High-Performance Sustainable Electrochromic Devices Based on Carrageenan Solid Polymer Electrolytes with Ionic Liquid

Area of Science:

• Materials Science
• Electrochemistry
• Sustainable Chemistry

Background:

• Growing interest in sustainable functional materials to mitigate environmental impact.
• Electrochromic materials are crucial for applications in sensing and smart devices.
• Natural polymers offer a sustainable alternative to conventional synthetic materials.

Purpose of the Study:

• To develop sustainable electrochromic materials based on carrageenan and ionic liquids.
• To investigate the effect of ionic liquid content on material properties and device performance.
• To demonstrate the feasibility of creating efficient and eco-friendly electrochromic devices.

Main Methods:

• Blending natural carrageenan with varying amounts of 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]) ionic liquid.
• Characterization of material morphology, physicochemical, thermal properties, and ionic conductivity.
• Fabrication and testing of electrochromic devices using carrageenan/ionic liquid electrolytes and PEDOT:PSS electrodes.

Main Results:

• Ionic conductivity increased significantly with ionic liquid content, reaching 4.6 × 10⁻⁴ S·cm⁻¹.
• Electrochromic devices operated effectively at low voltages (0.3 to -0.9 V).
• The optimal material (15 wt% IL) exhibited fast switching times (6s oxidation, 8s reduction) and 99% optical switching (Δ%Tx).

Conclusions:

• Sustainable electrochromic devices can be successfully developed using carrageenan and ionic liquids.
• The ionic liquid content is critical for enhancing ionic conductivity and device performance.
• These materials present a promising, eco-friendly alternative for advanced electrochromic applications.