Is Low Polydispersity\nAlways Beneficial? Exploring\nthe Impact of Size Polydispersity on the Microstructure and Rheological\nProperties of Graphene Oxide

Graphene oxide (GO) is a promising material widely utilized\nin\nadvanced materials engineering, such as in the development of soft\nrobotics, sensors, and flexible devices. Considering that GOs are\noften processed using solution-based methods, a comprehensive understanding\nof the fundamental characteristics of GO in dispersion states becomes\ncrucial given their significant influence on the ultimate properties\nof the device. GOs inherently exhibit polydispersity in solution,\nwhich plays a critical role in determining the mechanical behavior\nand flowability. However, research in the domain of 2D colloids concerning\nthe effects of GO’s polydispersity on its rheological properties\nand microstructure is relatively scant. Consequently, gaining a comprehensive\nunderstanding of how GO’s polydispersity affects these critical\naspects remains a pressing concern. In this study, we aim to investigate\nthe dispersions and structure of GOs and clarify the effect of polydispersity\non the rheological properties and yielding behavior. Using a rheometer,\npolarized optical microscopy, and small-angle X-ray scattering, we\nfound that higher polydispersity in the same average size leads to\noverall improved rheological properties and higher flowability during\nyielding. Thus, our study can be beneficial in the employment of polydispersity\nin the processing of GO such as 3D printing and fiber spinning.