Molten components

Several members of this (often endothermic) group of compounds which contain heavy metals tend to explosive instability, and most are capable of violent oxidation under appropriate circumstances. Fusion of mixtures of metal cyanides with metal chlorates, perchlorates, nitrates or nitrites causes a violent explosion [1], Addition of one solid component (even as a residue in small amount) to another molten component is also highly dangerous [2], Individually indexed compounds are ... 

Although in crystalline phases determination of the enthalpy of formation from the constituent elements (or from constituent oxides) may be carried out directly through calorimetric measurements, this is not possible for molten components. If we adopt as standard state the condition of pure component at T = 298.15 K and P = bar , it is obvious that this condition is purely hypothetical and not directly measurable. If we adopt the standard state of pure component at P and T of interest , the measurement is equally difficult, because of the high melting temperature of silicates. 

The molar enthalpy of molten components in the standard reference conditions of r = 298.15 K and P = bar is usually obtained indirectly, by adding first the molar enthalpy of fusion to the molar enthalpy of the crystalline component at its melting point (see also figure 6.10) ... 

Once the enthalpy of fusion is known, because solid and liquid are at equilibrium at the melting point, the entropy of the molten component at 7) is also known through... 

If the heat capacity of the molten component is known (cf section 6.6.2), molar enthalpy and molar entropy at the standard state of the pure melt at T = 298.15 and P = 1 bar may be readily derived by applying... 

When the blend is now further cooled, two possible ways of primary nucleation are possible. In a first case, the matrix phase is nucleated by heterogeneous species present in this phase and instantly, newly created crystals appear. Hence, the crystallization temperature of the matrix will be situated at its bulk T. A second possibility for coincident crystallization occurs in the case one finds again a single crystallization peak for the matrix phase, which however takes place above its bulk T. Some novel mutual nucleating mechanism was suggested in such blends a molten component (minor phase) acts as nucleating substrate for the matrix, which instantaneously crystallizes [Erensch and Jungnickel, 1989]. 

At prolonged annealing (10-20 hours), the Interphase grows involving the entire amount of the isotropic (molten) component(s) and the amorphous portion of the flbrllllzed one in block copolymers. This process leads to the complete transformation of the homopolymerlc matrix into a copolymerlc one ... 

Miscibility/Solubility In order to form a one-phase system, the two molten components (drug and polymer) have to be miscible. It has been reported that the changes in melting point/Tg as a function of polymer concentration provide a phase diagram to establish the boundary of solid-state miscibility and helps in selecting the processing temperature (Chokshi et al. 2005). 

Solid-solid solutions include alloys (some of which are formed by mixing molten components) and waxes. 

LiClOa—HaO mixtures molten component is a molecular solvent ... 

These capillary effects contribute to the vitrification of silicate ceramics, because the viscous liquid formed by the molten components infiltrates into the interstices between the non-molten particles. 

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