A waterproof cellulose nanofibril sheet prepared by the deposition of an alkyl ketene dimer on a controlled porous structure

Yujin Oh; Shin Young Park; Simyub Yook; Heenae Shin; Hak Lae Lee; Hye Jung Youn

doi:10.1007/s10570-022-04701-8

A waterproof cellulose nanofibril sheet prepared by the deposition of an alkyl ketene dimer on a controlled porous structure

Cellulose (Lond). 2022;29(12):6645-6657. doi: 10.1007/s10570-022-04701-8. Epub 2022 Jun 30.

Authors

Yujin Oh^{1

2}, Shin Young Park³, Simyub Yook¹, Heenae Shin³, Hak Lae Lee^{1

3

4}, Hye Jung Youn^{1

3

4}

Affiliations

¹ Department of Agriculture, Forestry and Bioresources, College of Agriculture and Life Sciences, Seoul National University, 08826 Seoul, Korea.
² National Institute of Forest Science, 02455 Seoul, Korea.
³ Research Institute of Agriculture and Life Sciences, Seoul National University, 08826 Seoul, Korea.
⁴ State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, 250353 Jinan, Shandong Province China.

Abstract

This study prepared a waterproof cellulose nanofibril (CNF) sheet via the deposition of an alkyl ketene dimer (AKD) on the sheet's controlled porous structure. The porosity of the CNF sheet was controlled by drying under different conditions, which included hot-press drying (HD) and solvent-exchange drying (SD), and the effect on the hydrophobization and water-related barrier performance of the sheet were investigated. When the SD sheet was immersed in an AKD wax solution, the sheet exhibited super-hydrophobicity and a lower water vapor transmission rate, compared with the HD sheet. This indicated that the porous structure of the SD sheet enabled AKD to be adsorbed on both the surface and the inner surface and it filled in the pores of the sheet, thereby giving rise to excellent waterproofing properties. The performance of a hydrophobized SD sheet as a water barrier material was comparable to a linear low-density polyethylene film. This study confirms the possibility for AKD wax to be immersed in a porous CNF sheet and used as a potential barrier material in hydrogel packaging.

Keywords: Alkyl ketene dimer; Cellulose nanofibril; Hydrophobization; Porosity; Waterproof sheet.