Stable Aqueous Dispersion of Reduced Graphene Nanosheets via Non-Covalent Functionalization with Conducting Polymers and Application in Transparent Electrodes

Abstract

We developed a simple and facile method of producing a stable aqueous suspension of reduced graphene oxide (RGO) nanosheets through the chemical reduction of graphene oxide in the presence of a conducting polymer dispersant, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). This approach involves the cooperative interactions of strong π- π interactions between a two-dimensional graphene sheet and a rigid backbone of PEDOT and the intermolecular electrostatic repulsions between negatively charged PSS bound on the RGO sheets, which impart the colloidal stability of the resulting hybrid nanocomposite of RGO/PEDOT. Moreover, our one-step solution-based method allows preserving the intrinsic chemical and electronic properties of both components, yielding a hybrid film of RGO nanosheets of high conductivity of 2.3 kΩ/sq with a transmittance of 80%. By taking advantage of conducting network structure of conducting polymers which provides an additional flexibility and mechanical stability of RGO nanosheets, we demonstrate the potential application of hybrid RGO/PEDOT as highly flexible and transparent electrodes.

Liquid Crystalline Graphene Oxide/PEDOT:PSS Self-Assembled 3D Architecture for Binder-Free Supercapacitor Electrodes

“…The XPS survey spectra of GO and GO-PP composite in Figure 4B show the presence of C 1s and O 1s signals, which resemble the typical S 2p signal of PEDOT:PSS, indicating that PEDOT:PSS had been coated on the GO sheets uniformly. The high-resolution C 1s XPS spectrum (Figure 4C) of the GO-PEDOT:PSS composite shows four peak components with binding energies at about 284.4, 285.5, 286.8, and 287.8 eV, which are attributed to sp 2 -hybridized carbon, sp 3 -hybridized carbon, C-S, C-O, C=O, and O-C=O species, respectively (Jo et al, 2011).…”

Study on the Oxidative Polymerization of EDOT Induced by Graphene Oxide

“…그래핀 계열 물질과 PEDOT/PSS의 복합체에서 sulfur는 PEDOT/ PSS쪽에만 존재하므로 복합체 중의 sulfur 함량으로부터 복합체 중의 그래핀 함량을 측정하는 것이 일반적인 방법이다 [13,20,22]. PEDOT/ PSS에서의 sulfur 함량은 8.28%, 본 연구에서 합성한 GO-P의 경우에 는 4.78%로 나타났으며, 동일한 방법으로 계산한 GO-P 중의 GO 함 량은 42%로 나타났다.…”

“…또한 일반적으로 촉 매라고 표현하고는 있지만 실제적으로는 GO 자체의 환원도 동시에 일어나므로 "촉매"라기보다는 "산화제"라는 표현이 더 적합한 것이라 는 의견도 있으나 [6], 관습적으로 "촉매"라는 표현을 사용하여 왔으므 로 여전히 "촉매"라는 표현을 더 많이 사용하고 있다. 이와 같은 특성 에 더해서 π전자가 풍부한 GO의 특성을 활용하여 π-π 상호작용에 의해서 다양한 고분자와의 복합화 [10,11]가 시도되었으며, 특히 전도 성 고분자인 polythiophene의 유도체와 π-π 상호작용으로 복합화한 GO가 광촉매로서 매우 유용한 것으로 나타났다 [12]. 동일한 상호작용 에 의해 최근 투명전극용으로 주목을 받고 있는 polythiophene 치환체 인 3,4-ethylene dioxythiophene (EDOT)과 GO의 복합화도 가능하며, 이와 같은 현상을 기초로 하여 microwave 하에서 GO에 의한 EDOT 의 중합 [13] 및 산화도가 높은 GO (highly oxidative GO)에 의해서 EDOT의 올리고머가 생성되는 현상 [14] 등도 보고되어있다.…”

Preparation of polyvinylpyrrolidone-decorated hydrophilic graphene via in situ ball milling

“…Unfortunately, like carbon nanotubes and many other nanomaterials, graphene sheets have a high surface area and surface energy, easily resulting in the formation of agglomerates [6]. To eliminate or alleviate such an issue, there are efforts to modify graphene with varieties of chemicals, by formation of covalently or non-covalently bonded surfaces [7][8][9][10]. Frequently, these modifications require toxic chemicals and involve complicated procedures.…”