Materials Science, Surfaces, Coatings and Films, Materials Chemistry, General Materials Science
39
Scopus Publications
Scopus Publications
Structure-property relationships in dimeric metallosurfactants: counterion-driven modulation of rheology, wettability and antibacterial performance Ana Ivančić, Krunoslav Bojanić, Mirna Perkušić, Ivana Tartaro Bujak, Katarina Marušić, Nives Novosel Vlašić, Tea Mišić Radić, Darija Domazet Jurašin Chemical Engineering Journal Advances, 2026 The development of next-generation surface coatings benefits from surfactant systems whose interfacial and bulk properties can be tuned to achieve targeted functionalities. In this work, we examine the influence of tetrabromometallate counterions, [MBr₄]²⁻ (M = Co, Ni, Cu, Zn), on the rheological, wetting, and antibacterial properties of dimeric metallosurfactants derived from bis(N,N-dimethyl-N-dodecyl)ethylene-1,2-diammonium dibromide (12-2-12). Dissociation of the complex counterions increases ionic strength and promotes micellar transitions from spherical to cylindrical to wormlike aggregates. This results in a pronounced increase in viscosity and viscoelasticity in the low millimolar concentration range, without added salts or co-surfactants.Similarly, at the stainless steel interface, electrostatic screening reduces repulsion between quaternary ammonium headgroups, enabling tighter interfacial packing and improved wetting compared with the metal-free precursor.Antibacterial assays demonstrate potent activity in the low micromolar range against both Gram-positive and Gram-negative bacteria. Antibacterial performance is primarily governed by the amphiphilic dication (12-2-12)²⁺, as evidenced by comparable minimum inhibitory (MIC) and minimum bactericidal (MBC) concentrations across the metallosurfactants and parent surfactant. For all tested species, minimum biofilm eradication concentrations (MBEC) exceed biofilm prevention concentrations (BPC), highlighting the increased resilience of established biofilms while confirming antibiofilm efficacy at micromolar levels.This combination of viscoelasticity, surface wettability, and antibacterial performance is relevant to coating applications through its impact on film retention, thickness control, and bioprotective functionality. The limited influence of the metal ion on these properties allows metal selection to introduce additional functionalities without compromising the fundamental performance of the surfactant.
Atmosphere-Dependent Radiation Stabilization of Stearic Acid on Vaterite CaCO3: A Comparison of Gamma and Electron-Beam Irradiation Helena Biljanić, Urszula Gryczka, Marta Walo, Damir Kralj, Katarina Marušić Polymers, 2026 Calcium carbonate is a widely used filler in polymer composites due to its low cost and ability to improve stiffness, dimensional stability, and impact resistance. However, its hydrophilic surface limits compatibility with nonpolar polymer matrices, making surface modification essential to improve filler dispersion and interfacial adhesion. Stearic acid is commonly applied as a surface modifier for calcium carbonate because it readily chemisorbs onto the mineral surface and forms densely packed self-assembled monolayers that improve hydrophobic character. Despite its widespread use, stearic acid exhibits limited thermal and interfacial stability under polymer processing conditions, motivating the development of stabilization strategies. In this work, gamma and electron-beam irradiation were applied to stearic-acid-modified calcium carbonate to modify the surface-bound stearic acid layer with the aim of enhancing its interfacial stability, surface resistance, and hydrophobic performance, and to evaluate the influence of irradiation atmosphere on these effects. The modified materials were characterized in terms of structural integrity, surface wettability, surface free energy, thermal stability, and optical properties. The results demonstrate that ionizing radiation enhances surface hydrophobicity and coating durability while preserving the crystal structure of the CaCO3 substrate. Gamma irradiation of stearic-acid-modified vaterite exhibited strong atmosphere dependence, with improved hydrophobicity under oxygen-free conditions, whereas electron-beam irradiation showed more robust and oxygen-insensitive behavior. Based on the observed improvements in hydrophobicity, surface free energy, and thermal stability, electron-beam irradiation emerges as a promising and less atmosphere-sensitive approach for producing durable stearic-acid-modified CaCO3 fillers suitable for polymer composite applications.
Microplastics encapsulation in aragonite: efficiency, detection and insight into potential environmental impacts Nives Matijaković Mlinarić, Katarina Marušić, Antun Lovro Brkić, Marijan Marciuš, Tamara Aleksandrov Fabijanić, Nenad Tomašić, Atiđa Selmani, Eva Roblegg, Damir Kralj, Ivana Stanić, Branka Njegić Džakula, Jasminka Kontrec Environmental Science Processes and Impacts, 2024 This study confirms encapsulation of nontreated and humic acid treated polystyrene and polyethylene microplastics into aragonite, main building block of coral skeleton.
