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Indonesian Journal of Chemistry

ijc
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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).

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Articles 25 Documents

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Search results for , issue "Vol 18, No 3 (2018)" : 25 Documents clear

Heat Treatment of Pitch Obtained from Atmospheric Fixed-Bed Coal Gasification Phiciato Phiciato; Ika Monika; Arie Hardian
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

A medium temperature pitch obtained from atmospheric fixed-bed gasifier was distilled at a various time (1, 2, 3 and 4 h) to induce polymerization and the results were compared with a commercial pitch. Aromaticity level of pitches was examined using infrared spectroscopy, elemental analysis and simultaneous thermal analysis (TG-DSC). Longer heating time promoted lower moisture content, lower residue yield, higher insoluble fractions, as well as higher ash and carbon content. Although prolonged heat treatments lead to higher aromatization, there was no significant change in aromatization for heat treatment longer than 1 h. The index of aromaticity measured by using elemental analysis was ranged between 0.47 to 1.01, while the result from FTIR spectra showed stagnant value at 0.52. These values were slightly higher than that of pressurized Sasol-Lurgi gasification pitch (0.27).

Bulk Polymerization Kinetics of Hydroxy Terminated Polybutadiene and Toluene Diisocyanate with Infrared Spectroscopy Heri Budi Wibowo; Widhi Cahyo; Ratih Sanggra
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

A study on bulk polymerization kinetics of HTPB (Hydroxy Terminated Polybutadiene) and TDI (Toluene Diisocyanate) with infrared (IR) spectroscopy has been conducted. The investigations included the molar ratio of 2,4-TDI to 2,6-TDI isomers, the initial molar ratio of isocyanate group to a hydroxyl group, and the reaction temperature. The polymerization rate constant was calculated based on the decrease rate of TDI. Kinetics model had been evaluated through the following reaction steps: (1) 2,4-urethane production, (2) 2,6-urethane production, (3) the reaction between 2,4-urethane and the isocyanate group of 2,4-TDI, (4) the reaction between 2,4-urethane and the isocyanate group of 2,4-TDI, (5) the reaction between 2,6-urethane and isocyanate group of 2,4-TDI, and (6) the reaction between 2,6-urethane and the isocyanate group of 2,6-TDI. Those reaction steps were assumed to be the first order reaction with the reaction rate constants k1, k2, k3, k4, k5, and k6, respectively. The reaction rate constants obtained at molar ratio of 2,4-TDI to 2,6-TDI of 80:20, isocyanate group to hydroxyl group (RNCO/OH) initial molar ratio of 1:1, and reaction temperature of 40 °C were 6.2 × 10-5, 5.8 × 10-5, 3.1 × 10-5, 2.8 × 10-5, and 2.5 × 10-5 L.mole-1.min-1 for k1, k2, k3, k4, k5, and k6, respectively, with the activation energy of 1152, 952, 1001, 656, and 1001 kJ/mole for reaction (1)–(6), respectively. The results show that the polymerization reaction rate-determining step was the reaction of 2,6-urethane and isocyanate group of 2,6-TDI (reaction (6)).

Preparation of Graphene-Polyaniline-Cellulose Double Network Hydrogels Using One Pot Method by Gamma Irradiation with Electrochemical Properties Deni Swantomo; Kris Tri Basuki; Sigit Sigit; Yadi Yunus
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

In order to achieve high performance of electrochemical properties, numerous efforts have been devoted to the development of advanced multi-component hybrid double network hydrogel materials. In this research, the double network hydrogels were synthesized using one pot method by graft copolymerization of aniline onto graphene and cellulose using gamma irradiation as initiator. The formation of the double network hydrogels was confirmed by the Fourier Transform Infrared Spectroscopy (FTIR) study. X-ray Diffraction (XRD) analysis showed that the crystalline was increased through graft copolymerization graphene-aniline-cellulose double network. It was found that the crosslink density increased with increasing aniline volume and increasing radiation doses inversely with the swelling degree. Electrochemical measurements exhibited that increasing aniline volume and radiation doses increased specific capacitance and conductivity of the hydrogels. When compared with the pure graphene, the synthesized double network hydrogels exhibits remarkably enhanced specific capacitance of 9.774 F g-1 and conductivity i.e. 4.766 x 10-2 Scm-1 in 0.5 M HCl solution at aniline volume 8 mL and radiation dose 80 kGy. The improved electrochemical properties of the double network hydrogels represented an alternative promising candidate for the application as energy storage devices and offered a new facile method.

Analysis Methods for Development of Standard Reference Material (SRM) Zircon Minerals Synthesis Samin Samin; Susanna Tuning Sunanti
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The synthesis method of in-house zircon minerals certified reference material (CRM) from Kalimantan (Tumbang Titi), and Bangka has been studied with statistical method of ISO 13528-2008 and ISO 35-2006. Zircon Minerals weighing of 10 kg, and it was dried at 90 °C for 2 × 6 h in a closed room, then crushed with a Ball-Mill up to passes 200 mesh, and homogenized in a homogenizer for 3 × 6 h. The water content in zircon minerals powder is tested by gravimetric method, whereas the homogeneity and stability assessed by statistical methods. Zircon mineral powders are distributed to seven accredited testing laboratory for testing the composition and content of the oxides with the validated analytical methods. Standardization and characterization of candidate zircon mineral certified reference materials are done by using XRD (X-Ray Diffraction) and used standard materials of JCRM R 502 from Japan. The test results of oxide concentrations from various laboratories processed with statistical methods. From the data by test laboratories obtained 40 bottles of the prototype in-house certified reference materials zircon mineral powders from Kalimantan and Bangka with a capacity of 100 g. Based on standardization and characterization test data obtained a major chemical compound on zircon minerals Kalimantan and Bangka similar to the standard that is ZrSiO4. This in-house CRM is traced to certified reference materials from Japan (JCRM-502).

Synthesis of Ce-Mesoporous Silica Catalyst and Its Lifetime Determination for the Hydrocracking of Waste Lubricant Wega Trisunaryanti; Triyono Triyono; Iip Izul Falah; Andreas David Siagian; Muhammad Fajar Marsuki
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The synthesis of Ce/mesoporous silica (Ce/MS) and its lifetime determination for the hydrocracking of waste lubricant has been carried out. The MS was synthesized using tetraethyl orthosilicate (TEOS) and gelatin extracted from bovine bone as a template. Cerium was impregnated onto the MS by wet impregnation method using Ce(NO3)3.6H2O. The MS and Ce/MS were then characterized by means of acidity using ammonia base vapor adsorption, Fourier Transform Spectrophotometer (FTIR), Transmission Electron Microscope (TEM), Scanning Electron Microscope-Energy Dispersive X-ray Spectrometer (SEM-EDX), and surface area analyzer (SAA) based on the BET and BJH equation. The Ce/MS catalyst was tested in hydrocracking of waste lubricant in three runs. Lifetime of Ce/MS catalyst was determined using a linear regression of the liquid product yields vs hydrocracking time. The Ce/MS catalyst showed an acidity of 2.79 mmol/g, BJH desorption pore diameter of 3.84 nm, BET surface area of 246.55 m2/g, and total pore volume of 0.44 cm3/g. The yield of liquid product obtained from hydrocracking of waste lubricant using the Ce/MS catalyst for the first, second, and third runs was 21.42, 17.23 and 10.54 wt.%, respectively for 2.5 h per each run. Lifetime of Ce/MS catalyst in hydrocracking of waste lubricant was 12.54 h.

Synthesis and Photoactivity of Fe3O4/TiO2-Co as a Magnetically Separable Visible Light Responsive Photocatalyst Eko Sri Kunarti; Indriana Kartini; Akhmad Syoufian; Karolina Martha Widyandari
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.

Integrative Assessment of Pb and Cd Pollution in Porong Estuaries Using Sediment Chemistry, Bioavailability, and Bioconcentration Factor Barlah Rumhayati; Catur Retnaningdyah
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The aims of the research were to perform an integrative assessment of high metal pollution in Porong Estuary by determining (i) the distribution of heavy metals fraction in sediment, (ii) the potential risk of sediment to the metal bioavailability, and (iii) the bioaccumulation factor of heavy metals in benthic. Fractionation of heavy metals in the sediments was carried out by the European Community Bureau of Reference (BCR) sequential extraction method. The potential risk of sediment was determined from RAC (risk assessment code) value. Bioconcentration factor was determined based on the ratio of the concentration of heavy metals in benthic to the concentration of bioavailable metals from sediments. Heavy metal concentrations were measured using AAS. The results showed that non-resistant Pb and Cd was higher than resistant fractions. As a non-resistant fraction, Pb was found mostly as fraction 2, i.e., metal fraction adsorbed on the surface of the iron oxy/hydroxide sediment (34.5 ± 4.9%). Cd was more prevalent as fraction 3, i.e., an organic bound fraction (29.0 ± 1.8%). Furthermore, Porong Estuary sediments had medium risk for contributing the bioavailable Cd in the water bodies based on the RAC (15.6 ± 1.8%). Based on the bioconcentration factor, accumulation of Cd and Pb was low (48.00 ± 7.62% for BCF-Cd and 32.29 ± 6.90% for BCF-Pb). Based on the results above, it could be concluded that the Porong Estuary water bodies have not been polluted by Pb and Cd released from the aquatic sediment.

Characteristics of Trace Elements in Volcanic ash of Kelud Eruption in East Java, Indonesia Diah Dwiana Lestiani; Revi Apryani; Linda Lestari; Muhayatun Santoso; Eko Prabowo Hadisantoso; Syukria Kurniawati
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The eruption of Mount Kelud that occurred on February 13, 2014, ejected a huge plume of ash and sand exceeding 26 km into the air which moved west over the island. The elements content in volcanic ash is important information for further study such as the possibility to utilize the ash. In this study, the volcanic ashes collected from four affected areas in Java were analyzed using neutron activation analysis (NAA) with HPGe detector and X-ray fluorescence. Method validation was applied using the standard reference material SRM NIST 2711a Montana Soil with recovery and accuracy in a good agreement for all elements. The analysis results of volcanic ashes showed a wide range of elements, major elements Al, Ca, Fe, K, Mg, Mn, Na, Si and Ti, trace elements As, Cd, Cu, Co, Cr, V, Zn, Hf, Th and U, and rare earth elements were identified. The results showed heavy metals As, Cd, Cu, Co, Cr, and Pb were ranged 3.23–4.42, 17.63–24.09, 49.26–77.10, 10.86–16.03, 11.19–17.79 and 31.4–42.7 mg/kg, respectively, while rare earth elements such as Ce, Eu, La, and Sm were 9.84–18.43, 0.73–1.02, 2.25–5.66 and 1.34–2.63 mg/kg respectively. Comparison with other volcanic ashes from Indonesia such as Merapi and Sinabung and world volcanic ashes were applied. The results of the characteristic of elements in Kelud volcanic ash would be valuable information as reference data for their potential utilization.

The Synthesis and Stability Study of Silver Nanoparticles Prepared by Using p-Aminobenzoic Acid as Reducing and Stabilizing Agent Dian Susanthy; Sri Juari Santosa; Eko Sri Kunarti
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

A study to examine the performance of p-aminobenzoic acid as both reducing agent for silver nitrate to silver nanoparticles (AgNPs) and stabilizing agent for the formed AgNPs has been done. The synthesis of AgNPs was performed by mixing silver nitrate solution as precursor with p-aminobenzoic acid solution and heating it in a boiling water bath. After the solution turned to yellow, the reaction stopped by cooling it in tap water. The formed AgNPs were analyzed by using UV-Vis spectrophotometry to evaluate their SPR absorption in wavelength range of 400–500 nm. The synthesis process was highly depend on the pH, reaction time, and mole ratios of the reactants. The synthesis only occur in pH 11 and at reaction time 30 min, the particle size of the formed AgNPs was 12 ± 7 nm. Longer reaction time increased the reducing performance of p-aminobenzoic acid in AgNPs synthesis but decreased its stabilizing performance. The increase of silver nitrate amount relative to p-aminobenzoic acid in the synthesis increased the reducing and stabilizing performance of p-aminobenzoic acid and the optimum mole ratio between AgNO3 and p-aminobenzoic acid was 5:100 (AgNO3 to p-aminobenzoic acid).

Synthesis of Citrate-Capped Gold Nanoparticles from Reduced [AuCl4]– on Ascorbic Acid-Immobilized Mg/Al Hydrotalcite Agustina Sus Andreani; Suyanta Suyanta; Eko Sri Kunarti; Sri Juari Santosa
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

Reductive adsorption of [AuCl4]-– by using ascorbic acid immobilized on Mg/Al hydrotalcite (Mg/Al HT) and synthesis of gold nanoparticles (AuNPs) from the reduced gold using sodium citrate have been conducted. Mg/Al HT was synthesized by co-precipitation method at pH 10 with molar ratio of Mg(II) and Al(III) 2:1. Ascorbic acid (AA) was then immobilized on Mg/Al HT to form hybrid of AA and Mg/Al HT (Mg/Al HT-AA). Mg/Al HT-AA was used to reductively adsorb [AuCl4]– and the formed Au(0) was extracted by using sodium citrate to form citrate-capped AuNPs. The formation of AuNPs from 100 mg/L [AuCl4]– solution removed by 60 mg Mg/Al HT-AA was optimum at pH 5.0, by using 70 mM sodium citrate and 2 h sonication time. This optimum condition was successfully applied to synthesize AuNPs from [AuCl4]– as the leaching product of gold from PCB using aquaregia.

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