Poly , crystal lamella solution-grown

Solution-grown single lamellar crystals of, eg, PEO (147), POM (148), PE (149,150), syndiotactic PP, poly(dimethyl silane) (151), poly(4-methyl-pentene) (152), and poly[(i )-3-hydroxybutyrate] (153) deposited onto solid substrates have been studied by SFM. The habit and thickness of the lamellae in flat-on projection are directly accessible and in addition to these data, which have previously been typically provided by TEM in conjunction with shadow evaporation techniques (4), more subtle details of domain boundaries and fold direction orientation have been revealed. In Figure 14, the habit of a collapsed PE lamellae is depicted, as well as the anisotropic lateral force recorded in the different fold sectors (154). 

Poly(ethylene oxide) has been investigated in both a single-crystal form and in normal or commercial, partially crystalline form. Single crystals have been examined by X-ray analysis and have been shown to be flat platelets with the c-axis of the unit cell oriented normal to the basal plane (34). Electron microscopy has shown bulk crystallized polymer to have a lamellar structure (35, 36), and single-crystal lamellae have been grown from dilute solution (37, 38). 

To obtain isometric crystals as described in Fig. 5.41, one must restrict the width of the thin lamellae. This is illustrated in Fig. 5.74 with single-molecule single crystals grown from droplets of a very dilute solution of poly(oxyethylene) in benzene. Each of the crystals contains only one molecule [27]. The poly(oxyethylene) was of a broad... 

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