The part of the sentence "full of unknown" is correct and usable in written English.
It can be used in contexts where you want to emphasize something is filled with the unknown or uncertain. For example: "The future is full of unknowns and possibilities."
In the five months she spent as a first-time candidate, Liz Cheney found politics to be full of unknown unknowns — "things we do not know we don't know," as her father's friend Donald Rumsfeld would put it.
Meanwhile, there is growing recognition that climate engineering, nanotechnology and other emerging technologies are full of "unknown unknowns," factors that will not become obvious until they are put into widespread use at a scale impossible to turn back, as happened, in a sense, with the atomic bomb.
Science is full of unknown discoveries.
Now begins a Conservative-Liberal era full of unknown risks – and the chance for Labour to renew itself once more.
Dahl never forgot the delights of that plain gray box full of unknown confections, and the thrill of passing judgment.
The mist rolls into the town as a mystery at first, delicate and light gray and full of unknown possibility.
This example demonstrates that in some cases MS and MS n characterization is insufficient for full identification of unknown bioactive compounds.
It's full of virtually unknown places, Parisian people, stories and, above all, evokes the atmosphere of the city.
The Doctor's world is full of the unknown and someone else who is fascinated by secrets is chatshow host Jon Stewart, who quizzes a CIA insider – aka Jerry Seinfeld – with hilarious results.
On Friday, he described an apartment littered with jars full of an unknown liquid, other jars full of ammunition and yet more filled with what he said looked like mortar rounds.
The authorities have described the apartment as littered with jars, some full of an unknown liquid, other with ammunition and still more with what was described as looking like mortar rounds.
