Mechanical Investigations on Agar Gels Using Atomic Force Microscopy: Effect of Deuteration

• Published in: Macromolecular materials and engineering Vol. 297; no. 3; pp. 214 - 218
• Main Authors: Grant, Colin A., Twigg, Peter C., Savage, Michael D., Woon, W. Hong, Greig, Denis
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-03-2012; WILEY‐VCH Verlag; Wiley
• Subjects: agar gels; Applied sciences; atomic force microscopy; biopolymers; deuteration; Exact sciences and technology; nanoindentation; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Solvent isotope effect; deuteration; Nanoindentation; Mechanical properties; Surface topography; Experimental study; atomic force microscopy; Agarose; agar gels; Concentration effect; Microroughness; Oside polymer; Hydrogel; biopolymers; Deuterium Oxides
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.201100164

The isotopic effect of exchanging deuterium with hydrogen on the mechanical and surface properties of agar gel is examined. The elastic modulus of the D2O gels obtained by AFM nanoindentation is significantly higher (factor of ≈1.5–2) than the modulus found in H2O agar gels. Furthermore, the modulus is independent of loading rate. Surface imaging reveals that the surface roughness gets progressively smaller with increasing agar concentration. All these data suggest that the isotopic replacement of deuterium enhances the mechanical properties of the agar gel, with significant advantages in its use as a biphasic scaffold.
It is demonstrated that the mechanical properties of a naturally occurring gel (agar) can be improved by deuteration. A marked difference in modulus of D2O and H2O gel surfaces is confirmed using AFM nanoindentation. It is shown that the deuteration effect is consistent with increasing concentration and that the gel material shows no rate dependence at low strain. The surface roughness is lower for D2O gels than for H2O gels.