Characteristics of Lignocellulosic-Based Porous Materials with Drying Methods

Cellulose nanofibrils (CNFs) with hydrophilicity, and biodegradability can be used as raw materials for producing porous materials such as aerogels. The aerogels from CNFs are mainly produced through processes involving freeze-drying methods, but such methods are expensive, time-consuming, and suitable for a small-scale production. Therefore, to produce CNFs in a scalable production, a new production method capable of lowering the production cost with a short-drying time is required. In this study, lignocellulose comprising short fiber length and higher residual lignin content was used as a raw material to produce aerogels. A cross-linking agent and a catalyst were added to the lignocellulose suspension. After the reaction was completed, the sample was ice-templated and dried using several drying methods. Among the drying methods applied in this study, the oven-drying is a suitable method to make a cylinder-type aerogel in terms of drying time and strength properties. The drying time of the porous material oven-dried at 105°C was faster than freeze-drying, as well as it developed more tensile and compressive strengths than other drying methods. In addition, the aerogels deformed by an external force, produce excellent recovery ability when submerged in water.