Structurally tunable pH-responsive phosphine oxide based gels by facile synthesis strategy

Design and synthesis of nanostructured responsive gels have attracted increasing attention, particularly in the biomedical domain. Polymer chain configurations and nanodomain sizes within the network can be used to steer their functions as drug carriers. Here, a catalyst free facile one-step synthesis strategy is reported for the design of pH-responsive gels and controlled structures in nanoscale. Transparent and impurity-free gels were directly synthesized from trivinylphosphine oxide (TVPO) and cyclic secondary diamine monomers via Michael addition polymerization under mild conditions. NMR analysis confirmed the consumption of all TVPO and the absence of side products, thereby eliminating post purification steps. The small angle X-ray scattering (SAXS) elucidates the nanoscale structural features in gels, i.e., it demonstrates the presence of collapsed nanodomains within gel networks and it was possible to tune the size of these domains by varying the amine monomers and the nature of the solvent. The fa...