Synthesis and Superior Optical‐Limiting Properties of Fluorene‐Thiophene‐Benzothiadazole Polymer‐Functionalized Graphene Sheets

Abstract

A polymer based on fluorene, thiophene, and benzothiadazole as the donor-spacer-acceptor triad is covalently coupled to reduced graphene oxide (rGO) sheets via diazonium coupling with phenyl bromide, followed by Suzuki coupling. These polymer-graphene hybrids show good solubility in organic solvents, such as chloroform, tetrahydrofuran (THF), toluene, dichlorobenzene, and N,N-dimethylformamide (DMF), and exhibit an excellent optical-limiting effect with a 532-nm laser beam. The optical-limiting threshold energy values (0.93 J cm(-2) for G-polymer 1 and 1.12 J cm(-2) for G-polymer 2) of these G-polymer hybrids are better than that of carbon nanotubes (3.6 J cm(-2)).

Flexible and transparent resistive switching devices using Au nanoparticles decorated reduced graphene oxide in polyvinyl alcohol matrix

“…2(c) shows a strong plasmon resonance peak of gold at 520 nm in the absorption spectra of the hybrids, in agreement with previous reports on Au NPs with comparable particle size [31]. A broad hump at around 280 nm is attributed to π-π* transition in reduced graphene oxide [30].…”

“…Graphene oxide was synthesized by modified Hummer's method as described elsewhere [30] and detailed structure is given in the supporting information. The synthesis procedure of Au NPs and RGO hybrid is depicted in Fig.…”

Soluble fluorene–benzothiadiazole polymer-grafted graphene for photovoltaic devices

“…Thus, all these observations conrm the formation of a covalent bond between graphene and PFBT. 25 3.2 UV-vis absorption spectra analysis Fig. 3 shows the normalized absorption spectra of PFBT and G-PFBT in the THF solution.…”

“…30 These results were also discovered by Kian Ping Loh. 25 A study on PFBT and graphene shows that it is very likely that graphene can act as an active electron-accepting material for photovoltaic applications. 31,32 3.4 Solubility of the PFBT and G-PFBT…”

Nonlinear optical properties of graphene-based materials

“…RSA, NLS, and TPA [55]. Midya et al [56] synthesized two soluble polymer-grafted reduced GO (rGO) hybrids based on fluorene, thiophene, and benzothiadazole structures using the Suzuki coupling procedure. The donor-acceptor-type polymer-grafted rGO displays enhanced optical limiting properties for the 532 nm laser beam that are superior to those of CNTs, perhaps because of more efficient NLS.…”