Residual lignin in cellulose nanofibrils enhances the interfacial stabilization of Pickering emulsions

Shasha Guo; Xia Li; Yishan Kuang; Jianming Liao; Kai Liu; Jun Li; Lihuan Mo; Shuaiming He; Wenyuan Zhu; Junlong Song; Tao Song; Orlando J Rojas

doi:10.1016/j.carbpol.2020.117223

Residual lignin in cellulose nanofibrils enhances the interfacial stabilization of Pickering emulsions

Carbohydr Polym. 2021 Feb 1:253:117223. doi: 10.1016/j.carbpol.2020.117223. Epub 2020 Oct 20.

Authors

Shasha Guo¹, Xia Li², Yishan Kuang², Jianming Liao², Kai Liu², Jun Li³, Lihuan Mo², Shuaiming He², Wenyuan Zhu⁴, Junlong Song⁴, Tao Song⁵, Orlando J Rojas⁶

Affiliations

¹ State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China; Bioproducts Institute, Departments of Chemical & Biological Engineering, Chemistry, and Wood Science, 2360 East Mall, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
² State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China.
³ State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China. Electronic address: ppjunli@scut.edu.cn.
⁴ Jiangsu Provincial Key Laboratory of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu Province, 210037, China.
⁵ State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China; Jiangsu Provincial Key Laboratory of Pulp and Paper Science and Technology, Nanjing Forestry University, Nanjing, Jiangsu Province, 210037, China. Electronic address: songt@scut.edu.cn.
⁶ Bioproducts Institute, Departments of Chemical & Biological Engineering, Chemistry, and Wood Science, 2360 East Mall, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.

PMID: 33278985
DOI: 10.1016/j.carbpol.2020.117223

Abstract

Lignocellulose nanofibrils (LCNF) were used to prepare oil-in-water Pickering emulsions and to assess the role residual lignin in interfacial stabilization. Two LCNF fractions of similar morphology (length ∼700 nm and width ∼8 nm) and structure (polymorphism and crystallinity) were obtained by microfluidization of fibers obtained by hydrothermal treatment of wood with a recyclable organic acid. The LCNF with higher residual lignin was less hydrophilic and, correspondingly, performed better as Pickering stabilizer, producing emulsions of smaller droplet size and higher resistance to creaming. Long-term emulsion stabilization (over 40 days) was achieved with LCNF at concentrations as low as 0.24 (w/v)% based on emulsion volume. We conclude that LCNF-stabilized Pickering emulsions can be finely tuned by varying the residual lignin content, providing a rationale for LCNF selection according to lignin type and concentration as variables affecting stabilization. Complementary considerations include the possible benefits of the residual lignin in LCNF, including antioxidant and UV absorption properties.

Keywords: Interfacial stabilization; Lignocellulosic nanofibrils; Pickering emulsions; Residual lignin.