Thermogravimetric analysis showed an organic content of 14.4% after polymerization, a noticeable jump from the initiator-functionalized particles (Figure ). The molecular weight of the degrafted polymer brushes was 1.02×10 5 as measured by size exclusion chromatography, indicating a grafting density of 0.044 nm -2 . The transmission electron microscope further exhibited the presence of polymer brushes on silica surfaces (Figure ). These results demonstrated that ABC-sequence controlled polymer-inorganic hybrid particles are accessible via surface-initiated free radical polymerization of 4-thiocyanatobut-1-ene. In summary, we have developed a cyano group migration radical polymerization. This strategy allows us to homopolymerize linear α-olefins under radical conditions, which is known as a textbook case that is unable to radically homopolymerize. We can also expand this strategy to homopolymerize α-substituted styrenic monomers or acrylate monomers, which are also challenging to homopolymerize. By this cyano group migration pathway, a library of ABC sequence-controlled polyacrylonitrile copolymers is obtained.