Blown glass membranes

When the glass membrane is exposed to water, a hydrated layer, approximately 50-100 nm thick, is formed at its interface. In addition to water, the chemical composition of the glass in this layer is the same as that in dry bulk. The concentration of the anionic binding sites is estimated between 3 and 10 M. The membrane is usually blown into a bulb of a typical thickness of the wall 50-200 jitm. The optimum thickness of the wall is a compromise between mechanical stability and the electrical resistance. The latter is typically on the order of 10MQ. The interior of this bulb is sealed and contains the internal reference electrode. Thus, the glass membrane is bathed on both sides by solution and a similar hydrated layer develops on the inside of the glass bulb as well (Fig. 6.14). 

Glass membrane a thin bulb blown on the end of a tube of special glass... 

The membrane of the glass electrode is blown on the end of a glass tube. This tube is filled with a solution with a constant pH (acetate buffer, hydrochloric acid) and a reference electrode is placed in this solution (silver chloride or calomel electrodes). During the measurement, this whole system is immersed with another reference electrode into the test solution. The membrane potential of the glass electrode, when the internal and analysed... 

Nonwovens have been well established as traditional materials for alkaline batteries, NiCd and NiMH cells, and for absorbed glass matt (AGM) lead—acid batteries. Alkaline batteries use a variety of materials, mostly composed of wet-laid cellulose and polyvinyl alcohol (PVA). NiCd and NiMH use a variety of materials, from spunbond and melt blown to dry-laid materials. Lead—acid AGM batteries use a wet-laid glass matt as the separator, often in conjunction with another membrane. These materials range in thickness from 100 to 300 pm. One review article in 2007 even states that for lithium ion cells, nonwoven not possible. However, these traditional nonwovens are a significant industrial market for several manufacturers, with total sales into these types of cells of 450 million globally. 

Younger Embryos (<16 Hours AEL). As described in Protocol 15.2, embryos are removed from the vitelline membrane and transferred to poly-L-lysine-coated coverslips with the dorsal side up under saline. An incision is made along the dorsal midline with a glass electrode or sharpened tungsten needle. The embryo is blown flat to the coverslip surface with a gentle stream of saline from a glass pipette controlled by mouth (Bate 1990 Broadie and Bate 1993a). 

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