Preparation of Cellulose fiber for Oil Adsorption from Cattail using Two-Stage Pretreatment and Deep Eutectic Solvent Extraction

Cattail cellulose microfibers were produced through a sequence of hydrothermal (HTP) and sodium hydroxide (NaOH) pretreatments, followed by the synthesis of deep eutectic solvent (DESs). This study focuses on assessing the oil-adsorption capacity of these microfibers and explores the preparation of optimized adsorbent materials. The optimization involves DESs synthesis at temperatures of 50, 70, and 90°C, following a two-stage pretreatment process, including HTP at 180°C for 2 h and NaOH treatment at 90°C for 1 h, with an emphasis on maximizing cellulose content, hemicellulose removal, and delignification. Various oil absorption tests were conducted using the resulting absorbent materials under suitable conditions. The findings highlight that the optimal temperature for DESs synthesis is 70°C, resulting in microfibers with a composition of 43.13% cellulose, 3.88% hemicellulose, and 8.6% lignin. These absorbent materials exhibit a remarkable oil absorption capacity, capable of absorbing a variety of oils at a consistent rate of approximately 6–7 g/g. Notably, these cellulose fiber materials outperform conventional oil-absorbing materials while utilizing environmentally abundant cattails.