The Collaborative International Dictionary of English v.0.48:
nonadsorbent \nonadsorbent\, nonadsorptive \nonadsorptive\adj. lacking capacity to adsorb or cause to accumulate on a surface. Opposite of adsorbent. [WordNet 1.5]WordNet (r) 3.0 (2006):
nonadsorbent adj 1: lacking a capacity to adsorb or cause to accumulate on a surface [syn: nonadsorbent, nonadsorptive] [ant: adsorbent, adsorptive, surface-assimilative]