Bioactive cellulose foams produced by mussel-inspired polydopamine coating as a matrix for phenolic acid...

To shift from fossil-derived foams, cellulose-based foams are being increasingly explored, particularly when combined with value-added functionalities such as bioactivity to improve their applicability. In this work, cellulose fibers were modified using a two-step strategy combining dopamine-based coating and laccase-catalyzed ferulic acid modification. The modified fibers were converted to low-density cellulose foams using a wet foam processing method, which is based on mechanical agitation to introduce air and surfactant stabilization mechanisms. The ferulic acid-functionalized fibers were fabricated into cellulose-based foams exhibiting enhanced antioxidant activity (IC₅₀ = 0.5 g/L), measurable antibacterial performance (75%), and moderate changes in moisture uptake (0.00012 g/min). The resulting foams displayed ultra-low densities (11 kg m^-3), high porosity (99%), and compressive moduli (10-180 kPa) and were comparable to values reported for cellulose foams produced via wet-foaming routes, although with lower energy absorption capacities (0.3-32 kJ/m³). Phenolic functionalization was found to influence foam formation, stability, and mechanical behavior in both wet and dry states. Nonionic surfactants yielded foams with lower density, improved flexibility, and good resilience compared to ionic surfactants. Overall, this work demonstrates an integrated approach combining fiber functionalization and wet foam processing to produce multifunctional cellulose foams. Highlighting their potential for active packaging applications.