Jiao Shuhao, Yang Xuefei, Zheng Xuejing, Pei Ying, Liu Jie, Tang Keyong
School of Materials Science and Engineering, Zhengzhou University, Henan 450000, China.
School of Materials Science and Engineering, Zhengzhou University, Henan 450000, China.
Carbohydr Polym. 2024 Apr 15;330:121776. doi: 10.1016/j.carbpol.2024.121776. Epub 2024 Jan 5.
The present work investigates the effects of nano-chitin with different charge, obtained by acid hydrolysis and TEMPO oxidation, on the structure and properties of borax crosslinked polyvinyl alcohol (PVA) hydrogels. In detail, nano-chitin prepared by acid hydrolysis (ACh) is positively charged (+28.8 mV). The electrostatic attraction between ACh and borax ions leads to a maximum tensile stress of composite hydrogel (ACh/PB), 54.25 KPa, 17 times of the borax crosslinked PVA (PB). In contrast, nano-chitin prepared by TEMPO-oxidation (TCh) shows negative charge (-59.0 mV). Due to the electrostatic repulsion with borax ions, the maximum tensile stress of composite hydrogel (TCh/PB) is only 9.25 KPa, a very limit reinforcing effect. However, TCh/PB showed better self-healing efficiency (96.0 %) as well as ionic conductivity (1.25 × 10 S/m). The present work shows that the charge state of the nano-chitin exerts great influence on the interaction with the crosslinking agent borax, therefore, affects the structure and properties of the final PVA composite hydrogels. The results could provide important information about making full use of nano-chitin as a reinforcement by adjusting its surface charge state.
本研究考察了通过酸水解和TEMPO氧化获得的不同电荷的纳米几丁质对硼砂交联聚乙烯醇（PVA）水凝胶结构和性能的影响。具体而言，通过酸水解制备的纳米几丁质（ACh）带正电荷（+28.8 mV）。ACh与硼砂离子之间的静电吸引导致复合水凝胶（ACh/PB）的最大拉伸应力为54.25 KPa，是硼砂交联PVA（PB）的17倍。相比之下，通过TEMPO氧化制备的纳米几丁质（TCh）带负电荷（-59.0 mV）。由于与硼砂离子的静电排斥，复合水凝胶（TCh/PB）的最大拉伸应力仅为9.25 KPa，增强效果非常有限。然而，TCh/PB表现出更好的自愈效率（96.0%）以及离子电导率（1.25×10 S/m）。本研究表明，纳米几丁质的电荷状态对其与交联剂硼砂的相互作用有很大影响，因此，影响最终PVA复合水凝胶的结构和性能。这些结果可为通过调节纳米几丁质的表面电荷状态充分利用其作为增强剂提供重要信息。
