JPH03248039A - Method for evaluating material-permeability performance of film under test - Google Patents

Abstract

PURPOSE:To measure the permeability of diversified materials through a film at high sensitivity by measuring light emissions before and after the permeability of first and second materials through a film under test with a photodetector, and evaluating the material permeability property of the film under test based on the difference in light emissions before and after the through the film. CONSTITUTION:A container 1 made of glass as a testing jig is filled with a solution 2 of permeable material comprising the aqueous solution of CaCO3 which is second material. The upper surface of the solution 2 is covered with a film under test 3 comprising polyvinilidene chloride. A fluorescent reagent 4 which is the first material is further dropped and spread on the film 3. A cover glass 5 is mounted on the reagent. The light from a light source 11 comprising a mercury light and the like is reflected from a dichroic mirror DM through a condenser lens 12 and an exciting filter 13. The light is projected on a testing jig 15 through an objective lens 14. The fluorescence formed in this way is detected with a photodetector 18 through the lens 14, the mirror DM, an absorption filter 16 and an eyepiece 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for evaluating the substance permeation performance of a membrane to be tested.

[Conventional technology]

Control of substance permeation through membranes is one of the basic technologies in the chemical industry, pharmaceutical industry, etc., and designing an optimal membrane that meets the purpose is an essential issue when using this technology.

Methods for evaluating the substance permeability of membranes include analysis by gas chromatography, measurement of the volume of permeated gas, and measurement of the weight of a desiccant that changes depending on permeated moisture. There is also a method of transmitting a dye and measuring the absorbance or fluorescence intensity of the pigment, and another method of transmitting an electrolyte and measuring a minute amount of transmission based on changes in liquid resistance. However, since all of these conventional methods quantify the total amount of permeation within a certain period of time, it is not possible to evaluate the permeation performance of a membrane over a short period of time. Further, even if one wanted to obtain two-dimensional information such as film defects, pinholes, or uniformity, the above method was completely powerless.

Therefore, the present inventors previously proposed a method that uses chemiluminescence as a method that can measure the permeation performance of a membrane in real time over a short period of time and also measure two-dimensional information of the membrane (Unexamined Japanese Patent Publication No. (Sho 63-133039, Japanese Unexamined Patent Publication No. 1-307635)
. This method places two or more types of substances through a membrane,
The basic method is to use a photodetector to measure the light emitted when one substance permeates through the membrane and mixes with the other substance.

According to this method, not only can the transmission performance be evaluated in minute time units, but also two-dimensional information can be obtained.

[Problem to be solved by the invention]

However, in the method of the above-mentioned prior application, the principle is to utilize the luminescence of the reaction product itself of both substances;
It is not possible to evaluate the permeation performance of membranes for various substances that are not associated with chemiluminescence.

Therefore, an object of the present invention is to provide a method that can evaluate the permeation performance of a membrane for various substances that are not associated with chemiluminescence, and can also evaluate the permeation performance of a membrane with high sensitivity and speed.

[Means to solve the problem]

To this end, the present invention arranges a first substance and a second substance, which generates light under excitation light irradiation when reacting with the first substance, facing each other with a film to be tested interposed therebetween, and Excitation light consisting of ultraviolet light, visible light, or near-infrared light is applied to the interface on the side of the first substance or the interface on the side of the second substance, taking into account the fluorescence excitation spectra of the first substance, the second substance, and the reaction product. , and the luminescence before and after the first substance or the second substance passes through the membrane is measured by a photodetector, taking into account the fluorescence spectra of the first substance, the second substance, and the reaction product. This method is characterized by evaluating the substance permeation performance of the membrane under test from the difference in luminescence before and after membrane permeation.

Specifically, when evaluating the ion permeation performance of a membrane (for example, in the case of calcium ion permeation), the following procedure is performed. Fuller-2 (fura-2) is used as the first substance.
), and calcium carbonate, which is a source of calcium ions, is used as the second substance. Aqueous solutions in which the first and second substances are dissolved are placed facing each other through the thin film to be tested, and the interface of the film on the Fuller 2 side is irradiated with ultraviolet light. Then, a high-sensitivity imaging camera measures the fluorescence before and after the calcium ions pass through the membrane.
The calcium permeation performance of the membrane under test is evaluated from the difference in luminescence before and after membrane permeation.

[Effect]

According to the present invention, when either the first substance or the second substance passes through the membrane to be tested, reaction products with fluorescence excitation spectra or fluorescence spectra different from those of both substances are produced at the interface. appears in At this time, since the interface is irradiated with excitation light, light is generated by fluorescence or the like, and therefore the detection light is different before and after passing through the membrane. Therefore, the transmission performance can be evaluated using these detection lights.

〔Example〕

The present invention will be explained in detail below. First, before explaining specific examples, a jig and a device used in the animal evaluation method of the present invention will be explained.

FIG. 1 is a sectional view of two jigs applicable to the embodiment. As shown in Figure (a), a glass container (measuring cell) 1 is filled with a permeable substance solution 2, such as a CaCO3 aqueous solution, as a solution containing calcium ions as a second substance. . The upper surface of the permeable substance solution 2 is covered with a test membrane 3 made of polyvinylidene chloride, for example. Further, on the membrane to be tested 3, a fluorescent reagent 4, which is a first substance, is dripped and spread, and a cover glass 5 is placed on top of the fluorescent reagent 4. Note that the excitation light is irradiated from the cover glass 5 side, and the fluorescent light is detected by an upper photodetector (not shown).

FIG. 1(b) shows another example of the jig. A cover glass 5 is fixed to the lower side of the slide glass 6 with a through hole formed in the center using petrolatum 7, and the top thereof is filled with a fluorescent reagent 4. The upper surface of the fluorescent reagent 4 is covered with the membrane 3 to be tested, and the permeable substance solution 2 is spread over it. Note that the excitation light is irradiated from the cover glass 5 side, and the fluorescent light is detected by a photodetector below.

The above jig is set in an upright microscope or an inverted microscope, and an inverted fluorescence microscope is shown in FIG. 2 as an example. As shown in the figure, light from a light source 11 such as a mercury lamp passes through a condenser lens 12 to an excitation filter 13.
is irradiated. Here, only wavelength components suitable as excitation light are transmitted, and the excitation light reflected by the dichroic mirror (DM) is irradiated onto the test jig 15 via the objective lens 14. The fluorescent light generated thereby passes through the objective lens 14 again, passes through the DM, passes through an absorption filter 16 that transmits only light of a predetermined wavelength, passes through the eyepiece lens 17, and is detected by a photodetector 18. . This detection light is photoelectrically converted and output as an electrical signal (detection signal). This detection signal is stored in a frame memory (not shown) and subjected to processing such as subtraction.

When the above-mentioned device is used, both the light before and after passing through the membrane can be detected by the photodetector 18. At this time, a photomultiplier tube is used as the photodetector 18 to increase detection sensitivity, and an infrared sensor is used when the fluorescence is infrared. Further, when evaluating one-dimensional or two-dimensional transmission performance, a one-dimensional sensor or a two-dimensional sensor is used, respectively. In addition, when the diffusion of reaction products produced by membrane permeation is very slow, a confocal fluorescence laser scanning microscope is used, which can sufficiently remove fluorescence before and after the focal plane.

Next, a specific example will be described.

As the thin film to be tested, polyvinylidene chloride thin film (thickness 1
0 μm), and the − part was coated with KrF (N6 Burf
er) Excimer laser light (20KV248 rv)
Using UV25 cut-off filter (transmittance 35% [248rv]) with a spot diameter of approximately 100 μm, optical damage was applied to the membrane, and the effect of the optical damage on membrane permeation of calcium ions was investigated. The measurement was carried out using an upright microscope (not shown) in the arrangement shown in FIG. 1(a) using 0.1 mM calcium carbonate as a calcium ion source and 3 mM Fuller 2 as a fluorescent dye.

First, 2 ml of the calcium carbonate aqueous solution was collected in a measurement cell (container 1), a thin film to be tested was placed on top of the sample, and then 50 μg of the Fuller 2 aqueous solution was dropped onto the thin film and spread. First, the fluorescence image of Fuller 2 alone was measured before calcium ions were transmitted.

The wavelength of the excitation light at this time is 340 ns, taking into account the peak wavelength of the fluorescence excitation spectrum of the Fuller 2/calcium complex generated after calcium ions pass through the membrane. Next, when calcium ions begin to permeate through the membrane, they form a complex with Fuller 2 at the interface of the membrane on the Fuller 2 side. This complex has different fluorescence characteristics from Fuller 2, with a peak in the fluorescence excitation spectrum at a wavelength of 340 nm (Figure 3). Therefore, an image when calcium ions began to pass through was also obtained by irradiating light with a wavelength of 340 ns.

In this way, the fluorescent image of the free Fuller 2 before the calcium ions pass through the thin film is captured by the image camera and stored in the first frame memory (not shown), and the calcium ions pass through the thin film. A fluorescence image of Fuller 2 complexed with calcium ions, which are first generated as a result of the initial reaction, was captured by the same imaging camera and stored in another frame memory (second frame memory). The fluorescence image in the second frame memory partially contains the fluorescence of free Fuller 2, but the image analysis device subtracts the fluorescence image in the first frame memory from the fluorescence image in the second frame memory. By doing so, it was possible to remove the background fluorescent image of free Fuller 2 and obtain a net fluorescent image of complexed Fuller 2. In addition, fluorescent images of scratches on polyvinylidene chloride films that had been mechanically damaged in the same manner could also be obtained by the method of the present invention. In FIG. 4(a), a fluorescent image when spot-like optical damage is evaluated is shown with diagonal lines, and in FIG. 4(b), a fluorescent image when linear mechanical damage is evaluated is shown with diagonal lines.

Various modifications of the invention are possible.

For example, in addition to Fuller 2, there is also Fin-2 (Quin-2).
Fluorescent dyes such as 2) and Indo-1 can also be used in calcium ion transmission measurements by appropriately selecting the wavelength of the irradiated light by taking advantage of the fluorescent properties of each dye. In addition to calcium ions, magnesium ions, sodium ions, protons, etc. whose fluorescence properties change when complexed with fluorescent dyes can also be measured in the same manner.

〔Effect of the invention〕

According to the present invention, when one of the first substance or the second substance passes through the membrane to be tested, both substances produce a reaction with a fluorescence excitation spectrum or a fluorescence spectrum different from that of the first substance or the second substance. Objects appear at the interface. At this time, since the above-mentioned interface is irradiated with excitation light, light is generated by fluorescent light or the like, and therefore, the detection light is different before and after passing through the membrane, so that the transmission performance can be evaluated using these detection lights.

According to the present invention, membrane permeation of extremely diverse substances can be measured in real time and with high sensitivity and quickly, including two-dimensional information. In particular, the two-dimensional membrane permeation performance of ions cannot be obtained without the membrane evaluation method of the present invention, and moreover, the ions themselves usually do not chemically react with membrane constituents and do not pose any problem. This combination of advantages makes it extremely effective for membranes that separate extremely small molecules, such as reverse osmosis membranes.

In general, in the fluorescence method, so-called background fluorescence in all measurement systems is a very big problem, and background fluorescence is included in the fluorescence of the substance before it passes through the membrane. Therefore, in order to minimize the background of fluorescence before passing through the membrane, the excitation light and fluorescence There is an effect that the background can be removed by selecting the wavelength and performing subtraction before and after the substance passes through the membrane, provided that the background does not change before and after the substance passes through the membrane.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a jig applicable to the embodiment of the present invention, Figure 2 is a configuration diagram of an inverted microscope, Figure 3 is a diagram showing the Fuller 2 excitation spectrum, and Figure 4 is the evaluation result. FIG. DESCRIPTION OF SYMBOLS 1... Container, 2... Permeable substance solution, 3... Membrane to be tested, 4... Fluorescent reagent, 5... Cover glass, 6...
... Slide glass, 7 ... Vaseline, 11 ... Light source, 12 ... Condenser lens, 13 ... Excitation filter, 14 ... Objective lens, 15 ... Test jig, 16 ...・Absorption filter, 17...Eyepiece, 1
8...Photodetector.

Claims (1)

[Claims] 1. A first substance and a second substance that reacts with the first substance and whose reaction product generates light under irradiation with excitation light are tested. The excitation light consisting of ultraviolet light, visible light, or near-infrared light is irradiated to the interface of the film to be tested, and the excitation light of the first or second substance to be tested is A method of measuring the luminescence before and after passing through the membrane using a photodetector, and evaluating the substance permeation performance of the membrane under test from the difference in the luminescence before and after passing through the membrane. 2. The method for evaluating the substance permeation performance of a membrane to be tested according to claim 1, wherein the first or second substance and the reaction product have different fluorescence excitation spectra or fluorescence spectra. 3. The first substance is a solution containing a fluorescent dye,
The substance of the film to be tested according to claim 1, wherein the second substance is a solution containing ions, and the interface of the film to be tested whose luminescence is to be detected is on the first substance side of the film to be tested. How to evaluate transmission performance. 4. The substance permeation performance of the membrane to be tested according to claim 1, 2 or 3, wherein the photodetector is a photomultiplier tube, an infrared sensor, a one-dimensional sensor, a two-dimensional sensor or a confocal fluorescent laser scanning microscope. How to evaluate.