Budnyak Tetyana M, Aminzadeh Selda, Pylypchuk Ievgen V, Riazanova Anastasia V, Tertykh Valentin A, Lindström Mikael E, Sevastyanova Olena
Division of Wood Chemistry and Pulp Technology, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden.
Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 General Naumov Str., 03164 Kyiv, Ukraine.
Nanomaterials (Basel). 2018 Nov 18;8(11):950. doi: 10.3390/nano8110950.
The development of advanced hybrid materials based on polymers from biorenewable sources and mineral nanoparticles is currently of high importance. In this paper, we applied softwood kraft lignins for the synthesis of lignin/SiO₂ nanostructured composites. We described the peculiarities of composites formation in the sol-gel process through the incorporation of the lignin into a silica network during the hydrolysis of tetraethoxysilane (TEOS). The initial activation of lignins was achieved by means of a Mannich reaction with 3-aminopropyltriethoxysilane (APTES). In the study, we present a detailed investigation of the physicochemical characteristics of initial kraft lignins and modified lignins on each step of the synthesis. Thus, 2D-NMR, P-NMR, size-exclusion chromatography (SEC) and dynamic light scattering (DLS) were applied to analyze the characteristics of pristine lignins and lignins in dioxan:water solutions. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) were used to confirm the formation of the lignin⁻silica network and characterize the surface and bulk structures of the obtained hybrids. Termogravimetric analysis (TGA) in nitrogen and air atmosphere were applied to a detailed investigation of the thermal properties of pristine lignins and lignins on each step of modification. SEM confirmed the nanostructure of the obtained composites. As was demonstrated, the activation of lignin is crucial for the sol-gel formation of a silica network in order to create novel hybrid materials from lignins and alkoxysilanes (e.g., TEOS). It was concluded that the structure of the lignin had an impact on its reactivity during the activation reaction, and consequently affected the properties of the final hybrid materials.
基于生物可再生资源聚合物和矿物纳米颗粒的先进杂化材料的开发目前具有高度重要性。在本文中，我们将软木硫酸盐木质素应用于木质素/SiO₂纳米结构复合材料的合成。我们描述了在四乙氧基硅烷（TEOS）水解过程中通过将木质素掺入二氧化硅网络，在溶胶 - 凝胶过程中复合材料形成的特点。木质素的初始活化通过与3 - 氨丙基三乙氧基硅烷（APTES）的曼尼希反应实现。在该研究中，我们对合成各步骤中初始硫酸盐木质素和改性木质素的物理化学特性进行了详细研究。因此，应用二维核磁共振（2D - NMR）、磷核磁共振（P - NMR）、尺寸排阻色谱（SEC）和动态光散射（DLS）来分析原始木质素和二氧六环：水溶液中木质素的特性。采用X射线光电子能谱（XPS）和傅里叶变换红外光谱（FTIR）来确认木质素 - 二氧化硅网络的形成，并表征所得杂化物的表面和体相结构。在氮气和空气气氛中进行热重分析（TGA），以详细研究原始木质素和改性各步骤中木质素的热性能。扫描电子显微镜（SEM）证实了所得复合材料的纳米结构。结果表明，木质素的活化对于二氧化硅网络的溶胶 - 凝胶形成至关重要，以便从木质素和烷氧基硅烷（例如TEOS）制备新型杂化材料。得出的结论是，木质素的结构在活化反应过程中对其反应性有影响，从而影响最终杂化材料的性能。
