Enhanced Anisotropy of 3D-Printed Graphene–Polyurethane Composites with Optimized Laser Scan Parameters for Photo/Electrothermal Deicing Applications

Anisotropic thermal conductivity has demonstrated utility in photothermal anti-icing/deicing applications. This study focused on optimizing laser induction parameters for FDM 3D-printed graphene-enhanced TPU (G-TPU)/neat TPU (N-TPU) composites. Through precise control of laser power and scan patterns, the in-plane (IP) thermal conductivity of the LI-G-TPU/N-TPU double-layer augmented from 3.31 to 5.84 W/(m K) while through-plane (TP) thermal conductivity remained ∼0.50 W/(m K). This optimization increased the anisotropic thermal conductivity ratio from 6.49 to 11.02. Concurrently, the anisotropic electrical conductivity ratio dramatically improved by 2 orders of magnitude to 7.25 × 109, with IP resistivity decreasing from 85.31 to 0.53 Ω m and TP resistivity slightly reducing from 6.29 to 3.84 GΩ m. Analysis confirmed that structural integrity and graphene flake orientation were preserved after repeated laser scanning. This, coupled with enhanced crystallinity from graphene annealing, synergistically boosted anisotropic thermal and electrical conductivities. Laser ablation also induced porous graphene micro/nanostructures, improving hydrophobicity from 71.0° (hydrophilic) to 126.9° (strongly hydrophobic). The composite’s optical density increased over 50% due to scattering effects. These optimized properties yielded exceptional deicing performance. The C2 sample (two full cross-scans) achieved an equilibrium temperature exceeding 70.0 °C within 120 s under synergistic photothermal (1500 W/m2) and electrothermal (30 V) performance, surpassing electrothermal-only by 16.2 °C and photothermal-only by 41.3 °C. For deicing, the C2 sample melted a 1 g ice cube within just 359 s via combined photothermal and electrothermal heating mode, a 42 and 54% time reduction compared to electrothermal-only and photothermal-only modes, respectively. It was envisioned that the development of an economical deicing approach would be applicable to a wide range of surfaces, such as aircraft wings, wind turbine blades, power transmission lines, and bridge surfaces.