Chiral separations with crosslinked cellulose derivatives attached onto hybrid silica monolith particles via the thiol–ene click reaction
A hybrid silica monolith containing vinyl groups was synthesized by a sol–gel method, and then ground and treated, yielding silica particles with a 3–5 μm particle size and a 10–20 nm pore size. Cellulose derivatives containing 3,5-dimethylphenylcarbamate groups and methacrylate groups regioselectively were then immobilized onto the surface of the above particles by the thiol–ene click reaction using an alkanedithiol as the crosslinking agent, thus forming a solvent-resisting crosslinked network structure attached onto the surface of the particles. The immobilization degree was more than 80%, and the back pressure of the chiral stationary phase (CSP) packed column was relatively low and was maintained at around 3.0 MPa. The as-prepared CSPs were shown to be able to effectively separate various enantiomers with different mobile phases.