Surface Functionalization with (3-Glycidyloxypropyl)trimethoxysilane (GOPS) as an Alternative to Blending for Enhancing the Aqueous Stability and Electronic Performance of PEDOT:PSS Thin Films

Abstract

Organic mixed ionic−electronic conductors, such as poly (3,4ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), are essential materials for the fabrication of bioelectronic devices due to their unique ability to couple and transport ionic and electronic charges. The growing interest in bioelectronic devices has led to the development of organic electrochemical transistors (OECTs) that can operate in aqueous solutions and transduce ionic signals of biological origin into measurable electronic signals. A common challenge with OECTs is maintaining the stability and performance of the PEDOT:PSS films operating under aqueous conditions. Although the conventional approach of blending the PEDOT:PSS dispersions with a cross-linker such as (3glycidyloxypropyl)trimethoxysilane (GOPS) helps to ensure strong adhesion of the films to device substrates, it also impacts the morphology and thus electrical properties of the PEDOT:PSS films, which leads to a significant reduction in the performance of OECTs. In this study, we instead functionalize only the surface of the device substrates with GOPS to introduce a silane monolayer before spin-coating the PEDOT:PSS dispersion on the substrate. In all cases, having a GOPS monolayer instead of a blend leads to increased electronic performance metrics, such as three times higher electronic conductivity, volumetric capacitance, and mobility− capacitance product [μC*] value in OECT devices, ultimately leading to a record value of 406 ± 39 F cm −1 V −1 s −1 for amorphous PEDOT:PSS. This increased performance does not come at the expense of operational stability, as both the blend and surface functionalization show similar performance when subjected to pulsed gate bias stress, long-term electrochemical cycling tests, and aging over 150 days. Overall, this study establishes a novel approach to using GOPS as a surface monolayer instead of a blended cross-linker, for achieving high-performance organic mixed ionic−electronic conductors that are stable in water for bioelectronics.

Conductive and alignment-optimized porous fiber conduits with electrical stimulation for peripheral nerve regeneration

“…Numerous CPs have been utilized in the field of tissue engineering, including PPy, PANI, PEDOT, and poly(3-hexylthiophene) [ 22 ]. The conducting polymer PEDOT is commonly doped with PSS to form a stable aqueous suspension of particles [ 35 ]. Due to its exceptional chemical stability and conductivity, PEDOT finds applications in diverse fields including energy reserves, sensors, conductor electrode materials, biotechnology, and medicine [ 36 ].…”

One Pot Photomediated Formation of Electrically Conductive Hydrogels

“…The films sufficiently well adhered to the glass slide, thanks to the plasma treatment. However, to ensure a higher mechanical stability and adhesion, we would recommend using a glass surface treatment with an adhesive monolayer such as (3-glycidyloxypropyl)­trimethoxysilane (GOPS) . While this photoprinting experiment was not fully optimized, it showed that we can achieve patterns of conductive hydrogels with micron-scale resolution.…”

“…However, to ensure a higher mechanical stability and adhesion, we would recommend using a glass surface treatment with an adhesive monolayer such as (3glycidyloxypropyl)trimethoxysilane (GOPS). 62 While this photoprinting experiment was not fully optimized, it showed that we can achieve patterns of conductive hydrogels with micron-scale resolution. Higher resolution (down to submicrons) could be obtained by two-photon stereolithography.…”

Integrated Temperature–Humidity Sensors for a Pouch-Type Battery Using 100% Printing Process

“…Figure 7 b shows that bands at 438, 988, and 1257 cm −1 are, respectively, assigned to C-O-C deformation, oxacyclic ring deformation, and C α –C α inter-ring stretching. Particularly, the characteristic band at 1428 cm −1 , attributed to symmetric C α = C β (-O) stretching, indicates a high degree of conjugation [ 49 ]. Furthermore, a shift from 1428 to 1438 cm −1 is observed, indicating a decrease in the concentration of charge carriers [ 50 ].…”