Designing enhanced entropy binding in associative polymers

Abstract

Associative polymers are a class of functionalised polymeric objects in which a fraction of the monomers can bind to each other, forming either intra- or inter-polymer bonds. If the chain flexibility is large enough and the associative monomers can form only single bonds, then at low density bonding takes place essentially within the same polymer, forming soft nano-objects named single-chain nanoparticles (SCNP). At larger densities, these particles form an interconnected spanning network, and a continuous cross-over from isolated SCNPs to a network state has been observed in experiments and simulations, with no hints of a first-order transition, consistent with predictions of mean-field theory.
In this contribution, I will show by theory and simulation that a judicious design of the patterns of reactive monomers along the polymer chain can drive a fully-entropic gas-liquid phase separation in SCNP systems, achieving control over the discontinuous (first-order) change, from a phase of diluted (fully-bonded) polymers to a phase in which polymers entropically bind to each other to form a (fully-bonded) polymer network.
I will show that this effect is robust, and rests on the balance between the distinct entropic contributions controlling the binding, which can be exploited to design new self-assembling systems, as well as to better understand phase separation phenomena in associative (bio-)macromolecular systems.

Who is Lorenzo Rovigatti?

Lorenzo Rovigatti is an associate professor at the Physics Department of the Sapienza University of Rome. He holds a PhD in Materials Science and was a Lise Meitner Fellow at the University of Vienna (Austria) and a Marie Curie Fellow at the University of Oxford (UK). He is a computational physicist working on soft matter systems such as colloids, polymers and self-assembling biomatter.

A Quantum of Matter

Quantum of Matter is a series of events dedicated to the research in Physics of Matter that is carried out in the Physics Department of the University of Trento.  The goal of A Quantum of Matter is to develop synergies and collaborations between research groups: for this reason, the seminars will focus not only on the results obtained, but also on the techniques employed by the groups and on the possible research themes that could be developed in partnership, leaving plenty of room for exchange of opinions and discussion.