UV-blocking, transparent and hazy cellulose nanopaper with superior strength based on varied components of poplar mechanical pulp

The components of poplar mechanical pulp (PMP), including cellulose, hemicellulose, and lignin, were regulated through a drop-down synthesis method to prepare a series of mechanically superior raw, hemicellulose-containing (HNP), lignin-containing (LNP), and pure cellulose nanopaper (CNP). The effects of hemicellulose and lignin components on the transparency, haze, and mechanical properties were comprehensively investigated. Consequently, the resulting HNP and LNP combined high transparency (> 95%) and optical haze (> 76%) and possessed superior mechanical properties (182 and 148 MPa tensile strength). The residual lignin content (17.2–14.7 wt%) in LNP gave rise to efficient ultraviolet radiation blocking (~ 100%) in the range of 200–320 nm. Moreover, HNP and LNP exhibited excellent flexibility and hydrophobicity and good thermal stability, which offered the potential for a wide range of applications in solar cells, light softening substrate, and light diffusers.