable polyether organic silicon, composition, preparation method and application thereof |
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| CN101229489A (en) * | 2007-10-26 | 2008-07-30 | 吴特殊 | Film making liquid for polyvinyl chloride hydrophilicity alloy separating film and preparing method thereof |
| CN102698608A (en) * | 2012-05-23 | 2012-10-03 | 中国海洋大学 | Method for preparing ultrafiltration membrane with permanent hydrophilic and antimicrobial properties |
| CN103263861A (en) * | 2013-05-30 | 2013-08-28 | 哈尔滨工业大学 | Hydrophilic modification method for polyvinylidene fluoride hollow fiber membrane |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101229489A (en) * | 2007-10-26 | 2008-07-30 | 吴特殊 | Film making liquid for polyvinyl chloride hydrophilicity alloy separating film and preparing method thereof |
| CN102698608A (en) * | 2012-05-23 | 2012-10-03 | 中国海洋大学 | Method for preparing ultrafiltration membrane with permanent hydrophilic and antimicrobial properties |
| CN103263861A (en) * | 2013-05-30 | 2013-08-28 | 哈尔滨工业大学 | Hydrophilic modification method for polyvinylidene fluoride hollow fiber membrane |
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