Supplementary Information Files for Investigating the adsorption of anisotropic diblock copolymer worms onto planar silica and nanocellulose surfaces using a quartz crystal microbalance

Supplementary Information Files for Investigating the adsorption of anisotropic diblock copolymer worms onto planar silica and nanocellulose surfaces using a quartz crystal microbalance<br>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.

使用石英晶体微天平（quartz crystal microbalance）研究各向异性二嵌段共聚物蠕虫状胶束在平面二氧化硅与纳米纤维素表面吸附行为的补充信息文件
将阳离子聚电解质静电吸附于阴离子纤维素基材表面，是实现生物可再生材料便捷表面改性的极具应用前景的途径。近期，研究焦点多集中于将阳离子球形二嵌段共聚物纳米颗粒吸附于模式纤维素及/或纳米纤维素基材表面。本文中，我们采用带耗散监测的石英晶体微天平（quartz crystal microbalance with dissipation monitoring），探究了携带阴离子或阳离子电荷的高各向异性共聚物蠕虫状胶束在平面二氧化硅、纤维素纳米晶（CNC）以及纤维素纳米纤丝（CNF）表面的物理吸附行为。对于阴离子型二氧化硅与CNC表面，静电相互作用占据主导：阳离子蠕虫状胶束的吸附质量高于阴离子蠕虫状胶束。但原位生成的CNF基材可吸附阴离子或阳离子型蠕虫状胶束，这表明体系中存在额外相互作用：氢键、范德华力，或可能存在共价键形成。吸附实验结束后对干燥平面基材开展的扫描电子显微镜与原子力显微镜表征，证实了共聚物蠕虫状胶束的吸附存在。最后，与纯CNF薄膜参比样相比，蠕虫状胶束/CNF复合薄膜在水中浸泡时表现出受限溶胀行为，这表明蠕虫状胶束可作为物理交联剂强化CNC薄膜性能。本研究是首次针对高各向异性二嵌段共聚物蠕虫状胶束在纤维素表面的物理吸附行为开展的探究。