Theoretical study of thermoresponsive dendritic polymeric micelles: Micellar phase control and the extraction of organic molecules by temperature effects

Abstract

Smart dendritic micelles are stimuli-sensitive dendritic polymeric micelles that combine the characteristics of double-hydrophilic diblock copolymers and hyperbranched dendritic molecules. The micellar phase control of the smart dendritic micelles consisting of Boltorn-H40 hyperbranched dendrimer and poly(N,N-diethylacrylamide)-b-poly(2-(dimethylamino)ethyl methacrylate) diblock copolymer (H40-PDEA–PDMA) and their capacity to extract organic molecules in an aqueous environment are explored using dissipative particle dynamics simulations. The mesoscopic outcomes show that the H40-PDEA–PDMA micelles exhibit two consecutive low critical solution temperatures and three specific conformations with a cloud point: (1) stable dendritic micelles with a dendritic-H40 core and double micellar corona (PDEA-PDMA) at room temperature, (2) dendritic micelles with a core-shell (dendrimer-H40-PDEA) and PDMA corona at intermediate temperature, and (3) polymeric particles with a dendritic-H40 core and polymeric double-shell (PDEA-PDMA) at high temperature. The thermal behaviour of smart dendritic micelles is exploited for the extraction of rose bengal organic molecules from an aqueous solution. The extraction process of organic molecules consists of three transitory stages: molecular loading on the dendritic-H40 core, molecular encapsulation via core-shell formation, and the generation of compact polymeric particles with a dendritic-H40 core and polymeric double-shell via a cloud point through temperature effects. All micellar phases and transitory states that include the H40-PDEA–PDMA micelles in the thermal process are analysed in detail. Our simulations are in agreement with the experimental outcomes observed for this smart dendritic material.