3D Printable Graphene Composite

Abstract

In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

Figure 1. Composite preparation and 3D printing.

a, Picture of graphite flakes. b,c, Dispersions of GO and ABS in NMP solvent. d,e, Pictures showing a homogeneous mixture of GO-ABS in NMP before and after chemical reduction by hydrazine hydrate at 95 °C for 1 h. Brownish GO-ABS turned into black G-ABS suspension during chemical reduction. f, G-ABS coagulations obtained after isolation (e) with water. g, G-ABS composite powder after washing and drying. h, Schematic illustration of fused deposition modelling 3D printing process. Inset is the graphene-based filament winding on a roller. The filament was deposited through a nozzle onto a heated building plated, whose temperature was set at 80 °C. i, A typical 3D printed model using 3.8 wt% G-ABS composite filament, scale bar: 1 cm.

Figure 2. Spectroscopic and electrical analysis of graphene composites.

a, A typical cross-section SEM image of 3.8 wt% G-ABS composite’s revealed partially incorporated dangling graphene sheets. b, Electrical conductivity (σ_c) of G-ABS composites as a function of graphene loading. Inset is the four-probe schematic setup used in the σ_c measurement. c, Representive Raman spectra in prepared GO, rGO, ABS and G-ABS samples. d, UV-vis spectra of separated samples dispersed in aqueous solutions, including GO, GO-ABS, G-ABS, rGO.

Figure 3. Thermal and mechanical analysis of ABS and G-ABS composites.

a, Representative DSC curves of ABS and G-ABS composites. The T_g value slightly increased as the graphene loading in composites increased, calculated from the DSC curves. b, Loss factor (tan δ) derived from DMA. In all prepared samples, pure ABS claims the highest tan δ. by adding graphene sheets into ABS, ABS’s chain mobility was constrained with graphene’s stiff frameworks, which induces smaller tan δ values. c,d, TGA and TMA curves of ABS and G-ABS composites as a function of temperature. CTE values were calculated from the linear region (RT to 110 °C) in TMA.