Scaling laws in side-chain liquid crystalline polymers: Experimental evidence of main-chain layer hopping in the smectic phase

The average dimensions and the anisotropy of the main chain of a side-chain liquid crystalline polymer are determined in the different mesophases on a series of five different molecular weights. From the comparison of the main-chain dimensions, one deduces that the main chains adopt nearly a self-avoided walk in the isotropic phase. In the smectic phase, the walk adopted between mesogen layers tends to a Gaussian walk, whereas a rodlike behavior is found in the direction parallel to the mesogens.