Zhang Zhuying, Zeng Jinfeng, Matsusaki Michiya
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Langmuir. 2024 Jul 17. doi: 10.1021/acs.langmuir.4c01327.
Nanofilms fabricated by layer-by-layer (LbL) assembly from polyelectrolytes (PEs) are important materials for various applications. However, PE films cannot retain the charges along the polymer chains during fabrication, resulting in a low charge density. In this study, the preparation of LbL nanofilms with preserved positive charges via a controllable and efficient approach was achieved. To fabricate fully positively charged (FPC) LbL nanofilms, a polycation, poly-l-lysine, was partially grafted with azide and alkyne groups. Through copper-catalyzed azide-alkyne cycloaddition and the LbL procedure, nanofilms were fabricated with all of the individual layers covalently bonded, improving the pH stability of the nanofilms. Because the resulting nanofilms had a high charge density with positive charges both inside and on the surface, they showed unique pH-dependent swelling properties and adsorption of negatively charged molecules compared with those of traditional polyelectrolyte LbL nanofilms. This kind of FPC nanofilm has great potential for use in sensors, diagnostics, and filter nanomaterials in the biomedical and environmental fields.
通过层层（LbL）组装法由聚电解质（PEs）制备的纳米薄膜是用于各种应用的重要材料。然而，PE薄膜在制备过程中无法沿聚合物链保留电荷，导致电荷密度较低。在本研究中，通过一种可控且高效的方法实现了具有保留正电荷的LbL纳米薄膜的制备。为了制备完全带正电（FPC）的LbL纳米薄膜，将一种聚阳离子聚-L-赖氨酸部分接枝叠氮基和炔基。通过铜催化的叠氮-炔环加成反应和LbL过程，制备出所有单层均共价键合的纳米薄膜，提高了纳米薄膜的pH稳定性。由于所得纳米薄膜具有高电荷密度，内部和表面均带正电荷，与传统聚电解质LbL纳米薄膜相比，它们表现出独特的pH依赖性溶胀特性和对带负电分子的吸附作用。这种FPC纳米薄膜在生物医学和环境领域的传感器、诊断和过滤纳米材料方面具有巨大的应用潜力。
