| Abstract
| - The ordering of a series of side-chain liquid-crystalline/amorphous diblock copolymers withdifferent molecular weights, compositions, and polydispersities is reported. The diblock copolymerscomprise polystyrene and poly(methacrylate) bearing methoxy biphenyl mesogenic groups. All samplesshow a lamellar morphology regardless of their molecular weights, compositions, and polydispersities.Apart from the low-molecular-weight sample, a smectic phase is observed at elevated temperatures. Atroom temperature, the mesogenic groups partially crystallize. For the sample with the lowest molecularweight the crystalline layers are uncorrelated, and their melting induces the order-to-disorder transition.Samples with relatively long main chains exhibit a three-dimensional ordered crystalline structure witha finite correlation length along the layer normal. This correlation length is longer for the sample withthe lowest polydispersity. The mesogenic layers are always perpendicular to the block interfaces. Theseresults can be understood in terms of changes in the conformation of the main chain of the liquid-crystallineblock with its length. In thin films, the lamellae orient parallel to the interfaces in an asymmetric fashionwith PS at the air interface. At the substrate a thin parallel mesogenic layer is induced. However, thisparallel orientation does not propagate into the film interior, and the mesogenic crystalline layers retaintheir preferred perpendicular orientation with respect to the block lamellae.
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