Membranes Chemical Company

Other perfluorinated ionomer membranes, chemically very similar to Nafion, are also available commercially. Aciplex, manufactured by the Asahi Chemical Company, is very similar to Nafion, except that it has perfluoropropanesulfonic acid side chains. Flemion (Asahi Glass Company), in contrast, possesses perfluorobutanoic acid functions. 

Such new RP-HPLC stationary-phase materials have been available for some years (Regis Chemical Company, Morton Grove, IL, USA). These so-called immobilized artificial membrane (IAM) columns consist of lipid molecules covalently bound to propylamine-silica. The unreacted propylamine moieties are end-capped with methylglycolate. The membrane lipid, phosphatidylcholine, possesses polar head groups and two non-polar hydrocarbon chains (C18). One of the alkyl chains is linked to the propylamine-silica surface. 

FT-30 membrane patented and assigned to FilmTec (now owned by Dow Chemical Company, Midland, MI). 

Dow Chemical Company, FUmTec Reverse Osmosis Membranes Technical Manual, Form no. 609-00071-0705, Dow Liquid Separations, 2007. 

Dow Water Solutions, "FilmTec Membranes Factors Affecting RO Membrane Performance," Dow Chemical Company, form number 609-00055-498XQRP, 1998. 

CORRS [C02 Onsite Recovery and Recycling System] A process for recovering carbon dioxide from gas mixtures containing >8% C02 by diffusion through a selective Generon membrane. Offered by the Messer Group, based on technology developed by the Dow Chemical Company. 

Generon Not a process, but a trademark used by BOC and Dow to designate their processes for separating nitrogen from air by either the PSA process or a membrane process. The PSA process is based on the Bergbau-Forschung process. The membrane process uses the GENERON HP membrane developed by the Dow Chemical Company. See also NOVOX. 

Polymer Membranes - Materials, Structures and Separation Performance, T. deV. Naylor, The Smart Chemical Company. 

Standard sample stages (stainless steel) were masked and sprayed with an aerosol adhesive. After evaporation of residual solvent the membrane spots were affixed with gentle pressure. All protein samples were acquired from Sigma Chemical Company (St. Louis, MO) and were used without further purification. 

The inorganic silica membranes, also commercial, have solved the problem of thermal and chemical stability however, these membranes are only used for dehydration purposes, leaving the problem of separation of organic mixtures unsolved. As we have seen previously, due to the versatility and special feamres of zeolites, new applications in pervaporation that are not possible with other membranes could be developed with zeolite membranes. GaUego-Lizon et al. [110] compared different types of commercial available membranes zeolite NaA from SMART Chemical Company Ltd., sUica (PERVAP SMS) and polymeric (PERVAP 2202 and PERVAP 2510) both from Sulzer Chemtech GmbH, for the pervaporation of water/f-butanol mixtures. The highest water flux was obtained with the silica membrane (3.5 kg/m h) while the zeolite membrane exhibited the highest selectivity (16,000). 

The reaction products, then, remain in place and slow down further approach of the fluids to the surface of the membrane. Thus a membrane lining material that is unacceptable when exposed directly to the fluids may become acceptable by the interposition of a brick lining. A large chemical company has for years been able to protect rubber lined steel tanks from damage... 

Lise Dahuron, Ph.D. Sr. Research Specialist, The Dow Chemical Company (Liquid Density, Viscosity, and Interfacial Tension Liquid-Liquid Dispersion Fundamentals Liquid-Liquid Phase Separation Equipment Membrane-Based Processes)... 

A membrane designated "Solrox" made by Sumitomo Chemical Company is closely related to the above plasma polymerized composite membranes. A 1980 report by T. Sano described the Sumitomo process (31). A support film was cast from a polyacrylonitrile copolymer containing at least 40 mole percent acrylonitrile. The support film was dried and exposed to a helium or hydrogen plasma to form a tight cross-linked surface skin on the porous polyacrylonitrile support film. Data in a U.S. Patent issued in 1979 to Sano et al showed that the unmodified support film had a water flux of 87 gfd (145 L/ sq m/hr) at 142 psi (10 kg/sq cm). After the plasma treatment a reverse osmosis test using 0.55 percent NaCl at 710 psi (4895 kPa) showed 10.5 gfd (17.5 L/sq m/hr) flux at 98.3 percent salt rejection (32). This membrane appears to fall between a conventional asymmetric membrane and a composite membrane. If the surface skin is only cross-linked, one might call it a modified asymmetric membrane. However, if the surface skin is substantially modified chemically to make it distinct from the bulk of the membrane it could be considered as a composite type. 

General Motors Allison Gas Turbine Division began work on a methanol-fueled 10-kilowatt Proton Exchange Membrane (PEM) fuel cell in conjunction with the Los Alamos National Laboratory, the Dow Chemical Company, and Ballard Power Systems, Inc. 

The Asahi Chemical Company of Japan has developed a perfluorocarboxylic acid membrane (54) (55) (56). It is reported to be formed from Nafion films wherein the SO3H groups on the cathode surface are split off and the adjacent CF2 groups thereafter oxidized to carboxylic acid groups. 

Figure 16. Power consumption of the Asahi Chemical Company membrane cell electrolyzer.

Based on Goetz s developments, the Lovell Chemical Company in Water-town, Massachusetts was awarded further contracts in 1952 to commercialize production. In 1954, the Lovell Chemical Company sold its membrane manufacturing facility to the newly organized Millipore Corporation. Other companies in both the United States and England then began to exploit the German technology base to manufacture membrane filters. 

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