Green Engineering of Reconfigurable Cellulosic Nonwoven Networks via Nanofibril Binding of Short Cotton Fibers

The development of sustainable nonwovens requires materials that not only originate from renewable resources but can also be repeatedly recovered, regenerated, and reused. In this study, hemp-derived cellulose nanofibrils (HNFs) were used as a renewable structural binder for nonwovens made from short cotton fibers to develop a reconfigurable fiber network capable of repeated deconstruction and reconstruction. Response surface modeling was used to optimize cotton fiber length, cotton content, and HNF loading to achieve a balance between breaking force and water absorbency comparable to a commercial cotton cosmetic pad. The optimum formulation consisted of 4 mm cotton fibers, 2.4 g fiber content, and 146 mg HNF loading, yielding a breaking force of ∼0.96 N and a water absorbency of 12.2 g/g. Structural analyses revealed that HNF loading was the primary factor dominating network consolidation, increasing fiber–fiber interactions, bulk density, and breaking force while reducing porosity and water absorbency. Repeated deconstruction–reconstruction cycles gradually decreased breaking force and increased water absorbency, accompanied by small but cumulative material losses during processing. The addition of 30 mg HNF during each reconstruction cycle maintained around 97–99% of the original breaking force and water absorbency over four regeneration cycles despite ongoing material losses. These findings show that targeted replenishment of HNF binder can restore the material properties of reconstructed cellulose fiber networks without replacing the entire material.