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INDONESIA
Indonesian Journal of Chemistry
Published by Universitas Gadjah Mada
ISSN : 14119420     EISSN : 24601578     DOI : -
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology and Higher Education (RISTEKDIKTI) No : 21/E/KPT/2018 (in First Rank) and indexed in Scopus since 2012. Since 2018 (Volume 18), Indonesian Journal of Chemistry publish four issues (numbers) annually (February, May, August and November).
Arjuna Subject : -
Articles 1,956 Documents
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Enhancement of Cobalt Concentration Supported on Mesoporous Silica towards the Characteristics and Activities of Catalysts for the Conversion of Waste Coconut Oil into Gasoline and Diesel Oil Wega Trisunaryanti; Triyono Triyono; Nugroho Raka Santoso; Savitri Larasati; Cahyarani Paramesti; Dyah Ayu Fatmawati
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55633

Abstract

The analysis of the effect of cobalt concentration supported on mesoporous silica (MS) has been evaluated. This study was aimed to observe the physical and chemical characteristics of the catalysts, and also to study the catalytic activity and its selectivity towards gasoline and diesel oil products in the hydrocracking process of waste coconut oil. The MS was produced using Lapindo mud, where the CTAB was used as the mesopore templating agent. The Co/MS catalyst was prepared by the wet impregnation method with various concentrations of Co. The characterization of the catalyst includes silica purity test by XRF, determination of Co content by AAS, the crystallinity by XRD, the catalyst porosity by SAA, physical pore structure by SEM and TEM, and total acidity by the gravimetric method using NH3 base vapor adsorption. The hydrocracking was carried out in a hydrocracking reactor using various concentrations of Co/MS catalysts with the ratio of catalyst/feed = 1/50. The products of the hydrocracking process were liquid, coke, and gas. The composition of the hydrocracking liquid products was analyzed by GC-MS. Based on the results of the catalytic activity test, it was concluded that the Co(1)/MS catalyst, which had the highest acidity, showed the best catalyst selectivity towards gasoline and diesel fractions.
Influence of Calcination Temperature on Size, Morphology and Optical Properties of ZNO/C Composite Synthesized by a Colloidal Method Siham Lhimr; Saidati Bouhlassa; Bouchaib Ammary
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.56309

Abstract

ZnO is one of the most studied semiconductor materials because of its interesting chemicals, and from a technological point of view, mainly as a consequence of their outstanding properties, such as wurtzite type, non-toxic nature, large band gap, low cost, and environment-friendly. In this work, the ZnO/C composite was synthesized by a simple and fast low-temperature method; the solid product was calcination temperature at 100 to 400 °C. The influence of variation in calcination temperature was studied using X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-visible diffuse reflectance spectroscopy. The X-ray diffraction patterns indicated a high crystallinity and a nanocrystalline size of the ZnO/C composite hexagonal structure of wurtzite. The SEM image of the samples showed that the powder has a spherical structure of flakes aggregated in the common nucleus like a grid. The sphere consists of spindle and flower-like structures. The optical properties were determined by UV-vis diffuse reflectance spectroscopy, and it was found that the band gap energy of ZnO/C composite increase from 3.210 to 3.329 eV with an increase in calcination temperature from 100 to 400 °C. FTIR spectra and EDS analysis showed that the existence of carbon in the composite.
Phytochemical Analysis of Bioactive Extracts and Seed Oil of Three Euphorbia Species from Algerian Flora by LC-MS and GC-MS Nadia Toudert; Farida Zakkad; Noureddine Dadda; Abdelouaheb Djilani; Amadou Dicko; Salah Eddine Djilani
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.56679

Abstract

Euphorbia species possess pharmacological properties that have been widely used for medical purposes worldwide. In this paper, three plants belonging to the Euphorbia genus growing in North-East of Algeria were studied. The phenolic contents were identified using LC-MS, while the fatty acid composition of their fixed oils was determined with GC-MS. The quantification of the total condensed tannins and the leaves' entire anthocyanin content were performed using photometric methods. The main constituents of the polyphenolic compounds identified by LC-MS were ascorbic, chlorogenic, and ellagic acids. The oil yield of the seeds of E. terracina, E. biumbellata, and E. dendroides was 17.48%, 18.5%, and 20.05%, respectively. Quantitative analyses of these oils using GC-MS showed variations in the species' fatty acid constituents' concentrations and compositions. Besides, the phytochemical screening results showed that E. terracina possessed a high amount of tannin and anthocyanin content compared with other studied plants.
Equilibrium Modeling of Astaxanthin Extraction from Haematococcus pluvialis Putri Restu Dewati; Rochmadi Rochmadi; Abdul Rohman; Avido Yuliestyan; Arief Budiman
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.56965

Abstract

Astaxanthin is a natural antioxidant, and the highest content of this compound is found in Haematococcus pluvialis microalgae. Microwave-assisted extraction (MAE) is one of the environmentally friendly extraction methods and has many advantages. This study aims to investigate the extraction of astaxanthin through the MAE method using various solvents. Several equilibrium models were proposed to describe this solid-liquid equilibrium. The solid-liquid extraction equilibrium parameters were determined by minimizing the sum of squares of errors (SSE), in which equilibrium constants were needed for scaling up purposes. Previously, the microalgae were pretreated with HCl to soften their cell walls in order to improve the extraction recovery. In this study, dichloromethane, acetone, methanol, and ethanol were used as the solvents for extraction. The astaxanthin concentration was determined by high-performance liquid chromatography (HPLC) and spectrophotometry. Astaxanthin was found to attain equilibrium at 57.42% recovery in a single-step extraction. Thus, several steps were required in sequence to obtain an optimum recovery. The experimental data were fitted to three equilibrium models, namely, Henry, Freundlich, and Langmuir models. The experimental data were well fitted to all the models for the extraction in dichloromethane, methanol, ethanol and acetone, as evident from the almost same SSE value for each model.
Synthesis of Cu2+ Doped ZnO by the Combination of Sol-Gel-Sonochemical Methods with Duck Egg Albumen as Additive for Photocatalytic Degradation of Methyl Orange Sherly Kasuma Warda Ningsih; Hary Sanjaya; Bahrizal Bahrizal; Edi Nasra; Syuhada Yurnas
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.57077

Abstract

Cu2+ doped ZnO by green synthesis was successfully prepared by using a combination of the Sol-Gel-Sonochemical method. Duck egg albumen was used as an additive, a substitute for chemical additives, such as monoethanolamine (MEA) and diethanolamine (DEA). Zn(CH3COO)2·2H2O was used as a precursor, Cu(CH3COO)2·H2O was used as a dopant source with concentrations of 5 wt.%, and isopropanol was used as the solvent. The addition of albumen variations was 10, 20, 30, 40, and 50 mL. The prepared catalyst was applied for the degradation of the methyl orange dyes by using photosonolysis with variations of the degradation time of methyl orange for 30, 60, 90, 120, 150, 180, and 240 min. FTIR spectra showed stretching at 400–550 cm–1 indicating the presence of Zn–O and Zn–O–Cu metal oxides. The optimum bandgap energy value was 2.82 eV with the addition of 30 mL of albumen. XRD analysis showed the optimum particle size of 16.62–53.21 nm after adding 30 mL of additives. The SEM image showed a spherical shape with an average diameter of 2.7 μm. The optimum percentage of degradation obtained was 94.88%, with the irradiation time under UV light for 210 min.
Synthesis, Antiproliferative and Antimalarial Activities of Dinuclear Silver(I) Complexes with Triphenylphosphine and Thiosemicarbazones Ligands Nur Adila Fatin Mohd Khir; Mohd Ridzuan Mohd Abdul Razak; Fariza Juliana Nordin; Nur Rahimah Fitrah Mohd Sofyan; Nur Fadilah Rajab; Rozie Sarip
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.57343

Abstract

A series of six sulfur-bridged dinuclear silver(I) thiosemicarbazone complexes were synthesized through the reaction of silver(I) nitrate with 4-phenyl-3-thiosemicarbazone derivatives together with triphenylphosphine (PPh3) (in a 1:1:2 molar ratio). Following structural characterizations using various techniques such as elemental analysis, Fourier-transform infrared (FTIR) spectroscopy, as well as 1H, 13C, 31P{1H}s, COSY, and 1H-13C nuclear magnetic resonance (NMR) spectroscopy, it was found that the thiosemicarbazone ligand exists in the form of a thione rather than thiol tautomer. Subsequently, MDA-MB-231 and MCF-7 breast cancer cell lines, as well as the HT-29 colon cancer cell lines, were used to investigate the in vitro antiproliferative activities of these complexes. In all cases, the IC50 values were in the potent micromolar range. Besides, the aforementioned complexes also had good antiplasmodial activity against chloroquine-resistant P. falciparum, as per the results of histidine-rich protein 2 (HRP2) assays and cytotoxicity evaluations of MDBK cells.
Deposition of Hydroxyapatite on Silica Made from Rice Husk Ash to Produce the Powder Component of Calcium Phosphate Cement Tri Windarti; Widjijono Widjijono; Nuryono Nuryono
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.57900

Abstract

Hydroxyapatite (HA) has been deposited on silica (SiO2) particles to produce HA-SiO2 composite that will be used as the powder component of calcium phosphate cement. HA was expected to be on the composite surface to maintain its bioactivity. SiO2 was made by the sol-gel method, in which silicate solution was extracted from rice husk ash with NaOH solution. Deposition of HA on SiO2 was carried out by wet chemical deposition method at various Ca/Si molar ratio (in a range of 5–25) followed by calcination at 600 °C for 2 h. Results showed that HA was successfully deposited on SiO2 particles. The cell parameters of the HA crystals were slightly distorted by the presence of SiO2 and HA in the composite had a bigger cell volume than pure HA. The crystallite size of HA in the composites increased with the increase of the Ca/Si ratio but the values were smaller than pure HA. SiO2 acted as a morphology directing agent. At low Ca/Si ratio, the HA-SiO2 particles were in a form of short rod-like particles with sizes of < 50 nm, while at high Ca/Si ratio, a mixture of short and long rod-like particles with the size of < 100 nm was obtained. The zeta potential of composites was almost similar to pure HA. These properties indicated that HA-SiO2 composites support the bioactivity of injectable calcium phosphate cement.
Polarity Effect on the Electronic Structure of Molybdenum Dichalcogenides MoXY (X, Y = S, Se): A Computational Study Based on Density-Functional Theory Salsabila Amanda Putri; Edi Suharyadi; Moh. Adhib Ulil Absor
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.57949

Abstract

Computational research based on the Density Functional Theory (DFT) has been performed to explore the electronic structure of monolayer material Transition Metal Dichalcogenides (TMDCs) Molybdenum Dichalcogenides MoXY (X; Y = S; Se) in the first Brillouin zone by breaking its mirror symmetry due to the polarity effect. Our study discovered that Rashba spin-splitting could be identified around the Γ point by proposing the polarity effect on the system. Moreover, the anisotropic characteristic of Rashba spin-splitting in this system can be explicitly analyzed by using  perturbation theory and the third-order symmetry group analysis. By performing the spin textures analysis, this research also recognizes the in-plane direction of spin textures. The tunable characteristic of the Rashba parameter of this monolayer polar MoSSe system under the strain effects control exhibits its potential to be the candidate of semiconductor material for the Spin Field Effect Transistor (SFET) device.
Groundwater Recharge Area Based on Hydrochemical and Environmental Isotopes Analysis in the South Bandung Volcanic Area Rizka Maria; Satrio Satrio; Teuku Yan Waliyana Muda Iskandarsyah; Bombom Rachmat Suganda; Robert Mohammad Delinom; Dyah Marganingrum; Wahyu Purwoko; Dady Sukmayadi; Hendarmawan Hendarmawan
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.58633

Abstract

The determination of recharge areas needs to support the groundwater conservation in the southern volcanic Bandung area. This study aims to determine the recharge area based on environmental isotopes and hydrochemical. A sampling of 26 groundwater was carried out at springs, dug wells, and drilling wells. The variation in groundwater chemistry principally is controlled by a combination of ion exchange, silicate weathering, calcite, and dolomite dissolution of minerals. The hydrochemical facies were CaCl, CaMgCl, CaMgHCO3, CaHCO3, and NaKHCO3. The CaHCO3 facies describe moderate groundwater flows. The NaKHCO3 facies shows the mixing of shallow and deep groundwater. The recharge area in the central, proximal, and medial facies zone consists of 3 groups. Group I is considered water originating from local rainwater infiltration; Group II is considered the infiltration elevation which ranges from 980–1230 m asl; Group III estimated to be derived from the recharge elevation between 750–970 m asl, Group IV are more likely to show symptoms of evaporation or interaction with surface water. The discharge area is characterized by less active groundwater circulation, with dominant HCO3– and TDS value in the distal facies zone. Hydrochemical variation helped the identification of recharge areas in the volcanic facies.
Morphology of NdFeB-Type Permanent Magnet Coercivity Enhancement by Heat Treatment Process Eva Afrilinda; Dagus Resmana Djuanda; Shinta Virdhian; Martin Doloksaribu; Moch Iqbal Zaelana Muttahar; Sri Bimo Pratomo
Indonesian Journal of Chemistry Vol 21, No 3 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.59096

Abstract

To understand the morphology of the coercivity enhancement by heat treatment, a commercial sintered NdFeB-type permanent magnet is annealed, and the coercivity is measured by Permagraph. It is shown that the coercivity is increased compared to the initial. Observation by X-Ray Diffraction (XRD) analysis and Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy (SEM-EDS) is then conducted. The XRD result shows the amount of NdFeB content in the NdFeB-type permanent magnet is increased after heat treatment. The more significant amount of NdFeB content causes higher coercivity. The maximum coercivity, 19 kOe, is achieved at 850 °C of heat treatment temperature, where the NdFeB content is at the highest amount. Microstructural characterizations using SEM-EDS show that at 850 °C of heat treatment temperature, the iron (Fe) content in the grain boundaries is the lowest. It causes higher coercivity. This is due to the magnetically decoupled between NdFeB grains. The decoupling magnet of the NdFeB grains is affected by the Fe content in the grain boundaries. High-temperature heat treatment at 900 and 1050 °C led to the decomposition of NdFeB content in the grains and increased the Fe content in the grain boundaries, which resulted in a substantial reduction of magnetic coercivity.

Page 131 of 196 | Total Record : 1956

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