Janus Colloidal Dimer by Intramolecular Cross-Linking in Concentrated Solutions

We propose a new method to large-scale synthesize polymeric colloidal dimers by electrostatically-mediated intramolecular cross-linking of an example di-block copolymer of poly(isoprene)- b -poly(vinylpyridine) (PI- b -P4VP) in highly concentrated solutions. The synthesis is orthogonally performed in a highly polar solvent such as DMSO. The first colloid is achieved by intramolecular cross-linking of the PI block with 1,6-hexanediisothiocyanate after modification with 2-mercaptoethylamine hydrochloride to introduce an electrostatic interaction. The Janus single-chain nanoparticle of c PI-P4VP is derived. In the sequential step, the other colloid is achieved by intramolecular cross-linking the P4VP block of c PI-P4VP with 1,5-diiodopentane after modification with iodoethane. The polymer colloidal dimer of c PI- c P4VP is thus achieved. The Janus c PI- c P4VP dimer is composed of two different domains: the c PI containing residual amine and cyanate groups and the c P4VP containing residual pyridine and quaternized groups. The dimer can be synthesized at a higher concentration of 100 mg/mL. A huge family of functional colloidal dimers is expected after selectively loading materials within the desired colloidal domains.