2. Materials and methods
2.1. Raw materials
Wood powder from poplar trees sieved through a 60 mesh was
used as the source of native cellulose fibers. All samples were airdried
and stored at room temperature. The sections were dewaxed
in a Soxhlet apparatus with a 2:1 (v/v) mixture of benzene/ethanol
at 90 ◦C for 6 h. Benzene, ethanol, sodium chlorite, acetic acid,
potassium hydroxide, and other chemicals were of laboratory grade
and used without further purification.