Polyphenylene oxide membrane

Matsuura, T. Reverse osmosis and nanofiltration by composite polyphenylene oxide membranes. In Polyphenylene Oxide and Modified Polyphenylene Oxide Membranes, Gas, Vapor and Liquid Separation Chowdhury, G., Kruczek, B., Matsuura, T., Eds. Kluwer Academic Boston, 2001 181-212. 

Plummer, C.W. Kimura, G. and LaConti, A.B. "Development of Sulfonated Polyphenylene Oxide Membranes for Reverse Osmosis",... 

After the initial work on asymmetric sulfonated polyphenylene oxide membranes, sulfonated polysulfone was subsequently examined by several research groups. However, the appearance of patents in 1973 and 1977 by Rhone-PoulencM 8S covering asymmetric membranes of sulfonated polysulfones appeared to dampen such research efforts. Also, a basic problem with sulfonated polysulfone was the fact that salt rejections fell rapidly when a critical level of sulfonation was exceeded, but water fluxes were too low until this sulfonation level was exceeded. 

G. Chowdhury, B. Kruczek, and T. Matsuura, editors. Polyphenylene oxide and modified polyphenylene oxide membranes gas, vapor and liquid separation. Kluwer Academic Publishers, Dordrecht, The Netherlands, 2001. 

G. A. Polotskaya, A. V. Penkova, and A. M. Toikka. Fullerene-containing polyphenylene oxide membranes for pervaporation. Desalination, 200(1-3) 400-402, November 2006. 

A number of woiks published recently concern the application of polymeric GS manbranes for separation of hydrogen isotopes, with particular consideration of tritium compounds (HT, HTO) [202-212]. For this purpose, membranes manufactured from glassy and amorphous polymers are applied, mainly polyimide and polycarbonate membranes, as well as polyphenylene oxide membranes assembled in modules of different configuration (e.g., McGeneron Inc., type B210 ... 

Hoehn HH (1985) Aromatic polyamide membranes. In Lloyd DR (ed) Materials science of synthetic membranes. ACS Symposium Series 269. American Chemical Society, Washington, DC, p 81 Matsuura T (2001) Reverse osmosis and nanofiltration by composite polyphenylene oxide membranes. In Chowdhury G, Kruczek B, Matsuura T (eds) Polyphenylene oxide and modified polyphenylene oxide membranes. Kluwer, Dordrecht, p 181... 

K. Ramya, B. Vishnupriya and K.S. Dhathathreyan, Methanol permeability studies on sulpho-nated polyphenylene oxide membrane for direct methanol fuel ceU, J. New Mater. Electrochem. 

The most frequently used unit of permeability coefficient is termed Barrer 1 Barrer = IxlO" cm (STP)xcmxcm xs" (cm Hg), where STP indicates the volume of the gas at standard temperature and pressure. In this chapter Barrer is used to characterize the permeability of polyphenylene oxides membranes. The conversion coefficient to SI units is as follows 1 Barrer = 3.35x10 molxmxm xs xPa. 

The experimental results on separation of the mixtures of light paraffins and olefins over polyphenylene oxides membranes revealed that the desired separation was achieved [35-37]. In separation of the mixture of methane, ethane and ethylene over the films of the copolymers, the permeability coefficients for ethylene were found to be up to ca. 4-fold higher than those for ethane (Table 4). 

Pressure-Driven Transient Separations of Gaseous Mixtures over Polyphenylene Oxides Membranes Diffusion in a Membrane as a Key to the Improved Selectivity... 

In conclusion, note that the inert spherical molecules of the noble gases are the ideal probes for investigations of the mechanism of gas transport in polymers. The experimental data show in particular that diffusion coefficients of gases in polyphenylene oxide membranes increase in sequence Dn2 E>xe, in line with the increase in kinetic diameters of the... 

This atypical permeability vs. pressure behavior is directly related to the transformations of the free volume structure (i.e. swelling and relaxation) of the polyphenylene oxide membrane. These aspects will be considered below in more detail. 

MECHANISM OF GAS PERMEATION AND INTRINSIC MICROPOROSITY OF POLYPHENYLENE OXIDES MEMBRANES... 

To clarify the issue of crystallinity for the case of gas transport through polyphenylene oxides membranes, XRD study was carried out for the series of polymers. The same samples were repeatedly analyzed over the period of several years. The XRD patterns of polyphenylene oxides shown in Figs. 10-12 revealed the following ... 

Intrinsic microporosity of polyphenylene oxides corresponds to the throat and cavity model, where a cavity may have several throats. Effective diameters of the pore throats are in the range of ca. 0.4 nm at 77 K, increasing up to ca. 0.5 nm as the temperature rises to ambient. At these temperatures the intrinsic micropores are accessible for the molecules of simple gases. Apparently it is through these micropores that the gas transport in the dense polyphenylene oxides membranes occurs, with pore throats playing a role of a size caliber for the molecular sieve effect that manifests itself in membrane separations of certain gaseous mixtures. 

Kruczek B, Matsuura T. Effect of metal substitution of high molecular weight sulfonated polyphenylene oxide membranes on their gas separation performance. J, Membrane Sci. 2000 167 203-216. 

ADVANCES IN THE DEVELOPMENT OF MODIFIED POLYPHENYLENE OXIDE MEMBRANES FOR GAS SEPARATION APPLICATIONS... 

REVERSE OSMOSIS AND NANOFILTRATION BY COMPOSITE POLYPHENYLENE OXIDE MEMBRANES... 

C.W. Plummer, G. Kimura and A.B. LaConti, Development of Sulfonated Polyphenylene Oxide Membrane for Reverse Osmosis. In Research and Development Progress Report 557, Office of Saline Water, United States Department of Interior, (1970). 

Plummer C. W., Kimura G., and La Conti A. B., Development of Sulfonated Polyphenylene Oxide Membranes for Reverse Osmosis, Office of Saline Water Research and Development Progress Report No. 551, General Electric Company, Lynn, Massachusetts, 1970. 

POLYPHENYLENE OXIDE AND MODIFIED POLYPHENYLENE OXIDE MEMBRANES GaSy Vapor and Liquid Separation... 

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