Water displacement drying method

In addition both methods and processes are claimed for drying surfaces using similar (but apparently different) technology. They include USPs 5,980,642 and 6,096,240 which involve use of a (per)fluoropolyether coupled with an non ionic additive, and USP 5,733,416 which involves a process wherein water is displaced and entrained in a water-displacement composition comprising an organic liquid and a surfactant with the water evaporated at a rate exceeding the entrainment rate. 

In a study on dewatering methods for peat, displacement dewatering was done using acetone, a polar solvent having a lower heat of vapori2ation than water. Dewatering was improved in terms of both the pressure filtering step and the quantity of heat required. Less heat was required to dry the cake and recover the acetone from the filtrate by distillation (31). 

The chemical constituents of the backwash water (which may be acidified) and of the various eluants (recycling, new and special) are specific to the problem of displacing the captured ions from the resin and reactivating its sites. The final stage of IX, namely, the recovery in a solid form of the values from the eluting solution, is effected by chemical methods which yield the desired precipitate. This is settled out, filtered and dried for despatch. 

If the resin were insufficiently dried, the moisture present could cause voids within the molded part. This happens when the water evaporates and leaves open spaces. One effect of voids can be a lower bulk density. Bulk density was measured by the displacement method in accordance with ASTM D792 [7], and was found to be substantially equivalent for the two samples, as shown in Table 12. 

Effect of Water. Wood is usually treated with ammonia in the presence of some amount of water. The effect of water depends not only on the amount of water but also somewhat on the history of the wood sample and the method of treatment. Thus, when oven-dried veneer strips were treated with cold liquid ammonia-water mixtures at ambient pressure, the flexibility of the treated wood was substantially decreased when the moisture content of the ammonia was much above 10% (26). Other protonic solvents act similarly (26). In apparent contrast, the rate of sorption of ammonia from the gas phase by wood is markedly enhanced by moisture in the wood (19). Bone dry wood absorbs ammonia quite slowly at ambient temperatures but if the wood has ten to twenty percent moisture content, sorption and plasticization occur much more rapidly. Presumably the moisture opens the pore structure of the wood and also dissolves ammonia much more readily than bone-dry wood. On continued treatment, the water is presumably displaced from the wood by the ammonia... 

The ammines of cobalt(II) are much less stable than those of cobalt(III) thermal decomposition of [Co(NH3)6]Cl2 is characterized by reversible loss of ammonia, whereas that of [Co(NH3)6]Cl3 is not. In his classic dichotomy of complexes, Biltz regarded [Co (NH 3)3] Cl 2 as the prototype of the normal complex and [Co(NH3)6]Cl3 as that of the Werner or penetration complex. Hexaamminecobalt-(II) chloride has been prepared by the action of gaseous ammonia on anhydrous cobalt (II) chloride or by displacing water from cobalt(II) chloride 6-hydrate with gaseous ammonia. It may also be synthesized in nonaqueous solvents by passing dry ammonia through solutions of cobalt(II) chloride in ethanol, acetone, or methyl acetate. Syntheses in the presence of water include heating cobalt(II) chloride 6-hydrate in a sealed tube with aqueous ammonia and alcohol and the treatment of aqueous cobalt(II) chloride with aqueous ammonia followed by precipitation of the product with ethanol. The latter method is used in this synthesis. Inasmuch as the compound is readily oxidized by air, especially when wet, the synthesis should be performed in an inert atmosphere. 

Density of the Dry Cell Wall. The dry cell wall of wood has a density of approximately 1.5 g/cm when measured by pycnometric or volume-displacement methods. Somewhat higher values are obtained when using water as opposed to nonswelling displacement media such as toluene or benzene (22). 

Complex formation between Mg + and NH3 leads to [Mg(NH3)5], isolated as [Mg(NH3)6]Cl2. Similarly, in liquid NH3, CaCl2 forms [Ca(NH3)6]Cl2 and this is the reason that anhydrous CaCl2 (which readily absorbs water, see Section 11.5) cannot be used to dry NH3. Ammine complexes such as [Ni(NH3)5] can be prepared in aqueous solution by the displacement of aqua ligands by NH3. Not all hexaammine complexes are, however, directly accessible by this method. Two examples are [V(NH3)6] + and [Cu(NH3)6]. The ion [V(H20)g] + is readily oxidized in aqueous solution, making the preparation of V(II) complexes in aqueous conditions difficult. In liquid NH3, dissolution of VI2 gives [V(NH3)6]l2 containing the octahedral [V(NH3)g] ion. The [Cu(NH3)g] ion is not accessible in aqueous solution (see Figure 20.29) but can be formed in liquid NH3. 

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