An approach for the multilayer density analysis of polysaccharide thin films at the example of cellulose is presented. We explore whether there is any difference of swelling capacity of the outermost layer (the ‘surface’ or ‘roughness’ layer) in comparison to the bulk layer of these thin films. For this approach, a combination of Multi-Parameter Surface Plasmon Resonance (MP-SPR) Spectroscopy and Atomic Force Microscopy (AFM) has been employed. MP-SPR is based on the determination of refractive index / layer thickness couples, so any change in air or water content in a particular film segment leads to a change in the refractive index of the system, given that the RI of the pure system is known. In detail the refractive index and the film thickness of the cellulose thin film was determined in the first step and afterwards the film was split in a surface and a bulk layer and subjected to data evaluation. As it turned out, the surface layer features a much lower refractive index than the bulk region. This is in alignment with X-ray reflectivity studies of cellulose thin films, which revealed much lower electron density for the outermost layer. Limitations and challenges in the evaluation of the data will be presented.

Multilayer density analysis of cellulose thin films

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.