Preparation and In‐Situ High‐Throughput Screening of Bi Thixotropic Ink

Abstract

Preparing thin‐layer thermoelectric (TE) material libraries through inkjet printing (IJP) combined with selective laser melting (SLM) is a feasible solution to achieve high‐throughput screening (HTS) of high‐performance TE materials. The preparation of stable printable elementary inks with solid particle size in micron‐level is a prerequisite for the realization of the above technical objective. In this work, a series of thixotropic inks containing micron‐sized Bi powder, mixed organic solvent of ethanol/ethylene glycol (EG), and polyurea rheological additive of BYK‐420 are prepared. According to the proposed screening principles for printability and sedimentation stability, the best composition of the Bi thixotropic ink is determined with a solid content of 2–10 vol%, a relative EG content of 2–8 vol%, and a relative additive BYK‐420 content of 2.5 vol%. The effectiveness of the above mentioned HTS method is further proven through the printability Z value and the sedimentation rate of the selected inks. This work provides an effective way for in‐situ high‐throughput screening the printability and sedimentation stability of thixotropic inks, even though the solid density is high and the particle size is in micron‐level. It would lay a solid foundation for further high‐throughput screening of high‐performance TE materials.

Characterization of Coating Films of Thixotropic Solvent Gel Containing Organo‐modified Nanodiamonds

“…Thixotropy [27] has been shown to be important for decorative coatings to impart fluidity when applied, but it gels and adheres after application to prevent dripping (Figure 1(b)). Techniques for introducing thixotropic additives [28] are used to artificially impart thixotropic properties to solvents. Approximately 1 wt% thixotropic agents introduced into symmetric solvents form nanofibers by hydrogen bonding, and the sponge‐like structure formed by the entanglement of these nanofibers traps the solvent, leading to gelation [29–31] .…”