Supplementary Information Files for Investigating the adsorption of anisotropic diblock copolymer worms onto planar silica and nanocellulose surfaces using a quartz crystal microbalance
posted on 2021-11-29, 12:09authored byJoakim Engstrom, Michael S. Reid, Emma E. Brotherton, Eva Malmström, Steven P. Armes, Fiona HattonFiona Hatton
Supplementary Information Files for Investigating the adsorption of anisotropic diblock copolymer worms onto planar silica and nanocellulose surfaces using a quartz crystal microbalance Electrostatic adsorption of cationic polyelectrolytes onto anionic cellulosic substrates is an attractive
route for facile surface modification of biorenewable materials. Recently, attention has focused on
adsorbing cationic spherical diblock copolymer nanoparticles onto model cellulose and/or nanocellulosic
substrates. Herein, we investigate physical adsorption of highly anisotropic copolymer worms bearing
either anionic or cationic charge onto planar silica, cellulose nanocrystal (CNC) or cellulose nanofibril
(CNF) surfaces using quartz crystal microbalance with dissipation monitoring. Electrostatic interactions
dominate in the case of anionic silica and CNC surfaces because the adsorbed mass of cationic worms
was greater than that of anionic worms. However, either anionic or cationic worms could be adsorbed
onto in situ generated CNF substrates, suggesting that additional interactions were involved: hydrogen
bonding, van der Waals forces, and possibly covalent bond formation. Scanning electron and atomic
force microscopy studies of the dried planar substrates after adsorption experiments confirmed the presence of adsorbed copolymer worms. Finally, composite worm/CNF films exhibited restricted swelling behavior when immersed in water compared to reference CNF films, suggesting that the worms reinforce
CNF films by acting as a physical crosslinker. This study is the first investigation of the physical adsorption
of highly anisotropic diblock copolymer worms onto cellulosic surfaces.
Funding
Particle Technology Established Career Fellowship Proposal: Characterisation and Evaluation of New Block Copolymer Nanoparticles
Engineering and Physical Sciences Research Council