High Colloidal Stable Carbon Dots Armored Liquid Metal Nano‐Droplets for Versatile 3D/4D Printing Through Digital Light Processing (DLP)

Abstract

Liquid metal (LM) and liquid metal alloys (LMs) possess unique physicochemical features, which have become emerging and functionalized materials that are attractive applicants in various fields. Herein, uniform LM nanodroplets armored by carbon dots (LMD@CDs) were prepared and exhibited high colloidal stability in various solvents, as well as water. After optimization, LMD@CDs can be applied as functional additives for the 3D/4D printing of hydrogel and cross‐linked resin through digital light processing (DLP). The light absorption of LMD@CDs not only improved the printing accuracy, but also led to the cross‐linking density differential during the post‐curing process. Base on the cross‐linking density differential of soft hydrogel and photothermal performance of the LM, the 3D printed objects can exhibit stimulus responses to both water and laser irradiation. Additionally, the CDs shell and LM core of LMD@CDs provide the printed objects interesting photoluminescence and electric conductivity capabilities, respectively. We deduce this versatile 3D/4D printing system would provide a new platform for the preparation of multi‐functional and stimuli‐responsive advance materials.

Starlike Copolymer Nanoreactors for the Controlled Preparation of Highly Uniform Liquid Metal Nanoparticles

“…Top-down synthetic methods excelled at producing LM nanostructures with high stoichiometric fidelity and suppressing undesirable phase segregation in LM nanoalloys in comparison to bottom-up methods . Moreover, conducting top-down approaches were energy-saving, simple, and straightforward without exploiting high temperature, expensive chemicals, and air/moisture-sensitive Schlenk line, as required by bottom-up approaches. − Therefore, a few top-down strategies, such as mechanical agitation, microfluidics, and ultrasonication, were developed to fabricate LM nanomaterials or LM–polymer hybrids. , These preparation strategies were primarily based on common rationale that the introduced external mechanical force shattered bulk LM into microdroplets/nanodroplets (i.e., microparticles/nanoparticles) during nanoparticle formation or mixing with polymers to fabricate mechanically robust and stretchable composites with targeted thermal and electrical conductivity. − However, external mechanical force usually resulted in irregularly shaped microparticles embedded in polymer matrices with inhomogeneous properties due to anisotropic distribution of LM. Uneven distribution of LM was attributed to the substantial surface tension of LM and surface chemistry discrepancy between LM and polymer matrices. , Recently, mechanical mixing in the presence of the surface stabilizing molecules was proposed to obtain LM nanostructures with improved morphology and homogeneity .…”