Organically Functionalized Magnesium Phyllosilicates: Surface Engineering and Antibacterial Performance

Viktoria Sakavitsi; Renia Fotiadou; Mohammed Subrati; Kasibhatta Kumara Ramanatha Datta; Turki N Baroud; Swarnamayee Behera; Konstantinos Spyrou; Mohamed A Hammami; Panagiota Zygouri; Haralambos Stamatis; Ioannis V Yentekakis; Dimitrios P Gournis

doi:10.1021/acsomega.5c02154

Organically Functionalized Magnesium Phyllosilicates: Surface Engineering and Antibacterial Performance

ACS Omega. 2025 Jul 17;10(29):31568-31576. doi: 10.1021/acsomega.5c02154. eCollection 2025 Jul 29.

Authors

Affiliations

¹ Department of Materials Science and Engineering, University of Ioannina, Ioannina 45110, Greece.
² Laboratory of Biotechnology, Department of Biological Applications and Technology, University of Ioannina, 45110 Ioannina, Greece.
³ Functional Nanomaterials Laboratory, Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu 603203, India.
⁴ Interdisciplinary Research Center for Membranes and Water Security and Department of Materials Science and Engineering, King Fahd University of Petroleum & Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
⁵ Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States.
⁶ Laboratory of Physical Chemistry & Chemical Processes, School of Chemical and Environmental Engineering, Technical University of Crete (TUC), GR-73100 Chania, Crete, Greece.
⁷ Institute of GeoEnergy, Foundation for Research and Technology-Hellas, GR-73100 Chania, Crete, Greece.

Abstract

Synthetic clay analogues (SCAs) of a new organosilicate layered material family, in contrast to common clays, are produced via an in situ room-temperature sol-gel route, providing the possibility for the design and synthesis of diverse, tailor-made functional groups on the surface and interior of the synthetic clay sheets. In this work, we introduce organophyllosilicates bearing different functional end groups, which are synthesized by a magnesium metal salt precursor and organosilanes such as (3-aminopropyl)-triethoxysilane (APTEOS), N-[3-(trimethoxysilyl)-propyl]-ethylenediamine (EDAPTEOS), N-(3-trimethoxysilylpropyl)-diethylenetriamine (TAPTMOS), 1,4-bis-(triethoxysilyl)-benzene (BTB), tetraethyl orthosilicate (TEOS), 3-glycidoxypropyltrimethoxysilane (GLYMO), and (3-chloropropyl)-trimethoxysilane (CPTMOS). The surface free energy for various organosynthetic clay analogues lies in the 29-252 mJ/m² range. SCA's antimicrobial activity was tested against both Gram-negative and Gram-positive bacteria to evaluate the effect of surface functionalization on the viability of these microorganisms. The amino-SCAs displayed higher antibacterial activity compared to epoxy-SCAs, presenting a dose-dependent effect and a structure-dependent motif. Furthermore, Gram-positive bacteria were more susceptible to SCA treatment than Gram-negative.