Surface functionality analysis by Boehm titration of graphene nanoplatelets functionalized via a solvent-free cycloaddition reactionCitation formats

TY - JOUR

T1 - Surface functionality analysis by Boehm titration of graphene nanoplatelets functionalized via a solvent-free cycloaddition reaction

AU - Ren, He

AU - Cunha, Eunice

AU - Sun, Quanji

AU - Li, Zheling

AU - Kinloch, Ian A.

AU - Young, Robert J.

AU - Fan, Zhaodong

PY - 2019

Y1 - 2019

N2 - Carboxylic acid-terminated pyrrolidine functionalities were covalently bonded to the surface of graphene nanoplatelets via a solvent-free approach and characterized by Boehm titration. In this work, the functionalization of graphene nanoplatelets (GNPs) performed by a solvent-free cycloaddition reaction on GNPs with iminodiacetic acid (IDA) and paraformaldehyde (PFA), and the functionality analysis of the resulting functionalized GNPs (f-GNPs) by Boehm titration are introduced. The f-GNPs synthesized at different temperatures were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) for structural and morphological properties. Back titration of the f-GNPs selectively identified 3 types of functional groups on the f-GNP surface, carboxylic, lactonic and phenolic, and suggested that 200 °C gives the highest carboxylic group functionality. With the reaction temperature increasing from 180 to 220 °C, a decrease in the phenolic functionality and an increase in that of lactonic are observed. In the case of 250 °C reactions, it was found that the carboxylic functionality is greatly reduced, while the phenolic functionality showed a significant increase. The f-GNP samples were further characterized by thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), the results of which showed a good agreement with the titration analysis.

AB - Carboxylic acid-terminated pyrrolidine functionalities were covalently bonded to the surface of graphene nanoplatelets via a solvent-free approach and characterized by Boehm titration. In this work, the functionalization of graphene nanoplatelets (GNPs) performed by a solvent-free cycloaddition reaction on GNPs with iminodiacetic acid (IDA) and paraformaldehyde (PFA), and the functionality analysis of the resulting functionalized GNPs (f-GNPs) by Boehm titration are introduced. The f-GNPs synthesized at different temperatures were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) for structural and morphological properties. Back titration of the f-GNPs selectively identified 3 types of functional groups on the f-GNP surface, carboxylic, lactonic and phenolic, and suggested that 200 °C gives the highest carboxylic group functionality. With the reaction temperature increasing from 180 to 220 °C, a decrease in the phenolic functionality and an increase in that of lactonic are observed. In the case of 250 °C reactions, it was found that the carboxylic functionality is greatly reduced, while the phenolic functionality showed a significant increase. The f-GNP samples were further characterized by thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS), the results of which showed a good agreement with the titration analysis.

UR - http://www.mendeley.com/research/surface-functionality-analysis-boehm-titration-graphene-nanoplatelets-functionalized-via-solventfree

U2 - 10.1039/C8NA00280K

DO - 10.1039/C8NA00280K

M3 - Article

VL - 1

SP - 1432

EP - 1441

JO - Nanoscale Advances

JF - Nanoscale Advances

SN - 2516-0230

IS - 4

ER -