Inner waters

Downward extmsion of a bubble into a water bath and over an inner water-cooled mandrel is used in a few instances for polypropylene and polyesters. The water is removed prior to slitting and winding. 

Double surface condenser. A tube in which the vapour is condensed between an outer and inner water-cooled jacket after impinging on the latter. Very useful for liquids boiling below 40°. 

An alternative to traditional chemicals is the use of VCI materials, such as Boiler Lizard from the Cortec Corporation. This product is a VCI powder contained in an inner, water-soluble polyvinyl alcohol (PVA) bag and outer wrapping. The wrapping is removed, the inner lining slit open, and the bag left in a suitable place within... 

The type of double surface condenser most often found in laboratories is the Davies improved double surface condenser which appeared in 1905, and was designed by J. Davies of A. Gallenkamp Co. as a direct development from Thresh s modification of the Bidet condenser. All rubber bungs and tubing were eliminated in the Davies condenser, which has retained its popularity for 50 years. To make a condenser of this kind the inner water jacket is connected to the outer one by two internal seals wWch are made by a sli t modification of Method 2 described on p. 75. The rest of the assembly is similar to that for an ordinary Liebig condenser. 

Y Sela, S Magdassi, N Garti. Release of markers from the inner water phase of W/O/W emulsions stabilized by silicone based polymeric surfactants. J Control Release 33(1) 1-12, 1995. 

Packing in / Im 2 H20 also shows some distinct features that may be related to the existence of the ionic species in the crystal. Hydrogen bonding is, of course, a primary feature (Fig. 43). An extensive network exists in this crystal which has the form of endless chains rather than that of loops usually found for the similarly double-faced (H-bond donor and acceptor) alcohols (cf. Fig. 19). As already mentioned, the carboxylate function has four connections, while its neutral —COOH neighbor maintains three H-bond contacts. The inner water molecule with respect... 

The width of the bubble wall decreases as the inner water layer drains downward under the influence of gravity (Figure 2). 

Figure 1 Schematic structures of micelle and liposome, their formation and loading with a contrast agent, (a) A micelle is formed spontaneously in aqueous media from an amphiphilic compound (1) that consists of distinct hydrophilic (2) and hydrophobic (3) moieties. Hydrophobic moieties form the micelle core (4). Contrast agent (asterisk gamma- or MR-active metal-loaded chelating group, or heavy element, such as iodine or bromine) can be directly coupled to the hydrophobic moiety within the micelle core (5), or incorporated into the micelle as an individual monomeric (6) or polymeric (7) amphiphilic unit, (b) A liposome can be prepared from individual phospholipid molecules (1) that consists of a bilayered membrane (2) and internal aqueous compartment (3). Contrast agent (asterisk) can be entrapped in the inner water space of the liposome as a soluble entity (4) or incorporated into the liposome membrane as a part of monomeric (5) or polymeric (6) amphiphilic unit (similar to that in case of micelle). Additionally, liposomes can be sterically protected by amphiphilic derivatization with PEG or PEG-like polymer (7) [1].

Y. Sela, Y. Magdassi, and N. Garti Release of Markers from the Inner Water Phase of W/O/W Emulsions Stabilized by Silicone Based Polymeric Surfactants. J. Controlled Release 33, 1 (1995). 

Figure 1.7 Effects of hydration on a drug molecule A drug molecule does not exist in a vacuum it is hydrated. In order to interact with its receptor, it must be dehydrated. Water molecules hydrogen-bond to the functional groups of the drug molecule. Additional water molecules then hydrogen-bond to these inner water molecules. The overall result consists of many layers of hydration.

Bilayer membranes and vesicles provide not only charged surfaces but also two phases, separating the reaction sites and products. It was first demonstrated that photoinduced electron transfer occurs from EDTA in the inner water phase of vesicles incorporated with surfactant Ru(bpy)2+ to MV2+ in the outer water phase22 (Eq. (14)). 

In addition to the properties of micelles described above, vesicles, which are bilayer structures and can be considered to be model membranes, separate two distinct aqueous phases an entrapped or inner water pool and the bulk aqueous phase. In principle, therefore, electron transfer may be possible across the bilayer and the sites of hydrogen and oxygen production in a water splitting system can be separated spatially. 

Frolova LA (2002) Biology of inner waters problems of ecology and biodiversity (in Russian). Borok, p 227... 

Figure 47.4. Chemical modification of the protein with a water-insoluble reagent in the reverse micelles of Aerosol OT in octane. (1) Protein molecule incorporates into the inner water pool of the reverse micelle, acquiring a monolayer cover of the hydrated surfactant molecules. (2) The modifying reagent incorporates into the surfactant layer of the micelle coming into contact with the modified group of the protein. (3) Following the completion of the reaction the modified protein is precipitated and the surfactant and excess of the reagent are removed by adding cold acetone. Proteins modified with fatty acid residues with controlled and low degree of modification are obtained.

In this system the average particle size depends on the BH4 Ni " ratio, the nickel salt concentration and the size of the inner water core of the reversed micelle. A BH4" Ni ratio of three gives the smallest size catalyst particles. Lower ratios lead to the formation of larger particles while higher ratios have no further effect on particle size. Micelles with smaller water cores produce smaller catalyst particles. The effect of nickel salt concentration on particle size is complex the smallest particles are formed with a concentration of 5x10"2M. Fig. 12.3 shows the relationship between the micelle composition, nickel salt concentration and the nickel boride particle size. For any given preparation the catalyst particles are essentially uniformly sized with only a 0.5 run distribution. ... 

Using surfactant chromophores, trans-bilayer electron transfer can also be observed, although in the absence of a mediator, the chromophore must be embedded in both surfaces of the bilayer structure. Thus, MV " in the bulk aqueous phase can be reduced by EDTA or sodium ascorbate in the inner water pools if they are separated by a bilayer consisting of 5,10,15-tris(l-methyl-pyridine)-4-yl-20-(4-stearoxyphenyl)porphinatozinc colyophilized with dipalmitoyl-L-phos-phatidylcholine (DPPC). l imilar results are obtained using surfactant derivatives of [Ru(bipy)3] and increased rates of formation are observed if mediators such as hexadecyl-viologen, 2-methyl-1,4-naphthoquinone (vitamin didodecyl- or dibutyl-alloxazine... 

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