Oxygen permeability applications

A large membrane pack of this type will act like an artificial gill, permitting a swimmer to breathe like a fish and remain submerged for much longer periods of time than are possible with scuba equipment. Speculative fiction has man returning to live in the seas, and this type of application may make it possible. Their application in spacecraft is obvious as a part of a continuously recycled air support system. The oxygen permeability of silicone materials is just one example of the selective permeability of plastics. 

The metal ion, e.g. Fe or Co, when in its lower oxidation state can share electron charge with the oxygen molecule adduct. Several iron and cobalt prophyrin derivatives and cobalt-Schiff bases show the necessary reversibility and rates for successful application [e.g. 23]. a, a, a", a" -weso-tetrakis[(o-piralamidophenyl)-po phinato] Co (II) has been complexed with 1-methylimidazole to make a complex (CoPIm) which, when mixed with polybutyl methacrylate gave oxygen permeabilities on the order of 10-9 sec-cm/(cm2-s-cmHg) with a selectivity of about 5 over nitrogen [23]. 

Examples of silicones in ophthalmic application have been described.5 1 However, some problems have been reported with the use of silicones in retinal tamponade.542 Silicones are widely used in contact lenses because of their unusually good oxygen permeability and bioinertness, but the need for novel materials continues. Low-modulus fluorosiloxane-based hydrogel lenses with a wide range of water content and high-oxygen permeability have been described in a number of papers.543-... 

Cross-linked versions of water-soluble polymers swollen in aqueous media are broadly referred to as hydrogels and have a growing commercial utility in such applications as oxygen-permeable soft contact lenses and... 

The conventional PSP consists of sensor probe molecules contained in a transparent oxygen-permeable polymer film matrix (Fig. 3). The oxygen molecules permeate into the polymer film matrix by diffusion. In contrast, PSP consists of sensor molecules directly adsorbed onto a substrate such as an anodic oxidized aluminum plate (Fig. 4). Thus, polymers and probes are important factors for PSP application. 

In optical applications, in addition to optical liber claddings, special optical adhesives matching refractive indexes of optical glass components based on fluorinated epoxyacrylates and epoxymethacrylates are used.29 Fluoroalkyl methacrylates are frequently incorporated as comonomers with siloxanyl methacrylates into contact lenses for the improvement of oxygen permeability.31... 

Soft and hard contact lenses with good oxygen permeability, optical clarity, flexibility, and biocompatibility dental composites denture linings surgical adhesives catheters and hydrophobic microporous membranes are examples of applications of fluorinated polyurethanes in the medical and dental fields.53... 

Oxide ion conductors have been extensively investigated for their applications in fuel cells, oxygen sensors, oxygen pumps, and oxygen permeable membranes [81-108], The ion conduction effect was discovered more than a century ago by Nernst in zirconia products [83,84], To use zirconia, it... 

Cross-linked versions of water-soluble polymers swollen in aqueous media are broadly referred to as hydrogels (52) and have a growing commercial utility in such applications as oxygen-permeable soft contact lenses (qv) (53) (Table 4) and controlled-release pharmaceutical drug delivery devices (54). Cross-linked PVP and selected copolymers fit this definition and are of interest because of the following structure/performance characteristics ... 

The only other metal that has received some serious attention for membrane reactor applications is Ag [14,38] which is permeable to oxygen. Ag has similar thermal/mechanical stability problem as Pd and in addition its oxygen permeability is orders of magnitude lower. 

The QSPR techniques developed for polymers in this book utilize connectivity indices as their principal set of descriptors of the topology of the repeat unit of a polymer. An extensive literature search prior to the publication of the first edidon of this book in 1993 had resulted in die finding of only two papers on the application of connectivity indices in a manner simple enough to be of practical utility in predicting industrially important properties (the dielectric constant [27] and the oxygen permeability [28]) of polymers. 

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