Publication details
Chemical and mechanical characterization of plasma-activated and APTES-functionalized glass/epoxy interfaces
| Authors | |
|---|---|
| Year of publication | 2026 |
| Type | Article in Periodical |
| Magazine / Source | Progress in Organic Coatings |
| MU Faculty or unit | |
| Citation | |
| web | https://www.sciencedirect.com/science/article/pii/S0300944026003140 |
| Doi | https://doi.org/10.1016/j.porgcoat.2026.110258 |
| Keywords | Non-thermal plasma; DCSBD; Glass; Functionalization; APTES; Adhesive bonding |
| Attached files | |
| Description | Achieving robust adhesion between epoxy-bonded glass specimens remains challenging due to the inherent inertness and smoothness of the glass surface. This study investigates a dual-stage pretreatment comprising atmospheric-pressure plasma activation followed by functionalization with (3-Aminopropyl)triethoxysilane (APTES). The objective was to use plasma-induced hydroxyl groups to covalently anchor an APTES layer, thereby facilitating nucleophilic reactions between pendant amine groups and the epoxy rings of the adhesive to strengthen the interface. X-ray photoelectron spectroscopy (XPS) confirmed that plasma treatment times of 30–60 s effectively activated the surface by increasing the number of oxygen-containing functional groups. Under optimized silanization conditions, a high-density APTES layer was successfully grafted, as revealed by XPS, which showed a high concentration of free amine groups (27–35%) – theoretically ideal for covalent bonding. However, mechanical testing of silanized low-iron glass joints revealed an unexpected decrease in shear strength relative to the reference (12.6 MPa): the tin side was measured at 9.9 MPa – near the rated strength of the adhesive – while the air side dropped substantially to 2.2 MPa. On the tin side, failure occurred within the substrate, precluding direct assessment of the silane interface; on the air side, failure was localized at the glass/silane interface, confirming insufficient interfacial bonding. XPS analysis suggests that incomplete hydrolysis of ethoxy groups and differences in silane layer density between the two sides contributed to this outcome, with silane multilayer formation also likely playing a role. These results indicate that high chemical functionalization density alone is insufficient to ensure macroscale structural bonding performance. |
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