Polyethylene crystal growth spiral

Fig. 4.13 Electron micrograph of a polyethylene crystal grown from CCU at 8ff C showing a large growth spiral. The micrograph was obtained by replication and the replica has been shadowed with a heavy metal (courtesy of Dr G. Lieser).

Figure 3.28 Transmission electron micrograph of polyethylene crystals grown from dilute tetrachloroethylene solution. The spiral growth in the upper part of the central crystal is believed to have originated from a tear at the growth face. The larger spiral in the top left of the figure is centered on a sector boundary. Reproduced from Geil [1] with kind permission from the author.

Figure 3.32 Sketches of polyethylene crystals in (a) hollow pyramid shape (b) chair shape (schematic) (c) chair shape with two spiral growths of opposite hand centered on the short 6-axis of the crystal. From Toda et al. [19] with permission from Elsevier.

Figure 334 Edge view along the short A-axis diagonal of a lozenge-shaped polyethylene crystal suspended in solution. The spiral growth layers are clearly splayed from one another. See text for more discussion. Phase contrast optical micrograph from Mitsuhashi and KeUer [52] with permission from Elsevier.

Figure 3.41 Transmission electron micrograph of a polyethylene crystal grown at 130°C from a molten film. A screw dislocation was centered in the etched hole abont which spiral growth has started. Scale bar is 2 pm. From Al-Raheil and Al-Share [58] with permission from John Wiley Sons, Inc.

Figure 3.1 Monolayer crystals of polyethylene grown from 0.1% tetrachloroethylene solution by free cooling from about 120°C. The pleats were formed when the hollow pyramid shape crystals collapsed. A small spiral growth is evident on the largest crystal. Transmission electron micrograph from Reneker and Geil [2] with permission from the American Institute of Physics.

Figure 3.12 (a) TEM of monolayer crystals of polyethylene, M = 10 kDa, grown at 80°C from 0.01 % xylene solution. There are no pleats or creases that indicate a nonplanar shape, (b) Exactly as in (a), except that the polyethylene has M = 120 kDa. The pleat along the b-axis (small diagonal) indicates that the crystal was a hollow pyramid in solution. Note also the spiral growths. From Holland and Lindenmeyer [16] with permission from John Wiley Sons, Inc. 

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