点击反应制备木质素-纳米SiO_2复合微粒及其结构表征

以竹木质素为原料,利用Cu(Ⅰ)催化的炔基-叠氮环加成点击反应将木质素修饰到纳米SiO_2材料表面,制备木质素-纳米SiO_2复合微粒(LS-NPs)。首先采用硅烷基化反应在纳米SiO_2微粒表面引入叠氮结构,并由竹木质素制备炔基木质素,再通过Cu(Ⅰ)催化炔基木质素与叠氮基纳米SiO_2的点击反应生成含三氮唑结构单元的LS-NPs。采用红外光谱(FT-IR)、元素分析(EA)、X射线光电子能谱(XPS)等分析手段表征了LS-NPs的化学结构,并通过扫描电镜(SEM)、透射电镜(TEM)、Zeta电位分析仪和热重分析(TGA)等表征方法考察了LS-NPs的形貌结构和理化性质。结果表明,点击反应成功将木质素结构通过三氮唑单元接枝到纳米SiO_2表面,LS-NPs微粒为球形,粒径为50~100 nm,分散性能和热稳定性能均有明显提高。

Preparation and Characterization of Lignin-silica Nanoparticles via Click Reaction

Lignin-silica nanoparticles ( LS-NPs) were prepared by grafting biodegradable lignin onto silica nanoparticles surface via the copper(I) catalyzed azide-alkyne cycloaddition reaction using bamboo lignin as raw material. Azido group was firstly grafted onto the surface of silica nanoparticles by silanization reaction, then the azido silica nanoparticles were modified with propargylated lignin obtained from bamboo lignin to yield LS-NPs through triazole unitsvia click reaction catalyzed by copper( I) . The chemical structures of LS-NPs were characterized by FT-IR, elemental analysis and XPS. The morphology and physicochemical properties of LS-NPs were investigated by scanning electron microscopy ( SEM ) , transmission electron microscopy ( TEM) , Zeta potential and thermal gravimetric analysis ( TGA) . Experimental results indicated that the diameter of LS-NPs was ranged from 50 to 100 nm. Particularly, the dispersibility and thermo stability of LS-NPs improved significantly.