Silsesquioxane-Polythiophene Hybrid Copolymer as an Efficient Modifier for Single-Walled Carbon Nanotubes

Shuxi Gao,Xiaoyong Hu,Yongqiang Dai,Yuliang Mai,Bing Liao,Lei Zhang,Hao Pang

doi:10.1155/2020/7659405

Abstract

One silsesquioxane-polythiophene hybrid copolymer, with combined star-like structure and intramolecular heterogeneity, was synthesized and sufficiently characterized via various methods, including FTIR, NMR, and SEC measurements. According to the exploration and characterization results, it was much more efficient at modifying SWNTs than its linear analogs in aqueous solution. The hydrophobic silsesquioxane core and PEDOT chains could locally anchor to the surface of the nanotubes, while the soluble flexible copolymer chains extended into the solution and rigid conjugated chains provided some π-π stacking effect to enhance adhesive force with the conjugated structure of the carbon nanotube, imparting steric stabilization to nanotube dispersion. The noncovalent interaction with SWNTs and solubility in aqueous solution improved the electrochemical characteristics of the modified-SWNT composite and availed for the preparation of a flexible and transparent electroactive film. Accordingly, this kind of silsesquioxane-polythiophene hybrid copolymer will be forwarded to apply to the assembling of flexible optoelectronic devices.

Highlights

Carbon nanotubes (CNTs) classified as multiwalled nanotubes (MWNTs) and single-walled nanotubes (SWNTs), upon the wrapped amount of a graphite sheet, have been used in multiple fields, such as composites, optoelectronic devices, field emission display, and energy storage, due to their unique physical, chemical, and structural properties [1,2,3]
The polymer precursor was subsequently copolymerized with the EDOT monomer to form PEDOT branches grafted from the hydrophobic T10 core, and the extension of the conjugated system was realized at the interface between the immiscible organic and aqueous phases by a modified interfacial synthesis protocol (MIP) [24]
Due to the extremely high reactivity of thiyl radical addition toward the carbon-carbon double bond, excess thiolactone could promote the conversion rate of amine and ensure complete conversion [26]; PDMA-b-PMA obtained by reversible addition-fragmentation transfer (RAFT) polymerization was linked to T10(5-5) by thiol-ene conjugation after nucleophilic cleavage of the thiocarbonyl group

Summary

Introduction

Carbon nanotubes (CNTs) classified as multiwalled nanotubes (MWNTs) and single-walled nanotubes (SWNTs), upon the wrapped amount of a graphite sheet, have been used in multiple fields, such as composites, optoelectronic devices, field emission display, and energy storage, due to their unique physical, chemical, and structural properties [1,2,3]. The versatile chemistry of copolymer modifiers allows for tailoring and functionalizing polymer/nanotube composites with finely various properties, enhancing the application of CNTs, especially in fabricating carbon-based flexible transparent electrodes [18,19,20,21]. A novel star-shaped copolymer is reported to stabilize single-walled carbon nanotubes (SWNTs) in aqueous solution through noncovalent interactions. H HN yielding much better efficiencies toward functionalization and dispersion, and multiple binding sites could assemble larger polymer aggregation that locally anchored onto the nanotube surface compared to its linear analogs that sequentially reduced the hydrophobicity of the sidewall surface for minimizing the connection with water and other tubes. We report a star-like conjugated copolymer T10(PDMA-b-PMA)-PEDOT (P5-5) standing on hydrophobic cage-like decakis(methacryloxypropyl) silsesquioxane (T10) and the linear analog PDMA-b-PMA-b-PEDOT, to explore the mechanism of SQ-based star configuration and conjugated system generating the efficient dispersion of SWNTs

Experimental Section

Results and Discussion

Dispersion Properties

Conclusion