Interfacial activity and Pickering stabilization of kraft lignin particles obtained by solvent fractionation

This study aims to overcome the challenges of high-value utilization of technical lignins that encounters chemical complexity, heterogeneity and broad molecular mass distribution. Kraft lignin was fractionated through a practical strategy involving sequential dissolution in solvents of different polarities (water, tetrahydrofuran, and water/tetrahydrofuran v/v = 3/7). Lignin self-assembled drawing on the anti-solvent method, generating particles of controllable surface energy. Considering the governing factors in multiphase stabilization, the morphology, wetting characteristics and chemical composition of the kraft lignin particles (KLPs) were examined as a means to achieve controllable Pickering stabilization of oil-in-water (O/W) emulsions. The most anionic and hydrophilic KLPs formed aggregated networks (∼185 nm), which acted as a surfactant-type emulsifier following reversible adsorption at the O/W interfaces. Notably, the particles of the least hydrophilicity (∼146 nm) displayed a characteristic hollow structure. Such particles adsorbed slowly and weakly at the O/W interface, forming a viscoelastic layer around the oil droplets. The smallest lignin particles (∼39 nm) presented an intermediate hydrophilic character. They were uniform in size and formed rigid interfacial layers on the oil droplets. Accordingly, the devised relationship between particle morphogenesis and O/W stabilization capacity enabled the customization of lignin (size and wetting characteristics), allowing broader utilization in multiphase systems.

Description

Funding Information: The authors are grateful for the support from the National Natural Science Foundation of China (Grant no. 31770623 and 31730106), the Chinese Scholar Committee, the Postgraduate Research & Practice Innovation Program of Jiangsu Province (KYCX20_0856), the Priority Academic Program Development of the Jiangsu Higher Education Institutions of China, the Canada Excellence Research Chair Program (CERC-2018-00006), the Canada Foundation for Innovation (Project number 38623), and the Researchers Supporting Project number (RSP2023R138), King Saud University, Riyadh, Saudi Arabia. Publisher Copyright: © 2023 The Royal Society of Chemistry.

DOI

10.1039/d3gc00692a

Citation

Tian , J , Chen , J , Wang , P , Guo , J , Zhu , W , Khan , M R , Jin , Y , Song , J & Rojas , O J 2023 , ' Interfacial activity and Pickering stabilization of kraft lignin particles obtained by solvent fractionation ' , Green Chemistry , vol. 25 , no. 9 , pp. 3671-3679 . https://doi.org/10.1039/d3gc00692a

Permanent link to this item

https://urn.fi/URN:NBN:fi:aalto-202306053610

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[article-cris] Kemian tekniikan korkeakoulu / CHEM

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