Interfacial morphology and nanomechanics of cement of the barnacle, Amphibalanus reticulatus on metallic and non-metallic substrata

Abstract

The barnacle exhibits a high degree of control over its attachment onto different types of solid surface. The structure and composition of barnacle cement have been reported previously, but mostly for barnacles growing on low surface energy materials. This article focuses on the strategies used by barnacles when they attach to engineering materials such as polymethylmethacrylate (PMMA), titanium (Ti) and stainless steel 316L (SS316L). Adhesion to these substrata is compared in terms of morphological structure, thickness and functional groups of the primary cement, the molting cycle and the nanomechanical properties of the cement. Structural characterization studies using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in conjunction with nanomechanical characterization and infrared spectroscopy (FTIR) are used to understand the differences in the adhesion of primary barnacle cement to the different substrata. The results provide new insights into understanding the mechanisms at work across the barnacle–substratum interface.

Keywords:

• barnacle cement
• titanium
• stainless steel 316L
• PMMA
• interfacial morphology
• nanomechanics

Acknowledgements

The contact angle measurements were carried out at the Department of Biotechnology, IIT Madras, which is gratefully acknowledged. The authors thank Ms D. Kanchanamala, Senior Technical Assistant, IIT Madras, for the TEM imaging. The authors also thank the Sophisticated Analytical Instruments Facility (SAIF), IIT Madras, for carrying out the FTIR measurements.