Synthesis of Catalytic Microswimmers Based on Anisotropic Platinum Sorption on Melamine Barbiturate Supramolecular Structures

Abstract

Herein, a straightforward synthesis approach for the formation of anisotropic microswimmers is proposed as an alternative to a top–down fabrication for asymmetric artificial swimmers. Melamine barbiturate (MBA)–self‐assembled supramolecular crystals are utilized as an asymmetric matrix for selective chemical platinum deposition. Surface functional groups of prevalent crystallographic planes for platinum sorption are presented by acidic sites of the assembly. The formed platinum catalytic layer is separated from the bulk MBA and investigated using X‐Ray photoelectron spectroscopy and scanning electron microscope energy‐dispersive X‐Ray spectroscopy analysis. Both methods confirm platinum adsorption and reduction of platinum ions during the deposition process. The MBA asymmetric swimmers show directional motion in a fuel environment, proved by the mean‐squared displacement study. Previously reported pH‐dependency and encapsulation capacity of MBA opens wide opportunities for functional materials formation.

Supramolecular Assemblies of Melamine-2-Thiobarbiturate and Melamine-Barbiturate-2-Thiobarbiturate: Experimental and Theoretical Studies

“…BA and cyanuric acids have a similar structural motif to TBA. For these compounds, supramolecular assemblies with M are known [24][25][26][27][28][29][30][31][32]. Despite their similar spatial shape, these acids form different co-crystals with M. M cyanurate forms monoclinic crystals with the space group I2/m, composed of flat two-dimensional layers with a threefold rotation axis [33], while for M-BA the symmetry space group was defined as Ccc2 [29].…”