Crystal lamella solution-grown

The solution-grown crystal (SGC) from dilute solution forms diamond-like crystals of lateral dimension up to several micrometres, but their thickness is about 10 nm in which polymer chains are folded. The chain axes are parallel to the thickness direction of these lamellar crystals. In SGC materials precipitated from dilute solutions (Figure 3A), the lamellae are stacked and oriented parallel to the material surface. 

Figure 6 (a) Sketch of the chain arrangement in shish-kebab structures. Reproduced from [67] with permission, (b) Polyethylene shish-kebabs crystalled from solution [68]. Reproduced with permission from H. D. Keith, 1996 American Institute of Physics, (c) Mannan-lamellae, epitaxially grown on cellulose fibres [69]. Reproduced from H. Chanzy, reprinted with permission from John Wiley Sons, Inc. 

Solution-Grown Lamellae of POM and PE by CM-AFM Sample Preparation Crystallization from Solution... 

That applies even to single crystals grown from dilute solution. The amorphous component is partially distributed all over the crystal in form of crystal defects, i.e. vacancies and kinks, and to a larger extent on the surfaces of the crystal lamellae and mosaic blocks. 

The next thermal analyses are for solution-grown dendrites, hedrites, and melt-grown lamellae, represented by Eigs. 6.93 and 6.94. The dendrites melt at much lower temperatures than the extended-chain crystals and show multiple melting peaks. 

Early experiments on solution-grown lamellae revealed not only the earlier melting of the 100 sectors in polyethylene lamellae (25) [which Atomic Force Microscopy (AFM) has confirmed (33) to be thinner than 110 sectors in collapsed, and presumably as-grown, crystals] but also the presence of holes (43) in lamellae that had been heated in contact with a carbon film (Fig. 2). While providing clear evidence of lamellar thickening, the presence of holes is a response to the carbon film, which restrains lateral contraction holes do not appear on thickened upper layers of the same sample that are not so restrained. 

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). 

Single crystals of many polymers may be grown from dilute solution [8]. Linear polyethylene, for example, forms single-crystal lamellae with lateral dimensions of the order of 10-20 /Electron diffraction shows that the molecular chains are oriented approximately normal to the lamellar... 

The component of the radius of gyration in the lamella plane was measured for solution-grown polyethylene crystals as a function of tag molecular weight. It was found that was independant of My/. The authors ascribe this to... 

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