Synthesis and characterization of poly(acrylic acid) brushes: 'Grafting-onto' route

摘要

A guideline for the synthesis of poly(acrylic acid) brushes on planar silica surfaces by the "grafting-onto" approach is described. It is demonstrated that some thermal precautions must be taken to obtain extended brushes. It is also shown that neutron reflectivity is well suited for the characterization of each step of the synthesis, while it is (unfortunately) rarely used for that purpose. The steps are the following: first, the substrates are covered with a self-assembled monolayer of epoxy-terminated molecules; then, the poly(tert-butyl acrylate) brushes are built using preformed and end-functionalized chains; finally, the deprotection of the ester group is performed using a pyrolysis reaction to convert the poly(tert-butyl acrylate) brushes into poly(acrylic acid) brushes.