Depolymerizable Polyimines Triggered by Heat or Acid as Binders for Conductive Inks

Abstract

The ability to print electronic devices on soft substrates has the potential to revolutionize the world of consumable electronics. Electronic inks are typically constituted of an active nanomaterial dispersed in a solvent and stabilized by a surfactant which is necessary to impart colloidal stability. However, once the ink is applied, the surfactant presence in the final product is detrimental to the device performance. Here, we report the preparation of polyimines that can depolymerize and evaporate in the presence of light and heat. These polyimines were used for the formulation of Ag nanoparticle inks as well as for the dispersion of multiwalled carbon nanotubes (MWCNTs). In both cases, stable dispersions were obtained and were applied on a variety of substrates, leading to low-conductivity inks. However, the depolymerization and evaporation of the polyimine surfactant could be triggered by light and heat, then leading to a high-conductivity ink. By use of a laser engraver equipped with a CO2 laser, it was possible to spatially control the depolymerization of the MWCNT ink applied on a poly­(ethylene terephthalate) film, while the nonexposed MWCNT ink was removed by simple solvent washing. Via this technique, it was possible to direct-write MWCNTs on a flexible substrate, thus demonstrating the potential of polyimines for the fabrication of electronic inks.

Self‐Healable, Malleable, Ecofriendly Recyclable and Robust Polyimine Thermosets Derived from Trifluoromethyl Diphenoxybenzene Backbones

“…Thereinto, polyimine vitrimers, prepared from amine and aldehyde, attracted much research attention due to their plasticity, recyclability, reprocessability and self-healability, offering new opportunities for traditional thermosets by improving the life-span and simultaneously providing additional functionalities such as phase-sensitive membrane probe, [18] exogenous pollutant detection, [19] electronic ink, [20] osmotic energy conversion, [21] emulsion separation, [22] and flame retardancy. [23] Beyond that, they can not only be permanently cross-linked by stable covalent bonds but also change their molecular topologies through thermally activated bond-exchange reactions.…”

High-Performance Poly(imide-imine) Vitrimers Derived from Semiaromatic Bisimide Diamines

“…However, 16 h later, all solutions turned faint yellow, and Un -PIIH film fragments decomposed into small pieces (Figure S40b, Supporting Information). When further prolonging the soaking time to 24 h (Figure S40c, Supporting Information) and even 60 h (Figure S40d, Supporting Information) at room temperature, all PIIH film fragments broke into small pieces but still did not totally dissolve and gave a clear faint yellow solution rather than a turbid suspension with small film pieces sinking to the bottom of the vial, which is different from those reported imide-free polyimines. ,,,,– We speculate that it is the imide linkages accompanying the aliphatic structures that impede the resulting PIIH s rapid degradation in acid solution, since the aliphatic structures are hydrophobic and the imide linkages are water- and acid-stable, which makes it difficult for H + to enter into the polyimine network in aqueous solution to attack the imine bonds. Moreover, the hydrolyzed products have poor solubility in water.…”

Self-reducing molecular ink for printed electronics and lithium-ion battery cathodes as conductive binder

“…10 Several schemes have been proposed to remove the insulating additive layer by a degradationevaporation process. [11][12][13][14] To further avoid the negative effects of additives on high-conductivity inks, the introduction of a binder with both high-conductivity and dispersion properties can be a good option.…”