Photocurable formulations containing trifunctional thiol, trifunctional ene, and antibacterial allylimidazolium salts have been employed for transparent antibacterial coatings. The antibacterial component 1-ally1-3-dodecylimidazolium salt (ADIm) is prepared and chemically attached to polymer networks using a one-step thiol ene photocuring reaction. Ultra-small (USANS) and small angle neutron scattering (SANS) measurements show that the photocured polymers are loosely networked three-dimensional structures with a mass fractal of approximately 2.7 +/- 0.2. The minimum inhibitory concentration (MIC) for the ADIm was determined to be 500 mu g/ml and 15.63 mu g/ml for Escherichia coil (Gram negative) and Staphylococcus aureus (Gram positive) bacteria, respectively. Coating formulations containing 10 mol% of the antibacterial ADIm photocured on glass substrates showed strong antibacterial activity against environmental bacteria such as E. coli and/or S. aureus. (C) 2015 Elsevier B.V. All rights reserved.