Unusual Shell Morphologies of Responsive Amino Core‐Shell Microgels Induced by pH During Shell Synthesis

Abstract

The properties of pH‐responsive microgels are strongly influenced by the pH value during synthesis. In this work, based on a N‐n‐propylacrylamide (NNPAM) core with N‐3‐(dimethylamino)propylmethacrylamide (DAPMA) as a comonomer, a series of core‐shell microgels with shells from NNPAM and N‐(3‐aminopropyl)methacrylamide hydrochloride (APMH) were synthesized at different pH values. While the swelling behavior was studied with temperature‐ and angle‐dependent photon correlation spectroscopy (PCS), the size and morphology were also investigated by means of atomic force microscopy (AFM) and static light scattering (SLS). At acidic pH, rather monodisperse microgels with a very fuzzy shell are obtained. The microgels evolve particulate structures on their shell at intermediate pH until not only a core‐shell microgel but also a secondary microgel species is produced at basic pH. By altering the synthesis pH, it is possible to influence the morphology of core‐shell microgels to suit future applications like uptake and release of drugs or surface modification.This article is protected by copyright. All rights reserved