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New material for artificial lungs
iSSN 0 9 5 8 - 2 1 1 8
1994/10
An International Newsletter
Number 54
Membrane Technology N e w m a t e r i a l for artificial lungs The s p e c i a l p r o p e r t i e s of p o l y i m i d e h a v e b e e n h a r n e s s e d for u s e a s a n artificial l u n g m a t e r i a l b y a g r o u p from the Tokyo M e t r o p o l i t a n University, r e p o r t s
The Nlkkel Weekly. The g r o u p f a s h i o n e d p o l y i m i d e i n t o a t h i n m e m b r a n e that, it says, is e v e n m o r e effective t h a n silicon a n d p o l y p r o p y l e n e m a t e r i a l s a t r e m o v i n g c a r b o n dioxide from t h e blood. The m e m b r a n e also r e a d i l y a b s o r b s o x y g e n from the a t m o s p h e r e a n d d o e s n o t trigger b l o o d clotting, the r e s e a r c h e r s said. Polyimide h a s a n i n t e r n a l s t r u c t u r e t h a t e n a b l e s it to s e p a r a t e c e r t a i n gases. While t h i s p o i n t s to o b v i o u s a p p l i c a t i o n s i n m e d i c i n e , t h e m a t e r i a l p r o v e d difficult to u s e i n t h e p a s t b e c a u s e of p r o b l e m s p r o c e s s i n g it into ultra-thin sheets. The p o l y m e r r e s i s t s m e l t i n g a n d is very u n r e a c t i v e , e v e n i n solvents. I n fact, b e c a u s e of its h i g h r e s i s t a n c e to t h e r m a l s t r e s s , p o l y i m i d e r e s i n is u s e d to m a k e p a r t s for t h e r m a l c o m b u s t i o n e n g i n e s . The u n i v e r s i t y g r o u p u s e d a d e h y d r a t i n g a g e n t a n d relatively low t e m p e r a t u r e s of 7 0 - 8 0 ° C to o b t a i n s t r a i g h t c h a i n s of p o l y i m i d e w h i c h r e a d i l y m e l t i n a c e t o n e a n d o t h e r o r g a n i c s o l v e n t s . With t h e m e l t i n h a n d , the g r o u p c o u l d f a s h i o n a t h i n m e m b r a n e . In c r o s s - s e c t i o n , t h e p o l y l m i d e m e m b r a n e looks like a s p o n g e . The two o u t e r s u r f a c e s a r e a r o u n d 0.1 m i c r o n thick, a n d t h e i n t e r n a l s t r u c t u r e c o n s i s t s of n u m e r o u s p o r e s with d i a m e t e r s r a n g i n g b e t w e e n 2 and 3 microns. The r e s e a r c h e r s p l a n to c o n t i n u e to i m p r o v e t h e m a t e r i a l , w i t h t h e specific a i m of f u r t h e r r e d u c i n g t h e c h a n c e s of blood clotting.
A g r e e m e n t for fuel cell research ELSEVIER ADVANCED TECHNOLOGY
E n e r g y P a r t n e r s , T e x a s A&M U n i v e r s i t y , a n d S o u t h w e s t R e s e a r c h I n s t i t u t e i n t h e USA, h a v e s i g n e d
per i t e m . . . . No part of this publication may be reproduced, stored in a retrieval system, or transmittea .?y. any form or by a n y means, electronic, mechanical, photocopying, recordingor otherwise, without the prior permission of me puonsners, treaders In the U.S.A. - - please see special regulations lisled on back cover.)
@ 1 9 9 4 E l s e v i e r S c i e n c e Ltd., E n g l a n d . / 9 4 / $ 7 . 0 0
1994/10
An International Newsletter
Number 54
Membrane Technology N e w m a t e r i a l for artificial lungs The s p e c i a l p r o p e r t i e s of p o l y i m i d e h a v e b e e n h a r n e s s e d for u s e a s a n artificial l u n g m a t e r i a l b y a g r o u p from the Tokyo M e t r o p o l i t a n University, r e p o r t s
The Nlkkel Weekly. The g r o u p f a s h i o n e d p o l y i m i d e i n t o a t h i n m e m b r a n e that, it says, is e v e n m o r e effective t h a n silicon a n d p o l y p r o p y l e n e m a t e r i a l s a t r e m o v i n g c a r b o n dioxide from t h e blood. The m e m b r a n e also r e a d i l y a b s o r b s o x y g e n from the a t m o s p h e r e a n d d o e s n o t trigger b l o o d clotting, the r e s e a r c h e r s said. Polyimide h a s a n i n t e r n a l s t r u c t u r e t h a t e n a b l e s it to s e p a r a t e c e r t a i n gases. While t h i s p o i n t s to o b v i o u s a p p l i c a t i o n s i n m e d i c i n e , t h e m a t e r i a l p r o v e d difficult to u s e i n t h e p a s t b e c a u s e of p r o b l e m s p r o c e s s i n g it into ultra-thin sheets. The p o l y m e r r e s i s t s m e l t i n g a n d is very u n r e a c t i v e , e v e n i n solvents. I n fact, b e c a u s e of its h i g h r e s i s t a n c e to t h e r m a l s t r e s s , p o l y i m i d e r e s i n is u s e d to m a k e p a r t s for t h e r m a l c o m b u s t i o n e n g i n e s . The u n i v e r s i t y g r o u p u s e d a d e h y d r a t i n g a g e n t a n d relatively low t e m p e r a t u r e s of 7 0 - 8 0 ° C to o b t a i n s t r a i g h t c h a i n s of p o l y i m i d e w h i c h r e a d i l y m e l t i n a c e t o n e a n d o t h e r o r g a n i c s o l v e n t s . With t h e m e l t i n h a n d , the g r o u p c o u l d f a s h i o n a t h i n m e m b r a n e . In c r o s s - s e c t i o n , t h e p o l y l m i d e m e m b r a n e looks like a s p o n g e . The two o u t e r s u r f a c e s a r e a r o u n d 0.1 m i c r o n thick, a n d t h e i n t e r n a l s t r u c t u r e c o n s i s t s of n u m e r o u s p o r e s with d i a m e t e r s r a n g i n g b e t w e e n 2 and 3 microns. The r e s e a r c h e r s p l a n to c o n t i n u e to i m p r o v e t h e m a t e r i a l , w i t h t h e specific a i m of f u r t h e r r e d u c i n g t h e c h a n c e s of blood clotting.
A g r e e m e n t for fuel cell research ELSEVIER ADVANCED TECHNOLOGY
E n e r g y P a r t n e r s , T e x a s A&M U n i v e r s i t y , a n d S o u t h w e s t R e s e a r c h I n s t i t u t e i n t h e USA, h a v e s i g n e d
per i t e m . . . . No part of this publication may be reproduced, stored in a retrieval system, or transmittea .?y. any form or by a n y means, electronic, mechanical, photocopying, recordingor otherwise, without the prior permission of me puonsners, treaders In the U.S.A. - - please see special regulations lisled on back cover.)
@ 1 9 9 4 E l s e v i e r S c i e n c e Ltd., E n g l a n d . / 9 4 / $ 7 . 0 0