No. Every intellectual substance is altogether immaterial because the operation belonging to anything is according to the mode of its substance and to understand is an altogether immaterial operation, as appears from its object, whence any act receives its species and nature.
For a thing is understood according to its degree of immateriality; because forms that exist in matter are individual forms which the intellect cannot apprehend as such.
But things distinguished by the intellect are not necessarily distinguished in reality; because the intellect does not apprehend things according to their mode, but according to its own mode.
Hence material things which are below our intellect exist in our intellect in a simpler mode than they exist in themselves.
Angelic substances, on the other hand, are above our intellect; and hence our intellect cannot attain to apprehend them, as they are in themselves, but by its own mode, according as it apprehends composite things; and in this way also it apprehends God.
Although there is no composition of matter and form in an angel, yet there is act and potentiality. And this can be made evident if we consider the nature of material things which contain a twofold composition.
The first is that of form and matter, whereby the nature is constituted. Such a composite nature is not its own existence but existence is its act. Hence the nature itself is related to its own existence as potentiality to act.
Therefore if there be no matter, and supposing that the form itself subsists without matter, there nevertheless still remains the relation of the form to its very existence, as of potentiality to act. And such a kind of composition is understood to be in the angels; and this is what some say, that an angel is composed of, "whereby he is," and "what is," or "existence," and "what is," as Boethius says. For "what is," is the form itself subsisting; and the existence itself is whereby the substance is; as the running is whereby the runner runs.
But in God "existence" and "what is" are not different. Hence God alone is pure act.