Polymer-based membranes

Basically, three kinds of membranes are being studied inorganic oxide membranes, polymer-based membranes, and metal and metal alloy membranes. Some combinations of these are also used, such as impregnating inorganic oxide membranes with catalytic materials. A key term in this held is permselective membrane, which is a thin material that can allow a certain component of a mixture, but not other components, to pass through (or permeate) from one side to the other. 

Poor adhesion of membrane to metal is the leading cause of failure in solid-state potentiometric sensors [116], For glass membranes, the mismatch of thermal coefficients of expansion between thin glass membrane and metal (mostly Pt) has been attributed to premature failure due to hairline crack formations in the glass layer [60], For polymer-based membranes, water vapor penetration was reported to compromise the membrane-metal interface, therefore affecting the sensor s performance. 

In contrast, in most ion-selective membranes the charge conduction is done by ions. Thus, a mismatch between the charge-transfer carriers can exist at the noble metal/membrane interface. This is particularly true for polymer-based membranes, which are invariably ionic conductors. On the other hand, solid-state membranes that exhibit mixed ionic and electronic conductivity such as chalcogenide glasses, perovskites, and silver halides and conducting polymers (Lewenstam and Hulanicky, 1990) form good contact with noble metals. 

Molecular Modeling, A Tool for the Knowledge-Based Design of Polymer-Based Membrane Materials... 

Most important macroscopic transport properties (i.e., permeabilities, solubilities, constants of diffusion) of polymer-based membranes have their foundation in microscopic features (e.g., free-volume distribution, segmental dynamics, distribution of polar groups, etc.) which are not sufficiently accessible to experimental characterization. Here, the simulation of reasonably equilibrated and validated atomistic models provides great opportunities to gain a deeper insight into these microscopic features that in turn will help to develop more knowledge-based approaches in membrane development. 

Basics of Molecular Modeling of Polymer-Based Membrane Materials S... 

Polymer-Based Membranes Battery Separators Medical Equipment Filtration Membranes... 

Ceramic membranes are proposed as advantageous with respect to resistance toward fouling as compared to organic polymer-based membranes. In this category, zeolite membranes have received considerable attention because of their superior characteristics of thermal, mechanical, chemical, and radiation stability. 

Naturally, swelling may be undesirable in many instances as well. For example, swelling of organic polymer based membranes decreased selectivity. Other possible deleterious effects could include malfunctions due to solubilization and swelling of sealants such as gaskets or o-rings. 

NG 01] Ng L.-T., Guthrie J.T., Yuan Y.J. et al, UV-cured natural polymer-based membrane for biosensor application . Journal of Applied Polymer Science, vol. 79, pp. 466 72,2001. 

As shown in Fig. 14.2, scrims made from polyester and/or glass fibres, and also scrim laminates made with glass or polyester nonwovens, are in use for many different polymer-based membranes. Scrims can often be found in roofing membranes made from PVC, PO, EPDM, or bitumen [9—12]. 

Abstract The world s first highly durable perfluorinated polymer-based membrane electrode assembly (MEA) for polymer electrolyte membrane fuel cells, under conditions of high temperature and low humidity, has been developed. The newly developed MEA, which is composed of a new perfluorinated polymer composite membrane, reduces the degradation rate to 1/lOOth to l/l,000th of that of the conventional MEA. The new perfluorinated polymer composite MEA can be operated for more than 6,000h at 120°C and 50% relative humidity. 

Unlike zirconia nanoparticle synthesis, the preparation of anisotropic zirconia nanomaterials has been rarely reported, with the preparation of nanoparticles with a rice- or fiber-hke morphology having been achieved in solution-based processes, and the underlying mechanisms not yet understood. Template-based processes, both in solution and in gas phase, have however been successfully employed to prepare nanorods and nanotubes, using common polymer-based membranes and anodic alumina as templates. 

With respect to electrodes potentiometry started with the glass electrode from Cremer in 1906 starting in the 1960s the development of polymer-based membranes had a strong impact on the popularity of ion-sensitive electrodes. 

The pH of the martian regolith was measured using two polymer-based membrane ISEs and an iridium oxide electrode. Measurement of pH of the martian regolith was seen as a critical objective for the mission, which is why this measurement was performed in triplicate. The dynamic range of the polymer-based pH ISEs as determined preflight was 1 < pH <9, while the dynamic range of the iridium... 

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