|
Authors
|
Thapa, Y. N.; Henning, S.; Lach, R.; Rajchal, B.; Karki, D.; Boldt, R.; Kafle, B. P.; Staudinger, U.; Adhikari, R.
|
|
Title
|
Traditional Nepali paper-CNT-polyaniline hybrid as a green humidity sensor
|
|
Date
|
04.05.2026
|
|
Number
|
0
|
|
Abstract
|
This study reports a simple and cost-effective strategy to integrate in situ-polymerised polyaniline (PANI) and multi-walled carbon nanotubes (CNTs) into traditional Nepali paper (TNP) to fabricate cellulose-based electrically conductive composite films. The resulting films exhibited enhanced electrical conductivity, thermal stability and humidity-sensing performance. An interpenetrating spongy PANI network formed on the TNP surface enabled efficient charge transfer, while the incorporation of CNTs provided a synergistic effect, reducing the electrical resistivity to 6.4 Ω·cm at 0.05 wt.% CNTs. The sensing behaviour of PANI is governed by proton-transfer-assisted electron hopping between its protonated reduced (–NH2+) and oxidized (–NH+) forms, facilitated by water molecules under humid conditions, which lowers the composite’s resistivity. At higher humidity levels, the Grotthuss mechanism becomes dominant, further decreasing the resistance. In humidity-sensing tests, PANI-coated TNP without CNTs showed a pronounced relative resistance drop of ∼78%, reaching saturation after 90 s of exposure to saturated humidity. However, during dynamic cycling with short exposure and recovery times of 30 s each, its reversibility was limited, with a recovery factor of only 13.6% in the first cycle. In contrast, PANI-coated TNP with 0.01 wt.% CNTs showed a smaller relative resistance drop (∼47%) and reached saturation faster, after 70 s, but demonstrated improved reversibility, with a recovery factor of 46.1% in the first cycle of dynamic cycling tests. From the second cycle onward, both composites displayed excellent cycle-to-cycle stability with high reversibility. These findings underline the potential of TNP–PANI–CNT composites as sustainable and tunable sensing materials built on a potentially biodegradable substrate for greener electronic applications. Caption: Porous TNP serves as a flexible and biodegradable substrate for the incorporation of CNTs and PANI. The conductive PANI-CNT network modulates the electrical signal in response to humidity, enabling the ternary hybrid system to exhibit sensitive humidity detection with stable and reversible electrical behaviour.
|
|
Publisher
|
Institute of Physics Publishing
|
|
Wikidata
|
|
|
Citation
|
Materials Research Express 13 (2026) 095303
|
|
DOI
|
https://doi.org/10.1088/2053-1591/ae602e
|
|
Tags
|
|
