The word "de materialization" refers to the process of becoming immaterial or intangible. The antonyms for this word would be "materialization" or "tangibility." Materialization refers to the process of becoming material or tangible, while tangibility refers to the quality of being able to be touched, felt, or perceived by the senses. The opposite of de-materialization can also be perceived as "re-materialization," a process of reappearing in a material form. In summary, the antonyms for de-materialization are materialization and tangibility, both of which refer to the opposite process of becoming tangible, available, or perceptible.