Biomass-Derived, Highly Conductive Aqueous Inks for Superior Electromagnetic Interference Shielding, Joule Heating, and Strain Sensing

Abstract

Conductive composite inks are widely used in various applications such as flexible electronics. However, grand challenges still remain associated with their relatively low electrical conductivity and require heavy use of organic solvents, which may limit their high performance in broad applications and cause environmental concerns. Here, we report a generalized and eco-friendly strategy to fabricate highly conductive aqueous inks using silver nanowires (AgNWs) and biomass-derived organic salts, including succinic acid–chitosan (SA–chitosan) and sebacic acid–chitosan. SA–chitosan/AgNW composite coatings can be prepared by directly casting conductive aqueous inks on various substrates, followed by subsequently heating for cross-linking. The composite coatings exhibit an ultrahigh electrical conductivity up to 1.4 × 104 S/cm, which are stable after being treated with various organic solvents and/or kept at a high temperature of 150 °C, indicating their high chemical and thermal resistance. The flexibility and performance durability of these composite coatings were demonstrated by a suite of characterization methods, including bending, folding, and adhesion tests. Moreover, a high electromagnetic interference shielding (EMI) effectiveness of 73.3 dB is achieved for SA–chitosan/AgNW composite coatings at a thickness of only 10 μm due to the ultrahigh electrical conductivity. Additionally, we further demonstrated that such conductive composite inks can be used for fabricating functional textiles for a variety of applications with high performance, such as EMI shielding, Joule heating, and strain sensing. The robust and highly conductive inks prepared by this simple and environmental-friendly method hold great promise as important material candidates for the potential large-scale manufacturing of flexible and wearable electronics.

Microstructural Tuning of Twisted Carbon Nanotube Yarns through the Wet-Compression Process: Implications for Multifunctional Textiles

“…Interestingly, only 3 V could drive this yarn up to around 60 °C temperature, representing its superb potential to be applied in personal heating systems and healthcare management, such as for heat preservation in textile/clothing, thermotherapy, and portable or flexible heaters applicable under many circumstances. 58 Figure 5f shows the infrared thermal images during straight, knotting, and bending positions at only 3 V, justifying the impressive flexibility along with the incredible Joule heating phenomenon (having admirable temperature) of the wet-compressed CNT yarn. Although, as shown in Figure S4a, lengthwise only 2% stretch had been applied, the stability of the electric heating was still beyond excellent, exhibiting no remarkable changes in temperature within 1 min.…”

“…The wet-compressed CNT yarn (A-P-CNTY), being embedded in a fabric, shows a fast thermal response (shorter than 5 s) to reach the saturated temperature under different voltages (2–4 V). Interestingly, only 3 V could drive this yarn up to around 60 °C temperature, representing its superb potential to be applied in personal heating systems and healthcare management, such as for heat preservation in textile/clothing, thermotherapy, and portable or flexible heaters applicable under many circumstances Figure f shows the infrared thermal images during straight, knotting, and bending positions at only 3 V, justifying the impressive flexibility along with the incredible Joule heating phenomenon (having admirable temperature) of the wet-compressed CNT yarn.…”

Achieving Highly Conductive, Stretchable, and Washable Fabric from Reactive Silver Ink and Increased Interfacial Adhesion

“…Previous strategies to achieve durable conductive fabrics have failed to achieve <1000 mΩ per square sheet resistance. − These strategies have utilized conductive polymers, metal salts, or integration of metal yarns, which do not demonstrate as high a conductance as coating pure metal films over fabric. Other works have achieved <1000 mΩ per square sheet resistance by using electroless metal deposition or metal nanowire composites; however, these studies have neglected to evaluate the degradation in sheet resistance after stretching and/or washing. Similarly, electroplating techniques have been utilized to create flexible conductors; however, these techniques have drawbacks such as slow throughput, high energy consumption, and high production of waste. , There is a need for simple fabrication methods to create high conductance fabrics with long lasting durability.…”

“…This provides for better electrical conductance and silver adhesion with the fabric microfibers than nanoparticles or nanowires. Highly electrically conductive microfibers are useful for electromagnetic shielding and extremely sensitive sensing applications. ,, The textiles are coated by a simple and efficient drop casting followed by oven curing; only a single coat of silver ink is necessary for sub Ω per square sheet resistance.…”

Biomass-Based Polyureas Derived from Rigid Furfurylamine and Isomannide

“…Despite a growing interest in the development of biomass-based monomers and polymers (Figure ), − the diols and dicarboxylic acids are the main driving forces of research into renewable polymers mainly because of their accessibility. − It is worth noting that very few natural diamines are available. , Among the biomass-based diamines synthesized from currently available renewable resources, the furan-based diamine and isomannide-derived (Im-derived) diamine are particularly interesting, owing to their renewability and rigid characters. Specifically, the furan-based diamine can be directly obtained from the transformation of furfurylamine, an important commercial bio-based chemical derived from furfural via reductive amination under mild conditions.…”