Universal behavior of low-temperature heat capacity of acrylonitrile-butadiene-styrene thermoplastic polymer and its composite with graphene oxide.

This article focuses on the low-temperature heat capacity behavior of acrylonitrile-butadiene-styrene (ABS) polymer and its composite with thermally reduced graphene oxide (trGO), emphasizing the presence and universality of the boson peak anomaly. The boson peak, observed as a local maximum in the heat capacity curve at around 3.5 K, is characteristic of both disordered (glassy) and some crystalline materials, suggesting a universal underlying mechanism. Experimental results show that adding 0.5 wt% trGO to ABS slightly increases the linear term of heat capacity below 1 K, attributed to the large linear heat capacity contribution of graphene oxide, while other parameters remain largely unchanged. The study introduces a normalized dimensionless function Δ* describing the boson peak anomaly across various amorphous and crystalline substances, indicating a general correlation in the mechanisms responsible for this feature in solids with different structural orders.