Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published 2010 | Supplemental Material + Published
Journal Article Open

pH-responsive aqueous/LC interfaces using SGLCP-b-polyacrylic acid block copolymers

Abstract

Block copolymers that combine a side-group liquid crystalline polymer (SGLCP) block and a pH-responsivehydrophilic block, poly(acrylic acid) (PAA), are shown to confer pH-dependent anchoring of the director orientation at the aqueous/LC interface. The SGLCP block, poly(4-cyanobiphenyl-4-oxyundecylacrylate), was chosen based on its ability to influence the director field of the 5CB (4-cyano-4'-pentylbiphenyl). At low pH the PAA block collapses and the inherent, planar alignment tendency of 5CB at a water interface prevails. As pH increases, the polyelectrolyte block becomes increasingly charged and expands, producing a change to homeotropic anchoring. The change in anchoring occurs as quickly as the buffer can be changed (within ~2 s) and is reversible, with a response that is repeatable over as many cycles as were tested (approximately 20 cycles). The polymer-mediated anchoring persists for 6 days, indicating that the SGLCP block secures the self-assembled layer on the 5CB, even under conditions that cause repulsive interactions among the PAA blocks. Thus, SGLCP blocks can translate conformational changes of a responsive hydrophilic block into rapid, reversible changes in the director field

Additional Information

© 2010 The Royal Society of Chemistry. Received 15th December 2009, Accepted 22nd February 2010. First published as an Advance Article on the web 26th March 2010.

Attached Files

Published - Lee2010p9955Soft_Matter.pdf

Supplemental Material - b926461b.mpg

Supplemental Material - b926461b.pdf

Files

b926461b.pdf
Files (5.7 MB)
Name Size Download all
md5:335c956b6c0fa1fba9201877ba53a84a
707.5 kB Preview Download
md5:68c174c6b57fb06cbf8ec0ab0646976d
413.9 kB Preview Download
md5:b4a4995c259404ae5172cf1eaf876558
4.6 MB Download

Additional details

Created:
August 19, 2023
Modified:
October 20, 2023