Phase thermally-induced

Human osteoblast-like MG63 cells were cultured on the macroporous chitosan scaffolds reinforced with hydroxyapatite or calcium phosphate invert glass were fabricated using a thermally induced phase separation technique. 

A case of a thermally induced phase change involving ring inversion was recently described by Kaftory (31). He found that a crystal of the exo isomer of the adduct, 7a, of ll-cyano-l,6-methano[10]annulene with 4-methyl-1,2,4-triazoline-3,5-dione is transformed to the endo isomer 7b on heating to 175°C. The process involves nucleation and growth of the product phase, but maintains... 

I. Miroshnyk, L. Khriachtchev, S. Mirza, J. Rantanen, J. Heinamaki and J. Yliruusi, Insight into thermally induced phase transformations of erythromycin A dihydrate, Cryst. Growth Des., 6, 369-374 (2006). 

In order to further understand the nature of this thermally-induced phase separation of NiO(lll) films, we have carried out a detailed XPS and AES investigation of this surface. Both the XPS 0(ls) and the AES O(KLL) features show a significant decrease in intensity (about a factor of 3) upon heating the NiO(l 11) film to 800 K, with the onset of the decrease starting at about 525 K. Considering the limited escape depth of the O Is electrons and the AES O(KLL) electrons (-10 A) [26], the attenuation in the XPS and AES intensities could be attributed to the formation of NiO(lOO) islands which are sufficiently thick that the escape probability of the XPS and AES electrons is reduced [25]. 

The model PBZT/ABPBI molecular composite system is limited since the rod and the matrix do not possess glass transition temperatures for subsequent post form consolidation. In an effort to improve the processability for molecular composites, thermoplastics were used as the host matrix. Processing from acidic solvents requires the thermoplastic host to be soluble and stable in meth-anesulfonic add. Thermoplastic matrices were investigated including both amorphous and semicrystalline nylons [71,72], polyphenylquinoxaline (PPQ) [73] and polyetheretherketone (PEEK) [74], Table 5 shows the mechanical properties obtained for various processed PBZT thermoplastic molecular composite systems. As an example, the PBZT/Nylon systems showed 50-300% improvement over uniaxially aligned chopped fiber composite of comparable compositions. However, the thermally-induced phase separation during consol-... 

Among the thermally-induced phase transitions, the thermoswelling type were successfully explained by Tanaka s model [3]. However, Tanaka s model could... 

The existence of a second class of complex phases, the modulated and perforated layer structures, has largely been explored by Bates and co-workers (Forster et al. 1994 Hamley et al. 1993, 1994 Khandpur et al. 1995 Schulz et al. 1996), who used SANS and TEM to investigate shear oriented structures. The thermally-induced phase transition from the lam to the hex phase in polyolefin diblocks was studied in detail by Hamley et al. (1993, 1994) using SANS, TEM and rheology. Intermediate hexagonal modulated lamellar (HML) and hexagonal perforated layer (HPL) structures were observed on heating PEP-PEE, PE-PEP and PE-PEE diblocks, where PEP is poly(ethylene-propylene), PEE is... 

D.R. Lloyd, J.W. Barlow and K.E. Kinzer, Microporous Membrane Formation via Thermally-induced Phase, in New Membrane Materials and Processes for Separation, K.K. Sirkar and D.R. Lloyd (eds), AIChE Symposium Series 261, AIChE, New York, NY, p. 84 (1988). 

Microcellular foams can be produced by thermally induced phase separation (TIPS) [47, 74, 76], The induced spinodal decomposition can be optimized to generate, e.g., polylactide scaffolds with the porous morphology and physicomechanical characteristics of a foam. Interesting materials can be constructed in a simple process. These materials exhibited bundles of channels with a diameter of 400 pm. The internal walls of the tubular macropores have a porous substructure with pore diameters of " 10 pm. It appears to be remarkable that the channels have a preferential... 

Fig. 17a-c. Phase morphologies resulting from thermally induced phase separation of PPTA/PA-6 blends, a 25/75, b 40/60 c 60/40... 

Several main synthesis methods widely applied to produce carbon nanotube-polyurethane nanocomposites were summarized above. In addition, latex technology (27), thermally induced phase separation (28), electrospinning (29,30) and many other methods also show their own advantages and promises, however, these methods will not be discussed here. 

Asymmetric membranes are usually produced by phase inversion techniques. In these techniques, an initially homogeneous polymer solution becomes thermodynamically unstable due to different external effects and the phase separates into polymer-lean and polymer-rich phases. The polymer-rich phase forms the matrix of the membrane, while the polymer-lean phase, rich in solvents and nonsolvents, fills the pores. Four main techniques exist to induce phase inversion and thus to prepare asymmetric porous membranes [85] (a) thermally induced phase separation (TIPS), (b) immersion precipitation (wet casting), (c) vapor-induced phase separation (VIPS), and (d) dry (air) casting. 

Thermally Induced Phase Separation In the TIPS process, an initially homogeneous solution consisting of a polymer and solvent(s) phase separates due to a decrease in the solvent quality when the temperature of the casting solution is decreased. After demixing is induced, the solvent is removed by extraction, evaporation, or freeze drying. 

The only single phase, miscible IPNs reported are homopolymer IPNs, in which both networks are composed of the same polymer, and IPNs based on poly (2,6-dime thy Iphenylene oxide) (PPO) and polystyrene (PS) (18). The corresponding blend of the latter system is miscible and does not undergo thermally induced phase separation below its degradation temperature (19). 

Differential scanning calorimetry measures the thermodynamic parameters associated with thermally induced phase transitions. Here, the sample of interest and an inert reference are heated or cooled independently at a programmed rate, and in tandem, such that their temperatures change in unison and the differential temperature is maintained at zero. If the sample undergoes a thermally induced transition, heat must be applied to or withdrawn from the sample in order to maintain the same temperature in both sample and reference compartments. The instrument measures the heat flow into the sample relative to the reference and this dijferential heat flow (or excess specific heat) is recorded as a function of temperature, resulting in a trace, as shown in Fig. 1... 

Theocaris, C. R. and Jones, W. (1984). The thermally induced phase transition of crystalline 9-cyanoanthracene dimer A single crystal study. J. Chem. Soc., Chem. Commun., 369-84. [234, 237]... 

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