Abstract
We show that functionalization of the surface of cellulose nanocrystals (CNCs) with either carboxylic acid (CNC-CO2H) or amine (CNC-NH 2) moieties renders the CNCs pHresponsive. At low pH, where the amine groups are protonated, CNC-NH2 forms aqueous dispersions in water on account of electrostatic repulsions of the ammonium moieties inhibiting aggregation. However, a transition to hydrogels is observed at higher pH where the CNC-NH2 are neutral and the attractive forces based on hydrogen bonding dominate. The opposite behavior is observed for CNC-CO2H, which are dispersible at high pH and form gels in an acidic environment. We further show that these pH-responsive CNCs can be incorporated into a poly(vinyl acetate) matrix to yield mechanically adaptive pH-responsive nanocomposite films.
| Original language | English |
|---|---|
| Pages (from-to) | 1001-1006 |
| Number of pages | 6 |
| Journal | ACS Macro Letters |
| Volume | 1 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2012 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Organic Chemistry
- Materials Chemistry
- Polymers and Plastics
- Inorganic Chemistry
Cite this
PH-responsive cellulose nanocrystal gels and nanocomposites. / Way, Amanda E.; Hsu, Lorraine; Shanmuganathan, Kadhiravan; Weder, Christoph; Rowan, Stuart J.
In: ACS Macro Letters, Vol. 1, No. 8, 2012, p. 1001-1006.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - PH-responsive cellulose nanocrystal gels and nanocomposites
AU - Way, Amanda E.
AU - Hsu, Lorraine
AU - Shanmuganathan, Kadhiravan
AU - Weder, Christoph
AU - Rowan, Stuart J.
PY - 2012
Y1 - 2012
N2 - We show that functionalization of the surface of cellulose nanocrystals (CNCs) with either carboxylic acid (CNC-CO2H) or amine (CNC-NH 2) moieties renders the CNCs pHresponsive. At low pH, where the amine groups are protonated, CNC-NH2 forms aqueous dispersions in water on account of electrostatic repulsions of the ammonium moieties inhibiting aggregation. However, a transition to hydrogels is observed at higher pH where the CNC-NH2 are neutral and the attractive forces based on hydrogen bonding dominate. The opposite behavior is observed for CNC-CO2H, which are dispersible at high pH and form gels in an acidic environment. We further show that these pH-responsive CNCs can be incorporated into a poly(vinyl acetate) matrix to yield mechanically adaptive pH-responsive nanocomposite films.
AB - We show that functionalization of the surface of cellulose nanocrystals (CNCs) with either carboxylic acid (CNC-CO2H) or amine (CNC-NH 2) moieties renders the CNCs pHresponsive. At low pH, where the amine groups are protonated, CNC-NH2 forms aqueous dispersions in water on account of electrostatic repulsions of the ammonium moieties inhibiting aggregation. However, a transition to hydrogels is observed at higher pH where the CNC-NH2 are neutral and the attractive forces based on hydrogen bonding dominate. The opposite behavior is observed for CNC-CO2H, which are dispersible at high pH and form gels in an acidic environment. We further show that these pH-responsive CNCs can be incorporated into a poly(vinyl acetate) matrix to yield mechanically adaptive pH-responsive nanocomposite films.
UR - http://www.scopus.com/inward/record.url?scp=84874227834&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84874227834&partnerID=8YFLogxK
U2 - 10.1021/mz3003006
DO - 10.1021/mz3003006
M3 - Article
AN - SCOPUS:84874227834
VL - 1
SP - 1001
EP - 1006
JO - ACS Macro Letters
JF - ACS Macro Letters
SN - 2161-1653
IS - 8
ER -