A strategy to stabilize the confined chiral TPPS J-aggregate by ionic block copolymer

Poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP), with a poly-cation building block, forms electrostatic complexes with the J-type chiral pre-aggregates of 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) in the water inner-phase of the TX-100 reverse microemulsion at pH 1.0 using l-tryptophan as the chiral source. The complexation with PEG₄₅-b-P4VP₆ prevents these chiral pre-aggregates from contacting with each other during the percolation of the droplets, so as to stabilize the circular dichroism intensity and the size of the complexes. After breaking the microemulsion, the PEG₄₅-b-P4VP₆/TPPS aggregates are also prevented from further clustering at optimized ratio of [polymer]/[TPPS], so these complex aggregates disperses in acetone with spherical morphology and well maintain their size and chiral signal for further storing. This method can be considered as one of extracting the confined chiral aggregates as an isolated form apart from the reverse microemulsion.