Premium
Shape transitions in polymer mushrooms compressed by a finite‐size obstacle
Author(s) -
Arteca Gustavo A.
Publication year - 1997
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1997)65:5<519::aid-qua17>3.0.co;2-y
Subject(s) - chain (unit) , polymer , obstacle , phase diagram , lattice (music) , phase transition , molecular dynamics , chemical physics , compression (physics) , materials science , statistical physics , physics , condensed matter physics , chemistry , computational chemistry , phase (matter) , thermodynamics , composite material , quantum mechanics , acoustics , political science , law
We study the interrelation between molecular‐shape changes and configurational transitions in isolated grafted chains (“polymer mushrooms”) under geometrical confinement. The confinement effects are due to a finite‐size obstacle, representing a simple model for the tip of an atomic‐force microscope . Using an off‐lattice polymer model, we monitor how the molecular shape of a short chain is affected by the geometry of the tip. We show the occurrence of shape transitions as the chain “tries to dodge” the approaching obstacle. These transitions can be correlated with changes in the nature of the dominant chain conformations. Using a descriptor of self‐entanglements in the polymer chain, we propose a “phase diagram” indicating the regions characterized by free chains, confined chains, chains that can “escape” the tip, and chains whose escape is “frustrated.” The results help in better understanding polymer behavior under compression, and they can be useful for designing interphases with targeted properties. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65 : 519–530, 1997