Zhao Wei, Sugunan Abhilash, Gillgren Thomas, Larsson Johan A, Zhang Zhi-Bin, Zhang Shi-Li, Nordgren Niklas, Sommertune Jens, Ahniyaz Anwar
RISE Research Institutes of Sweden, Stockholm SE-114 86, Sweden.
Division of Solid State Electronics, Department of Electrical Engineering, Uppsala University, Uppsala SE-751 03, Sweden.
ACS Omega. 2021 Apr 28;6(18):12050-12062. doi: 10.1021/acsomega.1c00699. eCollection 2021 May 11.
Attention to graphene dispersions in water with the aid of natural polymers is increasing with improved awareness of sustainability. However, the function of biopolymers that can act as dispersing agents in graphene dispersions is not well understood. In particular, the use of starch to disperse pristine graphene materials deserves further investigation. Here, we report the processing conditions of aqueous graphene dispersions using unmodified starch. We have found that the graphene content of the starch-graphene dispersion is dependent on the starch fraction. The starch-graphene sheets are few-layer graphene with a lateral size of 3.2 μm. Furthermore, topographical images of these starch-graphene sheets confirm the adsorption of starch nanoparticles with a height around 5 nm on the graphene surface. The adsorbed starch nanoparticles are ascribed to extend the storage time of the starch-graphene dispersion up to 1 month compared to spontaneous aggregation in a nonstabilized graphene dispersion without starch. Moreover, the ability to retain water by starch is reduced in the presence of graphene, likely due to environmental changes in the hydroxyl groups responsible for starch-water interactions. These findings demonstrate that starch can disperse graphene with a low oxygen content in water. The aqueous starch-graphene dispersion provides tremendous opportunities for environmental-friendly packaging applications.
随着对可持续性认识的提高，借助天然聚合物来关注石墨烯在水中的分散情况日益增加。然而，对于可在石墨烯分散体中充当分散剂的生物聚合物的功能，人们尚未完全理解。特别是，使用淀粉来分散原始石墨烯材料值得进一步研究。在此，我们报告了使用未改性淀粉制备水性石墨烯分散体的工艺条件。我们发现，淀粉 - 石墨烯分散体中的石墨烯含量取决于淀粉的比例。淀粉 - 石墨烯片是几层石墨烯，横向尺寸为3.2μm。此外，这些淀粉 - 石墨烯片的形貌图像证实了高度约为5nm的淀粉纳米颗粒吸附在石墨烯表面。与在没有淀粉的非稳定石墨烯分散体中自发聚集相比，吸附的淀粉纳米颗粒归因于将淀粉 - 石墨烯分散体的储存时间延长至1个月。此外，在存在石墨烯的情况下，淀粉的保水能力降低，这可能是由于负责淀粉 - 水相互作用的羟基的环境变化所致。这些发现表明，淀粉可以在水中分散低氧含量的石墨烯。水性淀粉 - 石墨烯分散体为环保包装应用提供了巨大机遇。
