1. Institute of Functional Polymers, School of Materials Science and Engineering, Tongji University, 4800 Cao‐an Road, Shanghai 201804, China;2. Key Laboratory of Advanced Civil Engineering Materials, Tongji University, Ministry of Education, Shanghai 201804, China
Abstract:
The cooperative entrapment of a specified guest is only available for a well‐defined host. Here it is reported that a common host conducts cooperative entrapment of guests. Alkylation of a hyperbranched polyethylenimine (PEI) by epoxy poly(ethylene glycol) monomethyl ethers (PEG1) leads to a water‐soluble PEI@PEG1 ( H1 ). The multifunctional core of H1 is modified to result in H2 – H4, with different polarities and ionic charges. H1 – H4 exist as unimolecular micelles, and can effectively entrap dyes of rose bengal (RB) or eosin Y (EY). Experiments indicate that the guest dyes are exclusively accommodated in the cores of H1 – H4 . The encapsulation proceeds in a cooperative manner, as analysis by the Hill equation (n > 1). It is found that the cooperativity stems from the enhanced π–π stacking of the dyes upon encapsulation, and a polar and ionic environment favors the cooperativity. This is the first example of a cooperative entrapment being realized by a common host.
