Stimuli-responsive mechanically adaptive polymer nanocomposites

Kadhiravan Shanmuganathan, Jeffrey R. Capadona, Stuart J. Rowan, Christoph Weder

Research output: Contribution to journalArticlepeer-review

126 Citations (Scopus)


A new series of biomimetic stimuli-responsive nanocomposites, which change their mechanical properties upon exposure to physiological conditions, was prepared and investigated. The materials were produced by introducing percolating networks of cellulose nanofibers or "whiskers" derived from tunicates into poly(vinyl acetate) (PVAc), poly(butyl methacrylate) (PBMA), and blends of these polymers, with the objective of determining how the hydrophobicity and glass-transition temperature (Tg) of the polymer matrix affect the water-induced mechanically dynamic behavior. Below the T g (∼60-70 °C), the incorporation of whiskers (15.1-16.5% v/v) modestly increased the tensile storage moduli (E') of the neat polymers from 0.6 to 3.8 GPa (PBMA) and from 2 to 5.2 GPa (PVAc). The reinforcement was much more dramatic above T g, where E' increased from 1.2 to 690 MPa (PVAc) and ∼1 MPa to 1.1 GPa (PBMA). Upon exposure to physiological conditions (immersion in artificial cerebrospinal fluid, ACSF, at 37 °C) all materials displayed a decrease in E'. The most significant contrast was seen in PVAc; for example, the E' of a 16.5% v/v PVAc/whisker nanocomposite decreased from 5.2 GPa to 12.7 MPa. Only a modest modulus decrease was measured for PBMA/whisker nanocomposite; here the E' of a 15.1% v/v PBMA/whisker nanocomposite decreased from 3.8 to 1.2 GPa. A systematic investigation revealed that the magnitude of the mechanical contrast was related to the degree of swelling with ACSF, which was shown to increase with whisker content, temperature, and polarity of the matrix (PVAc > PBMA). The mechanical morphing of the new materials can be described in the framework of both the percolation and Halpin-Kardos models for nanocomposite reinforcement, and is the result of changing interactions among the nanoparticles and plasticization of the matrix upon swelling.

Original languageEnglish
Pages (from-to)165-174
Number of pages10
JournalACS Applied Materials and Interfaces
Issue number1
Publication statusPublished - 2010 Jan 27
Externally publishedYes


  • Biomimetic
  • Cellulose nanofibers
  • Mechanically adaptive
  • Polymer nanocomposite
  • Responsive

ASJC Scopus subject areas

  • Materials Science(all)


Dive into the research topics of 'Stimuli-responsive mechanically adaptive polymer nanocomposites'. Together they form a unique fingerprint.

Cite this