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Journal Cover
Indonesian Journal of Chemistry
Journal Prestige (SJR): 0.209
Citation Impact (citeScore): 1
Number of Followers: 1  

  This is an Open Access Journal Open Access journal
ISSN (Print) 1411-9420 - ISSN (Online) 2460-1578
Published by Universitas Gadjah Mada Homepage  [42 journals]
  • Effect of CO2 Flow Rate and Carbonation Temperature in the Synthesis of
           Crystalline Precipitated Calcium Carbonate (PCC) from Limestone

    • Authors: Sri Wardhani, Fanny Prasetia, Mohammad Misbah Khunur, Danar Purwonugroho, Yuniar Ponco Prananto
      Pages: 573 - 579
      Abstract: The effect of CO2 flow rate and carbonation temperature were studied in the synthesis of PCC from limestone using carbonation method. The synthesis was started by dissolving CaO that was obtained from calcination of limestone into HNO3 6M. The solution was then added with ammonia solution and then streamed with CO2 until pH 8 with flow rates of 0.5; 1.0; 1.5; and 2.0 L/min. The optimum flow rate obtained from this stage was then applied in the carbonation process with temperatures of 50, 80, 100, 150, 200, and 250 °C. The results showed that low flow rate give reasonably high yield but the yields obtained in every flow rate used in this work has insignificant difference based on F-test. The optimum flow rate used for the synthesis of PCC in the next stage was 0.5 L/min with a yield of 62.95%. Different carbonation temperature influences the polymorphs and crystallinity of the synthesized PCC. The synthesized PCC was analyzed by FT-IT, powder-XRD, SEM-EDX, and PSA. FT-IR analysis showed stretching vibrations of C–O at 1419, 1479, and 1384 cm-1 which correspond to calcite, vaterite, and aragonite respectively. Powder-XRD and SEM-EDX confirms that at the carbonation temperature of 50 °C, calcite and vaterite were formed, while at the carbonation temperature of 80 °C, mixture of calcite-vaterite-aragonite were obtained. Higher carbonation temperature changes the vaterite and aragonite polymorphs into calcite, and the best crystallinity was obtained at 250 °C. PSA analysis showed that the particle diameter of the synthesized PCC was about 3.58 to 38.14 µm.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26608
      Issue No: Vol. 18, No. 4 (2018)
  • Synthesis of Amorphous Aluminosilicates from Bintan’s Red Mud as
           Alumina Source

    • Authors: Futri Wulandari, Eka Putra Ramdhani, Yatim Lailun Ni’mah, Ahmad Anwarud Dawam, Didik Prasetyoko
      Pages: 580 - 586
      Abstract: Red mud is a generated by-product in alumina production from bauxite ore. In this study, Bintan’s red mud has been used as alumina and silica source to synthesize amorphous mesoporous aluminosilicates material. Alkali fusion method with a NaOH/red mud ratio 0.8; 1.0; 1.2; 1.4 and 1.5 followed by hydrolysis method was used to extract dissolved alumina and silica from red mud. Synthesis of amorphous aluminosilicates by hydrothermal method was conducted at 80 °C for 24 h. Cetyltrimethylammonium bromide (CTABr) was added as the structure directing agent. Aluminosilicate products were characterized using FTIR spectroscopy (Fourier Transform Infra-Red Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and nitrogen adsorption-desorption. XRD and SEM result shows that the product was amorphous with low uniformity in terms of surface morphology and particle size. Nitrogen adsorption-desorption profile shows that all aluminosilicates products has a meso pore structure, confirmed by the highest pore distribution at 3.05–17.70 nm. The highest surface area and pore volume were obtained in ASM 0.8 (NaOH/red mud ratio = 0.8) i.e. 177.97 m2/g and 1.09 cm3/g, respectively.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.25184
      Issue No: Vol. 18, No. 4 (2018)
  • Preparation of Water Repellent Layer on Glass Using Hydrophobic Compound
           Modified Rice Hull Ash Silica

    • Authors: Alfa Akustia Widati, Nuryono Nuryono, Dessy Puspa Aryanti, Madjid Arie Wibowo, Eko Sri Kunarti, Indriana Kartini, Bambang Rusdiarso
      Pages: 587 - 593
      Abstract: In this study water repellent layered glass has been prepared by coating silica (SiO2) combined with a hydrophobic silane compound. SiO2 was extracted from rice hull ash and two silane compounds, namely hexadecyltrimethoxysilane (HDTMS) and trimethylchlorosilane (TMCS) were used. Coating was performed through two deposition techniques, i.e. one step (mono-layer) and layer by layer (LBL, multi-layer). The effect of silane to SiO2 mole ratio, silane type and layer number on the glass characters was evaluated. Characterization included hydrophobicity, transparency, surface roughness and stability of coating. Results showed that increasing the mole ratio of silane to SiO2 and the layer number increased the hydrophobicity of the glass surface. The optimum mole ratio was 5:1 and the significant increase of contact angle occurred at lower mole ratio, but the stability tends to be increased at higher mole ratio. For HDTMS-SiO2 layer, the technique of LBL technique produced a coating with higher hydrophobicity and transparency than single-stage one. The LBL technique produced the highest water contact angle of 103.7° with transmittance of 96%, while for TMCS-SiO2 layer the one stage technique produced hydrophobic layer with higher water contact angle of 108.0° and transparency about 94.52%. The prepared hydrophobic glasses were relatively stable in polar and non-polar solvents, but unstable to ambient conditions.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26714
      Issue No: Vol. 18, No. 4 (2018)
  • C Dots Derived from Waste of Biomass and Their Photocatalytic Activities

    • Authors: Haryadi Haryadi, Muhammad Ridwhan Wira Purnama, Ari Wibowo
      Pages: 594 - 599
      Abstract: Carbon nanodots (CNDs) which are part family of carbon nanoparticles have drawn a lot of attention due to their prominent characters and wide prospective applications. The materials are non-toxic and exhibit fluorescence properties that are potential for application in photocatalysis, optoelectronic, bioimaging and sensors. Various approaches of CNDs synthesis have been investigated by means of a large variety of starting materials and techniques. A green and an effective approach in gaining CNDs from wastes biomass-carbonaceous particles of a dried solid waste of cow manure have been employed by hydrothermal treatment. The CNDs were then attained after carbonaceous particles dissolution step under microwave irradiation. The temperature range of hydrothermal treatment was in between 250 to 300 °C. The formation of C=C, C-O bonds, and conjugated structures has been observed by FTIR and photoluminescence properties have been identified under 366 nm of UV irradiation. Furthermore, the morphology of as-synthesized CNDs was investigated by HR-TEM and crystallinity was observed by X-Ray Diffraction (XRD). Photocatalytic degradation of synthetic dye solution of methylene blue (MB) in the presence of carbon dots has been investigated under visible light.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26652
      Issue No: Vol. 18, No. 4 (2018)
  • Combination of Ozonation and Adsorption Using Granular Activated Carbon
           (GAC) for Tofu Industry Wastewater Treatment

    • Authors: Eva Fathul Karamah, Ika Putri Adripratiwi, Linggar Anindita
      Pages: 600 - 606
      Abstract: Tofu industry wastewater is one of the environmental pollutants that need more effective treatment. Ozonation and adsorption method is known to have the capability to oxidize organic compound in wastewater. Adsorption is done by using granular activated carbon (GAC) as an adsorbent to increase tofu wastewater degradation process by adsorbing organic materials and increasing production of hydroxyl radical as the main oxidizing agent. This research is carried out to evaluate the performance of ozonation, adsorption, and combination of both in processing tofu wastewater. To evaluate the significance of ozone dosage and amount of GAC used, these variations are varied which are 60, 111, and 155 mg/h of ozone dosage and 50, 75, and 100 g of the amount of GAC used. Parameters of the process are organic substances of tofu wastewater such as COD, TSS, and pH. The measurements are being done using a spectrophotometer, colorimeter, and pH meter. The outcome of this research is to provide an alternative method in the liquid waste treatment of the tofu industry and the processed wastewater to meet the environmental quality standards. The more ozone and the more quantity of GAC used, the higher the quantity of hydroxyl radicals formed. Addition of GAC in the ozonation process results in more than 100% increase in hydroxyl radical production. Combination of ozonation and adsorption is able to remove 377.12 mg/L of COD and 26 mg/L of TSS.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26724
      Issue No: Vol. 18, No. 4 (2018)
  • Direct Synthesis of Sodalite from Kaolin: The Influence of Alkalinity

    • Authors: Meyga Evi Ferama Sari, Suprapto Suprapto, Didik Prasetyoko
      Pages: 607 - 613
      Abstract: Alkalinity is one of the most important factors that influence the crystallization process of zeolite and the product properties. The influence of alkalinity on the synthesis of sodalite from kaolin without calcinations was reported in this research. The synthesis of sodalite using molar ratio of Na2O/Al2O3 = x, H2O/Na2O = 128/x and SiO2/Al2O3 = 2/x, where x was the variation of molar ratio of alkalinity: 10, 20, 30, and 40. The synthesis has done by stirring for 6 h, without aging, and the crystallization time was 24 h under hydrothermal method (100 °C). The products were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The X-ray diffraction pattern and infrared spectroscopy shown that pure sodalite was formed by using molar ratio of alkalinity 10, 20, and 30. The crystallinity and particle size increase along with increasing of alkalinity. Quartz was formed by using molar ratio of alkalinity 40.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.25191
      Issue No: Vol. 18, No. 4 (2018)
  • Effect of Reducing Agents on Physical and Chemical Properties of Silver

    • Authors: Roto Roto, Hani Prima Rasydta, Adhitasari Suratman, Nurul Hidayat Aprilita
      Pages: 614 - 620
      Abstract: Silver nanoparticles having uniform size and shape, a diameter range of 10–50 nm, excellent stability, and high zeta potential are always desirable for many applications. The silver nanoparticles were synthesized by chemical reduction method using some reducing agents in a polyvinyl alcohol solution. This study aims at determining the effect of reducing agents on the chemical and physical properties of silver nanoparticles. Ascorbic acid, sodium borohydride, hydrazine, sodium citrate, and glucose were used as reducing agents. Surface Plasmon Resonance (SPR) absorbance, morphology, zeta potential, crystal system, and stability of the products were studied. The results showed that the chemical and physical properties of the colloidal Ag nanoparticles were dependent on the reducing agents. In general, the produced silver nanoparticles have an fcc crystal system with a unit cell of 4.0906–4.0992 Å. The SPR absorbance of the colloids has the peak in the range of 401–433 nm. We found that the colloid of silver nanoparticles prepared by using ascorbic acid has uniform spherical shape, the diameter of about 20 nm, and zeta potential of -10.4 mV. After being stored for one month, the SPR absorbance of the colloid decreased by only 5%. This type of colloidal Ag nanoparticles prepared by using ascorbic acid is expected to be used for chemical sensors, an antibacterial agent, and so on.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26907
      Issue No: Vol. 18, No. 4 (2018)
  • Solar Based Photocatalytic Decolorization of Four Commercial Reactive Dyes
           Utilizing Bound TiO2-Fe3O4 Nanocomposite

    • Authors: Yoanes Maria Vianney, Ivana Rosalyn, Stephanie Angela
      Pages: 621 - 631
      Abstract: Dye effluent is one of the most prominent source of water contamination. This study investigated the solar based photocatalytic decolorization of four commercial reactive dyes, which are Reactive Turquoise Blue G 133, Reactive Yellow M4g, Reactive Bordeaux B, and Reactive Red M8b using immobilized TiO2-Fe3O4 on three kind of binders as the support, specifically cyanoacrylate glue, oil-based paint, and white Portland cement on PVC plate. TiO2-Fe3O4 was synthesized using sol-gel method and placed in muffle furnace at 773 K. The composite of TiO2-Fe3O4 was characterized using SEM-EDX and XRD. White cement emerged as the best binder in term of the color removal efficiency of all four dyes compared to other binders, which were more than 90% color removal after 3 h of solar irradiation. Moreover, there was significant enhancement on color removal using immobilized photocatalyst on white cement compared to mobile photocatalyst. The kinetic of the decolorization performance followed the pseudo-first-order reaction. The apparent reaction rate constant was found to decrease along with the increase of the dye concentration. The photodecolorization kinetics fitted the Langmuir-Hinshelwood model. These protocols and results can be applied into textile industrial primary wastewater treatment using solar as a sustainable light and energy source.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.27549
      Issue No: Vol. 18, No. 4 (2018)
  • Characterization of ZrO2-Montmorilonite Pillarization Process from Local
           Zirconium Oxychloride Local Made PSTA-BATAN

    • Authors: Muzakky Muzakky, Herry Poernomo
      Pages: 632 - 638
      Abstract: Characterization of the pillarization process product of ZrO2-montmorillonite from Zirconium oxychloride local made of PSTA-BATAN has been done. The objective of this research is to control the quality of pillarization process product of the new material ZrO2-montmorilonite.  This new material was produced from local made Zirconium oxychloride (ZOC) of PSTA-BATAN by dry process and bentonite (Na-montmorillonite) imported from Thailand by the pillarization process. During optimization the pillarization quality control would be followed by absorbance using Diffuse Reflectance Ultraviolet-Visible (UV-Vis DRS) spectroscopy and X-Ray Diffraction (XRD). While the type of functional group can be detected by Fourier Transform Infrared (FTIR) spectrophotometry, and the surface image was observed by using Transmission Electron Microscopy (TEM) and BET methods. The result gained showed that the optimum quality of ZrO2-montmorillonite was at Zr concentration of 0.2 M with the absorbance of 1.04 au by XRD and DRS. The best precursor used was ethylene glycol with a drying process in the cold conditions at the absorbance of 1.2 au. The best calcination process was at the temperature of 600 °C with the reached absorbance value of 1.3 au. The results of TEM image observation after calcination at the temperature of 600 °C were clearer and more porous than before and showed specific surface area of 105 m2/g. The interpretation results of FTIR spectra on the new material of ZrO2-montmorillonite contained the cluster of ΞSi-OH, ΞAl-OH and Si-O functional groups indicating pillar groups.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.28642
      Issue No: Vol. 18, No. 4 (2018)
  • One-Pot-Multicomponent Synthesis of
           2,6-Diamino-4-arylpyridine-3,5-dicarbonitrile Derivatives Using
           Nanomagnetic Fe3O4@SiO2@ZnCl2

    • Authors: Behrooz Maleki, Hadi Natheghi, Vahid Sokhanvaran, Samaneh Sedigh Ashrafi
      Pages: 639 - 646
      Abstract: Nanomagnetic Fe3O4@SiO2@ZnCl2 was used as a simple, cost-effective, and reusable heterogeneous catalyst for the synthesis of 2,6-diamino-4-arylpyridine-3,5-dicarbonitriles by a one-pot-three-component condensation reaction of malononitrile, ammonium acetate, and aldehydes under solvent-free conditions at 110 °C. Simple and mild reaction conditions, facile preparation of the catalyst, the use of a cheap catalyst and easy workup and isolation are notable features of this method.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.33062
      Issue No: Vol. 18, No. 4 (2018)
  • Integrating Treatment of Neutralization with Sulfidic Natural Water (SNW)
           to Capture Dissolved Copper (Cu2+) from Acid Mine Drainage (AMD) at Batu
           Hijau Site, Sumbawa Island Indonesia

    • Authors: Surya Hadi, Ni Made Sri Suliartini, Lely Kurniawati, Surayyal Hizmi
      Pages: 647 - 655
      Abstract: The overall objectives of the research were (1) to study the capability of sodium hydrosulfide (NaHS) and sulfidic natural water (SNW) of Sebau in recovery of Cu2+, (2) to investigate the potency of integrating treatments of neutralization with sulfidization using SNW of Sebau in removing Cu2+ from acid mine drainage (AMD) collected from Batu Hijau site. The first objective was achieved by separately reacting (in situ) NaHS and SNW with a Cu2+ solution at pH 5.5. The second objective was answered by conducting treatments of lime-neutralization by the use of three levels of pH (4.0; 5.5; 7.0) and sulfidization using SNW collected from Sebau, Lombok Island at three sampling points. The result showed that NaHS (61.6 mg/L) could precipitate Cu2+ solution (44.45 mg/L) up to 71.3%, while SNW of Sebau could precipitate Cu2+ solution (44.45 mg/L) for almost 100% at pH 5.5. The results also revealed that SNW could precipitate the remained Cu2+ in the AMD from the neutralization treatment (pH 4 = 113.5 mg/L; pH 5.5 = 85.01 mg/L; and pH 7.0 = 2.372 mg/L) to 83.84% (pH = 4.0) and 100% (pH = 5.5 and 7.0). Although both pH 5.5 and 7.0 could completely precipitate Cu2+ in the AMD, by comparing the experimental result with the stoichiometric analysis, it was predicted that pH 5.5 was an optimum pH level for the reaction between AMD and SNW to recover Cu2+ in the AMD. Without neutralization treatment, SNW showed potentiality to recover Cu2+ since the combination treatments of neutralization at pH 4 with SNW collected from three sample points resulted in a high percent recovery of Cu2+.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.28223
      Issue No: Vol. 18, No. 4 (2018)
  • Effect of Soaking Treatment on Anthocyanin, Flavonoid, Phenolic Content
           and Antioxidant Activities of Dioscorea alata Flour

    • Authors: Ratnaningsih Ratnaningsih, Nur Richana, Sakae Suzuki, Yoshiharu Fujii
      Pages: 656 - 663
      Abstract: Purple Dioscorea alata is one kind of tuber crops that rich in polyphenolic compounds. In Indonesia, the utilization of this yam is still very limited because it is easily damaged on the fresh form. Due to its high perishability, then the fresh tuber have to be processed into dried materials to expand its utilization. This study investigated the effect of browning inhibition treatments (immersion in water, Na-bisulfite, and ascorbic acid) on moisture, color, anthocyanin, flavonoid and phenolic content, and determined the antioxidant activities of D. alata flour. The moisture content of D. alata flour ranged between 6.89 to 7.71% db, which still in the range of wheat flour moisture content standards using Codex Standard. Browning inhibition treatment improved the color appearances and provided better values on anthocyanin, phenolic, and flavonoid content of D. alata flour. The color and antioxidant activities of D. alata flour were significantly correlated with its functional properties.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.23945
      Issue No: Vol. 18, No. 4 (2018)
  • Determination of Stevioside and Rebaudioside A in Stevia rebaudiana
           Bertoni Leaves Using near Infrared Spectroscopy and Multivariate Data

    • Authors: Yohanes Martono, Suryasatriya Trihandaru, Ferdy Semuel Rondonuwu
      Pages: 664 - 671
      Abstract: Rebaudioside A and stevioside are abundant steviol glycoside contained in Stevia rebaudiana leaves. These components are widely used as a natural sweetener. The objective of this study was to develop rapid determination method of stevioside, and rebaudioside A in S. rebaudiana leaves using near infrared trans-reflectance spectroscopy (NIRS) combined with multivariate analysis. The reference method used was HPLC. A prediction model was developed using partial least square (PLS) regression. Calibration parameters were calculated based on a calibration set of various stevioside, rebaudioside A from 23 samples. Performance of PLS model was assessed in term of optimum determination coefficient (R2), and minimum root mean square error of cross-validation (RMSEV). Validation of PLS model was performed using cross-validation and leave one out calibration of PLS component. Rebaudioside A has well PLS model in wavenumber region of 4100–5100 cm-1, and stevioside determination using difference wavenumber region of 4760-5016 cm-1. PLS model for total (sum of stevioside and rebaudioside A content) was exploited in wavenumber region of 4568-4928 cm-1. NIRS in combination with multivariate data analysis of PLSR can be applied as a rapid method for determining rebaudioside A and the total amount of steviol glycosides in S. rebaudiana leaves.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.25580
      Issue No: Vol. 18, No. 4 (2018)
  • Characteristics of Vulcanizate Rubber Using Composite Latex – Modified
           Cassava Starch as Filler

    • Authors: Hari Adi Prasetya, Popy Marlina, Arbi Dimyati
      Pages: 672 - 678
      Abstract: The research on Characteristic of vulcanizate rubber using cassava starch composite (Manihot glaziovii) modification - latex as filler has been done. The composite variation of cassava starch concentration is 0, 40, 80, 120, 160 and 200 phr in three replications. Microstructure and elemental samples in SEM EDX and FTIR Spectroscopy method analysis, while physical properties using the standard testing equipment. The results showed that the concentration of cassava has a significant influence that is hardness, tensile strength, elongation at break, tear resistance and ozone resistance. The best rubber hardness specification was composite with modified cassava starch concentrations of 120, 160 and 200 phr with value 57, 61 and 65 Shore A. The best tensile strength of cassava starch concentration 80 and 120 phr with value 160 and 167 kg/cm2, while the best result of the extension of cassava starch concentration elongation at break 80, 120, and 160 phr is 652, 741, and 748%, and tear resistance 80, 120, 160 and 200 phr with value 14.21, 15.96, 15.16 and 14.47. The ozone resistance for all concentrations meets the requirements of commercial vulcanizate rubber. The latex-modified cassava starch composite can be used as a filler for rubber products and as an alternative to commercial fillers.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.25713
      Issue No: Vol. 18, No. 4 (2018)
  • Preparation and Characterization of Edible Films Made from Modified Sweet
           Potato Starch through Heat Moisture Treatment

    • Authors: Novita Indrianti, Yudi Pranoto, Akmadi Abbas
      Pages: 679 - 687
      Abstract: The edible films were prepared from native sweet potato starch (SPS) or modified sweet potato starch through heat-moisture treatment (HMT). The treatments which were carried out in this research were the different durations of HMT (1, 2, and 3 h) and the SPS concentrations (1, 1.25 and 1.5%). The edible films were characterized by moisture content, thickness, tensile strength, elongation, water vapor permeability (WVP), solubility, morphology, thermal, and x-ray diffraction. The result showed that the thickness, the tensile strength, and the elongation of the modified SPS edible films were higher while the WVP and the solubility were lower than those of the native SPS edible films. The longer durations of HMT had no effects on the characteristics of the edible films. The increase of SPS concentrations enhanced the moisture content, the thickness, the WVP and the elongation but decreased the solubility and the tensile strength of edible films. The films surfaces of modified SPS edible films appeared to be denser and compact than those of native SPS edible films. The crystallinity and the thermal properties of the modified SPS edible films showed the higher increase than those of the native SPS edible films.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26740
      Issue No: Vol. 18, No. 4 (2018)
  • Preparation of Cassava Bagasse Starch-Based Biodegradable Film Reinforced
           with Chicken Feet Gelatin, Citric Acid as Crosslinker, and Glycerol as

    • Authors: Silviana Silviana, Piontek Benedictus Brandon, Bella Ayu Silawanda
      Pages: 688 - 695
      Abstract: Chicken feet is one of sources used to produce biodegradable films due to inexpensive and abundant source. Chicken feet contains extracted gelatin amount of 27.61 to 33%. This biofilm was prepared from cassava bagasse starch with citric acid as cross-linker and glycerol as plasticizer. Cassava bagasse contains about 40–64% of starch. This paper observes the optimum composition of cassava bagasse starch-based biofilm preparation upon Central Composite Design with variables of gelatin, glycerol, and citric acid concentration with response of tensile strength and elongation at break. This research was executed in several steps, i.e. extraction of gelatin, extraction of cassava bagasse starch, and casting. Optimum condition of this biofilm preparation can be obtained at 12.98% w of gelatin content, 0.22% w of glycerol and 0.27% w of citric acid by releasing 21.73 MPa of tensile strength and 19.73% of elongation at break. Mass loss of biofilm with lower gelatin content gave almost the same mass loss for blank biofilm (cassava bagasse starch-based without gelatin content). Increasing of gelatin content in the biofilm, increasing of the biofilm mass loss. However, the biofilm had good thermal stability by thermal gravimetric analysis with higher temperature to obtain inorganic residue than that of blank biofilm.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26766
      Issue No: Vol. 18, No. 4 (2018)
  • Synthesis and Structural Analysis of Powder Complex of
           Tris(bipyridine)cobalt(II) Trifluoromethanesulfonate Octahydrate

    • Authors: Kristian Handoyo Sugiyarto, Cahyorini Kusumawardani, Kristanti Eka Wulandari
      Pages: 696 - 701
      Abstract: The powder complex of tris(bipyridine)cobalt(II) trifluoromethanesulfonate octahydrate has been synthesized by direct interaction of the corresponding aqueous solutions (and drops of ethanol) of cobalt(II) nitrate, bipyridine, and potassium triflate. The yellow-orange powder produced was filtered off and allowed to dry on an aeration for characterization. AAS measurement showed the content of metal to be 6.06%, corresponding to the theoretical value of 6.06% in [Co(bipy)3](CF3SO3)2.8H2O. The analysis of conductance producing the charge ratio of cation to anion to be 2:1, confirms the formula. The magnetic moment, µeff, of this complex which was to be 4.5-4.9 BM, indicates that the complex is paramagnetic corresponding to the three unpaired electrons with a significantly orbital contribution. UV-Vis spectrum of the complex reveals the first band observed at about 11100 cm–1, which is associated with the spin-allowed transition, 4T1g → 4T2g. A distinct shoulder at only about 16100 cm–1 should be associated with the spin-forbidden transition of 4T1g → 2T2g,2T2g (G). The expected second and third bands which are associated with spin-allowed transitions of 4T1g → 4T1g(P) and 4T1g → 4A2g at higher energy were not well resolved. The infrared spectrum shows absorptions of the functional group of ligand which is influenced by the metal-ligand interaction in this complex. The powder XRD of this complex was refined using Le Bail method of Rietica program and found to be fit as monoclinic symmetry with a space group of C2/c.

      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26833
      Issue No: Vol. 18, No. 4 (2018)
  • Optimization of o-cresol degrading microorganism and kinetics of

    • Authors: Krishnan Nhattuketty Shainy, Rajamanickam Usha
      Pages: 702 - 708
      Abstract: In the present study, Pseudomonas monteilii CR13 isolated from petroleum contaminated soil demonstrated the highest specific o-cresol degradation rate at all tested o-cresol concentrations and also was not disturbed by the starting substrate concentration used (o-cresol-500 mg/L). After a serial transfer of the isolate into a series of increasing o-cresol level, the organism demonstrated significant improvement on degradation ability up to 3000 mg/L. The optimum condition for the cell mass increase and biodegradation of o-cresol by Pseudomonas monteilii was in the minimal mineral medium of 3 at a pH of 6.5 and temperature 30 °C, stirring velocity of 160 rpm, and the substrate concentration of 500 mg/L. The biodegradation kinetic study was carried out by bacteria in different initial substrate concentrations (500–3000 mg/L). In the present test the μmax, Ks and the μ were found 0.332 h-1, 0.166 mg/L and 0.0282 mg/L for 500 mg/L of o-cresol, respectively. The organism is highly promising and could be used to remove high concentrations of o-cresol from highly polluted aquatic and soil regions. The cells could be immobilized on a suitable matrix and the efficiency of degradation could be effectively improved.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.35326
      Issue No: Vol. 18, No. 4 (2018)
  • The Effect of Ingredients Mixing Sequence in Rubber Compounding upon
           Vulcanization Kinetics of Natural Rubber: An Autocatalytic Model Study

    • Authors: Abu Hasan, Rochmadi Rochmadi, Hary Sulistyo, Suharto Honggokusumo
      Pages: 709 - 717
      Abstract: This study examined the effect of ingredients mixing sequence to the vulcanization kinetics of natural rubber. The effects of mixing temperature, vulcanization temperature, and the carbon black type upon the kinetics were also studied by using rheography and an autocatalysis reaction model approach. The results showed that this model is good in providing information on vulcanization reaction kinetics of natural rubber. High vulcanization temperature resulted in high reaction rate constant. The more black carbon mixed at the beginning of the rubber mixing process, the higher reaction rate constant would be. The mixing of carbon black and rubber chemicals mixed into the rubber subsequently resulted in the higher reaction rate constant compared with that of simultaneously.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.25707
      Issue No: Vol. 18, No. 4 (2018)
  • Bioconversion of Palm Oil into Biosurfactant by Halomonas meridiana BK-AB4
           for the Application of Corrosion Inhibitor

    • Authors: Ira Prima Sari, Muhammad Imam Basyiruddin, Rukman Hertadi
      Pages: 718 - 723
      Abstract: Biosurfactant is environmentally friendly surfactant produced by a certain microorganism in a lipid-rich medium. A previous study has shown that Halomonas meridiana BK-AB4 had the potential of a moderately halophilic bacterium in converting olive oil into biosurfactant. In the present study, the effect of changing the carbon source from olive oil into cheaper and more abundant vegetable oil, which is palm oil, for the production of the biosurfactant was evaluated. The study began by optimizing the production medium with varying the nitrogen source, the concentration of palm oil and pH. The optimum condition of biosurfactant production was observed in the medium consisted of 0.6% (w/v) of urea, 2% (v/v) of palm oil and pH 9. The resulted biosurfactant was stable at pH 7–10 and in the salt concentration of 6–15%. Biosurfactant activity in lowering air-water surface tension was measured using the Du Noüy ring method, and the value of critical micelle concentration (CMC) was about 233 ppm. At this point, the surface tension of water dropped from 68.3 to 49.8 dyne/cm. Preliminary structural analysis by using FTIR technique suggested that the resulted biosurfactant has -OH, -C-H aliphatic C=C, H-C-C and C=O groups in its structure, which is similar to that of the fatty-acid type of biosurfactant. The potential of biosurfactant as a metal corrosion inhibitor was evaluated by using electrochemical impedance spectroscopy (EIS) that measured at 30 °C. The measurement revealed that the highest inhibition level was observed at the biosurfactant concentration about 200 ppm that corresponds to the inhibition level about 53.23%.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.27040
      Issue No: Vol. 18, No. 4 (2018)
  • Study of Adsorption Characteristics a Low-Cost Sawdust for the Removal of
           Direct Blue 85 Dye from Aqueous Solutions

    • Authors: Rahmah Hashim Abdullah, Amjed Mirza Oda, Alaa Rasheed Omran, Ameer Salem Mottaleb, Teeba Mudhefer Mubarakah
      Pages: 724 - 732
      Abstract: The performance sawdust as a low cost adsorbent to remove Direct Blue 85 (DB85) dye from aqueous solutions has been evaluated. The characteristic of sawdust analyzed by FTIR and XRD. The removal percentage of this dye was studied at different experimental conditions such as contact time, adsorbent dosage, particle size, temperature, and pH. The optimum removal percentage value was found at pH 2.Temperature also has a positive impact on adsorption, where the adsorption of this dye on the sawdust increased as the temperature increased. High values of correlation coefficient signified that the adsorption of (DB85) dye on the surface of sawdust obey Langmuir and Freundlich adsorption isotherms.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.31536
      Issue No: Vol. 18, No. 4 (2018)
  • Adsorption of Methylene Blue on the Composite Sorbent Based on
           Bentonite-Like Clay and Hydroxyapatite

    • Authors: Alexandr Ivanovich Vezentsev, Dang Minh Thuy, Lidia Fedotovna Goldovskaya-Peristaya, Nadezhda Alexandrovna Glukhareva
      Pages: 733 - 741
      Abstract: The adsorption of methylene blue from model aqueous solutions on bentonite-like clay, hydroxyapatite, and a composite sorbent has been investigated. The kinetic and thermodynamic parameters of adsorption in the temperature range 298–333 К have been calculated. The process is found to obey Langmuir isotherm equation. It is spontaneous but slightly endothermic. The maximal sorption capacity of the composite sorbent toward methylene blue is 175.4 mg/g at 25 °С that is 1.3 times more than that for bentonite-like clay and 17.8 times more than that for hydroxyapatite. Kinetics of the process is due to the combination of external and internal diffusion and can be described better by the model of pseudo-second order reaction.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.37050
      Issue No: Vol. 18, No. 4 (2018)
  • Study of Substituent Effect on Properties of Platinum(II) Porphyrin
           Semiconductor Using Density Functional Theory

    • Authors: Harno Dwi Pranowo, Fadjar Mulya, Hafiz Aji Aziz, Grisani Ambar Santoso
      Pages: 742 - 748
      Abstract: Study of substituent effect on properties of platinum(II) porphyrin had been performed using DFT method. The aim of the study is to investigate the effect of substituent group on the electronic and optical properties of the platinum(II) porphyrin. Geometry optimization was conducted using DFT/B3LYP/LANL2DZ to obtain molecular structure, electronic structure and energy profile. Band gap energy (Eg), the density of states (DOS), and UV-visible spectra are the semiconductor parameters to study. Computational results show that platinum(II) porphyrin and substituted platinum(II) porphyrin have properties of semiconductor based on Eg value, DOS, and UV-visible spectra. The results show that Mulliken partial charges of electron withdrawing substituents are higher than the electron donating substituents (CH3, OH, and NH2). Eg values of the complexes with respect to the substituents follow this order: NH2 < OH < NO2 < COOH < I < CH3 < Br < F < H, for DOSHOMO values, the order is CH3 < NO2 < I < OH < F < NH2 < COOH < Br < H and the maximum wavelength (λmax) for UV-visible adsorption spectra follows this order: NH2 > OH > COOH > NO2 > I > Br > CH3 > F > H. Molecules with smaller Eg and DOSHOMO values and higher λmax are considered as the most appropriate semiconductor materials. Our results show that Pt(II)P-NH2 has the smallest Eg and the highest λmax among other substituted platinum(II) porphyrin molecules. Therefore, Pt(II)P-NH2 are the most suitable semiconductor material based on the aforementioned criteria.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26121
      Issue No: Vol. 18, No. 4 (2018)
  • Density-Functional-Theory Calculations of Formation Energy of the
           Nitrogen-Doped Diamond

    • Authors: Sholihun Sholihun, Hana Pratiwi Kadarisman, Pekik Nurwantoro
      Pages: 749 - 754
      Abstract: The geometry optimization of the nitrogen-doped diamond has been carried out by the density functional theory (DFT) calculations. We model the defective diamond of substitutional and interstitial nitrogen atoms by using a simple-cubic supercell. Atoms in the supercell are relaxed by allowing them to move so that the atomic forces are less than 5.0 × 10-3 eV/Å. We calculate the formation energy for substitutional and interstitial sites. We find that the formation energy for the substitutional defect is10.89 eV. We check the convergence of the calculation with respect to the k×k×k - Monkhorst-Pack grids. We show that the energy difference between k = 4 and 6 is very small (7.0 meV). We also check the calculations by using a 216-sites supercell and find that the energy difference is 0.10 eV. Thus, the calculations of the formation energy converge well. As for the interstitial defect, we model some possible configurations and find that the smallest formation energy is 21.88 eV. Therefore, the most stable configuration of the nitrogen-doped diamond belongs to the substitutional site.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.26785
      Issue No: Vol. 18, No. 4 (2018)
  • Synthesis, Structural, Density Functional Theory, and X-Ray Diffraction
           Study of Zn(II) N-Isopropylbenzyldithiocarbamate: Anti-Corrosion Screening
           in Acid Media

    • Authors: Noor Syafiqah Habdul Latif, Sheikh Ahmad Izaddin Sheikh Mohd Ghazali, Erna Normaya Abdullah, Azizul Hakim Lahuri, Mohammad Fadzlee Ngatiman, Nur Nadia Dzulkifli
      Pages: 755 - 765
      Abstract: Corrosion of metal is a serious issue across many industries and is considered costly. Acids used during the cleaning process in industries may contribute to metal erosion. Dithiocarbamate is a ligand that can act as a corrosion inhibitor due to the presence of sulfur and nitrogen as electronegative atoms. Zn(II) N-isopropylbenzyldithiocarbamate (Zn[N-isopbenzdtc]2) complex was synthesized through direct synthetic method of < 4 °C and characterized using Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR), Ultraviolet-Visible (UV-Vis), Nuclear Magnetic Resonance (NMR), X-ray crystallography study, molar conductivity, melting point, and gravimetric analysis. Corrosion inhibition of mild steel was studied for different corrosive media (1 M HCl and 1 M H2SO4). The synthesized inhibitor was studied at different concentrations of 1, 2, 3, 4, and 5 mM at 40 °C. As a conclusion, as the inhibitor concentration decreased, the efficiency of the corrosion inhibitor also decreased at a constant temperature. In this study, it showed that the corrosion activity of mild steel in 1 M H2SO4 was higher compared to 1 M HCl due to the higher concentration of H+, which makes H2SO4 more corrosive than HCl.
      PubDate: 2018-11-12
      DOI: 10.22146/ijc.34703
      Issue No: Vol. 18, No. 4 (2018)
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
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Fax: +00 44 (0)131 4513327
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