Jiang Tianhui, Maddalena Lorenza, Gomez Julio, Carosio Federico, Fina Alberto
Department of Applied Science and Technology, Politecnico di Torino, Alessandria Campus, V.le Teresa Michel 5, 15121 Alessandria, Italy.
AVANZARE Innovacion Tecnologica S.L., 26370 Navarrete, La Rioja, Spain.
Polymers (Basel). 2022 Oct 4;14(19):4165. doi: 10.3390/polym14194165.
The polyelectrolyte (PE)-based water dispersion of graphene-related materials (GRMs) represents an interesting intermediate for the development of advanced materials by sustainable processes. Although the proof of concept has been demonstrated, there is a lack of knowledge for what concerns the effects of parameters typical of PEs such as functionalization, molecular weight, and charge density. In this work, we evaluate the effects of such parameters on the quality and long-term stability of reduced graphite oxide (rGO) dispersion in aqueous media prepared by ultrasound sonication in the presence of different PEs. Four PEs were evaluated: polyacrylic acid (PAA), branched poly(ethylenimine) (BPEI), sodium carboxymethyl cellulose (CMC), and poly(sodium 4-styrenesulfonic acid) (PSS). The prepared dispersions were thoroughly characterized by means of UV-visible spectroscopy, thermogravimetric analysis, dynamic light scattering, and Raman spectroscopy. The highest concentrations of rGO were achieved by BPEI with a molecular weight of 25,000 and 270,000 Da (33 and 26 µg/mL, respectively). For other PEs, the rGO concentration was found to be independent of the molecular weight. The PAA-based dispersions displayed the best through-time stability while yielding homogeneous dispersion with a smaller average size and narrower size distribution.
基于聚电解质（PE）的石墨烯相关材料（GRM）水分散体是通过可持续工艺开发先进材料的一种有趣中间体。尽管概念验证已经得到证实，但对于PE典型参数（如功能化、分子量和电荷密度）的影响仍缺乏了解。在这项工作中，我们评估了这些参数对在不同PE存在下通过超声处理在水性介质中制备的还原氧化石墨烯（rGO）分散体的质量和长期稳定性的影响。评估了四种PE：聚丙烯酸（PAA）、支化聚乙烯亚胺（BPEI）、羧甲基纤维素钠（CMC）和聚（4-苯乙烯磺酸钠）（PSS）。通过紫外可见光谱、热重分析、动态光散射和拉曼光谱对制备的分散体进行了全面表征。分子量为25,000和270,000 Da的BPEI实现了最高的rGO浓度（分别为33和26 µg/mL）。对于其他PE，发现rGO浓度与分子量无关。基于PAA的分散体表现出最佳的随时间稳定性，同时产生具有较小平均尺寸和较窄尺寸分布的均匀分散体。
