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The production of nuclear track microfilters and their applications
Nucl. Tracks Radiat. Meas., Vol. 15, Nos. 1-4, pp. 767-770, 1988 Int. J. Radiat. Appl. lnstrum., Part D Printed in Great Britain
0191-278X/89 $3.00 + .00
Pergamon Press pie
THE P R O D U C T I O N OF N U C L E A R T R A C K MICROFILTERS A N D T H E I R A P P L I C A T I O N S HUAN-HUA CUI, SHI-CHENG WANG, RI-SHENG WU and JIAN ZHOU Institute of High Energy Physics, 3inica, P.O.Box 2732, Beijing,
Academia China
ABSTRACT--Polycarbonate a n d p o l y e s t e r nuclear track microfilters (PCM and P ~ ) have been produced. The pore geometries of the microfilters have been investigated by means of scanning electron microscope (S~4), high-voltage transmission electron microscope (HV~4) and water flow rate method. All the results show that the pore is cylindrical. A self-made apparatus has been used for study of red blood cell (RBC) deformability. The index of 8BC deformability of normal persons is lower than that for patients of stasls of blood. Therefore, the index of P~C deformability is a useful parameter for the clinical observations of patients suffering from these diseases. POM can be used to clarify 11 kinds of ultra pure chemical reagents in common use. Negative photoresist for developer and hydrochloric acld clarified by using POM with pore size of 0 . 9 ~ m come up to BVI and MOS standards of ultra pure chemical reagents respectively. PCM has been used to industrial production of ultra pure chemical reagents. INTRODUCTION The pore geometries of PCM and P~4 are cylindrical. In applications, the surface structure and the pore geometry of the microfilters are important for understanding the details of the filtration processes I • The pore geometries of the microfilters have been studied by means of S~4, HV~4 and water flow rate method 2 • The RBC accounts for 45 percent of the whole volume in human blood. The pliability of the RBC influences the viscosity of blood while the deformability effects the flow of blood and microclrculation. The reduction of the RBC deformability is related to the blocking blood vessel a n d ~ h e obstacle in microcirculation. Recently the study on RBC deformability is paid more and more attention3. The normal RBC has deformability. It can pass through micropore or microblood vessel with pore size much less than that of itself. Its deformability will be weakened when the ~BC gets pathological change, and in this case it is difficult to pass through the above micropore or microblood vessel. The RBC's ability to pass through micropore can reflect its deformability. The PCM which has the uniform pore size and the regular pore shape is an ideal microfilter used to determine the index of KBC deformability. An apparatus is deslgne~ for measuring index of ~BC deformability by using PCM with pore size of 5 m m*. The particles in chemical reagents and water used in the production process of large scale integrated circuit must be removed for quality assurance. Microporous membranes can be used to clarify the particles in the reagents. PGM has high degree of selectivity because of its cylindrical pore and uniform pore size. It can completely retain ~ s particles with the size larger than pore size on its surface. PCM is inert to hydrocarbons, acids and alcohols.
767
768
H U A N - H U A CUI et al.
Therefore it can be used to clarify ultra pure chemical reagents in the semiconductor industry5,6. FD~PEKIMENTAL METHODS AND ~ESULTS Polycarbonate film (makrofol made by Bayer company and made in China) or polyester film (made in China) was irradiated in a nuclear reactor with a collimated beam of 235U fission fragments that yielded radiation damage across the entire thickness of the film. The irradiated film was etched in 6N NaOH solution containing 0.1% Dowex 2AI at 60"C, then the cylindrical pore formed on it. The microfilters ~ i t h pore s~zes ranging form 0.2 to 12 ~ n and pore densities ranging from 10 ° to IOD/cm L were obtained by controlling the etching time and the neutron fluence respectively. It can be seen from S~4 microphotograph of the microfilters (see Fig. 1,2) that the pores are cylindrical. The effective pore size measured by water flow rate method is consistent with the average pore size measured by SF/i (Table I). The pore width is measured by HV,~4 (Table 2) and is found to be uniform at various sections along the pore length. These results show that the pore is cylindrical too. PFM shows s~noothness on its surface and the inner wall of the pores.
pore size O.8~m Fig.1. SEM microphotograph of P~/~ Table I.
pore size 1 jam Fig.2. Cross cut of pores in PCM (made in China)
Pore sizes measured by water flow rate method
~ffective pore size measured by water flow rate method ~ m
0.42
0.58
O.71
1.6
2.3
Average pore size measured by SF~4 m m
0.42
O.61
0.73
1.6
2.5
Table 2.
Pore widths measured by H V ~
Average pore width measured by HVF,M ,urn
0.40
0.53
0.76
I .2
I .6
The least pore width measured by HVF2~ ~ m
O.38
O.50
O.72
1.1
1.5
The intravenous blood of elbow was drawn. Citric acid was added to it as an anticoagulator. The blood was separated centrifugally. The blood plasma and the white blood cell were removed. Then the ~BC was washed three t~nes with physiological saline. The washed ~BC was compounded with tris-HC1 suspension solution into a suspension solution of less than 10%. Under negative pressure of 10 cm water column, the filtration time when I ml suspension solution of ~BC passed through the microfilter was determined by the apparatus. Then the index of ~BC deformability O was calculated according to the following equation O =, T s TR
PCV
NUCLEAR
TRACK MICROFILTERS
769
where T s is the time when I ml suspension solution passes through the microfilter. TR is the time when I ml suspension solution of KBC passes through the microfilter. PO¥ is the packed cell volume. The experimental results show that the index of RBC deformability for 104 cases of stasis of blood is O.71 + 0.05. It is significantly reduced in comparison with that of normal people ( D = 0 . 9 8 + 0 . O 8 for 33 cases, P ( O . O 1 ) . The effects o f 13 kinds of chinese medicine that is helpful to activate the blood circulations and dissolve the blood sludge were studied. The experiments on hares were carried out. Before the hares took the medicine, the index of RBC deformability is I .55 +0.08. After the hares took the medicine, the index of RBC deformability is I."~8+O.17 (after taking angelica) and I .71 + 0.25 [after taking the rhizome of-Chuan Xiong (!i~ustictun wallichii)] ~P< 0.05). The index enhancements of RBC deformability for angelica and t h e rhizome of Chuan Xiong (ligusticum wallichii) are more significant than ~hat of theothers. This method can be used as one of the objective indexes for the patients of stasis of blood and used as one of the methods to study the effects of blood activating and stagnant blood reducing drugs.
,~
]~
Fig- 3.
/
:i,)-,.<
/~. ~
!(: :
12' T: i:'Et:!
pore size 5 ~Am SEM microphotograph of RBC on the surface of PCM
T u b e for filling blood
Height
of water pillar
// hold / . .
Water trough
Bottle
.fo~
steady
Filtration ~rough
pressure
Fig.4.
The device of RBC def ormab ility
The microfilter was put on the filter of 142 mm in diameter. Under the given pressure difference, chemical reagents and water were filtrated. Then the filtration rate~ the content of particles and impurity elements were determined • The solution containing the standard particles with the size of 2/urn was filtrated by using the microfilters with various pore sizes. The results show
770
H U A N - H U A CUI et al.
that the particles with size of 2 ~Am can be retained completely by using the microfilters with pore sizes less than 2 ~Am. The permeability of the microfilter with the pore size of O.8~Am is 9x 10-3 and 5 x IO@3 for particle sizes over I ~Am and 2 ~Am respectively. It means that about I% of particles can pass through the microfilter after filtrating once. After the reagents (ethyl alcohol, hydrochloric acid, ethylene glycol, hydrogen peroxide, negative photoresist for developer) and water were filtrated by using the microfilter with the pore size of 0.8 ~Am. The contents of particles with the size more than 2 ~Am in reagents were less than 430/1OO ml. 250 1 of negative photoresist for developer and hydrochloric acid were continuously filtrated by using the microfilter with the pore size of 0.9 jam. The results show that the particle contents for the size more than 2 ~am are leas than 280/100 ml of negative photoresiat for developer and less than 1300/100 ml of hydrochloric acid. The filtration rates of negative photoresist for developer and hydrochloric acid are 2610(at pressure difference of 0.5 kg/cm2)and 40Oml/min(at pressure difference of I .O kg/cm ~ respectively. These reagents come up to BVI and MOS standards of ultra pure chemical reagents respectively. Now the PCM has been used to industrial production of the ultra pure chemical reagents. I. 2. 3. 4. 5. 6.
REFERENCES B. E. Fischer et al., Rev. Mod. Phys. 55, 907 (1983). Huan-Hua Cui et al., Nuclear Techniques 4, 41 (1985). H. L. Reid et al., J. Clin Path. 29, 855 (1976). 8hi-Oheng Wang et al., Biochemistry and Biophysics I, 70 (1986). M. C. Porter, et al., Filtration Engineering Jan/Feb. 8 (1973). Huan-Hua Oui et al., Nuclear Techniques 4, 44 (1985).
0191-278X/89 $3.00 + .00
Pergamon Press pie
THE P R O D U C T I O N OF N U C L E A R T R A C K MICROFILTERS A N D T H E I R A P P L I C A T I O N S HUAN-HUA CUI, SHI-CHENG WANG, RI-SHENG WU and JIAN ZHOU Institute of High Energy Physics, 3inica, P.O.Box 2732, Beijing,
Academia China
ABSTRACT--Polycarbonate a n d p o l y e s t e r nuclear track microfilters (PCM and P ~ ) have been produced. The pore geometries of the microfilters have been investigated by means of scanning electron microscope (S~4), high-voltage transmission electron microscope (HV~4) and water flow rate method. All the results show that the pore is cylindrical. A self-made apparatus has been used for study of red blood cell (RBC) deformability. The index of 8BC deformability of normal persons is lower than that for patients of stasls of blood. Therefore, the index of P~C deformability is a useful parameter for the clinical observations of patients suffering from these diseases. POM can be used to clarify 11 kinds of ultra pure chemical reagents in common use. Negative photoresist for developer and hydrochloric acld clarified by using POM with pore size of 0 . 9 ~ m come up to BVI and MOS standards of ultra pure chemical reagents respectively. PCM has been used to industrial production of ultra pure chemical reagents. INTRODUCTION The pore geometries of PCM and P~4 are cylindrical. In applications, the surface structure and the pore geometry of the microfilters are important for understanding the details of the filtration processes I • The pore geometries of the microfilters have been studied by means of S~4, HV~4 and water flow rate method 2 • The RBC accounts for 45 percent of the whole volume in human blood. The pliability of the RBC influences the viscosity of blood while the deformability effects the flow of blood and microclrculation. The reduction of the RBC deformability is related to the blocking blood vessel a n d ~ h e obstacle in microcirculation. Recently the study on RBC deformability is paid more and more attention3. The normal RBC has deformability. It can pass through micropore or microblood vessel with pore size much less than that of itself. Its deformability will be weakened when the ~BC gets pathological change, and in this case it is difficult to pass through the above micropore or microblood vessel. The RBC's ability to pass through micropore can reflect its deformability. The PCM which has the uniform pore size and the regular pore shape is an ideal microfilter used to determine the index of KBC deformability. An apparatus is deslgne~ for measuring index of ~BC deformability by using PCM with pore size of 5 m m*. The particles in chemical reagents and water used in the production process of large scale integrated circuit must be removed for quality assurance. Microporous membranes can be used to clarify the particles in the reagents. PGM has high degree of selectivity because of its cylindrical pore and uniform pore size. It can completely retain ~ s particles with the size larger than pore size on its surface. PCM is inert to hydrocarbons, acids and alcohols.
767
768
H U A N - H U A CUI et al.
Therefore it can be used to clarify ultra pure chemical reagents in the semiconductor industry5,6. FD~PEKIMENTAL METHODS AND ~ESULTS Polycarbonate film (makrofol made by Bayer company and made in China) or polyester film (made in China) was irradiated in a nuclear reactor with a collimated beam of 235U fission fragments that yielded radiation damage across the entire thickness of the film. The irradiated film was etched in 6N NaOH solution containing 0.1% Dowex 2AI at 60"C, then the cylindrical pore formed on it. The microfilters ~ i t h pore s~zes ranging form 0.2 to 12 ~ n and pore densities ranging from 10 ° to IOD/cm L were obtained by controlling the etching time and the neutron fluence respectively. It can be seen from S~4 microphotograph of the microfilters (see Fig. 1,2) that the pores are cylindrical. The effective pore size measured by water flow rate method is consistent with the average pore size measured by SF/i (Table I). The pore width is measured by HV,~4 (Table 2) and is found to be uniform at various sections along the pore length. These results show that the pore is cylindrical too. PFM shows s~noothness on its surface and the inner wall of the pores.
pore size O.8~m Fig.1. SEM microphotograph of P~/~ Table I.
pore size 1 jam Fig.2. Cross cut of pores in PCM (made in China)
Pore sizes measured by water flow rate method
~ffective pore size measured by water flow rate method ~ m
0.42
0.58
O.71
1.6
2.3
Average pore size measured by SF~4 m m
0.42
O.61
0.73
1.6
2.5
Table 2.
Pore widths measured by H V ~
Average pore width measured by HVF,M ,urn
0.40
0.53
0.76
I .2
I .6
The least pore width measured by HVF2~ ~ m
O.38
O.50
O.72
1.1
1.5
The intravenous blood of elbow was drawn. Citric acid was added to it as an anticoagulator. The blood was separated centrifugally. The blood plasma and the white blood cell were removed. Then the ~BC was washed three t~nes with physiological saline. The washed ~BC was compounded with tris-HC1 suspension solution into a suspension solution of less than 10%. Under negative pressure of 10 cm water column, the filtration time when I ml suspension solution of ~BC passed through the microfilter was determined by the apparatus. Then the index of ~BC deformability O was calculated according to the following equation O =, T s TR
PCV
NUCLEAR
TRACK MICROFILTERS
769
where T s is the time when I ml suspension solution passes through the microfilter. TR is the time when I ml suspension solution of KBC passes through the microfilter. PO¥ is the packed cell volume. The experimental results show that the index of RBC deformability for 104 cases of stasis of blood is O.71 + 0.05. It is significantly reduced in comparison with that of normal people ( D = 0 . 9 8 + 0 . O 8 for 33 cases, P ( O . O 1 ) . The effects o f 13 kinds of chinese medicine that is helpful to activate the blood circulations and dissolve the blood sludge were studied. The experiments on hares were carried out. Before the hares took the medicine, the index of RBC deformability is I .55 +0.08. After the hares took the medicine, the index of RBC deformability is I."~8+O.17 (after taking angelica) and I .71 + 0.25 [after taking the rhizome of-Chuan Xiong (!i~ustictun wallichii)] ~P< 0.05). The index enhancements of RBC deformability for angelica and t h e rhizome of Chuan Xiong (ligusticum wallichii) are more significant than ~hat of theothers. This method can be used as one of the objective indexes for the patients of stasis of blood and used as one of the methods to study the effects of blood activating and stagnant blood reducing drugs.
,~
]~
Fig- 3.
/
:i,)-,.<
/~. ~
!(: :
12' T: i:'Et:!
pore size 5 ~Am SEM microphotograph of RBC on the surface of PCM
T u b e for filling blood
Height
of water pillar
// hold / . .
Water trough
Bottle
.fo~
steady
Filtration ~rough
pressure
Fig.4.
The device of RBC def ormab ility
The microfilter was put on the filter of 142 mm in diameter. Under the given pressure difference, chemical reagents and water were filtrated. Then the filtration rate~ the content of particles and impurity elements were determined • The solution containing the standard particles with the size of 2/urn was filtrated by using the microfilters with various pore sizes. The results show
770
H U A N - H U A CUI et al.
that the particles with size of 2 ~Am can be retained completely by using the microfilters with pore sizes less than 2 ~Am. The permeability of the microfilter with the pore size of O.8~Am is 9x 10-3 and 5 x IO@3 for particle sizes over I ~Am and 2 ~Am respectively. It means that about I% of particles can pass through the microfilter after filtrating once. After the reagents (ethyl alcohol, hydrochloric acid, ethylene glycol, hydrogen peroxide, negative photoresist for developer) and water were filtrated by using the microfilter with the pore size of 0.8 ~Am. The contents of particles with the size more than 2 ~Am in reagents were less than 430/1OO ml. 250 1 of negative photoresist for developer and hydrochloric acid were continuously filtrated by using the microfilter with the pore size of 0.9 jam. The results show that the particle contents for the size more than 2 ~am are leas than 280/100 ml of negative photoresiat for developer and less than 1300/100 ml of hydrochloric acid. The filtration rates of negative photoresist for developer and hydrochloric acid are 2610(at pressure difference of 0.5 kg/cm2)and 40Oml/min(at pressure difference of I .O kg/cm ~ respectively. These reagents come up to BVI and MOS standards of ultra pure chemical reagents respectively. Now the PCM has been used to industrial production of the ultra pure chemical reagents. I. 2. 3. 4. 5. 6.
REFERENCES B. E. Fischer et al., Rev. Mod. Phys. 55, 907 (1983). Huan-Hua Cui et al., Nuclear Techniques 4, 41 (1985). H. L. Reid et al., J. Clin Path. 29, 855 (1976). 8hi-Oheng Wang et al., Biochemistry and Biophysics I, 70 (1986). M. C. Porter, et al., Filtration Engineering Jan/Feb. 8 (1973). Huan-Hua Oui et al., Nuclear Techniques 4, 44 (1985).