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All Journal Indonesian Journal of Chemical Studies (Indones. J. Chem. Stud.) Sorption Studies
Renta, Hotma
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Chemical Engineering, Chemistry & Bioengineering Chemistry Materials Science & Nanotechnology

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Formulation of Digested Beverage Cans and Iron Plate Wastes as a Coagulant for Adequate Hygiene of Fresh River Water Gita, Mutiara; Stiawan, Elva; Renta, Hotma; Kuntjahjono, Mayang Fauziah Putri; Lestari, Aura Puja
Indonesian Journal of Chemical Studies Vol. 4 No. 1 (2025): Indones. J. Chem. Stud., June 2025
Publisher : Indonesian Scholar Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55749/ijcs.v4i1.57

Abstract

In terms of hygiene and sanitation, ensuring the availability of qualified water for those purposes remains challenging to perform under certain conditions. Accordingly, efforts to provide simple water processing technology are ongoing and innovatively developed. This study displayed an innovative approach to producing coagulants for water processing by utilizing metal salts obtained synthetically from used beverage cans and iron plates through the electrolysis principle and characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy - The Energy Dispersive X-ray (SEM-EDX), subsequently. After mixing with calcium hypochlorite and adding to water sample, subsequently, the coagulant showed the ability to reduce the turbidity level and several categories of impurities, i.e., nitrate, nitrite, dissolved Manganese, Cr6+ ion, and microbial levels. Future research and development in formulating coagulants derived from digested beverage cans and iron plate wastes hold significant potential to advance sustainable and efficient water treatment technologies, ensuring improved hygienic quality of fresh river water while contributing to waste valorization and environmental protection.
Fabrication and Characterization of Graphene Nanoplatelets/Zinc Oxide Nanocomposites as a Military Radar Absorbing Material Rasendriya, Anselmo Bima; Hardiansyah, Andri; Amalia, Gita Resty; Rahmadtullah, Ismail; Setiono, Andi; Piliang, M. Zuhnir; Renta, Hotma
Indonesian Journal of Chemical Studies Vol. 4 No. 1 (2025): Indones. J. Chem. Stud., June 2025
Publisher : Indonesian Scholar Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55749/ijcs.v4i1.69

Abstract

Stealth aircraft have the capability to intercept radar waves. One common technique involves the use of radar-absorbing materials (RAMs). This study focused on the synthesis of advanced lightweight functional materials derived from advanced carbon and semiconductor compounds for microwave absorbing through mechanical homogenization. Graphene nanoplatelets (GNP) and Zinc Oxide (ZnO) possess excellent dielectric and magnetic loss capability due to their thermal conductivity, small particle size, large surface area, disordered structure, and lightweight nature. The GNP and ZnO were developed as advanced carbon and semiconductor nanocomposites using Planetary Ball Milling (PBM) at a ratio of 1:1. This approach aimed to improve the structure, morphology, and electromagnetic performance of the materials. A comparison between the nanocomposite materials and their precursors was conducted to clarify the advantages of using nanocomposites. FE-SEM showed the layered carbon sheets in GNP. XRD exhibited the alteration in the crystallite structure of ZnO, while FTIR spectroscopy confirmed the presence of specific functional groups. In addition, the GNP/ZnO nanocomposites showed strong microwave polarization capabilities. Notably, the GNP/ZnO nanocomposite achieved the lowest RL value compared to the precursor materials with a value of -28.21 dB at 8.45 GHz and a thickness of 3 mm in the scope of X-band range. While the through power was calculated at 99.84%. Through mechanical homogenization, a well-structured disordered crystallite layered material was fabricated for military RAMs. In the industrial sector, GNP/ZnO nanocomposites showed promising potential as a lightweight and advanced functional material for future stealth aircraft applications.
Recent Advances in Nickel Ferrite-Polymer Nanocomposites for Radar Absorbing Material Applications Panjaitan, Thesalonika Br; Hijrianisa, Alya; Apriliyanto, Yusuf Bramastya; Ananda, Dea Dwi; Basuki, Rahmat; Renta, Hotma
Sorption Studies Vol. 1 No. 2 (2025): Sorption Studies, December 2025
Publisher : Indonesian Scholar Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55749/ss.v1i2.125

Abstract

Nickel ferrite (NiFe₂O₄) and its polymer-based composites have emerged as promising candidates for radar absorbing materials (RAMs) due to their unique combination of magnetic and dielectric loss mechanisms. This review highlights recent advances in synthesis strategies, including sol–gel, hydrothermal, co-precipitation, and microwave-assisted methods, which enable precise control of particle size, morphology, and crystallographic defects. Such control supports flexible structural design of nickel ferrite spinel structures, allowing dopant incorporation to tailor magnetic anisotropy and saturation magnetization. These structural features directly affect electromagnetic performance. Magnetic loss is mainly governed by natural resonance and, to a lesser extent, eddy current effects, while dielectric loss arises from dipole polarization, interfacial polarization, and conduction loss. The synergistic balance of magnetic and dielectric losses makes nickel ferrite–polymer nanocomposites promising broadband radar absorbing materials. The discussion emphasizes the role of cation substitution, polymer matrices, and hybridization with carbon-based materials in enhancing microwave absorption bandwidth and impedance matching. Various synthesis approaches, including sol–gel, hydrothermal, and in-situ polymerization, are compared with respect to their influence on particle size, morphology, and absorption efficiency. Challenges such as limited bandwidth, thermal and mechanical stability, and scalability are highlighted, along with potential solutions through advanced nanostructuring, multifunctional design, and sustainable synthesis. Future research directions are also outlined to support the development of next-generation stealth and electromagnetic interference shielding technologies.
Co-Authors Amalia, Gita Resty Ananda, Dea Dwi Andi Setiono Elva Stiawan Gita, Mutiara Hardiansyah, Andri Hijrianisa, Alya Kuntjahjono, Mayang Fauziah Putri Lestari, Aura Puja Panjaitan, Thesalonika Br Piliang, M. Zuhnir Rahmadtullah, Ismail Rahmat Basuki Rasendriya, Anselmo Bima Yusuf Bramastya Apriliyanto