Development of a facile aerogel-based ion-selective electrode using cellulose and carbon nanotubes as transducer materials for potentiometric application

Facile, lightweight, and sustainable aerogels have been a growing interest in their applications as support matrixes in the current environmental and energy challenges. In this study, a cellulose aerogel (CA) is fabricated using a homogeneous dispersion of cellulose fibers in an alkali-urea aqueous solution and a carbon nanotube ink (CNT-ink) to increase its electrical and conductive behavior in a potentiometric analysis. The physicochemical and morphological properties of the resultant composite aerogels (CA, CA1, and CA2) are investigated by thermal, water resistance, mechanical, FTIR, and SEM analysis. The prepared material exhibits a structured solid network that is visualized through SEM in which fibers are functionalized with CNTs. The results from compressive tests reveal that CA2 has excellent mechanical properties. A saturated CA with CNT-ink can turn on a white LED and potentiometric measurements by preparing an aerogel-based ion-selective electrode (CA2 - ISE) with a potassium ion-selective membrane (K+ - ISM) reveal good sensitivity at room temperature for the detection in a specific electrolyte solution.