Lee, Eun Goo Shin, Keun-Young Lee, Jonghwi Lee, Sang-Soo 2024-01-20T07:01:41Z 2024-01-20T07:01:41Z 2021-09-05 2015-06 1598-5032 https://pubs.kist.re.kr/handle/201004/125386 Graphene composites have great potential in electrical and electronic applications due to their outstanding physicochemical, electrical, and mechanical properties. Unfortunately, current graphene preparation technologies allow the exploitation of only an exceptionally low percentage of graphene's capability. Herein, free-standing graphene films based on three-dimensional (3D) continuous structures of hollow graphene ellipsoids were successfully fabricated, whose composite structure has never been investigated. Positively charged polystyrene (PS) spheres were first wrapped with negatively charged graphene upon simple mixing, and became ellipsoids by stretching. Due to their improved continuity, composites based on the ellipsoids and spherical microparticles have lower sheet resistances than those based on spherical nanoparticles. Upon folding and application of pressure, composites based on the hollow graphene ellipsoids exhibited superior electrical conductivity and structural stability owing to their high mechanical strength and effective electron transport pathway. The ability to control the face-contact structures of graphene in a polymer matrix by means of particle morphology represents an effective strategy for future composite engineering. English POLYMER SOC KOREA SHEETS ENERGY Flexible free-standing composite films having 3D continuous structures of hollow graphene ellipsoids Article 10.1007/s13233-015-3072-7 1 MACROMOLECULAR RESEARCH, v.23, no.6, pp.552 - 558 MACROMOLECULAR RESEARCH 23 6 552 558 scie scopus kci ART001999757 000356801500009 2-s2.0-84933181664 Polymer Science Polymer Science Article SHEETS ENERGY graphene composite polyvinyl pyrrolidone (PVP) spheroids conductivity