Macromolecules 2008, 41, 7131-7140
7131
Morphological Behavior of Thin Linear Low-Density Polyethylene Films Keesu Jeon and Ramanan Krishnamoorti* Department of Chemical and Biomolecular Engineering, UniVersity of Houston, Houston, Texas 77204-4004 ReceiVed March 24, 2008; ReVised Manuscript ReceiVed July 15, 2008
ABSTRACT: The crystalline morphology in thin and ultrathin films of linear low-density polyethylene is reported here. Films with thickness ranging from 20 to 800 nm were isothermally crystallized at temperatures ranging from 90 to 119 °C, and the supermolecular and lamellar morphologies were observed by contact and tapping mode atomic force microscopies. Four distinct supermolecular morphologies were observed: banded spherulite, sheaflike, and two intermediate morphologies. The morphological transitions were significant in the films thinner than 200 nm. The sheaflike morphology occurred in the thinner films (
