Phase transitions leading

First-order phase transitions can be detected by various thermoanalytical techniques, such as DSC, thermogravimetric analysis (TGA), and thermomechanical analysis (TMA) [31]. Phase transitions leading to visual changes can be detected by optical methods such as microscopy [3], Solid-solid transitions involving a change in the crystal structure can be detected by X-ray diffraction [32] or infrared spectroscopy [33], A combination of these techniques is usually employed to study the phase transitions in organic solids such as drugs. 

Figure 3 (A) Cooling and (B) heating thermal scanning rheograms for a vaginal cream formulation. The dashed vertical line indicates the 38° C point in both plots. This is clearly the initiation temperature of the phase transition leading to increased apparent viscosity during both heating and cooling.

The equality of chemical potentials in a first-order phase transition leads to two important relationships. The first is the Clapeyron equation1... 

Of course, this may not be true when the compound contains heavy atoms [e.g., (TMTSF)2Re04 undergoes an AO phase transition leading to relatively strong superlattice reflections]. In fact, Re is a very strong x-ray scatterer compared to other atoms in the material [121,122]. 

In the following, a general model [3.94] including formation of an expanded 2D Meads phase on a homogeneous substrate as well as a first order phase transition leading to a condensed 2D Meads phase is discussed for potentiostatic pulse polarization experiments. In this treatment, surface diffusion of Meads is neglected. 

Powder, txUred and kingle-crysUV amples. Unfortunately, many phase transitions lead to a degradation in the quality of single-crystal samples through the formation... 

FT Raman (near-IR excitation) and UV-Raman spectra were used to study tetragonal-monoclinic transitions in (Zr02)o.98(M203)o.o2, where M = Sc or Y. It was found that the temperature of the transition depends on the calcination temperature of the samples.4 High-pressure Raman spectra of Sc2(Mo04)3 gave evidence for two phase transitions, leading to an amorphous state.5... 

Glycine has three known polymorphs under ambient conditions, namely a, (5 and y. The a-polymorph is stable with respect to the application of pressures up to 23 GPa [30], whereas both the 3- and the y-polymorphs undergo phase transitions leading to two new forms. 3-glycine transforms into 8-glycine at a pressure of about 0.76 GPa [31], while a powder of the y-polymorph (single crystals do not survive the... 

This phase transition leading to a fundamental increase in order of the polymer on raising the temperature is called an inverse temperature transition. 

The electrochemical formation of adsorbed layers and their phase transitions leading to compact layers (or multilayers) can be conveniently simulated by Monte Carlo techniques [88]. 

PNIPAAm is a widely studied thermoresponsive polymer that exhibits a lower critical solution temperature (LCST) [51, 52]. Below the LCST, the polymer is expanded and hydrophihc and is thus soluble in water. Above this critical temperature, there is an abrupt phase transition leading to a collapsed and hydrophobic polymeric structure, which renders the polymer insoluble in water [53-55]. The LCST of... 

As far as thermodynamics of liquid-liquid phase transition leading to coacer-vahon is concerned, not everything is known. Phase separation models proposed in the hterature do not possess all the possible interactions adequately. However, there is unanimity in the following description ... 

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