Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Tarbiat Modares University, Tehran, Iran.
Department of Wood and Paper Science and Technology, Faculty of Natural Resources, Tarbiat Modares University, Tehran, Iran.
Int J Biol Macromol. 2018 Jan;106:1288-1296. doi: 10.1016/j.ijbiomac.2017.08.136. Epub 2017 Aug 31.
Surface functionalization of cellulose nanocrystals (CNCs) is valuable option to tailor properties as well as increase opportunities for their application. In this study, the surface of CNCs was functionalized with 3-aminopropyltriethoxysilane (APTES), without using hazardous solvents and by a direct, simple and straightforward method. APTES was firstly hydrolyzed in water and then adsorbed onto CNC through hydrogen bonds, finally the chain hydrocarbon was covalently linked to the surface of CNC through SiOC bonds which formed via the condensation reaction between hydroxyl and silanol groups. The chemical modification of the CNCs surface was confirmed by ATR-IR and NMR spectroscopy. Experiments conducted by AFM and XRD showed no significant change in the CNC dimensions and crystalline structure as a result of the modification. The EDX and XPS results confirmed the exsistence of APTES onto the CNCs. Silylated CNC exhibited good thermal stability and a greater amount of residual char was formed at 500 °C compared to non-chemically modified CNC. Thus, The silylation of CNCs may offer applications in composite manufacturing, where these nanoparticles have limited dispersibility in hydrophobic polymer matrices, and as nano-adsorbers due to the presence of amino groups attached on the surface.
纤维素纳米晶（CNC）的表面功能化是调整其性能和增加其应用机会的一种有价值的选择。在本研究中，通过直接、简单和直接的方法，在没有使用危险溶剂的情况下，用 3-氨丙基三乙氧基硅烷（APTES）对 CNC 的表面进行了功能化。APTES 首先在水中水解，然后通过氢键吸附到 CNC 上，最后通过 SiOC 键将链烃共价连接到 CNC 表面，该 SiOC 键通过羟基和硅醇基团之间的缩合反应形成。ATR-IR 和 NMR 光谱证实了 CNC 表面的化学修饰。AFM 和 XRD 实验表明，修饰后 CNC 的尺寸和晶体结构没有发生显著变化。EDX 和 XPS 结果证实了 APTES 存在于 CNC 上。与未化学修饰的 CNC 相比，硅烷化 CNC 表现出更好的热稳定性，在 500°C 时形成了更多的残余炭。因此，CNC 的硅烷化可能在复合材料制造中具有应用前景，因为这些纳米颗粒在疏水性聚合物基质中的分散性有限，并且由于表面上存在的氨基，它们也可以作为纳米吸附剂。
