Amino acids I

Amino acids I

Patents Metallized pervaporation membrane The s u b j e c t of t h i s p a t e n t is a composite membrane which has pervaporation properties, althou...

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Patents

Metallized pervaporation membrane The s u b j e c t of t h i s p a t e n t is a composite membrane which has pervaporation properties, although these are described In one translation as perspiration abi]ity a n d i n a n o t h e r a s artificial sweating properties. The m a j o r c o m p o n e n t is a hydrophobic polymer such as p o l y u r e t h a n e or a p o l y u r e t h a n e polymethylmethacrylate-polyethyle n e glycol copolymer. T h e m i n o r c o m p o n e n t c a n b e m e t a l wires, of s t a i n l e s s steel, k a n t h a l , n i c h r o m e or o t h e r relatively u n r e a c t i v e m e t a l s , a n d 8--300 m i c r o n s diameter. An alternative material p r o p o s e d is a p o l y a m i d e or c a r b o n fibre p l a t e d w i t h a n unreactive metal such as nickel or p a l l a d i u m . The wire or fibre is c o n n e c t e d to a s o u r c e of electric current. The m e m b r a n e p o s s e s s e s a n e x t r e m e l y low p r e s s u r e difference, a n d h a s s t r e t c h a b i l i t y , flexibility a n d sweating characteristics very s i m i l a r to h u m a n s k i n .

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MetaUlzed pervaporatlon membrane

Defect-free ultrathin

membranes The 40 n m - t h i c k m e m b r a n e h a s a n o x y g e n / n i t r o g e n selectivity of more t h a n 6.0 a n d a permeability

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Patent number: WO 9 3 2 5 3 0 0 Date: 23 D e c e m b e r 1993 Inventors: C.R. M a r t i n , C. Liu Applicant: R e s e a r c h C o r p o r a t i o n

Amino acids II The p o l y m e r s t r u c t u r e o b t a i n e d b y c r o s s l i n k i n g p e p t i d e s or p r o t e i n s with a w a t e r - s o l u b l e epoxy c o m p o u n d a n d a cross]Inking agent c a n be r e g u l a t e d so t h a t m o s t of t h e a m i n o a c i d s h a v e t h e s a m e steric c o n f i g u r a t i o n . This p r o p e r t y l e a d s to its a p p l i c a t i o n i n the a c c o m p l i s h m e n t of a n o t h e r of the c l a s s i c a l l y difficult s e p a r a t i o n s , t h a t of r a c e m i c m i x t u r e s . A n o t h e r a p p l i c a t i o n is i n blood dialysis, w h e r e the m e m b r a n e s h o w s good biocompatibility. I n practice, the n a t u r a l a m i n o acid s e r i c i n is the f o u n d a t i o n o n w h i c h the m e m b r a n e is b a s e d : t h e e p o x y c o m p o u n d is diglycidyl e t h e r a n d the c r o s s l i n k i n g a g e n t is d i e t h y l e n e t r i a m i n e or glutaraldehyde.

Patent number: J P 5 3 4 5 1 1 7 Date: 27 D e c e m b e r 1993 Inventor: H. Y a m a d a Applicant: S e i r e n Co. Ltd

T e c h n o l o g i e s Inc.

A m i n o acids I

Patent number: J P 5 3 0 9 2 4 4 Date: 12 D e c e m b e r 1993 Inventor: T. I m a m u r a Applicant: K o m a t s u Ltd

porous membrane

coefficient to oxygen of m o r e t h a n 0 . 5 5 b a r r e r s . It is f o r m e d o n o n e s u r f a c e of a c a r r i e r s u c h a s microporous alumina, a fluoropolymer, a p o l y c a r b o n a t e or a polyolefin. The m o n o m e r u s e d to c r e a t e t h e u l t r a t h i n m e m b r a n e is selected from a s u b s t i t u t e d styrene, a methacrylate, a m o n o m e r c o n t a i n i n g a vinyl g r o u p , or a t e r p o l y m e r of divinylbenzene, ethylvinylbenzene a n d either s o d i u m s t y r e n e s u l p h o n a t e or vinyKerrocene. Ultraviolet light, with the aid of a p h o t o i n i t i a t o r c o m p o u n d , is u s e d to c r o s s l i n k the m o n o m e r . P h o t o p o l y m e r i z a t i o n is n o t new, b u t o n e of t h e n o v e l t i e s of the p a t e n t is t h a t t h e light s t r i k e s the s u r f a c e a t a s m a l l a c u t e a n g l e of l e s s t h a n 3 0 °. I n t h i s w a y the m e m b r a n e is k e p t t h i n b e c a u s e t h e UV light p e n e t r a t e s t h e c a r r i e r m e m b r a n e l e s s t h a n if t h e i n c i d e n t a n g l e were 90 °.

A p e r v a p o r a t i o n m e m b r a n e , if d e s i g n e d to p a s s w a t e r m o l e c u l e s , s h o u l d h a v e a large n u m b e r of n e u t r a l polar f u n c t i o n a l g r o u p s w h i c h c a n form h y d r o g e n b o n d s w i t h t h e water. A m e m b r a n e c o n t a i n i n g a h i g h p r o p o r t i o n of certain amino acids a s p a r a g i n e , cysteine, g l u t a m i n e , s e r i n e , t h r e o n i n e or t y r o s i n e - fulfils t h i s r e q u i r e m e n t . The a m i n o acids, i n the form of p e p t i d e s or p r o t e i n m o l e c u l e s , a r e p o l y m e r i z e d b y r e a c t i o n with acrylonitrile. The c h o s e n a p p l i c a t i o n is i n o n e of the s e p a r a t i o n s w h i c h are difficult to achieve b y c o n v e n t i o n a l m e a n s , t h a t of azeotropic m i x t u r e s .

Patent number: J P 5 3 4 5 1 1 8 Date: 2 7 D e c e m b e r 1993 Inventor: H. Y a m a d a Applicant: S e i r e n Co. Ltd

Polycyanoaryl ether membranes P o l y c y a n o a r y l e t h e r is c l a i m e d a s the b a s i s of a n e w g r o u p of m e m b r a n e m a t e r i a l s . The b a s i c s t r u c t u r e is

The m e m b r a n e s a r e m o s t s u i t e d to p e r v a p o r a t i o n a n d v a p o u r p e r m e a t i o n , a n d c a n also be u s e d a s a b a s e for c o m p o s i t e m e m b r a n e s u s e d i n reverse o s m o s i s , u l t r a f i l t r a t i o n , gas s e p a r a t i o n or p e r v a p o r a t l o n .

Patent number: J P 5 3 3 7 3 4 4 Date: 21 D e c e m b e r 1993 Inventor: K. M a g a r a Applicant: Daicel C h e m i c a l I n d u s t r i e s Ltd

M e m b r a n e T e c h n o l o g y No. 5 2