Vs. crystallization

Figure 19 (a) Percentage of y phase vs. crystallization temperature,Tc, for metallocene... 

Finally, we were led to the last stage of research where we treated the crystallization from the melt in multiple chain systems [22-24]. In most cases, we considered relatively short chains made of 100 beads they were designed to be mobile and slightly stiff to accelerate crystallization. We could then observe the steady-state growth of chain-folded lamellae, and we discussed the growth rate vs. crystallization temperature. We also examined the molecular trajectories at the growth front. In addition, we also studied the spontaneous formation of fiber structures from an oriented amorphous state [25]. In this chapter of the book, we review our researches, which have been performed over the last seven years. We want to emphasize the potential power of the molecular simulation in the studies of polymer crystallization. 

Fig. 15 Limiting thickness of the lamella plotted vs. crystallization temperature. The lamella thickness shows steep increases around the melting point...

Figure 3(a). Effect of seed density on nucleation at 70 C. Number of crystals 1.2 im) vs crystallization time. 

Fig. 9.3 Initial degradation rate of C2HCi3 vs. crystal size of anatase.

Protein Explorer is a knowledge base with introductory information on many topics about protein structure, such as the origins and limitations of 3D protein structure data, specific oligomers vs. crystal contacts, hydrogen bonds, cahon-pl interactions, etc. Protein Explorer is more user-friendly than the comparable software RASMOL, also available on servers such as ExPASy. 

Fig. 13 Size vs. crystallization time for a C246H494 crystal growing from an initially 4.75% solution in octacosane at 108 °C. da and d, are crystal dimensions along the [100] (width) and [010] (length) directions...

Fig. 22 Ratio of growth rates Gioo/Gno vs. crystallization temperature for extended-chain crystals of Ciggfbgg from 2% (w/v) solution in octacosane (diamonds) and for linear polyethylene from 0.05% solutions in hexane (squares). The polyethylene crystal at Tc = 70.0 °C and the C198H398 crystals above Tc = 110 °C are non-truncated lozenges these form for any Guo/ cos( /2) > G100, where cp/2 = tan 1(flo/ o) and ao, b0 are unit cell parameters (cf Fig. 10). Data for PE are from [32] (from [45])...

Figure 4 Dependence of the initial sticking coefficient vs. crystal temperature for Ag(l 0 0) and Ag(l 1 0). The curves are normalised to the value at T = 100 K for an easier comparison. For Ag( l 0 0) desorption prevails and S0 drops above T = 170 K, when the lifetime of the admolecules becomes shorter than the time constant of the uptake experiment (typically 0.3 sec). On Ag(l 1 0), on the contrary, S0 decreases smoothly with T, suggesting that dissociation must take place also at terrace sites. The values of the initial sticking coefficient of 02/Ag(l 00), estimated from the intensity of the 0/Ag(l 00) vibration at 30meV, [71], is reported in the inset for 200 K < T < 400 K. The increase with 74 s attributed to the thermal generation of active sites, identified with kinks at closed packed steps.

Figure 34. Initial crystal growth rate (Gt, along [010]) vs crystallization temperature from 1.1 wt % ( . ) and 4.2 wt % solutions (A, a) of CigsThgs in 1-phenyldecane. ( , a) extended chain, ( , a) once-folded chain crystals. 7 and 7 are the dissolution temperatures of extended-chain and once-folded-chain crystals. The retardation in growth around 7dF is caused by self-poisoning (from ref 192 by permission of American Physical Society).

Fig. 4.29 (a) Lamellar growth rates for PEO as function of crystallization temperature Tc (inset lamellar dimensions vs. crystallization time) and (b) lamellar thickness plotted against inverse undercooling. The linear fit of the lamellar thickness vs. inverse undercooling plot with the boundary condition (0,0) yields a satisfactory result. Adapted with permission from [52]. Copyright 2002. American Chemical Society... 

Figure 16.6. Spherulite diameter vs. crystallization time for PCL/PVB blend with (5 wt%) and without carbon black. [Adapted, by permission, from Lee J-C, Nakajima K, Ikehara T, Nishi T, J. Appl. Polym. Sci., 64, 1997, 797-802.1...

The mass of azide used determines the minimum temperature of explosion, as first reported in 1917 [15]. Below a certain mass or crystal size ( 5 pm) explosion is not observed, as has been pointed out many times (see for example references [4,21]). The most recent work of Chaudhri and Field [21] is illustrated by Figure 5, which gives the explosion temperature of lead azide vs. crystal thickness (mass). The usual explanation for the phenomenon is that for small samples self-healing does not keep pace with heat dissipation. 

Figure 1.13 shows the calculated image contrast vs. crystal thickness. The image contrast deflned as 100 X (background - peak intensity)/background, increases with increasing thickness, and at the thickness of about 25 A, reaches about 80% for Ba(Y) columns and about 20% for oxygen columns. 

Highly-luminescent II-IV semiconductor nanocrystals, or quantum dots (QDs) have attracted much attention because of their applications in optoelectronics, non-linear optics and biology. It is known that the photoluminescence (PL) efficiency of QDs can be improved by growing a shell of a wide-band gap semiconductor around the QD core. A good example is the CdSe/ZnS core/shell QDs thatpossess highPL quantum yield (>50%) with a narrow PL line [1]. However, the dependence of PL efficiency on the shell parameters, e.g., structure of the shell (amorphous vs. crystal) and the quality of the core/shell interface have yet to be clarified. In this paper, we present results of optical phonon Raman studies of CdSe/ZnS QDs with different thickness of the ZnS shell which allow one to investigate the above mentioned problem. 

Figure 1. Critical explosion temperature, Tcr vs. crystal thickness. The dotted line is the theoretical curve. The boxed area is for small crystals which did not explode even up to the highest temperature tested (825 K) [17]...

The frequency at the maximum loss peak and overall crystallinity vs. crystallization time for constrained PLLA crystallized isothermally at 90 C. 

Fig, 19 Relative SAXS intensities vs crystallization time of iPP (a) in presence of shear-induced smectic bundles (b) without smectic bundles (after Li and de Jeu [6])... 

Figure 3. a. Absorption spectra of Mastigocladus PS-I-RC in solution (S) and in the crystal (C). b. First-order derivative of the absoption spectra of the solution (S) vs. crystal (C). c. Second-order derivative of the spectra (S and C). 

Fig. 12.13. Characteristic crystallization times Tc vs. crystallization temperature Tc for the homopolymer PODMA27 (squares) and block copolymers with lamellar (triangles) and cylindrical morphology (circles). The curves for different samples are labeled. The filled and partly-filled symbols are half times Tc. The open symbols correspond to Tc values taken from heat flux curves measured during isothermal crystallization (for details see [37])...

Fig. 19.6. Natural logarithm of G vs. crystallization temperature (Tc) (.4) and super-cooling (T /TziT) dependence of natural logarithm of G plus the molecular transport term of ziE/RT (Q) for PE [53]. Broken lines indicate morphological transition from truncated lozenge to leticular crystal...

Hardness vs. Crystal Orientation. The hardness varies depending on crystal orientation, the (111) orientation being the hardest as shown in Fig. 11.5.1 Extremely high hardness up to 50 GPa has been reported for epitaxial superlattices of interstitial nitrides sueh as NbN/TiN and VN/TiN.0 1... 

Figure 12.22. Plots of relative crystallinity X t) vs. crystallization time for neat iPP and PET/iPP MRCs with various PET concentrations at a predetermined cooling rate of 20°C/min. The hot stretch ratios...

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