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Y. Grigoryan

Publications and source records attributed to Y. Grigoryan.

2 recordsLinked to original sources

Polyvinylpyrrolidone planarized liquid crystalline 1T-WS2/rGO hybrid nanocomposites-based humidity sensing platform

Two-dimensional hybrid nanocomposites combining graphene-like materials and transition metal dichalcogenides (TMDCs) are created using various synthesis methods and are vital for environmental sensing due to the synergistic effects of their components. These hybrid materials offer enhanced sensitivity, selectivity, surface-to-volume ratio, tunable electronic properties, strong interaction with analytes, and fast detection capabilities, which address the limitations of individual materials. This is due to their outstanding surface-to-volume ratio, tunable electronic properties, strong interactions with analytes, as well as their high sensitivity, selectivity, and fast detection capabilities, which are crucial for environmental sensing. Herein, a hydrothermally synthesized and polyvinylpyrrolidone (PVP)-stabilized 1T phase tungsten disulfide/reduced graphene oxide, 1T-WS2/PVP/rGO, hybrid nanocomposite is reported. The intrinsic liquid crystalline behavior of the synthesized composite enables the formation of highly uniform films for effective humidity sensing. The optostructural characterization and key performance parameters, including response and recovery times, of the 1T-WS2/PVP/rGO hybrid nanocomposite-based structure are comprehensively analyzed and studied. This is the first to report on the synthesis of a 1T-WS2/PVP/rGO hybrid nanocomposite, its liquid crystalline phase formation, and application in humidity sensing. The proposed sensing platform introduces a novel approach to humidity sensing using 1T-WS2/PVP/rGO liquid crystalline films, which combine the metallic advantages of 1T-WS2, the stabilizing role of PVP and the conductive framework of rGO into aligned LC structures for enhanced sensitivity, rapid response and environmental robustness.

physics.app-ph

Enhancement of mechanical properties of graphene oxide fibers via liquid crystalline phase formation and flake size optimization

Graphene oxide (GO) fibers are promising materials for lightweight, high-strength applications due to their unique structural tunability and mechanical performance. However, the properties of GO fibers strongly depend on the ordering of GO flakes during the assembly process. In this work, we demonstrate that GO fibers spun from a liquid crystalline (LC) GO dispersion exhibit significantly enhanced mechanical properties compared to those produced from non-LC GO dispersions. The improved tensile strength is attributed to the larger GO flake size and highly ordered alignment achieved in the LC phase. The LC-derived fibers demonstrated a Young's modulus of 12.3 GPa, a tensile strength of 146.8 MPa, and an elongation at break of 2.5%. These findings emphasize the critical role of flake size and LC ordering in enhancing the performance of GO-based fibers and suggest a straightforward pathway toward scalable fabrication of strong yet flexible carbon-based materials.

cond-mat.mtrl-sci