Synthesis of Lignin Nanofibers with Ionic-Responsive Shells: Water-Expandable Lignin-Based Nanofibrous Mats
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- 作者：Guangzheng Gao ; James Ian Dallmeyer ; John F. Kadla
- 刊名：Biomacromolecules
- 出版年：2012
- 出版时间：November 12, 2012
- 年：2012
- 卷：13
- 期：11
- 页码：3602-3610
- 全文大小：552K
- 年卷期：v.13,no.11(November 12, 2012)
- ISSN：1526-4602
文摘
A series of ionic responsive poly(N-isopropylacrylamide) (PNIPAM) surface-modified lignin nanofiber mats were prepared by aqueous surface-initiated atom transfer radical polymerization (SI-ATRP). PNIPAM brushes with various molecular weights, thickness, and grafting densities were immobilized on electrospun lignin nanofiber mats by adjusting initial monomer concentration and surface initiator density. ATR-FTIR, SEM, TGA, XPS, and water contact angle measurements confirmed successful surface modification. Analysis of the PNIPAM-modified lignin nanofiber mats (Lig-PN) found that the lower critical solution temperature (LCST) was similar to that of PNIPAM and demonstrated ionic responsive characteristics. With increasing ionic concentration, the water contact angles of the Lig-PN increased correspondingly. AFM images showed that the PNIPAM on the lignin nanofiber mat surface expanded in water and contracted in 0.5 M Na2SO4.