Jurnal Riset Kimia
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Fabrication and Characterization of Chitosan/N-Phthaloyl Composite Membrane for DMFC Application
Get PDFModified chitosan membrane is one of the promising membranes for polymer electrolyte membrane. Chitosan/N-phthaloyl chitosan composite membranes were fabricated to obtain high proton conductivity and low methanol permeability. Membranes were fabricated by casting method and solvent evaporation. Surface morphology, mechanical analysis, methanol permeability, and proton conductivity were used to characterize the overall properties. FT-IR spectra exhibited the presence of interaction of chitosan and n-phthaloyl/chitosan. SEM analysis showed that the surface roughness of composite membrane increases as the n-phthaloyl loading increases. The highest proton conductivity of synthesized membrane is at 2.4 mS.cm-1 and is higher than pristine chitosan membrane at 1.6 mS.cm-1. Moreover, with n-phthaloyl/chitosan addition, the methanol permeability was also improved. The correlation between proton conductivity and methanol permeability in composite membranes suggests that the blend has its potential in DMFC application
Pemanfaatan Cangkang Telur dan Sekam Padi Sebagai Bioadsorben Metilen Biru pada Limbah Tekstil
Get PDFThe textile industry in Indonesia has increased since the 1980s. From the non-oil and gas sector, the textile industry is the government's largest source of income. In addition to its impressive growth, about 10-15% of the used textile dyestuff is wasted at the dyeing process can exceed the maximum Chemical Oxygen Demand level of 150 mg/L. Synthetic dyes contain carcinogenic ingredients that can harm the environment and aquatic biota. The alternative for handling the dye waste is the adsorption method using bio adsorbent from a mixture of chicken eggshells and rice husk ash. Both have the potential to be used as adsorbents because they have an active site, abundant amounts, and are economical. This study was to determine the effect of the process variables of the adsorbent mass ratio, contact time, and pH on the adsorption capacity of methylene blue using a mixture of eggshells and rice husk ash with the UV-Vis Spectrophotometer analysis method. The results showed that the optimal conditions for the adsorption of 20 ppm methylene blue were 0.2:0.8 gram of adsorbent ratio, 80 minutes, and pH of 3. The adsorption capacity obtained was 98.817%, reduced the methylene blue concentration to 0.237 ppm.Â
Activated Carbon Addition Methods on the Pre-impregnation Process of Co-Mo in Y-Zeolite Ultra Stable: A Properties Exploration and Enhancement of Metals Loaded
Get PDFThe amount of loaded Co-Mo metal on the Y-Zeolite Ultra Stable (USY) was increased by the addition of activated carbon in the pre-impregnation process. USY modification was done by adding activated carbon to USY as much as 10 wt%. The process of adding activated carbon is carried out by three methods, i.e., grinding with sucrose binder (ACU1), without sucrose (ACU2), and conducting by ball milling (ACU3). Wet impregnation method was employed to disperse the Co and Mo, sequentially. Composites were characterized using Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and surface area analyzer (SAA). Metal dispersions were observed by X-ray fluorescence (XRF). The FTIR suggests an interaction between USY and activated car-bon, while the XRD result indicated the none structural transformation of USY zeolite. The SAA analysis showed an increased total pore radius with the activated carbon addition. The XRF confirmed the increasing of total metals dispersion of 6.25% (ACU1); 5.48%(ACU2); 5.18% (ACU3); compare to USY origin with 3.28% metals loaded
Penggunaan ZnO/Zeolit Sebagai Katalis Dalam Degradasi Tartrazin Secara Ozonolisis
Get PDFAn investigation on modification of natural zeolite with ZnO for the degradation of tartrazine. In this study, ZnO as a semiconductor is modified into a natural zeolite as support to form ZnO/zeolite that can increase the efficiency degradation of tartrazine. Further, the formed catalyst was added to tartrazine by determining the variation in ozonolysis time, the amount of addition of the catalyst, and the addition of a catalyst time. The results of degradation were determined by UV-Vis spectrophotometer at 424 nm. The result showed that the percentage of degradation obtained on each catalyst in the degradation. The resulted percent degradation of 20 ml of tartrazine at concentration of 15 mg/L using 20 mg ZnO/zeolite was 56.80%, while using 0.77 mg ZnO was 42.25%, and with the addition of 19.23 mg of Zeolite was 31.18%, all of that condition was proceeded by 40 minutes of ozonolysis. Thus, the result indicates that the ZnO/zeolite catalyst can increase percentages of tartrazine degradation by ozonolysis. It is known that the catalyst ZnO/zeolite is very effective in increasing the degradation of tartrazine. Analysis of tartrazine compounds using fourier-transform infrared spectroscopy (FTIR) after degradation changes in wavenumber indicates that there is a breaking of the bonds of tartrazine compounds. Characterization of ZnO/zeolite catalyst using FTIR, X-Ray diffraction (XRD) and scanning electron microscope (SEM), in each spectrum there was no shift, indicating that there is no change in ZnO/zeolite structur
Pengolahan Minyak Jelantah Menggunakan Membran Poliamida/Titanium Dioksida/Arang Aktif Kulit Durian
Get PDFProcessing of wasted cooking oil uses the photocatalyst method with metal catalysts and zeolites to reduce organic compounds. In this study, researchers used activated charcoal from durian skin and titanium dioxide embedded in a polyamide membrane as an adsorbent which was used as a medium for processing wasted cooking oil. The purpose of this study was to determine the effect of processing used cooking oil using a membrane of polyamide/titanium dioxide/durian peels activated charcoal on changes in the characteristics of wasted cooking oil. Based on the results of research on the processing of wasted cooking oil with a membrane of polyamide/titanium dioxide/activated charcoal from durian peels, there was an increase in water content by 10.21%, a decrease in free fatty acids by 33.75%, a decrease in the peroxide number by 18.33%. Used cooking oil that has passed through the membrane has a decrease in %Transmission for the functional groups of C-H alkenes, C-O esters, and C-H alkanes. In the analysis of the compound content by mass spectrophotometry, it was found that the content of the methyl ester compound with the C17 and C19 chains was close to the composition of the biodiesel constituents
Biodecolorization of Remazol Brilliant Blue–R dye by Tropical White-Rot Fungi and Their Enzymes in The Presence of Guaiacol
Get PDFThe ability of the tropical white-rot fungi and their enzyme to decolorize synthetic dyes was investigated. Production of lignin-modifying enzymes (LMEs) from the three new isolated fungi, namely Trametes hirsuta D7, Ceriporia sp. BIOM 3, and Cymatoderma dendriticum WM01 were observed for 9 days incubation under static condition. The results showed that the LMEs production enhanced in the present of guaiacol. T. hirsuta D7 produced only laccase (Lac), with the highest activity was 22.6 U/L on the 5th-day of the cultivation. At the same time, Ceriporia sp. BIOM 3 and C. dendriticum WM01 secreted both laccases (Lac) with the activities 0.2 U/L and 1.0 U/L, respectively, and manganese peroxidase (MnP) with the activities 0.1 U/L and 1.0 U/L, respectively. Among the fungi, T. hirsuta D7 efficiently degraded 65% Remazol Brilliant Blue–R (RBBR) dye within 72 h using the only laccase. This study shows that laccase may have a major role in synthetic dyes' decolorization process, followed by MnP and LiP
Pengembangan Metode Serbuk Daun Suji (Pleomele angustifolia N.E.Br) sebagai Identifikasi Sidik Jari Laten
Get PDFFingerprint is a technology that can be used to identify a person. The dusting method is most often used on latent fingerprints because it is relatively easy and simple. However, the composition of the ingredients used in latent fingerprint powder is toxic and can be hazardous to health. This research was carried out using a new natural powder from Suji leaf as a simple, non-toxic, and cheaper. Suji leaf powder produces a green color that comes from the chlorophyll compounds contained in it. This chlorophyll compound will bind to alanine to identify latent fingerprints. The particle sizes used in this study were of 60-200 mesh. The results found that the particle sizes of 100 and 200 mesh provided good green contrast and clear visualization of the fingerprint patterns. Meanwhile, at the particle size of 60 and 80 mesh, it was found that the results were not clear visualized. The highest percentage of fingerprint patterns based on blood group, gender and ethnicity was found in form of loops. The percentage of fingerprint patterns formed based on the highest was of O 31.1; B 12.2; AB 8.8; and A 6.6 percent. The highest percentage of fingerprint patterns formed by gender were of 45.5 for women and 13.3 percent for men. The highest percentage of fingerprint patterns formed by ethnicity were Malay 21.1, Batak 20, and Javanese 17.7 percent
Struktur dan Sifat Dielektrik Senyawa Aurivillius CaBi3LaTi4O15 yang Disintesis dengan Teknik Hidrotermal
Get PDFSynthesis of four-layer Aurivillius CaBi3LaTi4O15 has been successfully carried out by hydrothermal technique using NaOH 4 M as mineralizer. The reaction was carried out at 220 °C for 72 h. Crystal structure, morphology, and dielectric properties were analyzed in this study. X-ray diffraction confirmed that the single-phase product was successfully obtained. The refinement result shows the product has orthorhombic crystal structure with space group A21am. The morphology analyzed using SEM shows plate-like grains are observed, which is characteristic of Aurivillius phase. Dielectric curves show peaks at 585 °C which indicate ferroelectric transition temperature
Penetapan Kadar Fenolik dan Flavonoid Hasil Ultrasonic Assisted Extraction Daun Binahong (Anredera cordifolia [Ten] Steenis)
Get PDFAnredera cordifolia [Ten] Steenis has been proven to have pharmacological activity that is thought to be influenced by the presence of phenolic compounds and flavonoids. However, both compounds are found in small concentrations through conventional extraction (maceration, decoction, soxhlet, and reflux). This study aims to prove that the ultrasonic assisted extraction method can obtain higher concentrations of phenolic and flavonoid compounds. Dried binahong leaves were extracted using ultrasonic assisted extraction with 70% ethanol. Phenolic levels were determined using Folin-Ciocalteu, while flavonoid levels were determined using the colorimetric aluminum method. The results showed binahong leaves ethanolic extract had phenolic levels of 10.16 % GAE and flavonoid levels of 10.58 % QE. These results are much higher than the results obtained using conventional extraction so that ultrasonic assisted extraction can be recommended to maximize the extraction of phenolic and flavonoid levels from the leaves of Binahong (Anredera cordifolia [Ten] Steenis).Â