Switchable polymer-grafted mesoporous silicaʹs: from polyesters to polyamides biosilica hybrid materials

We report in this piece of work the synthesis of biosilica hybrid materials able to develop from hydrophobic polyesters to intermediate hydrophilic polyesters and then to polyamides through an O–N acyl transfer shift. After demonstration of the O–N acyl shift on a model depsipeptide anchored in the pores of ordered mesoporous silica (OMS), the preparation of three bio oligomer–silica hybrid materials is described. The oligomerisation of protected serine lactones was initiated in the pores of carboxylate functionalized OMS. Hybrid protected serine polyester–OMS were obtained and could be converted (i) into cationic polyesters, which could be switched (ii) into neutral polyamide–OMS in basic conditions through a multi O–N acyl shift.