Hefei University

About: Hefei University is a education organization based out in Hefei, China. It is known for research contribution in the topics: Catalysis & Adsorption. The organization has 2317 authors who have published 1747 publications receiving 16955 citations. The organization is also known as: Hefei Union University & Héféi Xuéyuàn.

In situ polymerization of graphene nanosheets and polyurethane with enhanced mechanical and thermal properties

Abstract: Polyurethane (PU) composites reinforced with graphene nanosheets (GNSs) were prepared by in situpolymerization. Graphene nanosheets, which were derived from chemically reduced graphite oxide (GO) nanosheets, were characterized by solid-state 13C MAS NMR, XRD and FTIR. A morphological study showed that, due to the formation of chemical bonds, the GNS was dispersed well in the PU matrix. With the incorporation of 2.0 wt% of GNSs, the tensile strength and storage modulus of the PU increased by 239% and 202%, respectively. The nanocomposites displayed high electrical conductivity, and good thermal stability of PU was also achieved. The facile and rapid technique presented here will provide an effective and promising method of preparing graphene-based polymer composites.

Enhancement of the mechanical properties of graphene–copper composites with graphene–nickel hybrids

Abstract: The present work reports the mechanical improvement in Cu matrix composites reinforced with graphene nanosheets decorated with Ni nanoparticles (GNS–Ni) hybrids. The GNS–Ni hybrids were firstly synthesized by an in situ chemical reduction method and then incorporated into the Cu matrix to fabricate bulk GNS–Ni/Cu composites by spark plasma sintering. Benefiting from the unique characteristic of GNS–Ni hybrids, the GNS–Ni/Cu composites exhibited homogeneously dispersed GNSs and a strong GNS–Cu interface interaction, therefore leading to a 61% increase in Young׳s modulus (132 GPa) and a 94% improvement in yield strength (268 MPa) by addition of only 1.0 vol% GNSs. The GNS–Ni/Cu composites exhibited a load transfer mechanism as verified by a modified shear-lag model. Our study thus shows the potential for GNS–Ni hybrids to be successfully used as a reinforcing phase in metal matrix composites.