Problems currently under experimental and theoretical investigation at MIT include the conformations of membranes and the phases of random copolymers as a model of complex proteins, and the behavior of polymers near fluctuating membranes. The transitions can be induced by slight changes in environment such as temperature, solvent, pH, light, electric field, or magnetic field. A gel can be designed to be responsive to a specific molecule. Phase behaviors of gels appear to be a key to the physical basis of protein functions such as molecular recognition, memory of conformations, motions and catalysis. Experimental and theoretical studies on responsive gels are underway.
Micelles are self-assembling structures of amphiphilic molecules in aqueous solution.
MIT researchers are studying the phase transitions, critical phenomena, and growth of micellar size distributions in the vicinity of the critical point for liquid-liquid phase separation in micellar solutions. These findings are then interpreted using statistical mechanics to construct an appropriate form of the Gibbs free energy, including intermicellar interactions. This phase transition would occur in a gas of non-interacting bosons, driven only by the quantum statistics of the particles. This temperature is only a factor of three above the transition temperature for the gas. Below the transition, the small residual interactions between the atoms should make the Bose-Einstein state superfluid as well.