eprintid: 1814
rev_number: 8
eprint_status: archive
userid: 6
dir: disk0/00/00/18/14
datestamp: 2013-10-03 13:31:30
lastmod: 2016-04-06 10:05:02
status_changed: 2013-10-03 13:31:30
type: article
metadata_visibility: show
creators_name: Morrison, Greg
creators_name: Hyeon, Changbong
creators_name: Toan, Ngo Minh
creators_name: Ha, Bae-Yeun
creators_name: Thirumalai, D.
creators_id: greg.morrison@imtlucca.it
creators_id: 
creators_id: 
creators_id: 
creators_id: 
title: Stretching Homopolymers
ispublished: pub
subjects: QD
divisions: EIC
full_text_status: none
abstract: Force-induced stretching of polymers is important in a variety of contexts. We have used theory and simulations to describe the response of homopolymers, with N monomers, to an external force (f ) in good and poor solvents. In good solvents and for sufficiently large N we show, in accord with scaling predictions, that the mean extension along the f axis 〈Z〉 ∼ f for small f and 〈Z〉 ∼ f 2/3 (the Pincus regime) for intermediate values of f. The theoretical predictions for 〈Z〉 as a function of f are in excellent agreement with simulations for N = 100 and 1600. However, even with N = 1600, the expected Pincus regime is not observed due to the breakdown of the assumptions in the blob picture for finite N. We predict the Pincus scaling in a good solvent will be observed for N ≳ 105. The force-dependent structure factors for a polymer in a poor solvent show that there is a hierarchy of structures, depending on the nature of the solvent. For a weakly hydrophobic polymer, various structures (ideal conformations, self-avoiding chains, globules, and rods) emerge on distinct length scales as f is varied. A strongly hydrophobic polymer remains globular as long as f is less than a critical value fc. Above fc, an abrupt first-order transition to a rodlike structure occurs. Our predictions can be tested using single molecule experiments. 
date: 2007
date_type: published
publication: Macromolecules
volume: 40
number: 20
publisher: American Chemical Society
pagerange: 7343-7353
id_number: 10.1021/ma071117b
refereed: TRUE
issn: 0024-9297
official_url: http://pubs.acs.org/doi/abs/10.1021/ma071117b
related_url_url: http://arxiv.org/abs/0705.3029
citation:   Morrison, Greg and Hyeon, Changbong and Toan, Ngo Minh and Ha, Bae-Yeun and Thirumalai, D.  Stretching Homopolymers.  Macromolecules, 40 (20).  pp. 7343-7353.  ISSN 0024-9297      (2007)