Purposive Assembling of Poly(3-hexylthiophene) onto Chemically Treated Multi-Wall Carbon Nanotube versus Reduced Graphene Oxide
Authors: Charoughchi, Somaiyeh
Agbolaghi, Samira
Sarvari, Raana
Aghapour, Sahar
Journal: Macromolecular Research (2018)
Discipline: CHEMISTRY
Keywords: multi-walled carbon nanotubes; reduced graphene oxide; donor-acceptor nano-hybrids; morphology; orientation

Abstract: Surfaces of multi-walled carbon nanotubes (CNTs) and reduced graphene oxide (rGO) nanosheets were chemically modified to design distinct donor-acceptor nano-hybrids having different morphologies and orientations. In unmodified CNTs and their derivatives functionalized with 2-hydroxymethyl thiophene (CNT-f-COOTh) and grafted with poly(3-dodecylthiophene) (CNT-g-PDDT), double-fibrillar, shishkebab, and stem-leaf nanostructures were decorated. Furthermore, rGO nanosheets functionalized with 2-thiophene acetic acid (rGO-f-TAA) and grafted with poly(3-dodecylthiophene) (rGO-g-PDDT) were prepared to study differences in CNT and rGO supramolecules. Three types of orientations subsuming face-on, edge-on, and flat-on were detected in nano-hybrids based on CNT and rGO. Morphology (fibrillar) and orientation (face-on) of poly(3-hexylthiophene) (P3HT) assemblies were similar onto unmodified CNT and rGO nanostructures. Although patternings of P3HT chains were completely different onto functionalized CNT and rGO (shish-kebab versus nanocrystal decorated nanosheets), edge-on orientation was detected in CNT-f-COOTh/P3HT and rGO-f-TAA/P3HT nano-hybrids. In CNT-g-PDDT/P3HT and rGO-g-PDDT/P3HT systems, P3HT chains were extendedly assembled onto grafted carbonic materials; however, their different natures reflected stem-leaf and patched-like configurations, respectively. For unmodified, functionalized, and grafted CNT and rGO patterned with P3HT chains, a photoluminescence quenching was detected for a donor-acceptor nature. Owing to flat-on oriented P3HTs, the best photoluminescence quenching, thereby the best donating-accepting features were detected for CNT-g-PDDT/P3HT and rGO-g-PDDT/P3HT supramolecules.

Retracted: Yes

PubPeer comments:
 All of the transmission electron microscopy (TEM) images reported in this work have unusual appearance: background with repetitive motifs, unusual texture in the background, inexplicably high contrast and regular shapes of the objects, unnaturally blurred focus. In short, the images have an appearance of heavily-processed at best and artificially created data at worst rather than experimentally obtained ones. Figure 6a is very concerning as there is an exact and repeated motif present in the image -- vertically elongated particle -- which is repeated across the  nanowire with slight distortions. Could authors address the doubts and clarify how the images were obtained and processed? Figure 3a:  Figure 3b:  Figure 5a:  Figure 5b:  Figure 6a:  Figure 7a:  , 
 Fig 3b, compared with 3c from [Agbolaghi et al (2018)] .  Background texture, texture on the central object, and the coarser mottling on the object are all the same, , 
 Hello dear, Thanks a lot for your focus on our paper. Some impurities on the TEM images have covered by the pieces of background for enhancing the image qualities. That is to say, the impurities were some ineffective black dots, which did not impact the final results. In addition, the repetitive polymer crystals onto the CNT could be originated from similar paterning of polymer precursors by somehow similar seeding situations on the CNT. Thanks again Samira Agbolaghi , 
 #3 Could the authors rephrase this sentence, u201cSome impurities on the TEM images have covered by the pieces of background for enhancing the image qualities.u201d? The way it is currently phrased, it suggests that the authors *edited the background of one or more of the images* to obscure visible impurities that detracted from the primary features being illustrated. Is this correct? , 
 The cost of TEM analysis is too high in our country. Each prepared sample was analyzed two or three times. The best images were selected and reported in the manuscript. Some little graphene spots were eliminated on the beckground. That is to say the main purpose of this manuscipt was the growth of supramolecules and the rare pieces of carbonic impurities were not important and omitted to report more beautiful images without damaging the scientific concept. , 
 Retracted [21 July 2022] . ------------------------- The Editor-in-Chief has retracted this Article. After publication, concerns were raised regarding the authenticity of the images presented in Figs. 3, 5, 6 and 8. The corresponding author has confirmed that the images were altered by a third party. Additionally, the article contains substantial text overlap with a previous paper from the same group [1] in the Introduction and Experimental sections. The Editor-in-Chief therefore no longer has confidence in the presented data. Samira Agbolaghi does not agree to this retraction. Somaiyeh Charoughchi, Raana Sarvari and Sahar Aghapour have not responded to any correspondence from the publisher about this retraction. ,