Sudirman Sudirman

The synthesis of high-purity lepidocrocite-type titanate nanotubes from natural ilmenite minerals remains challenging due to the presence of iron impurities and the limited understanding of their structural stability during thermal treatment. This study presents a controlled purification and hydrothermal synthesis route for producing high-purity lepidocrocite-type titanate nanotubes from ilmenite-derived titanium dioxide (TiO₂) nanoparticles. Titanium oxosulfate (TiOSO₄) leachate obtained from the sulfate process was prepared via ethylenediaminetetraacetic acid (EDTA)-assisted purification, yielding TiO₂ nanoparticles with a purity of 99%, which were subsequently converted into titanate nanotubes by hydrothermal treatment. Structural characterization confirmed that the nanotubes retained their multilayered lepidocrocite-type titanate (H₂Ti₃O₇) structure after calcination up to 300°C while exhibiting improved crystallinity and a well-defined tubular morphology. The optimized sample (PF300) exhibited the highest specific surface area (256.9 m²g⁻¹) and pore volume (0.54 cm³g⁻¹), together with a direct band gap of 3.29 eV. Photocatalytic performance was evaluated through the degradation of methylene blue (MB), achieving removal efficiencies of 98% and 96% under ultraviolet and visible light irradiation, respectively. The outstanding performance originated from the synergistic effect of adsorption and photocatalysis, with preserved tubular morphology, a layered lepidocrocite structure, a high specific surface area, favorable optical properties, and efficient charge separation. These findings demonstrate that EDTA-assisted purification combined with controlled thermal treatment provides an effective strategy for producing high-performance lepidocrocite-type titanate nanotubes from natural ilmenite, with promising potential for solar energy-harvesting applications.

Graphene nanoplatelet (GNP) has a good potential to be developed as a drug carrier material. In this study, the interaction of GNP with one type of drug, namely 1,3,6-trihydroxyxanthone (THX), has been studied. The results of XRD analysis and FTIR uptake show an excellent interaction between THX and GNP through the π–π stacking channel. This interaction makes the GNP surface more polar and soluble in the aqueous media. THX-graphene shows physical and chemical stabilities, where THX can be released under specific and controlled conditions. The results of this study show the potential of utilizing graphene as a drug carrier material for more specific disease targets with a longer drug release time.

Black cumin seed extract (Nigella sativa) is effective to control ASTM A36 steel corrosion in 1 M HCl solution. This study analyzed black cumin seed (BCS) extract as a corrosion inhibitor (0 to 500 ppm) by electrochemical method including Potentiodynamic Polarization (PDP) and Electrochemical Impedance Spectroscopy (EIS). The results revealed that with the PDP method the highest inhibition efficiency (IE) was 84.26% at the concentration of 500 ppm, and with the EIS method the IE value was 77.77% at the same concentration. The components of the extract were analyzed by GCMS and obtained major compounds are linoleic acid (22.12%), methyl linoleate (22.70%), 4-cyclopentene-1,3-dione,4-3-methyl-2-butenyl) (7.64%), methyl palmitate (6.66%), and palmitic acid (5.14%). A theoretical approach with computation was also carried out to investigate the performance and interaction of the major compounds in the BCS extract that a significant role as inhibitor. This was using Density Functional Theory (DFT) method and Monte Carlo simulation. The results showed that methyl linoleate compound as the most significant role.

Chitin is a biopolymer that can be used as a candidate material for a strong and environmentally friendly glass adhesive. In the form of nanoparticles with needle-like morphology and attractive functional groups in the form of amide and hydroxyl, Chitin Nanoparticle (ChNP) shows a strong Van der Walls adhesive force against glass. In the study, ChNP was successfully isolated from crab shells from the sea of Lombok. The isolated ChNP has a characteristic size around 351 nm with -chitin conformation and needle-shaped morphology. Based on the results of shear strength testing, 0.42 mg of ChNP can withstand a load of 21 kg and the addition of Gum Arabic (GA) and Hen Egg White lysozyme (HEWL) in a ratio of 1: 1 to ChNP succeeded in increasing adhesion by 72%.

Desa Sembalun Bumbung, yang terletak di lereng Gunung Rinjani, memiliki potensi alam besar dan diakui sebagai World Geopark oleh UNESCO. Meskipun desa ini menghasilkan berbagai produk pertanian dan perkebunan, kebanyakan produk hanya dijual dalam bentuk bahan mentah, terutama untuk wisatawan yang berkunjung langsung. Pengabdian ini berfokus pada upaya meningkatkan pengetahuan dan keterampilan warga Desa Sembalun Bumbung dalam pengemasan produk pertanian dengan metode SMART (Sehat, Menarik, Aman, Ramah Lingkungan, dan Tepat Sasaran). Kegiatan ini melibatkan pendekatan transfer pengetahuan, transfer teknologi, serta pembinaan dan pendampingan. Produk yang menjadi fokus adalah kopi bubuk dan black onion, dengan pengemasan yang lebih inovatif dan estetis. Selain itu, pelatihan juga mencakup pembukaan toko online di e-commerce dan teknik copywriting. Hasil kegiatan menunjukkan bahwa pelatihan berhasil meningkatkan pengetahuan dan keterampilan peserta dalam pengemasan produk. Beberapa dari mereka bahkan tertarik untuk menjalankan bisnis online. Dengan pengemasan yang baik dan pemasaran yang tepat, produk hasil olahan dari Desa Sembalun Bumbung memiliki peluang untuk meningkatkan pendapatan dan berkontribusi pada pertumbuhan ekonomi lokal.

The performance of calcium carbide residue in reducing two-wheel exhaust emissions has been studied. To perform this experiment, the carbide residue was first converted into adsorbent and then mounted in the exhaust gas line. Two-wheeler used are vehicles commonly used among Indonesian motorcyclists. The test was carried out by varying the adsorbent dimensions and engine transmission. Engine emission tests and adsorbent performance investigations were performed both before and after the exhaust emissions made contact with the adsorbent. The results showed that upon direct contact with the carbide adsorbent, the emission of two-wheeled engines decreased. Carbon-based emissions were reduced significantly in the early stages of the experiment. Moreover, emissions reduction benefits are seen in all adsorbent and transmission engine configurations. The greater the adsorbent's surface area, the better the emission reduction. A significant emissions reduction is also achieved when the first engine transmission condition is applied compared to the neutral transmission. However, the adsorption efficacy declined over time in all research variations. The presence of channels and pores in the adsorbent, and the high temperature attained by the adsorbent, keep improving the adsorbent's adsorption capabilities. However, as saturation increases, the adsorbent's adsorption, and oxidation capability decline.