کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5209420 | 1503058 | 2016 | 10 صفحه PDF | دانلود رایگان |
Direct titration with NaOH was used to quantify the acidic functional group content in graphene oxide (GO). Three different methods were used to evaluate the experimental data: the first derivation of the titration curve, Gran linearization and an empirical approach suggested by Ritchie and Perdue for the evaluation of the titration data for humic substances. Two types of acidic functional groups were identified and classified, more or less arbitrarily, as being either carboxylic or phenolic. Typically, the carboxylic acid group contents ranged from ca. 0.80 to 1.70Â mmol/g, except for the carboxylated GO prepared by the reaction with chloroacetic acid, which contained significantly more carboxylic acid groups. The titration results are consistent with those obtained by instrumental methods such as X-ray diffraction (XRD), infrared spectroscopy (IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). For modelling purposes (proton binding and metal binding), a bimodal continuous distribution model was proposed, and its parameters were estimated from the titration data.
Journal: Reactive and Functional Polymers - Volume 103, June 2016, Pages 44-53