CN103100307B - Characterization method of interface combination condition of enhancement type hollow fiber membrane - Google Patents
Characterization method of interface combination condition of enhancement type hollow fiber membrane Download PDFInfo
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- CN103100307B CN103100307B CN201310069438.0A CN201310069438A CN103100307B CN 103100307 B CN103100307 B CN 103100307B CN 201310069438 A CN201310069438 A CN 201310069438A CN 103100307 B CN103100307 B CN 103100307B
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Abstract
The invention discloses a characterization method of the interface combination condition of an enhancement type hollow fiber membrane. The characterization method comprises the following steps of: (1) enhancement type membrane sample preparation: (1) preparing a polyvinylidene fluoride-based enhancement type hollow fiber membrane sample: firstly preparing a polyvinylidene fluoride-based coating solution and a polyacrylonitrile-based coating solution, and then respectively uniformly coating the polyvinylidene fluoride-based coating solution and the polyacrylonitrile-based coating solution on the surface of a melt-spun polyvinylidene fluoride hollow fiber-based membrane through spinnerets to prepare a homogeneous enhancement type polyvinylidene fluoride hollow fiber membrane sample and a heterogenous enhancement type polyvinylidene fluoride hollow fiber membrane sample; and (2) preparing a polyacrylonitrile-based enhancement type membrane sample by the same method adopted in the step (1); (2) ultrasonic experiment: respectively placing the membrane samples prepared in the step (1) into an ultrasonic cleaner under the same condition for the ultrasonic experiment; and (3) flux test: carrying out pure water flux test on the membrane samples subjected to the ultrasonic experiment in the step (2), and indirectly characterizing the interface combination condition of the enhancement type hollow fiber membrane through obtained pure water flux change data.
Description
Technical field
The present invention relates to film quality detection technique, be specially a kind of characterizing method of enhancement type hollow fiber film interface bonding state.
Background technology
Kynoar (or polyacrylonitrile) hollow-fibre membrane is widely used in micro-filtration, ultra-filtration process with its good performance, its preparation method is mainly to adopt immersion precipitation at present, and the film of this wet method gained, intensity is lower, in actual membrane bioreactor (MBR) use procedure, often there is film silk disrepair phenomenon, film treatment effect is declined, shorten service life, production cost increases, and therefore improving film-strength has become Pvdf Microporous Hollow Fiber Membrane and need badly the problem of solution to adapt to Production requirement.
Chinese patent literature CN102068922A and CN102600733A disclose a kind of preparation method of homogeneity reinforced type polyvinylidene fluoride hollow fiber film, Chinese patent literature CN102580577A discloses a kind of preparation method of enhanced polyacrylonitrile hollow fiber membrane, above-mentioned patent has proposed better membrane preparation method for the deficiency of existing hollow-fibre membrane intensity in MBR application, but all fails enhancement type hollow fiber film interface is described in detail in conjunction with aspect and characterize.Enhancement type hollow fiber film has good mechanical property and the higher precision of holding back, in MBR application, the requirement of interface bond strength is greater than to its demand to hot strength but strengthen film, therefore the quality of film surface coating layer and film matrix bonding state will directly affect the serviceability of enhancement type hollow fiber film.In order better to be applied in practice, it is necessary that enhancing membrane interface bonding state is characterized.
(the D.Lian such as D.Lian, Y.Suga, G.Shou, and S.Kurihara.An UltrasonicTesting Method for Detecting Delamination of Sprayed Ceramic Coating.In:Proceedings of14th ITSC[C] .Japan, 1995.961～965) test the bonding state between ceramic layer and its matrix of coating with ultrasonic wave detector, can obtain more reliable data, but the method equipment complexity, and can only detect the material that is greater than 1mm separation diameter.In the scope of applicant's retrieval, there is no at present the research report of direct sign homogeneity enhancing membrane material interface bonding state.
Summary of the invention
For the deficiencies in the prior art, the technical problem that quasi-solution of the present invention is determined is, a kind of characterizing method of enhancement type hollow fiber film interface bonding state is provided, this characterizing method adopts the method for more ultrasonic rear homogeneity and heterogeneous enhancement type hollow fiber film variations of flux indirectly to characterize its interface bonding state, method is simple, easy operating, is suitable for industrialization practical application.
The technical scheme that the present invention solve the technical problem is: design a kind of characterizing method of enhancement type hollow fiber film interface bonding state, this characterizing method adopts following steps:
(1) prepare enhancement mode membrane sample
1. prepare polyvinylidene fluoride enhancement type hollow fiber film sample
First prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid, then it is evenly coated on respectively to melt-spun polyvinylidene fluoride hollow fiber membrane surface by spinning head, make homogeneity reinforced type polyvinylidene fluoride hollow fiber membrane sample and heterogeneous reinforced type polyvinylidene fluoride hollow fiber membrane sample, and gained doughnut membrane sample is soaked in the ultrafiltration water under room temperature to test after 2 days;
2. prepare polyacrylonitrile-radical enhancement mode membrane sample
Prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid, then it is evenly coated on respectively to polyacrylonitrile fibre hollow woven tube surface by spinning head, make heterogeneous enhanced polyacrylonitrile hollow fiber membrane sample and homogeneity enhanced polyacrylonitrile hollow fiber membrane sample, and gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to test after 2 days;
(2) Experimental Ultrasonic: obtained membrane sample in (1) is put into respectively to ultrasonic cleaner under the same conditions and carry out Experimental Ultrasonic;
(3) flux test: the membrane sample after Experimental Ultrasonic in (2) is carried out to pure water flux test, with the pure water flux delta data being obtained, indirectly characterize the bonding state at enhancement type hollow fiber film interface.
Compared with prior art, the feature of the characterizing method of enhancement type hollow fiber film interface bonding state of the present invention is: the effect by research ultrasonic cleaning to the combination of enhancement mode membrane interface, simulate under actual water environment, because the shake of film silk, aeration or backwash cause the segregation phenomenon of coat and the matrix of enhancement mode film.Characterizing method of the present invention to a certain extent can side light coat and the interface bonding state of matrix, and simple to operate, low for equipment requirements, is suitable for industrialization practical application.
Detailed description of the invention
Below in conjunction with specific embodiment, the present invention is further elaborated.
The characterizing method (hereinafter to be referred as characterizing method) of the enhancement type hollow fiber film interface bonding state of the present invention's design, this characterizing method adopts following steps:
1. prepare membrane sample
(1) prepare polyvinylidene fluoride and strengthen membrane sample
Prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid, then it is evenly coated on respectively to melt-spun polyvinylidene fluoride hollow fiber membrane surface by spinning head, make homogeneity reinforced type polyvinylidene fluoride hollow fiber membrane sample and heterogeneous reinforced type polyvinylidene fluoride hollow fiber membrane sample, and gained doughnut membrane sample is soaked in the ultrafiltration water under room temperature to test after 2 days; Describedly prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid is prior art.
(2) prepare polyacrylonitrile-radical enhancement mode membrane sample
Prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid (can together prepare with (1)), then it is evenly coated on respectively to polyacrylonitrile fibre hollow woven tube surface by spinning head, make heterogeneous enhanced polyacrylonitrile hollow fiber membrane sample and homogeneity enhanced polyacrylonitrile hollow fiber membrane sample, and gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to test after 2 days;
(3) prepare polyvinylidene fluoride flat film
Prepare Kynoar casting solution, then above-mentioned casting solution is scraped and made flat sheet membrane, and immerse immediately in the ultrafiltration water under room temperature to be tested after 2 days.
2. Experimental Ultrasonic: obtained sample and polyvinylidene fluoride hollow fiber basement membrane in (1) are put into respectively to ultrasonic cleaner ultrasonic tesint under the same conditions;
3. flux test: ultrasonic rear gained film in 2 is carried out to pure water flux test, obtain its pure water flux delta data, indirectly characterize the situation of this enhancing membrane interface combination with these data.
Obviously, in ultrasonic cleaning process, when different supersonic frequencies acts on different films, can produce different impacts to membrane structure, change thereby obtain different membrane fluxs.On the one hand, if supersonic frequency is too high, enhancement type hollow fiber film basement membrane and this body structure of coat are by serious destruction, and in ultrasonic cleaning process, the situation of change of membrane interface junction cannot clearly show by the variation of flux; On the other hand, if supersonic frequency is too low, within the shorter testing time, cannot destroy the combination at membrane interface place, make test process seem tediously long.Therefore, more suitable supersonic frequency can maintain the integrally-built while of basement membrane and coat, effectively destroy the bonding state at interface, have sudden change (referring to table 1-3) thereby make to strengthen membrane flux, this sudden change can be used for indirectly judging the difference of this enhancing membrane interface bonding state.
In ultrasonic cleaning process, when the different ultrasonic times of same frequency act on different films, can produce different impacts to membrane structure, change thereby obtain different membrane fluxs.The process of the increase of ultrasonic time is the process of film silk long-term jitter in the actual water environment of simulation, considers the factor possibility that membrane structure is destroyed: one, passive basement membrane (PVDF basement membrane) destroys; Two, the surface coating layer (casting solution) that plays crown_interception destroys; Three, the destruction of junction, interface.Therefore, to strengthening in film carries out different ultrasonic time tests, to melt-spun PVDF basement membrane (or PAN woven tube) and PVDF(or PAN) coat also carries out same test, thereby determines the Causes for Mutation of flux.
The present invention does not address part and is applicable to prior art.
Provide specific embodiments of the invention below, but embodiment does not limit the protection domain of the present patent application claim.
Embodiment 1
Preparation homogeneity reinforced type polyvinylidene fluoride hollow fiber film: after the poly-methyl pyrrole alkane ketone K30 that the Kynoar that is 10% by mass fraction is 10% with mass fraction mixes, being dissolved in mass fraction is in 80% dimethylacetamide solvent, after the stirred in water bath of 70 DEG C are dissolved for 3 hours completely, obtain coating liquid 60 DEG C of vacuum drying oven deaerations.Then under identical spinning condition, it is evenly coated on respectively to melt-spun polyvinylidene fluoride hollow fiber membrane surface by spinning head, makes homogeneity reinforced type polyvinylidene fluoride hollow fiber film.Gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to be tested after 2 days.
Experimental Ultrasonic: homogeneity reinforced type polyvinylidene fluoride hollow fiber film is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic beginning, take out multistage basement membrane at 0min, 10min, 20min, 30min, 60min, 90min, 120min and 180min time point respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this supersonic frequency effect, homogeneity reinforced type polyvinylidene fluoride hollow fiber film significantly increases at 90min place, and it has shown that now destruction has been suffered in membrane interface junction indirectly.
Embodiment 2
Prepare heterogeneous reinforced type polyvinylidene fluoride hollow fiber film: after the poly-methyl pyrrole alkane ketone K30 that the polyacrylonitrile that is 10% by mass fraction is 10% with mass fraction mixes, being dissolved in mass fraction is in 80% dimethylacetamide solvent, after the stirred in water bath of 70 DEG C are dissolved for 3 hours completely, obtain coating liquid 60 DEG C of vacuum drying oven deaerations.Then under identical spinning condition, it is evenly coated on respectively to melt-spun polyvinylidene fluoride hollow fiber membrane surface by spinning head, makes heterogeneous reinforced type polyvinylidene fluoride hollow fiber film.Gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to be tested after 2 days.
Experimental Ultrasonic: heterogeneous reinforced type polyvinylidene fluoride hollow fiber film is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic beginning, take out multistage basement membrane at this above-mentioned time point of 0min, 10min, 20min, 30min, 60min, 90min, 120min and 180min respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this ultrasonication, heterogeneous reinforced type polyvinylidene fluoride hollow fiber film significantly increases at 20min place, and it has shown that now destruction has been suffered in membrane interface junction indirectly.
Embodiment 3
Preparation homogeneity enhanced polyacrylonitrile tunica fibrosa: after the poly-methyl pyrrole alkane ketone K30 that the polyacrylonitrile that is 10% by mass fraction is 7% with mass fraction mixes, being dissolved in mass fraction is in 83% dimethyl sulfoxide solvent, after the stirred in water bath of 70 DEG C are dissolved for 3 hours completely, obtain coating liquid 45 DEG C of vacuum drying oven deaerations.Then under identical spinning condition, it is evenly coated on respectively to polyacrylonitrile fibre hollow woven tube surface by spinning head, makes homogeneity enhanced polyacrylonitrile hollow fiber membrane.Gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to be tested after 2 days.
Experimental Ultrasonic: homogeneity enhanced polyacrylonitrile hollow fiber membrane is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic beginning, take out multistage basement membrane at this above-mentioned time point of 0min, 5min, 10min, 15min, 20min, 30min, 40min, 50min, 60min and 90min respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this supersonic frequency effect, homogeneity enhanced polyacrylonitrile hollow fiber membrane significantly increases at 15min place, and it has shown that now destruction has been suffered in membrane interface junction indirectly.
Embodiment 4
Prepare heterogeneous enhanced polyacrylonitrile tunica fibrosa: after the poly-methyl pyrrole alkane ketone K30 that the Kynoar that is 10% by mass fraction is 7% with mass fraction mixes, being dissolved in mass fraction is in 83% dimethyl sulfoxide solvent, after the stirred in water bath of 70 DEG C are dissolved for 3 hours completely, obtain coating liquid 45 DEG C of vacuum drying oven deaerations.Then under identical spinning condition, it is evenly coated on respectively to polyacrylonitrile fibre hollow woven tube surface by spinning head, makes heterogeneous enhanced polyacrylonitrile hollow fiber membrane.Gained hollow-fibre membrane is soaked in the ultrafiltration water under room temperature to be tested after 2 days.
Experimental Ultrasonic: homogeneity enhanced polyacrylonitrile hollow fiber membrane is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic beginning, take out multistage basement membrane at this above-mentioned time point of 0min, 5min, 10min, 15min, 20min, 30min, 40min, 50min, 60min and 90min respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this supersonic frequency effect, homogeneity enhanced polyacrylonitrile hollow fiber membrane significantly increases at 10min place, and it has shown that now destruction has been suffered in membrane interface junction indirectly.
Provide concrete comparative example of the present invention below, but comparative example does not limit the protection domain of the present patent application claim.
Comparative example 1
Prepare basement membrane: prepare Pvdf Microporous Hollow Fiber Membrane with melt spinning method, taking it as reinforcement basement membrane.
Experimental Ultrasonic: Pvdf Microporous Hollow Fiber Membrane basement membrane is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic cleaning starts, take out multistage basement membrane at 0min, 10min, 20min, 30min, 60min, 90min, 120min and 180min time point respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this supersonic frequency effect, Pvdf Microporous Hollow Fiber Membrane basement membrane variations of flux is little, and membrane structure maintains better.
Comparative example 2
Preparation flat sheet membrane: after the poly-methyl pyrrole alkane ketone K30 that the Kynoar that is 18% by mass fraction is 7% with mass fraction mixes, being dissolved in mass fraction is in 75% dimethylacetamide solvent, after the stirred in water bath of 70 DEG C are dissolved for 3 hours completely, obtain casting solution 70 DEG C of vacuum drying oven deaerations.Then above-mentioned casting solution is scraped and made flat sheet membrane, and immerse immediately in the ultrafiltration water under room temperature to be tested after 2 days.
Experimental Ultrasonic: polyvinylidene fluoride flat film is put into ultrasonic cleaner, supersonic frequency is 40KHz, after ultrasonic beginning, take out multistage basement membrane at 0min, 10min, 20min, 30min, 60min, 90min, 120min and 180min time point respectively and be one group, to be tested.
Performance Detection: gained film pure water flux the results are shown in table 1.Result shows, under this supersonic frequency effect, polyvinylidene fluoride flat membrane flux changes little, and membrane structure is maintained preferably;
Comparative example 3
Described in embodiment 2, in the constant situation of other conditions, change supersonic frequency into 60KHz.
Performance Detection: gained membrane structure is destroyed, can not measure its effective variations of flux.
All hollow-fibre membranes and the flat sheet membrane of the present invention to embodiment 1-4 and comparative example 1-3 gained carried out the actual test of water flux, and test result is listed in table 1,2 and 3.Water flux in embodiment and comparative example calculates can be according to following formula (a).The formula (a) of described calculating membrane flux is:
In formula (a): J----pure water flux (L/m
2h);
V-----sees through liquid long-pending (L);
Effective area (the m of A-----film
2);
T-----obtains V volume and sees through the required time (h) of liquid.
Table 1 embodiment 1 and 2 gained water flux data
Table 2 embodiment 3-4 gained water flux data
Table 3 comparative example 1-2 gained water flux data
Claims (1)
1. a characterizing method for enhancement type hollow fiber film interface bonding state, this characterizing method adopts following steps:
(1) prepare enhancement type hollow fiber film sample
1. prepare polyvinylidene fluoride enhancement type hollow fiber film sample
First prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid, then it is evenly coated on respectively to melt-spun polyvinylidene fluoride hollow fiber membrane surface by spinning head, make the heterogeneous enhancement type hollow fiber film sample of polyvinylidene fluoride homogeneity enhancement type hollow fiber film sample and polyvinylidene fluoride, and gained enhancement type hollow fiber film sample is soaked in the ultrafiltration water under room temperature to test after 2 days;
2. prepare polyacrylonitrile-radical enhancement type hollow fiber film sample
Prepare polyvinylidene fluoride and polyacrylonitrile-radical coating liquid, then it is evenly coated on respectively to polyacrylonitrile fibre hollow woven tube surface by spinning head, make the heterogeneous enhancement type hollow fiber film sample of polyacrylonitrile-radical and polyacrylonitrile-radical homogeneity enhancement type hollow fiber film sample, and gained enhancement type hollow fiber film sample is soaked in the ultrafiltration water under room temperature to test after 2 days;
(2) Experimental Ultrasonic: prepared enhancement type hollow fiber film sample in (1) is put into respectively to ultrasonic cleaner under the same conditions and carry out Experimental Ultrasonic;
(3) flux test: the enhancement type hollow fiber film sample after Experimental Ultrasonic in (2) is carried out to pure water flux test, with the pure water flux delta data being obtained, indirectly characterize the bonding state at enhancement type hollow fiber film interface.
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| CN104530642B (en) * | 2014-12-15 | 2018-06-19 | 天津工业大学 | One kind is based on homogeneous strata polyester fiber method of modifying |
| CN104801205B (en) | 2015-04-20 | 2017-06-06 | 天津工业大学 | A kind of preparation method of the enhanced PPTA hollow-fibre membranes of homogeneity |
| CN104815563A (en) * | 2015-04-20 | 2015-08-05 | 天津工业大学 | Reinforced hollow fibrous membrane and preparation method thereof |
| CN107596928B (en) * | 2017-10-12 | 2020-12-15 | 天津工业大学 | Homogeneous fiber reinforced PVDF hollow fiber membrane and preparation method thereof |
| CN107638812B (en) * | 2017-10-16 | 2021-05-04 | 苏州富淼膜科技有限公司 | Method for testing interface bonding strength of enhanced hollow fiber membrane |
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