I I II III II

P a t e n t s

Artificial lung membrane and device A composi te m e m b r a n e which avoids blood p l a s m a leakage, ma in ta ins hepa r in act ion a n d which does not suffer loss of the coating even after prolonged u s e is the object of th is invention. The bas is is a hydrophobic polyoleflnlc m e m b r a n e to which fine part icles are a t t ached within the m e m b r a n e ' s pores. The part icles are more hydrophflic t h a n is the basic m e m b r a n e : they are m a d e of a n acrylic polymer such as polymethyl methacryla te . Their a t t r ibu tes also include blocompatibflity, which can be expressed a s the proper ty of nei ther an tsgonls~ig the i m m u n e sys tem of the body nor of degrading blood ceils or p lasma .

Membrane th ickness is 5 -80 microns, porosi ty is 20--80% and average pore d iameter is 0 .01-5 microns. The hydrophflic part icles ' average size is smal ler t han tha t of the m e m b r a n e ' s pores. They are fixed in posi t ion either by part ial ly coat ing with a funct ional res in (JP 4033661) or by par t ly dissolving t h e m in acetone, then evaporating the solvent (JP 4033660}.

Patent numbers: J P 4033660, 4033661 Date: 5 Februa ry 1992 Inventor: K. Yokoyama AppllcanL. Tertuno Corporat ion

oxygen permeabi l i ty by two orders of magni tude , compared to complexes not containing cobalt.

Patent number: EP 475053 Date: 18 March 1992 Inventors: E. Tsuchida, H. Nishide, H. Kawakami, Y. S a s a m e Applicant.. Union Carbide Indus~ ia l Gases Technology Corp

Capsule for drinks packaging Milk and fruit Juice are often sold m polythene-llned or waxed cardboard packs. The packs themselves are sealed a n d therefore not open to the a tmosphere , bu t the packaging mater ia l m a y be pe rmeab le to oxygen. More problematically, the design of some packs m a y require free space above the liquid, which space will initially be occupied b y air. The oxygen content of the air can lead to spoilage or 'off f lavours developing in the bu lk liquid. The effect on wine in a pa r t ly -drunk bott le follows from the s ame reason.

The effects of the oxygen are directly proport ional to the quant i ty present . If the p res su re in the container is reduced, as when us ing a h a n d v a c u u m p u m p to remove m o s t of the air f rom a bott le of wine, then the wine survives (perhaps a t the cost of sacrificing some of the bouquet). If the air is purged by replacing it with nitrogen, which is a technique tha t c a n be u sed for wine, milk or frult-Juice, then

m/~Imal, bu t spotlage s ta r t s as soon a s the package is opened.

The p resen t invention consis ts of a .q~nall buoyan t cyiindrlcal capsule which c a n float in the a l r - space of a milk or fruit-Juice package. It h a s a weighted base of acetal resin, so th_e_t the other face is consis tent ly u p p e r m o s t a n d extends above the liquid level. The body of the capsule is impermeable , b u t the top face is covered b y a gas -permeab le b u t l iquid-resis tant m e m b r a n e of polyethylene or the du Pont mater ia l Tyvek. Inside the capsule is a n~Ixture of iron filings, dry silica gel a n d silica gel which h a s been impregna ted with a sodium ch/orlde solution. This mixture is a n effic/ent abso rben t of oxygen, and h a s the a t t r ibu te of not reac t ing ins tan t ly with the air: the d ry sWca gel inhibits the react ion by keeping the relative hum/d l ty in the _mA~s of the mix tu re a t a low level. This allows the mix tu re to be packed into the capsu les wi thout significant deterioration, after which the capsu les can be sealed and then kept f resh a lmos t indefinitely before be ing u n w r a p p e d and placed into a carton of mlik or fruit Juice. The scale of the canis ter relative to the car ton of milk or frui t Juice can be seen in the Figure. The capsule can also be inser ted in a par t - fu l /bo t t le of wine, to prevent or delay its oxidation.

Patent number: US 5092914 Date: 3 March 1 9 9 2 Inventors: J.S. Cullen, S.A. Incorvla App/Ican~ Multiform Desiccants,

Oxygen-selective ..eg eo, membrane Transi t ion meta l complexes a re known as componen t s of efficient and effective m e m b r a n e s for the selective pa s sage of oxygen. These new m e m b r a n e s conta in t ransi t ion meta l ions in oxidation s ta te If, preferably cobalt. The l igand can be a porphyrin , a Schiff base , a cyclidene or an amine-l ike m**crocycle. Also p resen t is an a romat ic amine. One preferred porphyr in is meso- te t rak is (alpha-O-pival- amidophenyl}porphyrinato or PPP.

The t ransi t ion meta l Improves the Oxygen-absorblng capsule for drink packaging

m , ,

Membrane Technology No. 28 11