Blowing Up Reversibility In Biomolecular Self-Assembly.

The self-assembly of hydrogels involves the interplay of many processes: thermodynamic demixing, molecular crosslinking and molecular conformational changes. Interactions among these processes lead to complex structures encompassing many length-scales. Here, we monitor experimentally changes of the structure of biomolecular aggregates during the melting of an agarose gel, that is during the inverse process of gelation, which exhibits a large hysteresis. Observations on different lengthscales clarify the role of the processes involved in sustaining irreversibility.