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INDONESIA
Indonesian Journal of Chemical Science
ISSN : 22526951     EISSN : -     DOI : -
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Articles 20 Documents
Search results for , issue "Vol 10 No 2 (2021)" : 20 Documents clear
Cerium, Neodimium, and Lanthanum Leaching from Rare Earth Oxides (REO) using Hydrochloric Acid Aulia, Muhammad Azmi; Kurniawan, Cepi; Setyadji, Moch.
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.45818

Abstract

Rare earth metal hydroxide (REOH) is a mixture of the elements lanthanide, yttrium, and scandium produced from the processing of monazite sand. This mixture has benefits in the modern technology industry, especially elements of Ce, La, and Nd. Separation of Ce, La, and Nd from the mixture has been carried out, but it has several drawbacks with the large use of chemicals that have an impact on the environment from the results of their processing waste and the length of time it takes, so the best solution is needed to overcome it. The perfect solution in the process of separating Ce, La, and Nd from REOH is leaching. Leaching is the extraction of acids with bases to form salt and water. This research begins with the REOH calcination process at a temperature of 1000⁰ C for 2 hours to evaporate volatiles and decompose the compounds. The results of calcination were leached using hydrochloric acid with a concentration variation of 0.3-1.2 M, temperature 30-75 ° C, a ratio of REO and solvent 1:5, and time variation of 5-20 minutes to optimize leaching efficiency. The results of leaching in residues were analyzed by XRF. The optimum leaching of the variation of the concentration of hydrochloric acid 1,2 M for 20 minutes resulted in the leaching efficiency of La and Nd respectively 33,297% dan 26,503%, and the leaching efficiency of Ce was 10,153% of the concentration of hydrochloric acid 0,9 M for 20 minutes. At a temperature variation of 75⁰ C and a time of 10 minutes, the leaching efficiency La and Ce were 55,87% dan 0,04%, respectively. The efficiency of Nd at 45⁰C for 20 minutes was 26,93%.
Isolation, Identification, and Activity Test of Flavonoid Compounds in Jamblang Leaves (Syzygium cumini L.) Skeel Jatmiko, Miracela Putri; Mursiti, Sri
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.47037

Abstract

Jamblang (Syzygium cumini L.) Skeel is a plant that has the potential to be a natural antioxidant. The jamblang plant contains chemical compounds including alkaloids, flavonoids, resins, tannins, and essential oils. This study aims to identify the class of flavonoid compounds contained in jamblang leaves using a spectrophotometer UV-Vis and FTIR and to determine the antioxidant activity of jamblang leaf determined by the percentage of resistance. Determination result of antioxidant activity in ethanol extract, ethyl acetate and isolate of jamblang leave against ABTS (2,2-azino-bis(3-etilbenzotiazolin)-6-asam sulfonat) the highest percentage was shown at 40 ppm of ethyl acetate extract equal is 46,77%. The Identification results of isolate jamblang leave contained flavonoid compounds from the flavonol groups.
Iron Extraction from Coal Fly Ash Using HCl Solution Setyo, Slamet Budi; Sulistyaningsih, Triastuti; Prasetya, Agung Tri; Kusumastuti, Ella
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.47881

Abstract

About 780 million tonnes of fly ash are produced annually worldwide. The use of fly ash is still minimal, causing fly ash piles to increase. Based on this, a study was conducted on the extraction of iron from coal fly ash using HCl as a solvent. This study aims to determine the Fe content in fly ash extracted using HCl with variations in HCl concentration and extraction time. This research begins with the preparation of fly ash samples using an oven. Fly ash that has been prepared and extracted using HCl added with MIBK and EDTA was then characterized using XRF, FTIR and AAS. The results showed that the highest Fe content (11.48%) was obtained from the extraction using 9N HCl for 1 minute. The greater the concentration of HCl and the faster the extraction time, the more Fe extracted.
Vinyl Ester Composite Synthesis Reinforced with Banana Tree Fiber with the Nanofiller Addition Darmansyah, Darmansyah; Novaringga, Adellia; Damaru, Restu; Ginting, Simparmin Br.
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.47890

Abstract

Indonesia has the potential for natural fiber wealth which is very abundant and varied therefore it is a very interesting opportunity in the development of polymer composites using natural fiber from a banana tree. To get a composite material that has strong mechanical properties, that is by adding other materials such as nanofiller (Al2O3, SiO2, and TiO2) combined with vinyl ester resin and banana tree fiber using the hand lay-up method to produce a composite that has stronger mechanical properties than fiberglass. In this research vinyl ester composite synthesis reinforced with banana tree fiber with the addition of nanofiller which aims to determine how the effect of nanofiller type and nanofiller concentration on the mechanical properties of composite and how the bonding strength of composites through SEM analysis. The results showed that for the Al2O3 nanofiller, the highest tensile strength was with a fraction of 5% with a value of 74,81 MPa with an elongation of 1,07%, for SiO2 nanofiller the highest tensile strength was with a fraction of 0,05% with a value of 89,57 MPawith an elongation of 1,20%, and for TiO2 nanofiller the highest tensile strength was with a fraction 0f 1% with a value of 75,33 MPawith an elongation of 1,05%. The results of SEM analysis show a fairly good matrix bond.
Extraction of Zr in Gold Mine Tailings to Produce TENORM Free Zirconium Oxychloride Octahidrate (ZOC) Sari, Erlin Purwita; Sajima, Sajima; Prabasiwi, Devi Swasti; Poernomo, Herry
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.47923

Abstract

Gold mine tailings causes environmental problems if disposed without previous processing. Nowadays, secondary resources recycling has become people worldwide consideration because the increasing awareness of the sustainable development urgency. This study aims to extract the valuable mineral content in gold mine tailings to produce ZOC. The research begins with an alkaline fusion process using NaOH. The water leaching process was performed to the smelted alkaline with ratio of solids mass to water volume of 1:30. The resulted solid was dried for further used in the synthesis of ZOC. A number of ZOCs were reacted with HCl at a ratio of solid mass to HCl volume of 1:20, HCl 4N, and temperature of 60 °C for 1.5 hours. The solution then be crystallized to obtain ZOC solids without centrifugation process. This reaction was done using 1-step ZOC synthesis method without passing over zirconium base sulfate (ZBS) manufacturing phase. The ZOC crystals were analyzed using FTIR, XRD, and XRF. The data indicated that the synthesized product was identified as zirconium oxychloride octahydrate (ZrOCl2·8H2O). The compound showed 0% of ThO2 and U3O8 content or could be called TENORM free. The calculation results showed that the % recovery of Zr was 85.94%.
Development and Validation of Infrared Spectroscopy Methods for Rutin Compound Analysis Auha, Nydia Ashfi; Alauhdin, Mohammad
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.47959

Abstract

Rutin is a glycoside resulting from the condensation of the aglycone quercetin with the sugar rutinose. Some study show that rutin can reduce cardiac hypertrophy and improve heart health. Appropiate levels can optimize rutin performance, it is necessary to develop methods for rutin assays and their validation. This study aims to develop an analytical method for rutin compound with FTIR and their validity. The FTIR methods has several advantages including simple preparation, fast scanning, high resolution, does not take long, and without the use of hazardous reagents and can be used for qualitative and quantitative analysis at the same time. The standard rutin with mass variation (0.5-1.75 mg) was mixed homogeneously with KBr so that the total mass was 16 mg. The mixture of rutin and KBr then made into pellets with a hydraulic machine so that transparent pellets were obtained. Measurement were carried out at wave number 4000-400 cm-1 with 8 scanning. Methods validation include linearity, LoD, LoQ, and precision test. Based on the result of the analysis, the typical peak of rutin compounds is in the wave number range of 900-690 cm-1 namely aromatic C-H. Rutin had linearity, LoD, and LoQ of 0.8719, 0.7 mg, and 2.5 mg, and %RSD repeatability 17.68 % and %RSD reproducibility 17.62 %.
Thin Film TiO2nanorod-PDMS on Glass Substrate for Self-Cleaning Surface Prayitno, Teguh; Wahyuni, Sri
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.48986

Abstract

Self-cleaning is the ability to clean itself on a surface through a hydrophobic mechanism and a photocatalytic mechanism. Self-cleaning properties can be affected by the material used. Titanium dioxide (TiO2) is a material that has photocatalytic properties and Polydimethylsiloxane (PDMS) is a material that is hydrophobic. The aim of this study was to determine the effect of PDMS on the hydrophobic properties of TiO2nanorod-PDMS thin films. TiO2nanorode was synthesized using the solvothermal method. The diffractogram from XRD analysis showed that the synthesized TiO2 was in the anatase phase and the crystallite size was 25.96 nm. TiO2nanonorod-PDMS can be coated on the surface of the glass plate by the spin coating method. The hydrophobic nature of the plate surface is indicated by the contact angle of 126.9° at a mole ratio of TiO2 : PDMS 1:2. Its hydrophobic nature contributes to its self-cleaning properties by inhibiting water-containing pollutants. TiO2 contributes to its self-cleaning properties through photocatalytic activity when absorbing UV light and is indicated by the largest decrease in methylene blue levels, which is 92.48% in TiO2nanorod-PDMS glass samples with a ratio of 1:2 and can remove the color of turmeric juice pollutants.
Effect of Cobalt Metal Insertion on Zinc Oxide Nanotube Structure for Hydrogen Gas Sensor Using Density Functional Theory Method Ariyanti, Widia; Kasmui, Kasmui
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.49534

Abstract

Hydrogen gas as a renewable energy has limitations, namely flammable, explosive, colorless, and odorless, making it difficult to detect its presence at normal temperature and pressure. Efforts to determine the presence of hydrogen gas need a gas sensor. This study aims to determine the effect of the insertion of Co metal on Zinc Oxide nanotubes (ZnONT) on changes in adsorption energy and sensor sensitivity on H2 gas with parallel and perpendicular positions. Geometry optimization was carried out using the DMol3 module in Material Studio, the parameters of this research were using Density Functional Theory method, GGA correlation exchange PBE function, and DNP basis set. The results of the calculation of the hydrogen gas adsorption energy from the structures ZnONT.H2 perpendicular, ZnONT.H2 parallel, ZnONT.Co.H2 perpendicular and ZnONT.Co.H2 parallel, respectively, are -23.121205 kJoule/mol; -23.541810 kJoule/mol; -252.783422 kJoule/mol; and -254.599480 kJoule/mol. The calculation of the sensitivity of the hydrogen gas sensor response from the structures ZnONT.H2 perpendicular, ZnONT.H2 parallel, ZnONT.Co.H2 perpendicular and ZnONT.Co.H2 parallel were 1.374; 1,527; 1654,827; and 375,857. Based on the results of the study, it was found that the insertion of Co metal was able to increase the adsorption energy and sensitivity of the hydrogen gas sensor.
The Utilization of Medical Mask Waste as a High-Quality Nanofiber Material a Review Victory, Shelly; Putri, Restani Eka; Sakhila, Shania; Hutagalung, Soluna Desbait; Amelia, Addela; Fabiani, Verry Andre
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.49538

Abstract

Medical mask waste is part of the covid waste that can threaten the living creatures and environment since it was pathogenic and indestructible. Moreover, the waste management of medical mask waste is still ineffective due to the limit of technology and resource. The purpose of this review is to learn the potency of medical mask waste as the main component of nanofiber fabrication. This review is using the literature review method. There are some fundamental stages for creating nanofiber from polypropylene of medical mask waste, such as pre-treatment, making polypropylene solution, fabrication, and characterization. Removal of medical mask waste contaminants can be using a chemical solvent, dry heat, or exposure to ultraviolet C. Type of solvent plays a principal role in producing polypropylene solvent that is ready to fabricate. On the industrial scale, electrospinning is a commonly used method for nanofiber fabrication. The characterization of the fiber and pore size can be analyzed with scanning electron microscope (SEM) analysis, material crystallinity using x-ray diffraction (XRD) spectroscopy, and thermogravimetric analysis (TGA) measuring the thermal stability of nanofiber.
Modification of Magnesium Oxide from Bittern Waste with Strontium Oxide for Palm Oil Transesterification Process Qoyyima, Diana; Jumaeri, Jumaeri
Indonesian Journal of Chemical Science Vol 10 No 2 (2021)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/ijcs.v10i2.50033

Abstract

Bittern has a high magnesium content, so that it can be used as a catalyst in the production of biodiesel through the transesterification process. MgO catalyst has a relatively low basicity, so it is necessary to add metal oxides such as SrO. This study aims to determine the characteristics and catalytic effectiveness of the SrO/MgO catalyst in the transesterification process of palm oil using GC and GCMS tests. Modification of SrO on the MgO catalyst was carried out using the impregnation method with a ratio of 1:3. The presence of SrO diffraction peaks on XRD analysis showed that SrO agglomerated on the MgO surface, this can be attributed to the morphology of the spheres which are homogeneously agglomerated. The result of basicity analysis shows that the addition of SrO can increase the number of moles of base of MgO. In the palm oil transesterification process using an SrO/MgO catalyst, the methyl ester conversion increased by 47.17% at the optimal reaction time of 2 hours, while the MgO catalyst only resulted in a conversion of 2.35%. Based on the results of the study, it was found that the addition of SrO could increase the catalytic effectiveness of MgO.

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