Layer-by-Layer Spray-Coating of Cellulose Nanofibrils and Silver Nanoparticles for Hydrophilic Interfaces

Silver nanoparticles (AgNPs) and AgNP-based composite materials have attracted growing interest due to their structure-dependent optical, electrical, catalytic, stimuli-responsive properties. For practical applications, polymeric are often combined with AgNPs provide flexibility offer a scaffold for homogenous distribution of the AgNPs. However, control over assembly process on substrates remains big challenge. Herein, we report fabrication AgNP/cellulose nanofibril (CNF) thin films via layer-by-layer (LBL) spray-coating. The morphology self-assembly increasing number spray cycles characterized by atomic force microscopy (AFM), grazing-incidence small-angle X-ray scattering (GISAXS), wide-angle (GIWAXS). We deduce that an individual AgNP (radius = 15 ± 3 nm) is composed multiple nanocrystallites (diameter 2.4 0.9 nm). Our results suggest assembled into large agglomerates SiO2 during spray-coating, which disadvantageous functionalization. incorporation CNF contributes more uniform its network structure absorbing partially dissolved agglomerates. Furthermore, demonstrate spray-coating AgNP/CNF mixture in similar topography agglomeration patterns compared depositing onto precoated film. Contact-angle measurements UV/vis spectroscopy deposition or within CNFs could increase hydrophilicity AgNP-containing surfaces localized surface plasmon resonance (LSPR) intensity sprayed substrates, suggesting potential applications antifouling coatings label-free biosensors. Thereby, our approach provides platform facile scalable production low rate two different methods as follows: (1) multistep (2) direct mixture. also ability flexible framework directing tailorable wettability plasmonic