Issue 7, 2012
From the journal:

Soft Matter

Anomalous increase in modulus upon hydration in random copolymers with hydrophobic segments and hydrophilic blocks

F. Bedoui,a   L. K. Widjaja,†b   A. Luk,b   D. Bolikal,b   N. S. Murthyb  and  J. Kohn*b  

* Corresponding authors

a Université de Technologie de Compiègne, Laboratoire Roberval UMR-CNRS 6253, Compiègne, France

b New Jersey Center for Biomaterials, Rutgers University, The State University of New Jersey, Piscataway, NJ, USA
E-mail: kohn@biology.rutgers.edu

Abstract

The polymers with hydrophilic moieties typically become soft upon hydration. Here we report an exception to this rule. The modulus was found to increase upon water uptake in polymers in which hydrophilic poly(ethylene glycol) (PEG) segments were incorporated randomly into a chain of hydrophobic segments of 3,5-diiodo desaminotyrosyl-tyrosine ethyl ester. The Young's modulus of the copolymer increased by as much as 15-fold upon hydration with 30 to 60 vol% of PEG. This increase in modulus was fully reversible and was observed at both 22 °C and the physiological temperature of 37 °C. A degree of hydration of ∼3 water molecules per ethylene glycol and hydration-induced phase separation of hydrophilic domains appear to be essential for the observed increase in modulus. This stiffening effect is attributed to the PEG segments in the hydrated domains that no longer participate in the transfer of stress through the polymer matrix as they do when they are molecularly dispersed along the polymer chain in the dry state.

Graphical abstract: Anomalous increase in modulus upon hydration in random copolymers with hydrophobic segments and hydrophilic blocks

About
Cited by
Related
Download options Please wait...

Article information

DOI
https://doi.org/10.1039/C1SM06619F
Article type
Paper
Submitted
24 Aug 2011
Accepted
17 Nov 2011
First published
06 Jan 2012

Soft Matter, 2012,8, 2230-2236

Permissions

Request permissions

Anomalous increase in modulus upon hydration in random copolymers with hydrophobic segments and hydrophilic blocks

F. Bedoui, L. K. Widjaja, A. Luk, D. Bolikal, N. S. Murthy and J. Kohn, Soft Matter, 2012, 8, 2230 DOI: 10.1039/C1SM06619F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements