Three-dimensional Inorganics Shaping Based On Deformable Polymers

The value of materials depends on their shapes.However,as rapid technological progress,traditional shaping methods are hard to meet the requirements of materials for new era:to be intelligent and customized.Therefore,several emerging shaping strategies,like chemical plasticity based on dynamic covalent bond exchange,3D printing,and 4D printing,have been highly demanded till now.The dynamic covalent bond exchange introduces the potential of permanent shape change into the polymer network owing to the internal stress relaxation.3D printing is relied on layer-by-layer printing mechanism,and 4D printing is based on the concept of "3D printing+time",which emphasizes the shape shifting over time.The deformation ability of the polymer is the key to the shaping potential of chemical plasticity and 4D printing,but also limited these shaping ways to polymeric materials.The non-traditional shaping methods of inorganics have been attracted much interest likewise.Polymer can play an important role in inorganics shaping as adhesive,but its nature of deformation is usually overlooked.Herein,we try to extend the shaping methods of deformable polymer to inorganic materials,and prepare three-dimensional glass,ceramics and metal.As follows are the research contents:1.Fabricate transparent three-dimensional glass using chemical plasticity.First,dynamic covalent polymer-silica nanoparticle composite film is prepared and shaped with two deformation mechanisms of chemical plasticity(dynamic covalent bond exchange)and physical plasticity(organic-inorganic cavitation).Then,the shaped composite is treated by pyrolysis and vacuum sintering to obtain transparent glass with complex 3D shapes.2.Produce three-dimensional ceramics using 4D printing.First,a two-dimensional film with localized cross-linking density difference is prepared by defining the digital light pattern and exposure time.Then the film is swelling in the mixture of tetraethoxysilane and catalyst,turning into a 3D shape through internal stress release.After that,the 3D film is soaked in water for in-situ silica generation and 3D shape fixation.The following pyrolysis turns the 3D composite film into ceramics with complex geometries.3.Prepare metal circuit on 4D-printed freeform surface.A dual-light controlled acrylate-nitrobenzyl system is designed.First,a film with a Z-axis crosslinking density gradient is produced with digital visible light,which introduces deformation potential,next the film surface is localized activated using ultraviolet light.The hydrophilic carboxyl groups generated at the activated area can adsorb the electroless plating catalyst.Then the film is turned from 2D to 3D.Subsequently,metal circuit is manufactured on the 3D film with electroless metal plating.