Humidity‐Induced Nanoscale Restructuring in PEDOT:PSS and Cellulose Nanofibrils Reinforced Biobased Organic Electronics

Abstract

In times where research focuses on the use of organic polymers as a base for complex organic electronic applications and improving device efficiencies, degradation is still less intensively addressed in fundamental studies. Hence, advanced neutron scattering methods are applied to investigate a model system for organic electronics composed of the widely used conductive polymer blend poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) together with nanocellulose as flexible reinforcing template material. In particular, the impact of relative humidity (RH) on the nanostructure evolution is studied in detail. The implications are discussed from a device performance point of view and the changing nanostructure is correlated with macroscale physical properties such as conductivity. The first humidification (95% RH) leads to an irreversible decrease of conductivity. After the first humidification cycle, however, the conductivity can be reversibly regained when returning to low humidity values (5% RH), which is important for device manufacturing. This finding can directly contribute to an improved usability of emerging organic electronics in daily live.

Neutron Reflectivity Study on the Suppression of Interfacial Water Accumulation between a Polypropylene Thin Film and Si Substrate Using a Silane-Coupling Agent

“…First, NR measurements of the PP films were performed at BL16 under vacuum and at the saturated vapor pressure of D 2 O at 25 °C by using a simple sealed sample chamber with a cup of water. Various experiments under humid conditions have been already conducted at BL16. − Then, the other samples were measured under dry conditions at 60 °C and humid conditions at 60 °C and 85 %RH, where the latter reflects one of the typical usage conditions of PP-based polymer/inorganic filler nanocomposites and metal/resin bonding materials. The humidity-control cell system previously reported by our research group was used in the NR experiments at BL17 .…”

Scalable Paper Supercapacitors for Printed Wearable Electronics

“…12,68 Due to better adhesion with conductive polymers and carbon particles, CNF generates a conductive path for electrons, a highly porous network for ion penetration, and mechanical robustness in the system. 25,40,68 Together with this ink property, spray coating can be examined to efficiently achieve a 30 μm thick paper electrode directly deposited onto a substrate. Figure 5a shows a thick 30 μm electrode, where characterization reveals the smooth, low roughness paper electrode for a 2 cm by 2 cm electrode.…”

“…23,24 Using CNF as a nanoscale binder provides a nanoporous polymeric scaffold, high surface area, and porosity, leading to high mass loadings throughout the film, and therefore opens a pathway to spray coat nanomaterials with a high control capability on the electrode thickness. 10,25,26 A variety of different conductive polymers with pseudocapacitive properties, such as polyaniline (PANI), polypyrrole (PPy), and PEDOT, have been incorporated into flexible scaffolds (paper, fibrils, etc.) to form electrodes for flexible batteries and supercapacitors.…”

“…Further, it allows less control of the thickness and drying patterns, and lastly, it suffers from fast clogging even for high-pressure gas-driven systems . To overcome these drawbacks, industrial air atomizing and ultrasonic spray technology are introduced, where ultrafine droplets with narrow size distribution and limited material loss can be created even with low gas pressure, achieving smooth films with large-area coverage and roll-to-roll compatibility due to the automatized systems. , Using CNF as a nanoscale binder provides a nanoporous polymeric scaffold, high surface area, and porosity, leading to high mass loadings throughout the film, and therefore opens a pathway to spray coat nanomaterials with a high control capability on the electrode thickness. ,, …”

Cellulose‐Reinforced Programmable and Stretch‐Healable Actuators for Smart Packaging

“…After drying the film in step (3), strong interactions among the CNF, PVA, and PSS chains promote the formation of an H-bonded supramolecular matrix, [52,53] which ensures the mechanical strength of the mate-rial. [54] In addition, the sulfonate groups of PSS are proposed to participate in the phase-separation and formation of PVA/ PSS percolating network, [55] which further increases the rate of water transportation and thereby a faster-actuating speed. The non-phase-separated portion of PVA remained as nanofillers of the CNF network to form a second CNF/PVA percolating network and a relatively flat surface of the CAS film.…”