Polypropylene microporous membranes

In lithium-based cells, the essential function of battery separator is to prevent electronic contact, while enabling ionic transport between the positive and negative electrodes. It should be usable on highspeed winding machines and possess good shutdown properties. The most commonly used separators for primary lithium batteries are microporous polypropylene membranes. Microporous polyethylene and laminates of polypropylene and polyethylene are widely used in lithium-ion batteries. These materials are chemically and electrochemically stable in secondary lithium batteries. 

Barbe, A.M., Hogan, P.A., and Johnson, R.A. Surface morphology changes during initial usage of hydrophobic, microporous polypropylene membranes, J. Membr. Sci., 172, 149, 2000. 

A 5-mL aliquot of the original Shirakawa catalyst was diluted with 100 ml of freshly distilled toluene. A 0.6905-gram sample of microporous polypropylene membrane, taken from the same lot as used in Procedure 1, was soaked in this solution. The sample weighed 0.6944 grams after catalyst pickup, or an increase of 0.56%. 

Rieser T, Lunkwitz K, Berwald S, Meier-Haack J, Muller M, Cassel F, Dioszeghy Z, Simon F (1999) Surface modification of microporous polypropylene membranes by polyelectrolyte multilayers. In Pinnau I, Freeman BD (eds) Membrane formation modification. American Chemical Society, Washington, DC, p 189... 

Figure 1.7 SEM of the surface of a microporous polypropylene membrane precipitated by thermal gelation from a hot homogeneous polymer solution.

Largman and sifnlades Baker, et al. Coupled transport 7n microporous polypropylene membranes... 

The commercially available transdernal systen of clonidine consists of an outer layer of pigmented polyester a drug reservoir of clonidine, mineral oil, polyisobutylene, and colloidal silicon dioxide a microporous polypropylene membrane that controls the rate of diffusion of the drug and a final adhesive layer that provides an initial release of drug and contains those ingredients found in the reservoir. The adhesive layer is covered by a protective strip which is removed prior to application (1). 

The use of UP membranes is therefore advised, as compared to MF membranes, since the smaller pores of the former led to higher breakthrough pressures [ 157,184]. However, microporous polypropylene membranes have been effectively used in several bioconversion systems [ 112,113,155,184,185], probably due to a high interfadal liquid-liquid tension in the reaction systems studied. A detailed theoretical discussion on the effects of pore geometry and the placement of the liquid phases in the breakthrough pressure can be found in an article by Vaidya et al. [127]. 

Wang et al. developed an extraction device with a Celgard 2400 microporous polypropylene membrane [11]. It has an average thickness of 25 pm, the pore size is 0.05 pm and 38% of the surface is porous. The channel is made of polycarbonate and... 

Transdermal scopolamine is a muscarinic receptor antagonist used for the prevention of post-operative nausea and vomiting. It is supplied as a circular adhesive patch (0.2 mm thick and 2.5 cm ) applied to the post-auricular skin. Each patch contains 1.5 mg of the belladonna alkaloid programmed to continuously release in vivo approximately 1.0 mg over 72 hours. The patch consists of four distinctive layers. Going from visible surface to the surface adherent to the skin, these layers are (1) backing layer (2) drug reservoir of scopolamine (3) microporous polypropylene membrane that controls the rate of scopolamine delivery (4) adhesive contact surface with the skin. 

Pronk et al., 1988), acryl (Taylor et al., 1986), or polyamide (Giomo et al., 1997). Aspergillus niger lipase immobilized by adsorption on a flat sheet of microporous polypropylene membrane for continuous hydrolysis of butter fat glycerides (Malcata et al., 1991) has been used. Figure 3.5 shows a schematic diagram of an example of FSMR in use. 

The microporous polypropylene membrane, typically Celgard (Celgard 3400, manufactured by Celgard LLC, Charlotte, NC, 28273), ° is utilized as the gas barrier while at the same time it offers minimum ionic resistance. This thin gas barrier, which becomes relatively soft when wetted, is frequently placed between two layers of the eloth separator and receives significant mechanical support from them. Substantial improvements have been made in recent years to the toughness of the plastic membrane gas barrier. 

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