Multifunctional lignin cellulose nanofibril thin films

Cellulose and lignin are the first and second most abundant biomaterials in the world.

Cellulose nanofibrils (CNF) extracted from wood show highest mechanical strength and light weight, making them ideal for bio-based, porous skeleton networks. Yet, CNF are hydrophilic limiting their applications. Lignin as byproduct from cellulose production shows UV-blocking capabilities and is hydrophobic.

Colloidal lignin nanoparticles (CLP) are obtainable via self-assembly and solvent shifting in aqueous solution.

Thus, combining CNF and CLP allows for creating CLP/CNF hybrid nanomaterials in a bottom up way using spray deposition; these hybrid nanomaterials as thin films maybe considered as thin artificial wood or templates with tunable surface energy for replacing synthetic substrates for organic electronics and photovoltaics (OE / OPV).

Spray deposition itself is a versatile, scalable method and industrially relevant.

In order to tailor the thin film fabrication and combine CLP and CNF in a bottom up approach, we use surface sensitive X-ray and neutron scattering to observe in situ the self-assembly and structure formation of CLP and CNF on the nanoscale in their corresponding hybrid thin films.

We investigate furthermore the influence of typically used solvents in OE on this hybrid materials to verify its useability in OE and OPV.

This novel bottom-up approach combines in ideal way the functionalities of both biomaterials and open new routes for sustainable, renewable OE and OPV.