Studies on thermal analysis and optical parameters of Cu doped poly(vinyl acetate)/polyindole composites

Homogenous Dispersion of MoS2 Nanosheets in Polyindole Matrix at Air–Water Interface Assisted by Langmuir Technique

“…UV–vis spectra (Figure ) of precursors in pristine form (PIn and MoS 2 nanosheets) and their MoS 2 –PIn composite were recorded to investigate the spectral changes after the composite formation. MoS 2 nanosheets exhibited characteristic absorptions at 390, 445, 608, and 660 nm (Figure a­(i) red star marked) which are absent in composite, signifying the interaction of nanosheets with PIn. , Figure a­(ii) showed characteristic absorptions of PIn at 253, 306, 347 (π–π*), 398 nm (n−π*), and polaronic transition (450–550 nm) consistent with reports in the literature. − These absorptions were consistent with the composite (Figure a­(iii)) justifying the polymerization of indole along with 20 nm shift in the first peak (characteristic of indole; blue star marked). This red shift could be attributed to the increased conjugation length and controlled polymerization of indole on MoS 2 nanosheets. , …”

“…At marked temperatures (a) 190 °C, the weight loss difference was ∼4%, but at higher temperature (b) 600 °C the difference increased to 12% indicating an enhancement in the thermal stability of the nanocomposite. All the above results validate the existence of noncovalent interaction between the polymerized indole and MoS 2 nanosheet with synergistic enhancement in conjugation length, polymer crystallinity, and thermal stability. ,− …”

“…Here, we have adopted a hydrothermal route directly yielding nanosheet morphology, which is later exfoliated in ethanol–water mixture in the presence of monomer (indole) discarding the usage of other intercalating agent. The reason for the interest in polyindole (PIn) among the most studied conducting polymers is their excellent thermal stability, high redox activity, fast electrochromic response, and better environmental stability with prominence in sensors, electrocatalysis, electrochromic devices, energy storage, and biosensor domains. − Besides all these, poor electrical conductivity of PIn relative to sulfur-containing polymers with alkyl chain like poly­(3-alkylthiophene) (P3-AT) diminishes the significance of the PIn family in organic electronics. − In the past few decades, remarkable enhancement in redox and electrical properties of the PIn family has been realized via composite formation with CNT, graphene, and other conducting materials . Nevertheless, the high cost, poor synthetic yield, and failure in large area film formation of these materials reduce their industrial implication.…”

Effect of sintering temperature on complex optical properties of 0.8(PbMg 1/3 Nb 2/3 O 3 )–0.2(PbTiO 3 ) system

“…Optical conductivity increases slowly over the range 225-590 nm. The steady rise in optical conductivity reflects decrease in absorption coefficient .Similar trend is observed in optical conductivity by Bhagat et al [20] .The values of optical conductivity for samples S1 and S2 are 3.01x10 7 S -1 and 2.51x10 7 S -1 respectively at 350 nm. Fig.6.…”

“…Figure 5 shows the variation of refractive index as a function of wavelength. The complex optical property such as optical conductivity and dielectric constant shows direct dependence on refractive index [19,20]. It is observed that refractive index curve shows deep around 200 nm and nearly flat behavior between 300-600 nm.…”