Proving the robustness of a PEDOT:PSS-based thermistorviafunctionalized graphene oxide–poly(vinylidene fluoride) composite encapsulation for food logistics

Bijendra Bishow Maskey,Subramaniyan Ramasundaram,Gyan Raj Koirala,Gyoujin Cho,Younsu Jung,Kiran Shrestha,Junfeng Sun,Sagar Shrestha,Jinhwa Park,Hyejin Park,Sajjan Parajuli

doi:10.1039/d0ra00554a

Bijendra Bishow Maskey, Subramaniyan Ramasundaram + Show 9 more

Open Access

https://doi.org/10.1039/d0ra00554a

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Abstract

The instability of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) under a humid condition is the major limitation in the practical development of a flexible thermistor. Here, we introduced a functionalized graphene oxide–polyvinylidene fluoride (FGO–PVDF) composite as an encapsulation layer to prove the reliability of PEDOT:PSS thermistors under high-humidity conditions. The FGO–PVDF-encapsulated thermistor exhibited good linearity, a resolution of 1272.57 Ω per °C, a temperature coefficient of resistance equal to −3.95 × 10−3 per °C, stable performance, and an acceptable response time (∼40 s per °C) calibrated in the temperature range between −10 °C and 30 °C, resembling the temperature of a cold chain system. For applications in a food cold chain system, this thermistor was integrated into a roll-to-roll (R2R) gravure-printed NFC antenna, a microcontroller-embedded Si-chip transponder, and a printed battery to work as a smart label to wirelessly monitor the time–temperature history (TTH) of a food package. A proof-of-concept study was demonstrated by attaching an NFC-enabled hybrid TTH logger, a smart label, in a chicken package.

Highlights

The intrinsic capability of conducting polymers, mainly derived from polyaniline, polypyrrole, polythiophene, and poly(3,4ethylenedioxythiophene), whose electrical and optical properties can be tailored by controlling the doping state, is pivotal to their widespread applications in sensors, displays, etc.[1,2,3] Among them, the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) electroactive polymer has been attracting attention owing to its low-cost processing, high conductivity ($103 S cmÀ1), optical transparency, improved wettability, and compatibility with the emerging printing technology.[4]
We demonstrated the utilization of functionalized graphene oxide (FGO)–PVDF as an encapsulation material for a PEDOT:PSS-based thermistor and successfully applied this thermistor to monitor the temperature range analogous to that of the cold chain
PEDOT:PSS-based thermistors exhibit negative temperature coefficient behaviour because fewer PSS microparticles exist at high temperatures and this reduces the resistance of the thermistors; the conducting PEDOT does not have sufficient energy to overcome the PSS boundaries at low temperatures, resulting in an increased resistance.[28]

Summary

Introduction

The intrinsic capability of conducting polymers, mainly derived from polyaniline, polypyrrole, polythiophene, and poly(3,4ethylenedioxythiophene), whose electrical and optical properties can be tailored by controlling the doping state, is pivotal to their widespread applications in sensors, displays, etc.[1,2,3] Among them, the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) electroactive polymer has been attracting attention owing to its low-cost processing, high conductivity ($103 S cmÀ1), optical transparency, improved wettability, and compatibility with the emerging printing technology.[4]. We demonstrated the utilization of FGO–PVDF as an encapsulation material for a PEDOT:PSS-based thermistor (hereina er abbreviated as FGO–PEDOT-based thermistor) and successfully applied this thermistor to monitor the temperature range analogous to that of the cold chain.

Results

Conclusion