A scaffold material: Reduced graphene oxide and carbon quantum dots filled polycaprolactone nanofibers

Abstract

In this study, a comparative analysis was conducted between the properties of poly(epsilon-caprolactone) (PCL)-based electrospun nanofibers filled with both reduced graphene oxide (RGO) and carbon quantum dots (CQDs). Both RGO and CQD fillers interacted with PCL, modifying the crystal structure and enhancing thermal stability. The addition of RGO increased the nanofiber diameter, whereas the inclusion of CQDs reduced it. The incorporation of CQDs resulted in a significant increase of up to 73 % in the elastic modulus, while RGO led to a smaller increase of only 1.9 %. CQDs also contributed to a 160 % increase in nanoscale hardness, while RGO caused a maximum increase of 40 %. Furthermore, CQDs enhanced the storage modulus by 210.79 % and the loss modulus by 595.27%. In terms of biodegradability, CQDs, with lower contact angles (72.29 degrees - 68.75 degrees), degraded more than the nanofibers containing RGO (74.96 degrees - 70.15 degrees), showing similar biodegradability. The bioactivity test results indicated that both RGO and CQD fillers promoted the formation of apatite; however, neither exhibited antibacterial activity. This study suggests that CQDs are a more advantageous filler compared to RGO, based on their greater impact on the structural, thermal, mechanical, and biological properties of PCL.