Do keratin, protein, and silicone treatments prevent water from reaching the hair, knowing that they chemically coat the hair without having a tangible mass and disappear after several washes?

We have no knowledge of the true nature of the mentioned materials. If they are insulative and prevent water from reaching the hair, their removal is obligatory before ablution, unless they are necessary for treatment, in which case it is permissible to wipe over them. However, if they do not prevent water from reaching [the hair], their removal is not obligatory.