Poly(vinyl alcohol) Reinforced and Toughened with Poly(dopamine)-Treated Graphene Oxide, and Its Use for Humidity Sensing

Abstract

Poly(dopamine)-treated graphene oxide/poly(vinyl alcohol) ("dG-O/PVA") composite films were made and characterized. G-O was modified with poly(dopamine) in aqueous solution and then chemically reduced to yield poly(dopamine)-treated reduced G-O. A combination of hydrogen bonding, strong adhesion of poly(dopamine) at the interface of PVA and G-O sheets, and reinforcement by G-O resulted in increases in tensile modulus, ultimate tensile strength, and strain-to-failure by 39, 100, and 89%, respectively, at 0.5 wt % dG-O loading of the PVA. The dG-O serves as a moisture barrier for water-soluble PVA, and the dG-O/PVA composite films were shown to be effective humidity sensors over the relative humidity range 40-100%.

Nanocellulose-assisted dispersion of graphene to fabricate poly(vinyl alcohol)/graphene nanocomposite for humidity sensing

“…In our work, it is 0.198/%RH and 0.347/%RH for PVA/NFC/rGO containing 3 wt% and 5 wt% rGO in the range of 30%e98%RH, respectively. The sensitivity achieved in our work is higher than that reported in the literature [6]. As shown in Fig.…”

“…Researchers have demonstrated that both covalent and noncovalent functionalization methods could improve the dispersibility of graphene in the polymer matrix effectively [30e34]. Especially, Hwang et al [6] reported that using poly(dopamine) modification on graphene oxide (GO) surface to enhance the dispersion of graphene as well as interfacial interaction between graphene and polyvinyl alcohol (PVA), to fabricate poly(dopamine) -treated graphene oxide/polyvinyl alcohol (dGO/PVA) composite film which exhibit good repeatable humidity sensitivity without sacrifice of long-term performance. Although the surface chemical or physical modifications of graphene, can improve the dispersion of graphene sheets in some extent, generally, they result in a decrease of conductivity and mechanical behavior of composite materials.…”

Nanoindentation and thermal study of polyvinylalcohol/graphene oxide nanocomposite film through organic/inorganic assembly

“…Due to its favorable mechanical, thermal resistance (melting point > 200 • C), biodegradable properties and flexibility, PVA has been widely applied in manufacturing fibers, coatings, food packages and medical devices [1][2][3]. Besides, its nontoxic, odorless and biocompatible features make PVA films promising candidates in biotechnological applications, such as tissue engineering, drug delivery, articular cartilage, and biosensors [2,4].…”

Advanced carbon materials for flexible and wearable sensors

“…Various types of humidity sensors such as capacitivetype [155,156], resistive-type [157][158][159][160], optical-type [161] and acoustic-type sensors [162] have been designed. The capacitive-type sensors, which are commonly composed of an active material film and electrodes, generally possess combined features of low power consumption, good linearity and excellent stability.…”