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Electroconvective liquid crystal membranes (ECLCMs)
Patents
Patents This is a list of r e c e n t l y p u b l i s h e d p a t e n t s covering d e s i g n s a n d inv e n t i o n s of r e l e v a n c e to s y n t h e t i c m e m b r a n e technology. W h e r e the s a m e device h a s b e e n p a t e n t e d i n several c o u n t r i e s , we n o r m a l l y give the British p a t e n t n u m b e r . If t h e r e is n o UK p a t e n t , we give the n u m b e r of a n E n g l i s h - l a n g u a g e p a t e n t , if o n e exists. The p a t e n t s list is compiled from i n t e r n a t i o n a l s o u r c e s b y BHR G r o u p ' s i n f o r m a t i o n service. The facility c a n also be u s e d to carry o u t retrospective p a t e n t s e a r c h e s - - to test the validity, novelty or i n f r i n g e m e n t of existing p a t e n t s or n e w ideas. BHR Group, Cranfield, Bedford MK43 OAJ, UK, will provide free estimates on request. C o u n t r i e s c a n be identified by the code in front of the n u m b e r as follows:
The J a p a n e s e P a t e n t Office 4-3 K a k s u m i g a s e k i 3 - c h o m e Chiyodaku, Tokyo 100, J a p a n
Relief-pattern filter discs
The u s e of m u l t i p l e layers of s t a c k e d filtration m a t e r i a l s , either in series or in parallel, is a feat u r e of m a n y s e p a r a t i o n devices. There are m a n y ways of s e p a r a t ing the i n d i v i d u a l leaves of the filter to e n s u r e effective fluid flow. This p a t e n t d e s c r i b e s the u s e of filter discs in w h i c h one or b o t h faces have a c r o s s - p a t t e r n textilelike relief p a t t e r n o n the discs. The p a t e n t claims the relief height of 0 . 2 5 - 4 m m , the projection length of 1-10 m m , a p a t t e r n c o u n t of 2 0 0 - 2 0 0 0 AU A u s t r a l i a AT A u s t r i a projections/cm2 and an angular BR Brazil BE B e l g i u m d i s p o s i t i o n of 10-75 degrees DD E a s t G e r m a n y CH S w i t z e r l a n d with r e s p e c t to the disc inlet DK D e n m a r k DE West G e r m a n y opening. The preferred v a l u e s EP E u r o p e a n P a t e n t s ES S p a i n w i t h i n this overall claim are FR F r a n c e FI F i n l a n d 0 . 5 - 2 . 0 m m high, 2-5 m m long, HU H u n g a r y GB B r i t a i n a nd an angular disposition IR Eire IL Israel of 2 5 - 4 5 °. JP Japan IT Italy LI L i e c h t e n s t e i n KP North Korea Patent number: EP 681861 NL N e t h e r l a n d s LU L u x e m b o u r g Date: 15th November 1995 NO Norway RO R o m a n i a US U n i t e d S t a t e s Inventors: K. Peters, RU R u s s i a WO World P a t e n t W. Hilgendorff, G. K a h n SE S w e d e n SU Soviet U n i o n (Patent T r e a t y Applicant: URT U m w e l t t e c h n i k Cooperation GmbH publication) BHR G r o u p does n o t o p e r a t e a d o c u m e n t delivery service for pate n t s , b u t full copies of the original p a t e n t d o c u m e n t s c a n be o b t a i n e d from the following addresses: The B r i t i s h Library P a t e n t E x p r e s s 25 S o u t h a m p t o n B u i l d i n g s L o n d o n WC2A lAW, UK Fax: 0171 323 7 2 3 0 (The B r i t i s h Library will also s u p ply a list of UK l i b r a r i e s i n c l u d e d i n the P a t e n t I n f o r m a t i o n Network.) US P a t e n t Office Scientific Library 15th a n d E a s t Streets, NW W a s h i n g t o n , DC 2 0 2 3 1 , USA
10
Variable length hollow fibre module A l t h o u g h the precise o p e r a t i n g circ u m s t a n c e s are n o t set out, the p a t e n t covers a h o u s i n g for hollow fibre m e m b r a n e s i n w h i c h the e n d p l a t e s w h i c h s e c u r e the fib r e s are movable. The d i s t a n c e b e t w e e n the two e n d plates c a n
be a d j u s t e d in o r d e r to a c c o m m o date fibres with a n e l o n g a t i o n ratio of 0.3-8%, a n d is a c c o m p l i s h e d by tie rod or t u r n b u c k l e a d j u s t m e n t . The effect of s o m e s o l v e n t s o n p o l y m e r s is to c a u s e t h e m to swell, so if the b u n d l e is to r e m a i n t a u t a n d the fibres rem a i n l i n e a r t h e n it is logical to take u p the s l a c k t h a t r e s u l t s from the e x p a n s i o n of the fibres w h e n wetted.
Patent number: J P 7 2 9 9 3 3 8 Date: 14th N o v e m b e r I 9 9 5 Inventor: M. S u g i m o t o Applicant: Daicel C h e m i c a l I n d u s t r i e s Ltd
Electroconvective liquid crystal membranes (ECLCMs) This p a t e n t is r e l a t e d to US pate n t 5 4 3 3 8 5 7 from the s a m e inventors, which has previously b e e n reported. The s e p a r a t i o n m e m b r a n e is a sandwich-like configuration; a liquid m e m b r a n e is c o n t a i n e d b e t w e e n two g a s - p e r m e a b l e electrodes. A n electric field generates electrohydrodynamic flow i n the layer a n d t h u s p r o m o t e s or i n h i b i t s diffusion of gases a c r o s s the m e m b r a n e . D o p a n t s c a n be a d d e d to the liquid layer, to act a s c a r r i e r s to the p a s s a g e of selected d i f f u s i n g species. The d o p a n t s c a n be c h e m i c a l l y b o n d e d to t h e active m o l e c u l e s i n the liquid layer, or c a n form a s e p a r a t e solid or liquid p h a s e . A c o m p l e x i n g a g e n t c a n be a d d e d to the liquid layer; it is electrolysed to high a n d low affinity redox s t a t e s i n o r d e r to s e p a r a t e different m o l e c u l a r species.
M e m b r a n e T e c h n o l o g y No. 74
Patents T h e const:.~tmlion o1 l h e ('ell a l l o w s tile l i q u i d n l e m b r a n e to resist differential pressures. The d i f l u s i m l of n i t r o g e n a n d m e t h a n e a c r o s s t h e m e m b r a n e is g r e a t l y accelerated when an alternating c~trrent e l e c t r i c field is i m p o s e d a c r o s s t h e l i q u i d layer. T h e s w i t c h a b h " c h m a c t e r i s t i c s of t h e i n e l n l ) r a n e a r e cl~/illled if) e x t e n d its s e p a r a t i o n c a p a b i l i t i e s a n d to r i v e a m u c h k~i~t~.er p o w e r - o n / power-off permeabilily than has s o lar h e e n a l l a i n c d . O n e previo~lsly t:,roposed c o m p o u n d s u i l a b l e lot t h i s a p p l i c a l i o n is N - 1 4 - n m t h o x y b e n z y l i d e n e ) ,1 b t l l y l a n i l i n c (MBBA). a l i q u i d c r y s l a l or nem~ttic i n a t e r i a l . W h e n u s e d a s l h c l i q u i d in l h e c e n t r a l v o l t m l e of n n el,-ct r o h v d r , ) d y n a m i c E C L C M ('ell. ~t (telllt)ns~ l-;ll e s elecl r() h y d r o d y n a m i c l],:)\v T h i s pate]~l extei-,ds l h e o p e r a l i o n of t h i s t e c n n i q u e to t h e u s e ~,l-polar s o l v e n t s s u c h a s 2 etl~ylhexan{)l a n d d i e t h v l p h t h a l a l e in ]~la,'v (~: M B B A in t h e EI.CI.M cell. TI~c i n v e n t o r s .~ive lwo ~ e a s o n s ft)l tl~e d e s i r a b i l i t y of t h i s step. ME,F,A is ~nore e x p e n s i v e l h a l i 1he lw() p o l a r s o l v c n l s , a n d it h a s a v e r y p o l a r (I=N /)Ol~d b e l \ v c c l l t h e two p h e n y l ring~, al tt,e l w a r l ol l h e m o l e c u l e . T h i s f o r m s a w e a k n e s s l}oln w h i t h m o i s t u r e ill t h e Iced ~as sIreaiill Cal~ ('~t~lSC h y d r o l y s i s a n d d e ~ l - ; l d a t i o n ,d tip." l q l e n l l ) r a l l e .
Palt nl m,mb,'r: t iS 5 4 4 1 6 3 c t l)at~ : 15ill A u ~ u s l ] .995 lm,cnlors:R.I) Noble. N.A. ( ' l a r k AppliccmI: R c a e n t s ,d lhc ( I / i \ e r ' q l v o l ( '(.](n+ado
to t h e l o r m a t i o n of a s e c o n d a W m e m b r a n e like l a y e r w h i c h re s u l t s in l h e m o l e c u l a r w e i g h t c u t o f f p o i n t of t h e m e m b r a n e b e i n g l o w e r e d . In t h e s e p a r a t i o n of w h e y p r o t e i n s f r o m m i l k or w h e y I b i s c a n b e o v e r c o m e by s p i n n i n g a d i s c c l o s c to t h e m e m b r a n e s u r face at 1000 3 4 5 0 r p m to ,~enerate a h i g h s h e a r force a c r o s s t h e m e m b r a n e surla.ce. T h i s p r e v e n t s l h e k ) r m a t i o n of t h e s e c o n d a r y layer. In a n c i t e d e x a m pie. two m e m b r a n e s of t h e s a m e material were compared, wilh and w i t h o u t a s p i n n i n ~ disc. T h e m e l n b r a n e w i t h a s p i n n i n g disc s h o w e d no b l i n d i n g to p r o t e i n s s u c h a s b e t a - l a c t o g l o b u l i n olr bovine serum albumin over a 6 hour lest, w h e r e a s t h e o t h e r m e r e b r a n e s h o w e d r e j e c t i o n s of 4 0 % l}}r boll1 p r o t e i n s a f t e r o n l y 5 m m
Paienl nttmber: U S 5 4 6 8 8 4 4 [)ale: 21 sl N o v e m b e r 1 9 9 5 11~venlor: P.Stnit h Applicant: P r o l o s e T e c h n o l o ~ g e s h~c.
Yarnsupported ceramic filter
S e p a r a t i n g p r o l c i n s l]-om s o l u tiOIlS u s i n K ll/enll)r.:llleS c a n l e a d
describes
M e m b r a n e T e c h n o l o g y No. 74
Patent nmnber: (JS 5 4 6 0 6 3 7 Date: 2 4 t h O c t o l m r 1 9 9 5 Inventors: E.S. C o n n o l l y . G.D. F o r s y t h e . Ci.P. R ~ t j e n d r a n Applican I: l)t i P( nit [.allxid e Composites t,.P
tiles.
t ; a s c h ' a n i n g at hit{h tempe;-a I l l r e s s u c h a s 8 0 0 (7 e m p l o y s c e r a m i c filters m a d e of a l u m i n o s i t i c a t e s , g l a s s e s or silicon c a r b i d e . T h e c l e a n i n g of t h e s e lnat e r i a l s by b a c k p u l s e llushi~q~ c a n c a u s e s t r u c t u r a l d a m a g e l,) t h e lil l e r il t h e t e m p e r a t u r e of t h e llushinK gas causes thermal s t r e s s e s m t h e filter m a t e r i a l . T h e liller l e n d s to be m a d e h e a v i e r t h a n is n e c e s s a r y to t W to Cotlnleract this tendency. This patent
Spinning disc filtration
c o n s t r u e l i o n in w h i c h a s u p p o r t is c o v e r e d by a m e m b r a n e . T h e s u p p o r t is m a d e of c c r a m i c o x i d e y a r n , w o u n d in ~ c r i s s - c r o s s lmann e r t o give s q / l a r e c r o s s - s e c t i o n p o r e s of 0.1 0 . 5 m m so t h a t i~ a c t s to c a p t u r e c o a r s e p a r t i c l e s . T h e m e m b r a n e l a y e r is f o r m e d of a n o t h e r l a y e r of van~. w o u n d ill a s i m i l a r m a n n e r Io l h c s u p p o r t , so t h a i in t h i s l a y e r t h e p o r e size is 0. 1 l 0 l l l i c r o n s . Yhe m e m b r a n e l a y e r is t h e n c o a t e d w i t h a n a l u m i n a s l u r ~ , d r i e d a n d fired.
a lightweight
alternative
Hydrophilic PTFE membranes T h e t r e a t m m t l (,1 t h e m a t e r i a l w h i c h r , ' n d e r s il h y d r o p h i l i e is a n initial h e a t l r e a t n l e J l l at t 7 0 ° C for 3 l l l i l l n l e s l o l l o w e d by i m m e r s i o n ill ;1 4()'!{~ s o l n t i o n ol p o t a s s i u m h y d r o x i d e for 10 ,days. T h i s c m l {il t h a i is [~ot s u f f i c i e n t ) h e l o l l o w e d b v ilmnersiop, in 3 0 % s u l p h u r W a c i d or {()% n i l r i c a c i d lot a n o l h e r 10 ~lav.'~ T h e p a t e n t a l s o c l a i m s lf!x' e x t ; n ste t, of f o r m in~ a v i n y l p y r i d i n e I)asect c r o s s - l i n k e d p o l y m u r i c l a v e r on l h e h y d r o p h i l i c Vq'FE m e m b r a n e . T h e a p p l i c a t i o n s of i h e m e m b r a n e a r e in m e d i c a l a n d l ) h a r n l a c e u t i cal s e p a r a t i o n s w h e r e l h e h i g h s u r l a c e e n e r e y ol l I i(' m e m b r a n e a r e tlsettfl iP~ dialysie; a n t i p r o t e i n sequencing.
Patent ,mmber: EP 6 8 2 9 7 8 Date: 2 2 n d N o v e n l b e r 1 9 9 5 Inventors: P.,]. l ) e ~ e n , J . Y . l . , e e Appliccmi: Pall Corp.
I1
Patents This is a list of r e c e n t l y p u b l i s h e d p a t e n t s covering d e s i g n s a n d inv e n t i o n s of r e l e v a n c e to s y n t h e t i c m e m b r a n e technology. W h e r e the s a m e device h a s b e e n p a t e n t e d i n several c o u n t r i e s , we n o r m a l l y give the British p a t e n t n u m b e r . If t h e r e is n o UK p a t e n t , we give the n u m b e r of a n E n g l i s h - l a n g u a g e p a t e n t , if o n e exists. The p a t e n t s list is compiled from i n t e r n a t i o n a l s o u r c e s b y BHR G r o u p ' s i n f o r m a t i o n service. The facility c a n also be u s e d to carry o u t retrospective p a t e n t s e a r c h e s - - to test the validity, novelty or i n f r i n g e m e n t of existing p a t e n t s or n e w ideas. BHR Group, Cranfield, Bedford MK43 OAJ, UK, will provide free estimates on request. C o u n t r i e s c a n be identified by the code in front of the n u m b e r as follows:
The J a p a n e s e P a t e n t Office 4-3 K a k s u m i g a s e k i 3 - c h o m e Chiyodaku, Tokyo 100, J a p a n
Relief-pattern filter discs
The u s e of m u l t i p l e layers of s t a c k e d filtration m a t e r i a l s , either in series or in parallel, is a feat u r e of m a n y s e p a r a t i o n devices. There are m a n y ways of s e p a r a t ing the i n d i v i d u a l leaves of the filter to e n s u r e effective fluid flow. This p a t e n t d e s c r i b e s the u s e of filter discs in w h i c h one or b o t h faces have a c r o s s - p a t t e r n textilelike relief p a t t e r n o n the discs. The p a t e n t claims the relief height of 0 . 2 5 - 4 m m , the projection length of 1-10 m m , a p a t t e r n c o u n t of 2 0 0 - 2 0 0 0 AU A u s t r a l i a AT A u s t r i a projections/cm2 and an angular BR Brazil BE B e l g i u m d i s p o s i t i o n of 10-75 degrees DD E a s t G e r m a n y CH S w i t z e r l a n d with r e s p e c t to the disc inlet DK D e n m a r k DE West G e r m a n y opening. The preferred v a l u e s EP E u r o p e a n P a t e n t s ES S p a i n w i t h i n this overall claim are FR F r a n c e FI F i n l a n d 0 . 5 - 2 . 0 m m high, 2-5 m m long, HU H u n g a r y GB B r i t a i n a nd an angular disposition IR Eire IL Israel of 2 5 - 4 5 °. JP Japan IT Italy LI L i e c h t e n s t e i n KP North Korea Patent number: EP 681861 NL N e t h e r l a n d s LU L u x e m b o u r g Date: 15th November 1995 NO Norway RO R o m a n i a US U n i t e d S t a t e s Inventors: K. Peters, RU R u s s i a WO World P a t e n t W. Hilgendorff, G. K a h n SE S w e d e n SU Soviet U n i o n (Patent T r e a t y Applicant: URT U m w e l t t e c h n i k Cooperation GmbH publication) BHR G r o u p does n o t o p e r a t e a d o c u m e n t delivery service for pate n t s , b u t full copies of the original p a t e n t d o c u m e n t s c a n be o b t a i n e d from the following addresses: The B r i t i s h Library P a t e n t E x p r e s s 25 S o u t h a m p t o n B u i l d i n g s L o n d o n WC2A lAW, UK Fax: 0171 323 7 2 3 0 (The B r i t i s h Library will also s u p ply a list of UK l i b r a r i e s i n c l u d e d i n the P a t e n t I n f o r m a t i o n Network.) US P a t e n t Office Scientific Library 15th a n d E a s t Streets, NW W a s h i n g t o n , DC 2 0 2 3 1 , USA
10
Variable length hollow fibre module A l t h o u g h the precise o p e r a t i n g circ u m s t a n c e s are n o t set out, the p a t e n t covers a h o u s i n g for hollow fibre m e m b r a n e s i n w h i c h the e n d p l a t e s w h i c h s e c u r e the fib r e s are movable. The d i s t a n c e b e t w e e n the two e n d plates c a n
be a d j u s t e d in o r d e r to a c c o m m o date fibres with a n e l o n g a t i o n ratio of 0.3-8%, a n d is a c c o m p l i s h e d by tie rod or t u r n b u c k l e a d j u s t m e n t . The effect of s o m e s o l v e n t s o n p o l y m e r s is to c a u s e t h e m to swell, so if the b u n d l e is to r e m a i n t a u t a n d the fibres rem a i n l i n e a r t h e n it is logical to take u p the s l a c k t h a t r e s u l t s from the e x p a n s i o n of the fibres w h e n wetted.
Patent number: J P 7 2 9 9 3 3 8 Date: 14th N o v e m b e r I 9 9 5 Inventor: M. S u g i m o t o Applicant: Daicel C h e m i c a l I n d u s t r i e s Ltd
Electroconvective liquid crystal membranes (ECLCMs) This p a t e n t is r e l a t e d to US pate n t 5 4 3 3 8 5 7 from the s a m e inventors, which has previously b e e n reported. The s e p a r a t i o n m e m b r a n e is a sandwich-like configuration; a liquid m e m b r a n e is c o n t a i n e d b e t w e e n two g a s - p e r m e a b l e electrodes. A n electric field generates electrohydrodynamic flow i n the layer a n d t h u s p r o m o t e s or i n h i b i t s diffusion of gases a c r o s s the m e m b r a n e . D o p a n t s c a n be a d d e d to the liquid layer, to act a s c a r r i e r s to the p a s s a g e of selected d i f f u s i n g species. The d o p a n t s c a n be c h e m i c a l l y b o n d e d to t h e active m o l e c u l e s i n the liquid layer, or c a n form a s e p a r a t e solid or liquid p h a s e . A c o m p l e x i n g a g e n t c a n be a d d e d to the liquid layer; it is electrolysed to high a n d low affinity redox s t a t e s i n o r d e r to s e p a r a t e different m o l e c u l a r species.
M e m b r a n e T e c h n o l o g y No. 74
Patents T h e const:.~tmlion o1 l h e ('ell a l l o w s tile l i q u i d n l e m b r a n e to resist differential pressures. The d i f l u s i m l of n i t r o g e n a n d m e t h a n e a c r o s s t h e m e m b r a n e is g r e a t l y accelerated when an alternating c~trrent e l e c t r i c field is i m p o s e d a c r o s s t h e l i q u i d layer. T h e s w i t c h a b h " c h m a c t e r i s t i c s of t h e i n e l n l ) r a n e a r e cl~/illled if) e x t e n d its s e p a r a t i o n c a p a b i l i t i e s a n d to r i v e a m u c h k~i~t~.er p o w e r - o n / power-off permeabilily than has s o lar h e e n a l l a i n c d . O n e previo~lsly t:,roposed c o m p o u n d s u i l a b l e lot t h i s a p p l i c a l i o n is N - 1 4 - n m t h o x y b e n z y l i d e n e ) ,1 b t l l y l a n i l i n c (MBBA). a l i q u i d c r y s l a l or nem~ttic i n a t e r i a l . W h e n u s e d a s l h c l i q u i d in l h e c e n t r a l v o l t m l e of n n el,-ct r o h v d r , ) d y n a m i c E C L C M ('ell. ~t (telllt)ns~ l-;ll e s elecl r() h y d r o d y n a m i c l],:)\v T h i s pate]~l extei-,ds l h e o p e r a l i o n of t h i s t e c n n i q u e to t h e u s e ~,l-polar s o l v e n t s s u c h a s 2 etl~ylhexan{)l a n d d i e t h v l p h t h a l a l e in ]~la,'v (~: M B B A in t h e EI.CI.M cell. TI~c i n v e n t o r s .~ive lwo ~ e a s o n s ft)l tl~e d e s i r a b i l i t y of t h i s step. ME,F,A is ~nore e x p e n s i v e l h a l i 1he lw() p o l a r s o l v c n l s , a n d it h a s a v e r y p o l a r (I=N /)Ol~d b e l \ v c c l l t h e two p h e n y l ring~, al tt,e l w a r l ol l h e m o l e c u l e . T h i s f o r m s a w e a k n e s s l}oln w h i t h m o i s t u r e ill t h e Iced ~as sIreaiill Cal~ ('~t~lSC h y d r o l y s i s a n d d e ~ l - ; l d a t i o n ,d tip." l q l e n l l ) r a l l e .
Palt nl m,mb,'r: t iS 5 4 4 1 6 3 c t l)at~ : 15ill A u ~ u s l ] .995 lm,cnlors:R.I) Noble. N.A. ( ' l a r k AppliccmI: R c a e n t s ,d lhc ( I / i \ e r ' q l v o l ( '(.](n+ado
to t h e l o r m a t i o n of a s e c o n d a W m e m b r a n e like l a y e r w h i c h re s u l t s in l h e m o l e c u l a r w e i g h t c u t o f f p o i n t of t h e m e m b r a n e b e i n g l o w e r e d . In t h e s e p a r a t i o n of w h e y p r o t e i n s f r o m m i l k or w h e y I b i s c a n b e o v e r c o m e by s p i n n i n g a d i s c c l o s c to t h e m e m b r a n e s u r face at 1000 3 4 5 0 r p m to ,~enerate a h i g h s h e a r force a c r o s s t h e m e m b r a n e surla.ce. T h i s p r e v e n t s l h e k ) r m a t i o n of t h e s e c o n d a r y layer. In a n c i t e d e x a m pie. two m e m b r a n e s of t h e s a m e material were compared, wilh and w i t h o u t a s p i n n i n ~ disc. T h e m e l n b r a n e w i t h a s p i n n i n g disc s h o w e d no b l i n d i n g to p r o t e i n s s u c h a s b e t a - l a c t o g l o b u l i n olr bovine serum albumin over a 6 hour lest, w h e r e a s t h e o t h e r m e r e b r a n e s h o w e d r e j e c t i o n s of 4 0 % l}}r boll1 p r o t e i n s a f t e r o n l y 5 m m
Paienl nttmber: U S 5 4 6 8 8 4 4 [)ale: 21 sl N o v e m b e r 1 9 9 5 11~venlor: P.Stnit h Applicant: P r o l o s e T e c h n o l o ~ g e s h~c.
Yarnsupported ceramic filter
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M e m b r a n e T e c h n o l o g y No. 74
Patent nmnber: (JS 5 4 6 0 6 3 7 Date: 2 4 t h O c t o l m r 1 9 9 5 Inventors: E.S. C o n n o l l y . G.D. F o r s y t h e . Ci.P. R ~ t j e n d r a n Applican I: l)t i P( nit [.allxid e Composites t,.P
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t ; a s c h ' a n i n g at hit{h tempe;-a I l l r e s s u c h a s 8 0 0 (7 e m p l o y s c e r a m i c filters m a d e of a l u m i n o s i t i c a t e s , g l a s s e s or silicon c a r b i d e . T h e c l e a n i n g of t h e s e lnat e r i a l s by b a c k p u l s e llushi~q~ c a n c a u s e s t r u c t u r a l d a m a g e l,) t h e lil l e r il t h e t e m p e r a t u r e of t h e llushinK gas causes thermal s t r e s s e s m t h e filter m a t e r i a l . T h e liller l e n d s to be m a d e h e a v i e r t h a n is n e c e s s a r y to t W to Cotlnleract this tendency. This patent
Spinning disc filtration
c o n s t r u e l i o n in w h i c h a s u p p o r t is c o v e r e d by a m e m b r a n e . T h e s u p p o r t is m a d e of c c r a m i c o x i d e y a r n , w o u n d in ~ c r i s s - c r o s s lmann e r t o give s q / l a r e c r o s s - s e c t i o n p o r e s of 0.1 0 . 5 m m so t h a t i~ a c t s to c a p t u r e c o a r s e p a r t i c l e s . T h e m e m b r a n e l a y e r is f o r m e d of a n o t h e r l a y e r of van~. w o u n d ill a s i m i l a r m a n n e r Io l h c s u p p o r t , so t h a i in t h i s l a y e r t h e p o r e size is 0. 1 l 0 l l l i c r o n s . Yhe m e m b r a n e l a y e r is t h e n c o a t e d w i t h a n a l u m i n a s l u r ~ , d r i e d a n d fired.
a lightweight
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Hydrophilic PTFE membranes T h e t r e a t m m t l (,1 t h e m a t e r i a l w h i c h r , ' n d e r s il h y d r o p h i l i e is a n initial h e a t l r e a t n l e J l l at t 7 0 ° C for 3 l l l i l l n l e s l o l l o w e d by i m m e r s i o n ill ;1 4()'!{~ s o l n t i o n ol p o t a s s i u m h y d r o x i d e for 10 ,days. T h i s c m l {il t h a i is [~ot s u f f i c i e n t ) h e l o l l o w e d b v ilmnersiop, in 3 0 % s u l p h u r W a c i d or {()% n i l r i c a c i d lot a n o l h e r 10 ~lav.'~ T h e p a t e n t a l s o c l a i m s lf!x' e x t ; n ste t, of f o r m in~ a v i n y l p y r i d i n e I)asect c r o s s - l i n k e d p o l y m u r i c l a v e r on l h e h y d r o p h i l i c Vq'FE m e m b r a n e . T h e a p p l i c a t i o n s of i h e m e m b r a n e a r e in m e d i c a l a n d l ) h a r n l a c e u t i cal s e p a r a t i o n s w h e r e l h e h i g h s u r l a c e e n e r e y ol l I i(' m e m b r a n e a r e tlsettfl iP~ dialysie; a n t i p r o t e i n sequencing.
Patent ,mmber: EP 6 8 2 9 7 8 Date: 2 2 n d N o v e n l b e r 1 9 9 5 Inventors: P.,]. l ) e ~ e n , J . Y . l . , e e Appliccmi: Pall Corp.
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