Lamellae corrugated

Fig. 11. Blend of two narrow distributions of di-block copolymers showing a mixture of two coexisting morphologies of wavy rods and corrugated lamellae...

Fig. 7-15. The corrugated surface produced during weathering of labradorite (An54) due to the more rapid weathering of the more calcic lamellae. Bdggild intergrowths (mostly 75-85 nm thick) are clearly visible (from Inskeep et al., 1991).

Ridges are formed by pleats of extra material deposited along one of the diagonals of each diamondshaped crystal. Obviously, therefore, crystals of polyethylene are not simply flat lamellae. Experimental evidence has shown that they may exist in solution as hollow pyramids. These pyramids may or may not be corrugated depending on the crystallization conditions. 

If the stacking is regular, as is often the case, 4 can be determined by SAXS, as described in section 3.4.2. If the stacking is very irregular, elee-tron microscopy must be used to sample different regions. Electron microscopy shows that the lamellae are not always flat but may be corrugated, particularly in melt-crystallised material. Electron diffraction shows that the chain axes are then usually perpendicular to the overall plane of the lamella rather than being normal to the local thickness direction. Information about the thicknesses of the crystalline layers can be obtained from Raman spectroscopy. 

In conclusion we have reached a morphology of stable lamellae oriented perpendicular to a nontreated substrate. Similar results have recently been reported by Hashimoto and co-workers using conventional lamellar block copolymers on a strongly corrugated substrate [46]. In both situations azimuthal ordering of the lamellae turned out to be difficult. We wanted to extend these experiments to a cylindrical morphology for which we should... 

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