1. ● Nanocellulose can be used in different applications only by carefully selecting a favourable characteristics of the material. The nanomaterial properties are driven by its micro- and nanoscopic features, such as structure, shape, strength, ability to self-assemble,.. and surface properties as they drive the interface characteristics and by that the nature of the interactions. ● Hence, with the shift from bulk cellulose to more sophisticated applications and products, it is necessary also to introduce new methods for characterization. ● Multi-Parametric Surface Plasmon Resonance (SPR) enables characterization of dynamic changes in model cellulose thin films and gels in real-time. 1 MP-SPR: A new optical technique for characterization of cellulose structure and kinetic interactions Gold, very thin polymer layers Cellulose, PS, PET, PMMA, SiO2, TiO2, Al2O3, ITO, graphene, CNT, Pt, Pd,...Thickness up to microns Kinetics, Affinity, Concentration, Adsorption/Absorption, Desorption, Adhesion Refractive index, Thickness, Extinction coefficient, Density, Surface coverage, Swelling, Optical dispersion

2. MP-SPR: A new optical technique for characterization of cellulose structure and kinetic interactions Orelma et al, Biomacromolecules (2011) 10 Malmström et.al., Macromolecules (2013) Glass substrate Adhesion layer Plasmonic layer Other material Functionalization Prism Optical interface Flow-cell SENSOR Typical experiment set-up: 1.Background measurement of an SPR sensor (typically SiO 2 or Au) 2.A model cellulose formed on the sensor (typically spin-coating or LB) 3.The sensor is measured in air at two wavelengths (=> thickness and refractive index of the cellulose layer) 4.Additional protective/functional coating can be added in-situ (electrodeposition, LbL) or ex-situ (ALD, CVD,..) 5.Coated sensor is measured in air (=> thickness and refractive index of the coating) 6.Gas or vapour or liquid can be introduced (=> dynamic swelling) 7.Injections of interacting samples can be introduced (=> kinetics of binding, surface coverage, dry mass)

3. MP-SPR: A new optical technique for characterization of cellulose structure and kinetic interactions Barrier coating properties Thickness optimization Dynamic structural changes Polymer at pH 9 Polymer at pH 4 Referenc at pH 9 Reference at pH 4 Interaction kinetics Surface coverage Self-assembly Future steps include testing of other functional characteristics also on cellulose model surfaces. On cellulose model surfaces Orelma et al, Biomacromolecules (2011) Malmström et.al., Macromolecules (2013))