Hierarchical ZnO structures templated with amino acid based surfactants

Three different amino acid surfactants were prepared from a coupling reaction of lauroyl chloride with aspartic acid, glutamic acid, and alanine. The newly synthesized amino acid surfactants were used to templated zinc oxide nanostructures using a simple sol–gel reaction. The use of amino acid surfactants with different side chain functionalities produced various ZnO structures. The differences in the molecular geometry of the surfactants, along with hydrophilic head group charges are responsible for the formation of spherical and filamentous mesoporous structures of ZnO. The morphologies of ZnO structures were further explored by using different solvents to change packing parameters and micellization behaviors of surfactants. The use of amino acid based surfactants with various head group functionalities opens the potential use of amino acid-based surfactants for templating various metal oxide nanostructures.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Synthesis of long chain N-acyl amino acids as a new class of surfactant for templating ZnO nanostructures. ► Tuning of the macroscopic structure of ZnO precipitates by changing the packing parameter of the surfactants. ► Formation of spherical and filamentous ZnO with nanostructures. ► Amino acid functional groups play vital roles in controlling overall ZnO morphology.