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Para-Toluene sulfonic acid doped polyaniline (PANI), PANI/chitosan composites, PANI/reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide have synthesised via oxidative polymerisation of aniline by Ammonium peroxydisulfate (APS). FTIR, XRD, FESEM and UV-VIS techniques were performed for the confirmation of the successful synthesis. The fundamental optical parameters such as, complex refractive index, complex dielectric constants and optical conductivity of the PANI and the composites were investigated in the UV-VIS-NIR range. The results show a clear dependence on the constituent component such as sulphur as well as the absorbance values of the polymers. This study would therefore serve as initial solution to the scarcity of studies on the optical contants of p-toluene sulfonic acid doped polyaniline and its composites that could have many potential electrical, optical and optoelectronic applications. Keywords: p-Toluene sulfonic acid doped polyaniline, Optical constant, Chitosan, Reduced graphene-oxide, Ternary composite, Optical conductivity

A ternary composite comprising of p-toluene sulfonic acid doped polyaniline (PANI), chitosan and reduced graphene oxide (RGO) with stable aqueous dispersibility has been synthesised via oxidative polymerisation of aniline in chitosan/RGO dispersion. For comparison; PANI, PANI/chitosan and PANI/RGO composites were also synthesised using the same procedure. FTIR, Raman, XPS, XRD and UV-VIS confirmed the successful synthesis of the PANI and the composites. The aqueous dispersions of the PANI/chitosan and the ternary composites were found to be stable even after more than four months. The stability of the dispersion was attributed to the polycationic nature of the chitosan. The thermogravimetric analysis (TGA) shows an improved thermal stability for the ternary composite compared to PANI, PANI/chitosan and PANI/RGO composites up to about 160 °C. In addition, the electrical conductivity of the ternary composite is around 33 and 2.6 times greater than that of PANI/chitosan composite and PANI, respectively. Interestingly, the analysis of the band gap shows the lowest value of optical band gap of 2.25 eV for the ternary composite compared to PANI, PANI/chitosan and PANI/RGO with 2.50 eV, 2.60 eV and 2.44 eV, respectively. The reduced band gap for the ternary composite might be attributed to the formation of conductive networks throughout the chitosan matrix due to uniform dispersion of RGO in the chitosan matrices as well as the possible grafting of PANI onto chitosan backbone. These observed properties indicate the potential utilisation of the ternary composite in optical, electrical, optoelectronic and many other industrial applications. Keywords: Ternary composite, Doped polyaniline, Optical band gap, Chitosan, Reduced graphene-oxide

In this letter, fused deposition modeling (FDM) was used to create a 1 × 2 array of the double ridge horn antenna (DRHA). The material used for FDM was acrylonitrile butadiene styrene. The DRHA was designed using an electromagnetic simulator and printed using FDM as well as the inner surface of the DRHA was painted with silver conducting paint. Two printed DRHA were connected together as a 1 × 2 array via a power divider. The main operating frequency of the array antenna was focussed on the range from 3 to 7 GHz. The 1 × 2 array DRHA is capable of better than −10 dB return loss, greater than 10 dBi gain, and a minimum half‐power bandwidth of 27.5°. [ABSTRACT FROM AUTHOR]

The optical constants of Para-Toluene sulfonic acid-doped polyaniline (PANI), PANIchitosan composites, PANI-reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide dispersed in diluted p-toluene sulfonic acid (PTSA) solution and N-Methyl-2-Pyrrolidone (NMP) solvent have been evaluated and compared. The optical constant values were extracted from the absorbance spectra of thin layers of the respective samples. The potential utilization of the materials as the active sensing materials of surface plasmon resonance biosensors has also been assessed in terms of the estimated value of the penetration depth through a dielectric medium. The results show a reasonable dependence of the optical constant parameters on the solvent type. Higher real part refractive index (n) and real part complex dielectric permittivity (ε’) values were observed for the samples prepared using PTSA solution, while higher optical conductivity values were observed for the NMP-based samples due to their relatively higher imaginary part refractive index (k) and imaginary part complex dielectric permittivity (ε″) values. In addition, NMP-based samples show improvement in terms of the penetration depth through a dielectric medium by around 9.5, 1.6, 4.4 and 2.9 times compared to PTSA-based samples for the PANI, PANI-chitosan, PANI-RGO and the ternary composites, respectively. Based on these, it is concluded that preparation of these materials using different dispersion solvents could produce materials of different optical properties. Thus, the variation of the dispersion solvent will allow the flexible utilization of the PANI and the composites for diverse applications.

Graphene is a promising material due to its fascinating properties, such as mechanical, electronic and thermal properties. Graphene based hybrids materials also have been widely studied due to its wide applications, such as sensors, energy storage and conversion, electronic device and others. The current study presents the synthesis of magnetite-reduced graphene oxide (M-rGO) nanocomposites through in situ chemical synthesis at different stirring durations. This synthesis process involves the redox reaction between the iron(II) salts and graphene oxide (GO) sheets. Various techniques were employed to characterize the synthesized M-rGO nanocomposites. From X-ray diffraction (XRD) results, the crystal structure of M-rGO was found to be independent on the stirring duration. Three magnetite vibrations, D band and G band were observed in Raman spectrum of M-rGO with 24 hours stirring duration. From Fourier transform infrared (FTIR) analysis, M-rGO with 24 hours stirring duration showed the strong intensity of Fe-O vibration. Thus, this indicated that a large amount of magnetite nanoparticles were covered on the surface of rGO sheets. This result is further supported by the morphology of nanocomposites from scanning electron microscopy (SEM) and the elemental analysis (EDX). A monolayer of rGO sheet (C= 33.79 atomic %) with full coverage of magnetite nanoparticles (Fe= 30.20 atomic %) was found for the M-rGO with 24 hours stirring duration. Overall, M-rGO require 24 hours of continuous stirring to ensure full coverage of magnetite nanoparticles on the surface of rGO sheets.

The article titled "A Review on Insights for Green Production of Unconventional Protein and Energy Sources Derived from the Larval Biomass of Black Soldier Fly" has been retracted by the Processes Editorial Office due to major scientific errors and concerns about the validity of the findings. An investigation confirmed the presence of a major scientific error, leading to the decision to retract the publication. The retraction was approved by the Editor-in-Chief of the journal, although the authors did not agree with the retraction. [Extracted from the article]

Water pollution has been a prevalent issue globally for some time. Some pollutants are released into the water system without treatment, making the water not suitable for consumption. This problem may lead to more grave problems in the future including the destruction of the ecosystem along with the organisms inhabiting it, and illness and diseases endangering human health. Conventional methods have been implemented to remove hazardous pollutants such as dyes, heavy metals, and oil but are incapable of doing so due to economic restraints and the inability to degrade the pollutants, leading to secondary pollution. Photocatalysis is a more recently applied concept and is proven to be able to completely remove and degrade pollutants into simpler organic compounds. Titanium dioxide (TiO2) is a fine example of a photocatalyst owing to its cost-effectiveness and superb efficiency. However, issues such as the high recombination rate of photogenerated electrons along with positive holes while being only limited to UV irradiation need to be addressed. Carbonaceous materials such as graphene oxide (GO) can overcome such issues by reducing the recombination rate and providing a platform for adsorption accompanied by photocatalytic degradation of TiO2. The history and development of the synthesis of GO will be discussed, followed by the methods used for GO/TiO2 synthesis. The hybrid of GO/TiO2 as a photocatalyst has received some attention in the application of wastewater treatment due to its efficiency and it being environmentally benign. This review paper thereby aims to identify the origins of different pollutants followed by the sickness they may potentially inflict. Recent findings, including that GO/TiO2-related nanocomposites can remove pollutants from the water system, and on the photodegradation mechanism for pollutants including aromatic dyes, heavy metal and crude oil, will be briefly discussed in this review. Moreover, several crucial factors that affect the performance of photocatalysis in pollutant removal will be discussed as well. Therefore, this paper presents a critical review of recent achievements in the use of GO/TiO2-related nanocomposites and photocatalysis for removing various pollutants in wastewater treatment. [ABSTRACT FROM AUTHOR]

There are errors in the Funding section. The correct Funding statement is: This research is supported financially by the Fundamental Research Grant Scheme (FRGS/1/ 2019/STG07/UTP/02/6) and the Yayasan Universiti Teknologi PETRONAS (YUTP) Grant (YUTP 0153AA-E40). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.By Xin Hui Yau; Cheng Seong Khe; Mohamed Shuaib Mohamed Saheed; Chin Wei Lai; Kok Yeow You and Wai Kian TanReported by Author; Author; Author; Author; Author; Author [Extracted from the article]