International Interlaboratory Comparison of Thermogravimetric Analysis of Graphene-Related Two-Dimensional Materials

Abstract

Research on graphene-related two-dimensional (2D) materials (GR2Ms) in recent years is strongly moving from academia to industrial sectors with many new developed products and devices on the market. Characterization and quality control of the GR2Ms and their properties are critical for growing industrial translation, which requires the development of appropriate and reliable analytical methods. These challenges are recognized by International Organization for Standardization (ISO 229) and International Electrotechnical Commission (IEC 113) committees to facilitate the development of these methods and standards which are currently in progress. Toward these efforts, the aim of this study was to perform an international interlaboratory comparison (ILC), conducted under Versailles Project on Advanced Materials and Standards (VAMAS) Technical Working Area (TWA) 41 “Graphene and Related 2D Materials” to evaluate the performance (reproducibility and confidence) of the thermogravimetric analysis (TGA) method as a potential new method for chemical characterization of GR2Ms. Three different types of representative and industrially manufactured GR2Ms samples, namely, pristine few-layer graphene (FLG), graphene oxide (GO), and reduced graphene oxide (rGO), were used and supplied to ILC participants to complete the study. The TGA method performance was evaluated by a series of measurements of selected parameters of the chemical and physical properties of these GR2Ms including the number of mass loss steps, thermal stability, temperature of maximum mass change rate (T p) for each decomposition step, and the mass contents (%) of moisture, oxygen groups, carbon, and impurities (organic and non-combustible residue). TGA measurements determining these parameters were performed using the provided optimized TGA protocol on the same GR2Ms by 12 participants across academia, industry stakeholders, and national metrology institutes. This paper presents these results with corresponding statistical analysis showing low standard deviation and statistical conformity across all participants that confirm that the TGA method can be satisfactorily used for characterization of these parameters and the chemical characterization and quality control of GR2Ms. The common measurement uncertainty for each parameter, key contribution factors were identified with explanations and recommendations for their elimination and improvements toward their implementation for the development of the ISO/IEC standard for chemical characterization of GR2Ms.

Redox-driven confinement of quinone with imidazole in sub-nanometer sized porous carbon space mitigating chemical degradation for aqueous energy storage

“…The pristine microporous carbon was decomposed at ∼470 °C, which agrees with previous literature. 35,36 On the other hand, the immersed microporous carbon in the Im solution began to decompose at around 230 °C, which is close to the reported evaporation temperature for Im. 37 The weight loss due to confined Im in porous networks was 20% until the temperature reached the decomposition temperature of the microporous carbon, which would be associated with confined Im.…”

Refining and Validating Thermogravimetric Analysis (TGA) for Robust Characterization and Quality Assurance of Graphene-Related Two-Dimensional Materials (GR2Ms)

“…Pioneering studies by our team have unveiled distinct thermal decomposition signatures for various GR2Ms, such as GO, rGO, and FLG. These unique signatures, elucidated through thermogravimetry (TG) and derivative thermogravimetry (DTG) graphs, have proven effective in characterizing and ensuring the quality control of GR2Ms [13,16,17]. Notably, TGA parameters, including the number of peaks, their shapes, and the peak temperature or the temperature of the maximum mass change rate (T p or T max ), have been demonstrated to differentiate between different types of GR2Ms, facilitating both qualitative and quantitative analyses [13,16,17].…”

“…These unique signatures, elucidated through thermogravimetry (TG) and derivative thermogravimetry (DTG) graphs, have proven effective in characterizing and ensuring the quality control of GR2Ms [13,16,17]. Notably, TGA parameters, including the number of peaks, their shapes, and the peak temperature or the temperature of the maximum mass change rate (T p or T max ), have been demonstrated to differentiate between different types of GR2Ms, facilitating both qualitative and quantitative analyses [13,16,17]. The studies also underscore that TGA results for GR2Ms can be influenced by various experimental conditions and parameters, such as sample size, heating rate, atmosphere, and gas flow rates, among others.…”

Oxidative debris in graphene oxide: a decade of research

“…The increasing integration of nanotechnology in our daily lives has led to the massive production and commercialization of different nanomaterials. 1–3 To ensure they are safe and appropriate for use, quality control and standardization of the manufacturing processes are paramount. Beyond the regulatory aspects for commercialization, quality control is essential since the properties of nanomaterials can vary significantly depending on their size, shape, composition, and the presence of impurities.…”

“…Beyond the regulatory aspects for commercialization, quality control is essential since the properties of nanomaterials can vary significantly depending on their size, shape, composition, and the presence of impurities. 2–4 The lack of quality control can have severe and far-reaching consequences for nanotechnology. For academia, the absence of quality control can lead to irreproducible laboratory results, hindering scientific advancement.…”