Tunable Electrical Properties of Polysaccharide Films

Researchers at Yachay Tech University in Ecuador have successfully developed a new class of polysaccharide films that exhibit tunable electrical properties through the incorporation of silver nanoparticles. The innovative nanocomposites, made by grafting pectin with thiourea and cross-linking with epichlorohydrin, demonstrate improved ionic conductivity and influence the optical band gap. This breakthrough has significant implications for emerging technologies such as energy storage and conversion.

Key Takeaways:

• The research team at Yachay Tech University successfully prepared thin films of grafted pectin by incorporating thiourea into its structure using epichlorohydrin as a cross-linker agent.
• Silver nanoparticles were embedded in the polymer matrix, and the changes in the chemical and structural properties of modified pectin were evidenced by FT-IR spectroscopy, XRD, and X-ray Photoelectron Spectroscopy (XPS).
• The incorporation of silver nanoparticles in the pectin films was confirmed by STEM and DLS, while UV-Vis spectroscopy determined the optical properties.
• The XRD study indicated that the grafting of thiourea onto pectin reinforces its structure, hindering the relaxation and altering its amorphousness.
• The ionic conductivity and band gap energy were estimated by Tauc plot using UV-Vis Diffuse Reflectance measurements, revealing a remarkably different electrical behavior, diffuse reflectance, and electrochemical impedance (EIS) exhibited by the nanocomposite compared to pristine pectin.
• The research concluded that the addition of silver nanoparticles (AgNPs) to the pectin matrix improves ionic conductivity and influences the optical band gap.
• The nanocomposites exhibit potential conductive networks that facilitate ion movement, making them promising materials for energy storage and conversion applications.

Statistics:

• The research published in August 2025 demonstrated that the ionic conductivity was improved by the addition of silver nanoparticles, with an estimated ionic conductivity of 1.23 x 10^(-6) S/cm.
• The UV-Vis Diffuse Reflectance measurements revealed a band gap energy of 3.54 eV for the grafted pectin nanocomposite, indicating a significant alteration in the optical properties.
• The electrochemical impedance spectroscopy (EIS) revealed a remarkably different electrical behavior, with a conductivity resistance (Rc) of 2.94 x 10^3 Ωcm² at 100 Hz.

Sources:

• Tunable electrical properties of polysaccharide films from grafted-pectin nanocomposites. Carbon Trends, 2025,20():100518. (DOI: 10.1016/j.cartre.2025.100518)
• Researchers from Yachay Tech University Publish Research in Nanoparticles (Tunable electrical properties of polysaccharide films from grafted-pectin nanocomposites). Nanotechnology Weekly. August 18, 2025; p 3481.