Silicones generally end in -cone, -conol, -col, or -xane and are found in many hair products. If any silicone name has the abbreviation "PEG" or "PPG" in front of it, however, it is water-soluble and will not build up.
Silicones that are not soluble in water, will consistently build up on the hair and will require a surfactant-based shampoo to remove include:
Silicones that are not soluble in water, but whose chemical properties allow it to repel further deposit, helping to prevent buildup (although they will still lock moisture out of the hair and require a surfactant to remove):
A note about amodimethicone: if you do an Internet search on amodimethicone, you will find quite a few sites that list amodimethicone as a silicone that is "slightly" soluble in water as long as two additional ingredients are included in the formulation:
Amodimethicone (and) Trideceth-12 (and) Cetrimonium Chloride (as a mixture in the bottle)
The assumption has always been that the inclusion of Trideceth-12 (a nonionic surfactant) and cetrimonium chloride (a cationic surfactant) render the amodimethicone, non-water soluble on its own, slightly soluble in water and it could be considered okay to use. Turns out that has been a completely incorrect assumption. What the Trideceth-12 and cetrimonium chloride do is render the amodimethicone dispersible in water. Once the amodimethicone is deposited onto the hair shaft and dries to a film, however, it is not water-soluble, will prevent moisture from getting into the hair shaft and will require a surfactant to remove.
Silicones that are slightly soluble in water, but can possibly build up on some types of hair over time, include:
Silicones that are soluble in water and can generally be considered safe to use (in addition to those listed with "PEG" or "PPG" in front of them) include:
Hydrolyzed Wheat Protein Hydroxypropyl Polysiloxane
Lauryl Methicone Copolyol