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Porphyrin indicator membrane
Patents i m p u r i t y c o m p o u n d s are r e m o v e d from the gas; t h e s e c a n arise (via o u t g a s s i n g ) from the m a t e r i als a n d c o n t a i n e r s u s e d to filter the gas. T h e s e two a i m s are achieved i n c o m b i n a t i o n i n the c u r r e n t i n v e n t i o n . The filter is a s i n t e r e d m e t a l m e m b r a n e , w h i c h h a s the a d v a n t a g e of p o s s e s s i n g low outgassing properties combined with high s t r e n g t h a n d t e m p e r a t u r e r e s i s t a n c e . The i m p u r i t y - r e m o v i n g p a r t of the invention, conventionally known a s the 'getter', is a z i r c o n i u m - a l u m i n i u m or z i r c o n i u m - t i t a n i u m - n i c k e l alloy. It h a s the p r o p e r t y of b e i n g u n r e a c t i v e at a m b i e n t t e m p e r a t u r e , b e c a u s e it is coated with a layer of m e t a l oxides, b u t is reactive to gas i m p u r i t i e s at elevated t e m p e r a t u r e s . It m a y i n s t e a d b e c o m e reactive at a m b i e n t t e m p e r a t u r e s after a s e p a r a t e a c t i v a t i o n step. The s e q u e n c e of o p e r a t i o n s i n the f o r m a t i o n of a m e m b r a n e is: fine m e t a l Zr-Ti-Ni alloy powder, with average particle size less t h a n 20 m i c r o n s , is m i x e d w i t h a s u i t a b l e c a r r i e r s u c h a s nickel powder. T h e p o w d e r m i x t u r e is compressed in a mould, then s i n t e r e d u n d e r v a c u u m at 800°C for 20 m i n u t e s . T h e m e m b r a n e so formed is t h e n c o m p r e s s e d for a s e c o n d time, a n d a n o t h e r layer of powder m i x t u r e c a n be a d d e d a n d the p r o c e s s r e p e a t e d to b u i l d u p the t h i c k n e s s of t h e m e m b r a n e .
Patent number:. US 5 4 5 6 7 4 0 Date: 10th O c t o b e r 1995 Inventors: J.T, Snow, W. Plante, R.S. Zeller Applicant: Millipore C o r p o r a t i o n
Tritiumcontaining water Tritiated or s u p e r - h e a v y w a t e r (T20 or HTO) is a very m i n o r comp o n e n t of n o r m a l H 2 0 s u p p l i e s , but some water sources contain s i g n i f i c a n t q u a n t i t i e s of this m a t e rial. The m a i n s o u r c e is from cooling w a t e r from n u c l e a r power p l a n t s a n d n u c l e a r w e a p o n prod u c t i o n facilities; if this w a t e r is
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r e l e a s e d to the e n v i r o n m e n t it c a n m a k e its w a y into aquifers or s u r f a c e waters, m a k i n g t h e m u n fit for d r i n k i n g . T h e r e are p r o c e s s e s t h a t c a n selectively remove t r i t i u m from water, b u t they are energy-inefficient a n d r e q u i r e s i g n i f i c a n t u s e of chemicals. Battelle have f o u n d t h a t a polyphosphazene membrane, preferably a poly(diphenoxy) p o l y p h o s p h a z e n e c o n t a i n i n g u p to 30% of a p o l a r g r o u p s u b s t i t u t e , will selectively r e t a i n tritiated water. The p a t e n t also covers the s y n t h e t i c r o u t e u s e d i n the p r e p a r a t i o n of the p o l y m e r a n d its f o r m a t i o n into a m e m b r a n e . The o p e r a t i n g t e m p e r a t u r e is 3-4°C, i.e. w h e r e the w a t e r is d e n s e s t , a n d the o p e r a t i n g p r e s s u r e is 10-60 psi.
Patent number:. US 5 4 5 1 3 2 2 Date: 19th S e p t e m b e r 1995 Inventors: D.A. Nelson, J.B. D u n can, G.A. J e n s e n Applicant: Battelle Memorial Institute
Bioremediation aided by membrane
Porphyrin indicator membrane For u s e i n the d i a g n o s i s of m e t a bolic d i s e a s e s ( h y p e r t e n s i o n , r e n a l a n d cardiac insufficiency), this m e m b r a n e is c o n s t r u c t e d to act a s a n i n d i c a t o r for the p r e s ence of chloride i o n s i n b o d y fluids. The b a s i s of the m e m b r a n e is a p o l y m e r / p l a s t i c i s e r m i x t u r e , otherwise u n s p e c i f i e d , into w h i c h is i n c o r p o r a t e d a porp h y r i n / m a n g a n e s e complex. This is formed w h e n b e n z a l d e h y d e a n d a pyrrole are reacted, a n d the porp h y r i n p r o d u c t of t h a t r e a c t i o n is c o m b i n e d w i t h a l o n g - c h a i n glycerol, Finally, t h a t p o r p h y r i n is r e a c t e d with m a n g a n e s e dioxide to give a d a r k g r e e n c o l o u r e d m e m b r a n e w h i c h is s e n s i t i v e to chloride ions.
Patent number:. J P 7 2 3 3 1 8 2 Date: 5th S e p t e m b e r 1995 Inventor:. H. Yanagi, Y. M a t s u i Applicant: T o k u y a m a Corp.
Halogenated polyimide membranes
Volatile organic c o m p o u n d s (VOCs) s u c h as c h l o r i n a t e d solv e n t s are a n i m p o r t a n t group of p o l l u t a n t s . Existing b i o r e m e d i a tion t e c h n i q u e s u s e large b e d s or tanks containing microorganisms or p l a n t s w h i c h c a n m e t a b o l i s e a n d d e s t r o y t h e s e m a t e r i a l s , This i n v e n t i o n r e d u c e s the v o l u m e of s u c h s y s t e m s . It e m p l o y s a hollow-fibre or envelope m e m b r a n e to s e p a r a t e the V O C - c o n t a i n i n g s t r e a m from the biological system. The VOCs diffuse a c r o s s the m e m b r a n e into the biological system, rather t h a n being added via a b u b b l e r , biofilter or other t r a n s f e r m e a n s , so t h a t they are t a k e n into solution. The m e m b r a n e c a n also be selected to hold back c o m p o u n d s that would damage the o p e r a t i o n of the b i o r e m e d i a t i o n system.
The s t a r t i n g p o i n t i n the p r e p a r a tion of this m e m b r a n e is a n o n - p o r o u s film of polyimide. The film is c o n t a c t e d with c h l o r i n e gas or b r o m i n e v a p o u r so t h a t s u r f a c e layer of the modified film contains 0.01-1.2 halogen atoms per c a r b o n a t o m . A n o t h e r a l t e r n a tive cited i n t h e p a t e n t is t h a t the h a l o g e n a t i o n t a k e s place u n d e r plasma-generating conditions. The specific c h a r a c t e r i s t i c of this m e m b r a n e is its h i g h o x y g e n / n i t r o g e n s e p a r a t i o n factor c o m b i n e d w i t h a c l a i m e d high t r a n s m i s s i o n c a p a c i t y for h y d r o g e n a n d c a r b o n dioxide. It w o u l d also find a p p l i c a t i o n in c a r b o n dioxide recovery from flue gases.
Patent number:. WO 9 5 2 6 8 0 6 Date: 12th October 1995 Inventors: A. Livingston, L.M. Freitas do S a n t o s Applicant: Imperial College of Science, T e c h n o l o g y a n d Medicine
Patent number:. J P 7 2 3 6 8 2 2 Date: 12th S e p t e m b e r 1995 Inventors: M. T a k a t a k e , T. S u g a n u m a , T. A n a z a w a Applicant: D a i n i p p o n I n k a n d C h e m i c a l s Inc.
M e m b r a n e T e c h n o l o g y No. 72
Patent number:. US 5 4 5 6 7 4 0 Date: 10th O c t o b e r 1995 Inventors: J.T, Snow, W. Plante, R.S. Zeller Applicant: Millipore C o r p o r a t i o n
Tritiumcontaining water Tritiated or s u p e r - h e a v y w a t e r (T20 or HTO) is a very m i n o r comp o n e n t of n o r m a l H 2 0 s u p p l i e s , but some water sources contain s i g n i f i c a n t q u a n t i t i e s of this m a t e rial. The m a i n s o u r c e is from cooling w a t e r from n u c l e a r power p l a n t s a n d n u c l e a r w e a p o n prod u c t i o n facilities; if this w a t e r is
10
r e l e a s e d to the e n v i r o n m e n t it c a n m a k e its w a y into aquifers or s u r f a c e waters, m a k i n g t h e m u n fit for d r i n k i n g . T h e r e are p r o c e s s e s t h a t c a n selectively remove t r i t i u m from water, b u t they are energy-inefficient a n d r e q u i r e s i g n i f i c a n t u s e of chemicals. Battelle have f o u n d t h a t a polyphosphazene membrane, preferably a poly(diphenoxy) p o l y p h o s p h a z e n e c o n t a i n i n g u p to 30% of a p o l a r g r o u p s u b s t i t u t e , will selectively r e t a i n tritiated water. The p a t e n t also covers the s y n t h e t i c r o u t e u s e d i n the p r e p a r a t i o n of the p o l y m e r a n d its f o r m a t i o n into a m e m b r a n e . The o p e r a t i n g t e m p e r a t u r e is 3-4°C, i.e. w h e r e the w a t e r is d e n s e s t , a n d the o p e r a t i n g p r e s s u r e is 10-60 psi.
Patent number:. US 5 4 5 1 3 2 2 Date: 19th S e p t e m b e r 1995 Inventors: D.A. Nelson, J.B. D u n can, G.A. J e n s e n Applicant: Battelle Memorial Institute
Bioremediation aided by membrane
Porphyrin indicator membrane For u s e i n the d i a g n o s i s of m e t a bolic d i s e a s e s ( h y p e r t e n s i o n , r e n a l a n d cardiac insufficiency), this m e m b r a n e is c o n s t r u c t e d to act a s a n i n d i c a t o r for the p r e s ence of chloride i o n s i n b o d y fluids. The b a s i s of the m e m b r a n e is a p o l y m e r / p l a s t i c i s e r m i x t u r e , otherwise u n s p e c i f i e d , into w h i c h is i n c o r p o r a t e d a porp h y r i n / m a n g a n e s e complex. This is formed w h e n b e n z a l d e h y d e a n d a pyrrole are reacted, a n d the porp h y r i n p r o d u c t of t h a t r e a c t i o n is c o m b i n e d w i t h a l o n g - c h a i n glycerol, Finally, t h a t p o r p h y r i n is r e a c t e d with m a n g a n e s e dioxide to give a d a r k g r e e n c o l o u r e d m e m b r a n e w h i c h is s e n s i t i v e to chloride ions.
Patent number:. J P 7 2 3 3 1 8 2 Date: 5th S e p t e m b e r 1995 Inventor:. H. Yanagi, Y. M a t s u i Applicant: T o k u y a m a Corp.
Halogenated polyimide membranes
Volatile organic c o m p o u n d s (VOCs) s u c h as c h l o r i n a t e d solv e n t s are a n i m p o r t a n t group of p o l l u t a n t s . Existing b i o r e m e d i a tion t e c h n i q u e s u s e large b e d s or tanks containing microorganisms or p l a n t s w h i c h c a n m e t a b o l i s e a n d d e s t r o y t h e s e m a t e r i a l s , This i n v e n t i o n r e d u c e s the v o l u m e of s u c h s y s t e m s . It e m p l o y s a hollow-fibre or envelope m e m b r a n e to s e p a r a t e the V O C - c o n t a i n i n g s t r e a m from the biological system. The VOCs diffuse a c r o s s the m e m b r a n e into the biological system, rather t h a n being added via a b u b b l e r , biofilter or other t r a n s f e r m e a n s , so t h a t they are t a k e n into solution. The m e m b r a n e c a n also be selected to hold back c o m p o u n d s that would damage the o p e r a t i o n of the b i o r e m e d i a t i o n system.
The s t a r t i n g p o i n t i n the p r e p a r a tion of this m e m b r a n e is a n o n - p o r o u s film of polyimide. The film is c o n t a c t e d with c h l o r i n e gas or b r o m i n e v a p o u r so t h a t s u r f a c e layer of the modified film contains 0.01-1.2 halogen atoms per c a r b o n a t o m . A n o t h e r a l t e r n a tive cited i n t h e p a t e n t is t h a t the h a l o g e n a t i o n t a k e s place u n d e r plasma-generating conditions. The specific c h a r a c t e r i s t i c of this m e m b r a n e is its h i g h o x y g e n / n i t r o g e n s e p a r a t i o n factor c o m b i n e d w i t h a c l a i m e d high t r a n s m i s s i o n c a p a c i t y for h y d r o g e n a n d c a r b o n dioxide. It w o u l d also find a p p l i c a t i o n in c a r b o n dioxide recovery from flue gases.
Patent number:. WO 9 5 2 6 8 0 6 Date: 12th October 1995 Inventors: A. Livingston, L.M. Freitas do S a n t o s Applicant: Imperial College of Science, T e c h n o l o g y a n d Medicine
Patent number:. J P 7 2 3 6 8 2 2 Date: 12th S e p t e m b e r 1995 Inventors: M. T a k a t a k e , T. S u g a n u m a , T. A n a z a w a Applicant: D a i n i p p o n I n k a n d C h e m i c a l s Inc.
M e m b r a n e T e c h n o l o g y No. 72