Selective cellulose fibril release from hardwoods libriform tissue.

Cellulose fibrils are a renewable and biodegradable resource, but their extraction typically requires complete destruction of the original wooden matrix. We present a targeted strategy that enables selective liberation of cellulose microfibrils while preserving the integrity of the surrounding native wood structure. By combining partial delignification with localized surface modification using the ionic liquid 1-butyl-3-methylimidazolium acetate ([Bmim][OAc]), we enable selective liberation and separation of cellulose microfibrils without bulk dissolution or structural damage. This spatially confined treatment exploits the intrinsic anisotropy of the native cellulose architecture, allowing controlled fibril release while maintaining the original orientation and structural framework. These findings reveal how precise chemical interventions can expand the toolbox of cellulose chemistry and unlock new opportunities for advanced wood-based material engineering.