Slow kinetics of water escape from randomly folded foils

We study the kinetics of water escape from balls folded from square aluminum foils of different thickness and edge size. We found that the water discharge rate obeys the scaling relation Q∝V_P(M-M_r)^α with the universal scaling exponents α=3±0.1, where V_P is the volume of pore space, M(t) is the actual mass of water in the ball, and M_r is the mass of residual water. The last is found to be a power-law function of V_P. The relation of these findings to the fractal geometry of randomly folded matter is discussed.