Marleen Kamperman: Bioinspired Functional Polymers

Biology provides numerous stimulating illustrations of successful design strategies. As biology evolved to complex designs, synthetic mimics are evolving towards new levels of complexity achieving larger combinations of properties within one material. In my group we utilize biologically inspired strategies to develop polymeric materials for next generation adhesives and functional materials.

In this talk I will present recent developments in mimicking the adhesive secretions of marine animals such as P. californica and M. edulis by creating fully synthetic polymeric systems. Characteristic of the proteins found in the adhesive plaque of mussels and sandcastle worms is a high proportion of cationic, anionic and catecholic residues (hydroxylated tyrosine, DOPA). DOPA is involved in a versatile combination of functions: covalent crosslinking, complexation to mineral substrates, and bonding to hydrophobic (fouled) surfaces. The anionic and cationic residues are often said to be involved in a secondary interaction that aids cohesion, namely complex coacervation. This is an attractive phase separation of mixtures of polyanions and polycations that results in a highly polyelectrolyte-rich phase in equilibrium with almost pure solvent. Complex coacervates have very low surface tensions and are water insoluble, which makes them highly desirable for underwater adhesives. Additionally, they are mechanically well-suited for adhesion due to their high storage and loss moduli that provide, respectively, bonding strength and dissipation of strain. We aim to reproduce the working mechanism of mussels and sandcastle worms by developing a new class of underwater adhesives based on complex coacervates reinforced with physical interactions.

Nature has developed elegant and economical strategies to produce materials with exquisite structure control to accomplish specific functions. The use of these concepts to synthesize and/or process materials (biomimetics) is a rapidly growing area of materials science. In the Kamperman Lab we utilize biologically inspired strategies to develop materials for next generation adhesives and functional materials. The research is a concerted effort to (i) extract principles from biological systems and mimic them to design synthetic polymeric materials; to (ii) experimentally test their adhesion and (iii) clarify the adhesion mechanisms based on quantitative experiments and theoretical modelling.