Disordered Heteropolymers with Crosslinks - Phase Diagram and   Conformational Transitions
  We study the phase behavior of random heteropolymers (RHPs) with quenched cross-links, a novel polymer class of technological and biological relevance, and show the possible occurrence of freezing with few chain conformations sampled. The sensitivity of the frozen phase microstructure to the disorder components is elucidated at positive solubility parameter values; at low T's segregated microphases form, while at a finite T, a first order conformational transition occurs, and is attributed to statistical matching of large microphases bounded by cross-links. The end of the symmetry broken regime stabilization by cross-links occurs at a higher T by a second order conformational transition. \\icrophases form, while at a finite T, a first order conformational transition occurs, and is attributed to statistical matching of large microphases bounded by cross-links. The end of the symmetry broken regime stabilization by cross-links occurs at a higher T by a second order conformational transition. 
L. Gutman, E. I. Shakhnovich (Department of Chemistry and Chemical   Biology, Harvard University)