COLLAPSE OF RANDOMLY SELF-INTERACTING POLYMERS

We use complete enumeration and Monte Carlo techniques to study self-avoiding walks with random nearest-neighbor interactions described by v0q(i)q(j), where q(i) = +/- 1 is a quenched sequence of ''charges'' on the chain. For equal numbers of positive and negative charges (N+ = N-), the polymer with v0 > 0 undergoes a transition from self-avoiding behavior to a compact state at a temperature theta almost-equal-to 1.2v0. The collapse temperature theta(x) decreases with the asymmetry x = \N+ - N-\/(N+ + N-) and vanishes at x almost-equal-to 0.6. For v0 < 0, a theta-point is present at all x.