Publication Date:
2009-02-07
Description:
The design and fabrication of ultrathin polymer layers are of increasing importance because of the rapid development of nanoscience and nanotechnology. Confined, two-dimensional crystallization of polymers presents challenges and opportunities due to the long-chain, covalently bonded nature of the macromolecule. Using an innovative layer-multiplying coextrusion process to obtain assemblies with thousands of polymer nanolayers, we discovered a morphology that emerges as confined polyethylene oxide (PEO) layers are made progressively thinner. When the thickness is confined to 20 nanometers, the PEO crystallizes as single, high-aspect-ratio lamellae that resemble single crystals. Unexpectedly, the crystallization habit imparts two orders of magnitude reduction in the gas permeability.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Haopeng -- Keum, Jong K -- Hiltner, Anne -- Baer, Eric -- Freeman, Benny -- Rozanski, Artur -- Galeski, Andrzej -- New York, N.Y. -- Science. 2009 Feb 6;323(5915):757-60. doi: 10.1126/science.1164601.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106-7202, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19197057" target="_blank"〉PubMed〈/a〉
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink