Use Of Nacre-inspired Structure To Control Microstructure And 3D Printing

Fused deposition modeling(FDM)is the widely adopted 3D printing technique.To extend the utility of such a technique,various filament materials have been synthesized.However,the properties of the printed structure not only depend on the material but also the microstructure of each filament.Here,we report a new strategy to synthesize filament,in which the orientation of nanofiller can be essentially controlled.This approach consists of spray-coating,scrolling,and then 3D printed by the FDM technique.The influence of printing speed,nozzle temperature,platform temperature,filling ratio,and GO arrangement directions on mechanical properties was studied.Firstly,the effects of different spraying processes on the uniformity and distribution density of GO were studied.Studies have shown that:increasing the spraying height and platform temperature can reduce GO agglomeration.Spraying pressure and spraying speed can affect the distribution of GO,and the distribution density of GO can be controlled by the spraying speed.The optimal spraying parameters are: spraying height is 150 mm,platform temperature is 135 ?,spraying pressure is 10 k Pa,spraying speed is 100 mm/s.Secondly,the influence of different printing parameters on the mechanical properties of printed samples was explored to guiding subsequent printing of composite materials.Studies have shown that: properly increasing the filling ratio can increase the density of the sample and improve the mechanical properties.Printing speed,nozzle temperature,and platform temperature affect the uniformity of the filament and the bonding of layers.The infill angle is very important to the orientation and arrangement of nanofillers.The optimal printing parameters are: printing speed is 20 mm/s,nozzle temperature is 150 ?,the platform temperature is 60 ?,the filling ratio is 100% and the infill angel is 90°.Finally,the uniaxial tensile test was used to test the mechanical properties of the GO/PLA spiral fiber and explore the influence of GO content on the mechanical properties of the GO/PLA printed samples.It showed that GO/PLA printed sample with GO content of 1 wt% exhibited outstanding mechanical properties with the strength increase of about 33.4%,while simultaneously ensuring the elongation at the break of about 555%.The proposed spiral fiber using this 3D printing approach offers great applicability to a vast range of various 2D materials and structural composites.