Graphene oxide nanosheets (GO) bring more interest in the tunable bandgap and enhanced the optical properties of nanocomposites. The developed method successfully mixed the PMMA- dissolved in dimethylformamide (DMF) with PVA dissolved in distilled water (DW) and DMF. New (PMMA-DMF)-(PVA-DW-DMF)/GO nanocomposite was successfully fabricated with various loading ratios of GO nanosheets for the first time. Several factors were applied to get fine desperation and homogeneous using the acoustic-solution casting method. Optical Microscope (OM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV–visible spectrophotometer were applied to investigate the structure and optical properties of the PMMA-PVA-GO nanocomposite. The OM images confirmed the fine homogenous matrix and GO distribution in the nanocomposites. FTIR spectra exhibited the most functional group of polymers and GO in the nanocomposites and strong interfacial interaction between the GO and matrix as confirmed by the shifting in the XRD patterns of the PMMA. The optical properties results of the PMMA-PVA/GO nanocomposites revealed an improvement up to 400% of the absorbance, 337% of the absorption coefficient, 51% of the refractive index, 210% of the real and 125% of the imaginary dielectric constants in terms to increase the GO concentrations, whereas the reduction in the transmittance and energy bandgap results of allowed and forbidden indirect transition were exhibited up to 9 and 16.4%, respectively. These results could grow for better and wide applications such as radiation shielding, specific optoelectronic applications, and filters ultraviolet also could use in landfilling the chemical, nuclear, and radioactive waste.

Graphene is one of the most interesting and attracting nanofillers. The investigation focused on the effect of two significant factors using graphene nanosheets and polymer molecular weights (Mw) on the optical properties of polymer graphene-based nanocomposites. New sonication-mixing-aquatic methods were applied using the three Mw, 4k, 8k and 20k of polyethylene glycol (PEG), as a polymer model, with low loading ratio graphene oxide nanosheets (GONSs) to synthesise the nanocomposites. Fine distribution and good homogeneity of GONSs were successfully presented in the PEG matrix as examined applying the optical microscope (OM). The results presented an enhance in the most optical properties, which shows significantly in the ultraviolet region (∼300 nm in wavelength), such as, absorbance, absorption coefficient, real and imaginary dielectric constants up to 71%, 355%, 37% and 41% after increasing the Mw, except the allowed and forbidden indirect optical energy gap were reduced to 18% and 29%, respectively. Moreover, the contribution of GO with Mw of PEG exhibited a notable improvement of the optical properties up to 100%, 440%, 48% and 61%, whereas the allowed and forbidden indirect optical energy gap were reduced to 43% and 86%. These results illustrated significant roles of the effect of MW and GO in the optical properties that give rise to better photovoltaic performances of heterojunction solar cells and may use as filters and antireflection coating in the substantial applications.

Polymer–graphene nanocomposites are attracting growing attention of scientists and engineers as graphene‐based nanofillers may enhance the properties of polymers significantly. This study aims to understand the adsorption behaviour of polymers on graphene oxide (GO) nanosheets. GO is synthesised using Hummerʼs method by oxidising graphite. Poly(ethylene glycol)s (PEGs) with different molecular weights are used as polymer models. A series of PEG/GO nanohybrids is prepared by applying different parameters in the solution processing method. Fourier transform infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, polarised optical microscopy, scanning electron microscopy and atomic force microscopy are used for characterising the hybrid nanomaterials. The characterisation results confirm the successful preparation of GO and the adsorption of the PEGs onto GO. The maximum amount of adsorbed PEG was 38 wt%. The adsorption amount of PEG increases by 46% after reducing the mixing time from 192 h to 72 h, 1700% due to an increase in the molecular weight from 1k to 100k, 13% for doubling the mixing ratio of PEG:GO from 1.5:1 to 3:1, 44% for applying no further washing procedure and 73% for applying all these parameters concurrently. The adsorption onto GO reduces the crystallinity of PEGs due to chain confinement. Different surface morphologies are observed in the hybrid nanomaterials showing various thicknesses of the PEG layer adsorbed on the GO nanosheets. This study may offer new insights into the manipulation of the interface in polymer–GO nanocomposites. © 2020 Society of Industrial Chemistry

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A green and easy technique was used to synthesize silver and silica (Ag@SiO 2 ) core–shell nanoparticles (NPs) in the matrix blend polymers matrix. Core–shell nanoparticles were loaded into polyvinyl alcohol (PVA) and ultrahigh molecular weight polyethylene oxide (UHMW-PEO) blended polymer to fabricate new nanocomposite films (NCFs) using the developed solution-sonication-casting technique. The spectroscopic properties of the resultant films were investigated using x-ray diffraction (XRD), Fourier transforms infrared (FTIR), visible light microscope (OLM), field emission scanning electron microscope (FESEM), FESEM-energy dispersive spectroscope (FESM-EDX), UV/visible spectrometer, and LCR meter to investigate the structural, morphological, optical, and electrical characteristics. XRD revealed the presence of the semi-crystalline nature of PVA-UHMWPEO/ Ag@SiO 2 NCFs. The degree of crystallinity increased after embedding. The NPs were well distributed within the NCFs according to OLM and SEM, and FESM-EDX confirmed the presence of C, O, Si, and Ag elements. FTIR spectrum observed strong bonding after the loading of NPs, and other peaks were hidden. The UV/visible spectrums suggested an absorption at ~ 210 nm. Based on the Tauc plot model, the optical bandgap (Eg) values decreased from 5.52 eV to 4.57 eV. The electrical conductivity values were significantly increased with the increasing frequency and (Ag@SiO 2 ) core–shell nanoparticles (NPs) loading ratio. The PVA-UHMWPEO/Ag@SiO 2 NCFs explained enhanced lattice strain. The obtained NCFs are suitable for use in various optoelectronic and nanodevice applications.

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In this study, the rubber batches composites were prepared using Natural rubber (NR) and synthetic rubber (SBR) as model materials. The composites were reinforced using oyster shell powder (OSP) with particle size less than (225μm). Two groups of samples were prepared with (0, 5, 10, 15, 20, 25, 30, 40 and 60 pphr) with loading ratio of OSP and (CB-10pphr) of CB, whereas other composites were without CB. Density, viscosity and multi ultrasound velocity wave devices were applied to characterize the density according to the specification (ASTM-D1817-66) (Densitron), rheological properties with specification (ASTM-D2084-89) standard and mechanical properties, respectively. The result showed significant influence of the reinforcements (OSP) material and (CB) on some of these properties that exhibited an increasing with the increasing of loading ratio of (OSP) and (CB), such as density, relaxation amplitude and compressibility, but the other properties were decreasing like viscosity, relaxation time, velocity waves, bulk modulus and specific acoustic impedance.