Supramolecular Silver Nanoparticle Hydrogels With Controlled Nanoparticle Size and Order: Synthesis Conditions and Possible Mechanism

Nanoparticle (NP)‐gel hybrid systems are multifunctional materials combining the properties of metal NPs with the structural versatility of hydrogels. They find application in advanced technologies, including controlled drug delivery, sensing, flexible electronics, and tissue engineering. Incorporation of metal NPs into a gel matrix offers structural confinement and spatial distribution of the NPs, but the control of the size, size distribution, and spatial organization remains a major challenge. In a recent work, we have shown that silver NPs of controlled size (diameter of 28.0 ± 3.6 Å) can form two‐dimensional arrays of long‐range order coaligned with self‐assembled fibers composed of a biobased bolaamphiphile glycolipid containing a single glucose headgroup opposite to a free carboxylic acid end‐group. The straightforward self‐assembly of the glycolipid with silver ions in water, followed by reduction, generates a silver NP hydrogel with an impressive order of NPs. The synthesis conditions of this process, which offers simplicity and enhanced sustainability are explored here by using and comparing various reduction methods (chemical, photochemical, and radiolytic) as well as by tuning the nature of the silver precursor. This article eventually proposes a mechanism of formation based on the excluded volume of the side‐by‐side assembly of four glycolipid molecules.