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In the present work, five novel non-fullerene acceptor molecules are represented to explore the significance of organic solar cells (OSCs). The electro-optical properties of the designed A–D–A-type molecules rely on the central core donor moiety associated with different halogen families such as fluorine, chlorine, and bromine atoms and acyl, nitrile, and nitro groups as acceptor moieties. Among these, M1 exhibits the maximum absorption (λ max ) at 728 nm in a chloroform solvent as M1 has nitro and nitrile groups in the terminal acceptor, which is responsible for the red shift in the absorption coefficient as compared to R (716 nm). M1 also shows the lowest value of the energy band gap (2.07 eV) with uniform binding energy in the range of 0.50 eV for all the molecules. The transition density matrix results reveal that easy dissociation of the exciton is possible in M1 . The highest value of the dipole moment (4.6 D) indicates the significance of M4 and M2 in OSCs as it reduces the chance of charge recombination. The low value of λ e is given by our designed molecules concerning reference molecules, indicating their enhanced electron mobility. Thus, these molecules can serve as the most economically efficient material. Hence, all newly designed non-fullerene acceptors provide an overview for further development in the performance of OSCs.

Aminosilane grafted and diamine modified reactive montmorillonite was exploited to generate aromatic polyamide based nanocomposites. For better compatibility, the hydrophilic nature of montmorillonite was changed into organophilic using 1,4-phenylenediamine, and the hydroxyl groups present on the clay surface and edges were used to graft 3aminopropyltriethoxysilane (APTS) on clay sheets. The dispersion of clay was monitored in the polyamide obtained from 1,4phenylenediamine, 4,4′-oxydianiline, and isophthaloyl chloride. These chains were converted into carbonyl chloride ends to interact with free amine groups of grafted APTS and diamine. Thin films were probed for FTIR, XRD, SEM, TEM, tensile testing, TGA, and DSC measurements. The results described ample dispersion of clay in the nanocomposites with tensile strength increased 110% and elongation increased 172% upon the addition of 4−6 wt % clay. Thermal decomposition temperatures of the nanocomposites were in the range 425−480 °C. The glass transition temperature increased up to 142.4 °C with 6 wt % addition of organoclay.

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In the present study, analysis and source apportionment of the elemental composition of PM 10 was conducted in the urban atmosphere of Karachi. Trace elements such as Ni, Ba, Cd, Ca, Mg, Cr, Mn, Fe, Co, Cu, Sr and Ti were measured. The PM 10 concentration ranged from 255 μg m -3 to 793 μg m -3 , with an average of 438 ± 161 μg m -3 . Among the various elements analyzed, concentrations of Ca, Al and Fe were the highest (> 10000 ng m -3 ), followed by Mg and S (> 1000 ng m -3 ). Elements such as Zn, P, Cu, Pb, Mn, Ti, Sr and Ba demonstrated medium concentrations (> 100 ng m -3 ), whereas the lowest concentrations were found for elements such as Cr, Ni and Se (> 10 ng m -3 ). The Positive Matrix Factorization (PMF) model identified five possible factors that contributed to PM 10 , namely, biomass burning, coal combustion, resuspended road/soil dust, vehicular emissions and industrial dust. Industrial dust was the highest contributor (23.2%) to PM 10 followed by Biomass burning (23%), Vehicular emissions (22.2%), Coal combustion (21.7%) and Re-suspended dust (9.9%). A strong positive correlation (R 2 = 0.98) was observed between the model predicted PM 10 mass and the gravimetrically measured mass collected on filters.