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ALCHEMY Jurnal Penelitian Kimia
Published by Universitas Sebelas Maret
ISSN : 14124092     EISSN : 24434183     DOI : -
Core Subject : Science, Social, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Environmental Science Materials Science & Nanotechnology
ALCHEMY Jurnal Penelitian Kimia is a chemistry journal published by Sebelas Maret University, Surakarta. ALCHEMY Jurnal Penelitian Kimia publishes original research articles or review articles in organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, biochemistry, and environmental chemistry.
Arjuna Subject : -
Articles 264 Documents
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Modifikasi Membran Kitosan Tertaut Silang Tripolifosfat Untuk Deteksi Ion Cu(II) Abu Masykur; Gaby Aprilia; Anggun Duwi Hapsari; Atmanto Heru Wibowo; Candra Purnawan; Sri Hastuti; Pranoto Pranoto; Tri Martini
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 1 (2023): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.1.56392.86-93

Abstract

Penelitian ini bertujuan untuk memodifikasi kitosan dan digunakan sebagai sensor ion logam Cu(II). Modifikasi dilakukan dengan penaut silang kitosan menggunakan tripolifosfat dan dibentuk menjadi membran. Membran yang dihasilkan dianalisis dengan spektrofotometer UV-Vis, Fourier Transform InfraRed (FTIR), dan Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX). Hasil analisis menunjukkan keberhasilan sintesis membran kitosan/tripolifosfat (CTS/TPP). Membran CTS/TPP dapat mendeteksi ion logam Cu(II) ditandai adanya perubahan warna membran dari bening menjadi biru. Keberhasilan deteksi ion logam Cu(II) oleh membran dikonfirmasi oleh pengujian UV-Vis, FTIR dan SEM-EDX. Pengujian spektrofotometer UV-Vis pada membran setelah dikontakkan dengan ion logam Cu(II) menunjukkan terjadinya pergeseran panjang gelombang maksimum akibat interaksi yang terjadi antara membran dengan ion logam Cu(II). Pada penentuan kondisi optimum pH, membran CTS/TPP optimum bekerja pada pH 7 dalam waktu 15 menit. Pada rentang konsentrasi ion Cu(II) 1‒10 ppm, nilai koefisien korelasi (R2) untuk membran CTS/TPP diperoleh sebesar 0,9917.Modification of Tripolyphosphate Cross-Linked Chitosan Membrane for Cu(II) Ion Sensor. This study aims to modify chitosan and use it as a sensor for Cu(II) metal ions. The modification was carried out by cross-linking chitosan using tripolyphosphate and forming it into a membrane. The resulting membranes were analyzed by UV-Vis, FTIR spectrophotometer, and SEM-EDX. The analysis results show the successful synthesis of the chitosan/tripolyphosphate (CTS/TPP) membrane. The CTS/TPP membrane can detect Cu(II) metal ions, as indicated by a change in the color of the membrane from clear to blue. The successful detection of Cu(II) metal ions by the membrane was confirmed by UV-Vis, FTIR spectrophotometer, and SEM-EDX. UV-Vis spectrophotometer testing on the membrane after contact with Cu(II) metal ions showed that the maximum wavelength was shifted due to the interaction that occurred between the membrane and Cu(II) metal ions. In the determination of the optimum pH condition, the CTS/TPP membrane optimally works at pH 7 for 15 minutes. In the Cu(II) concentration range of 1‒10 ppm, the correlation coefficient (R2) value for the CTS/TPP membrane was 0.9917.
Karbon dots (C-dots) dari Bahan Hayati untuk Deteksi Logam Berat Cut Navita Rahmi; Sri Sugiarti; Alvian Dea Yuliani
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.61881.234-246

Abstract

Pendeteksian logam berat pada limbah hasil industri perlu dilakukan untuk mencegah timbulnya penyakit apabila memasuki tubuh manusia. Salah satu bahan yang dapat digunakan untuk pendeteksian logam berat yaitu C-dots. C-dots yang berasal dari bahan hayati akan menghasilkan gugus fungsi yang dapat meningkatkan karakteristik optik C-dots agar lebih selektif dalam pendeteksian logam berat. Selain itu, penggunaan bahan hayati sebagai sumber C-dots akan memanfaatkan limbah sehingga mengurangi sampah. Penelitian ini bertujuan untuk mengkaji nanopartikel karbon C-dots yang berasal dari sumber hayati sebagai pendeteksian logam berat. C-dots yang berasal dari sumber hayati sudah banyak diteliti sebagai deteksi logam berat secara selektif. Gugus fungsi pada permukaan C-dots akan menentukan interaksi spesifik antara C-dots dan masing-masing logam. Reaksi pengompleksan antara C-dots dengan ion logam cenderung mengikuti aturan sebagai berikut, ion logam yang keras akan cenderung mengikat ligan yang keras dan ion logam lunak cenderung mengikat lebih banyak ligan yang lunak. C-dots tersintesis dengan metode hidrotermal cenderung menghasilkan quantum yield dan intensitas fluoresensi yang lebih tinggi yang sensitif untuk deteksi logam berat.Carbon Dots (C-Dots) from Biomass for Heavy Metal Detection. Detecting heavy metals in industrial waste is necessary to prevent the disease from entering the human body. One of the materials that can be used to detect heavy metals is carbon dots (C-dots). C-dots derived from biological materials have functional groups that can improve their optical characteristics to be more selective in detecting heavy metals. In addition, using natural materials as a source of C-dots will utilize waste, thereby reducing waste. This study aims to review carbon nanoparticles derived from natural sources for detecting heavy metals. C-dots derived from biological sources have been widely studied as selective heavy metal detection. The functional groups on the surface of the C-dots will determine the specific interactions between the C-dots and each metal. The complex reaction between C-dots and metal ions tends to follow the rules: hard metal ions tend to bind to hard ligands, and soft metal ions tend to bind more to soft ligands. C-dots synthesized via the hydrothermal method tend to produce a higher quantum yield and fluorescence intensity that are sensitive to heavy metal detection. ️
Cairan Ionik sebagai Penyerap Gas CO2 Yunita Anggraini; Inge Magdalena Sutjahja
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.62225.247-260

Abstract

Pemanasan global akibat emisi gas rumah kaca, terutama karbon dioksida (CO2), memiliki pengaruh yang signifikan terhadap perubahan iklim dan telah menjadi isu penting dalam beberapa tahun terakhir. Penangkapan dan pemanfaatan CO2 atau CO2 capture and utilization (CCU) adalah strategi yang efektif untuk mengurangi pemanasan global. Makalah ini bertujuan untuk memberikan gambaran singkat proses penangkapan CO2 dengan memanfaatkan cairan ionik (ionic liquid, IL). IL adalah jenis garam yang terdiri dari kation organik dan anion organik atau anorganik yang memiliki beberapa keunggulan, di antaranya volatilitas yang rendah, stabilitas termal yang cukup baik, tidak mudah korosif, laju degradasi yang rendah, dan biaya regenerasi yang rendah. Kombinasi kation-anion yang tepat membuat IL dapat digunakan sebagai pelarut untuk proses penangkapan CO2 menggantikan pelarut konvensional berbasis amina. Dalam perkembangan selanjutnya, generasi baru IL fungsional (IL berbasis basa kuat dan asam amino) dan deep eutectic solvent (DES) telah diperkenalkan sebagai larutan pengganti IL murni (IL konvensional) dengan keunggulan kapasitas penyerapan CO2 yang lebih besar, mudah terurai secara alami (biodegradable), mudah berinteraksi dengan jaringan hidup, tidak menimbulkan toksisitas (biokompatibel), dan mudah diproduksi dalam skala besar dengan biaya relatif rendah. Selain itu, dengan mempertimbangkan biokompatibilitas DES, pengembangan DES dengan mempertimbangkan aspek biologis menjadi terobosan baru yang menjanjikan sebagai bahan ramah lingkungan. Dalam hal ini DES menyerap CO2 dari gas buang dan kemudian menyediakannya sebagai sumber nutrisi bagi mikroalga.Ionic Liquid as CO2 Absorption. An increase in global warming as an impact of greenhouse gases, particularly carbon dioxide (CO2), has become an important issue in recent years. CO2 capture and utilization (CCU) are the effective strategy to mitigate global warming. This study briefly described the CO2 capture process using ionic liquid (IL). IL is a type of salt consisting of organic cations and organic or inorganic anions. IL as a solution in the CO2 capture process has several advantages, including low volatility, good thermal stability, non-corrosive, low degradation, and low regeneration costs. Using the proper cation and anion, IL acts as an effective solvent for CO2 capture, replacing amine. In subsequent developments, a new generation of functional IL (strong base and amino acid-based IL) and deep eutectic solvent (DES) has been introduced as a substitute for pure IL (conventional IL) with the advantages of more excellent CO2 absorption, biodegradable, easy to interact with live tissue, non-toxicity, biocompatible, and easy to produce on a large scale with relatively low cost. In addition, taking into account the biocompatibility of DES, the development of DES by considering the biological aspects is a promising alternative as an environmentally friendly material. In this case, DES absorbs CO2 from exhaust gases and provides it as a source of nutrition for microalgae.
Sintesis Senyawa 4-(Dimetilamino)calkon Menggunakan Microwave-Assisted Organic Synthesis (MAOS) dengan Variasi Konsentrasi NaOH dan Prediksi Profil Farmakokinetik Iin Narwanti; Aisyah Khairani Hidayati
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.66542.130-139

Abstract

Senyawa calkon dan turunannya mempunyai aktivitas farmakologi dengan aplikasi yang luas, karenya sintesis senyawa tersebut perlu dipelajari. Oleh karena itu, penelitian ini bertujuan untuk mensintesis 4-(dimetilamino)calkon dari dalam suasana basa dengan metode Microwave-Assisted Organic Synthesis (MAOS) dan memprediksi profil farmakokinetiknya. 4-(dimetilamino)calkon direaksikan dengan asetofenon dengan adanya basa NaOH. Sintesis 4-(dimetilamino)calkon dilakukan dengan iradiasi selama 25 detik dengan daya 140 watt. Variasi konsentrasi katalis NaOH yang digunakan adalah 40%, 50%, dan 60%. Rekristalisasi dilakukan dengan menggunakan pelarut etanol. Produk sintesis dikarakterisasi dengan penentuan titik lebur, KLT, spektrofotometri inframerah, spektrometri massa, 1H-NMR dan 13C-NMR. Selanjutnya, profil farmakokinetik 4-(dimetilamino)calkon diprediksi dengan menggunakan web server SwissADME. Hasil penelitian menunjukkan bahwa rata-rata rendemen sintesis 4-(dimetilamino)calkon dengan metode MAOS pada variasi konsentrasi katalis NaOH 40%, 50%, dan 60% berturut-turut adalah 73,4±1,72%; 90,9±0,68% dan 85,1±1,32%. Konsentrasi NaOH 50% menghasilkan rendemen produk sintesis yang paling optimal. Prediksi sifat fisikokimia dan profil farmakokinetik menggunakan SwissADME menunjukkan bahwa senyawa 4-(dimetilamino)calkon memenuhi aturan Lipinski’s Rule of Five dan mempunyai penyerapan gastrointestinal yang baik dan mampu melewati blood brain barrier (BBB).Synthesis of 4-(Dimethylamino)chalcone Compound Using Microwave-Assisted Organic Synthesis (MAOS) with Various NaOH Concentration and Pharmacokinetic Profile Prediction. Chalcones and their derivatives are widely established to have a wide application pharmacological activity; therefore, the synthesis is necessary to study. This study aimed to synthesize 4-dimethylaminochalcone in the presence of a base using Microwave-Assisted Organic Synthesis (MAOS) method and predict its pharmacokinetic profile. 4-(dimethylamino)benzaldehyde was treated with acetophenone in the presence of NaOH with various concentrations (40%, 50%, and 60%). Irradiation was conducted for 25 seconds with a power of 140 watts. Recrystallization was carried out from ethanol to give the expected product. The crude product was characterized by melting point determination, TLC, infrared spectrophotometry, mass spectrometry, 1H-NMR, and 13C-NMR. Furthermore, pharmacokinetic profiles of 4-(dimethylamino)chalcone were predicted using the SwissADME web server. The results showed that the average yield of the synthesized product using the MAOS method with catalyst NaOH 40%, 50%, and 60% was 73.4±1.72%, 90.9±0.68%, and 85.1±1.32%, respectively. The optimal yield was obtained using a 50% concentration of NaOH. The pharmacokinetic profiles of 4-(dimethylamino)chalcone analysis using the SwissADME web server showed that 4-(dimethylamino)chalcone complied with Lipinski's Rule of Five. Furthermore, it might have good gastrointestinal absorption and might be able to cross the blood-brain barrier (BBB).
Effect of Plasticizer Addition on The Characteristics of Chitosan-Alginate Edible Film Atmanto Heru Wibowo; Helmi Fehragucci; Candra Purnawan
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.71348.123-129

Abstract

The edible film of chitosan-alginate in this study showed characteristics of the physical and mechanical properties when various plasticizers of polyethylene glycol/PEG, polyvinyl alcohol/PVA, and glycerol were added into the origin film. It was also found that chitosan content in the edible film contributed to the change in the physical properties and the conductivity of the film. The general effect on the film because of the addition of plasticizers was the decrease of the tensile strength, the increase of the films' elongation, and the increase of the water vapor permeability (WVP). Among other plasticizers, PEG attracted the most attention in which it affected the most significant change on the properties. Meanwhile, the higher chitosan content in the chitosan-alginate film affected the increase of the tensile strength and the decrease of the elongation value, and the decrease of the WVP on the film. Characterization using FT-IR spectrophotometer showed that no chemical interaction was formed due to the mixing of alginate-chitosan in the film. Instead, only the physical blending of chitosan-alginate was formed in the edible film.
Improvement of Selectivity and Antifouling Properties of Chitosan-modified Polyvinylidene Fluoride (PVDF) Membrane for Protein Filtration Reza Zatadini; Aldita Fatchul Ni’mah; Yudi Setiawan; Agung Lucky Pradita; Desy Vita Pratiwi; Dina Syakirina; Mayzy Vanesia Insani; Widyan Muhammad Naufal; Wulida Rayhani; Ozi Adi Saputra; Edi Pramono
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.72110.210-222

Abstract

Protein with high purity is currently a valuable commercial commodity, prized for its high value and application in specialized functions. PVDF-based membrane technology has found widespread use in protein purification processes. However, the issue of fouling on the membrane surface frequently hampers the performance of PVDF membranes. The present study aims to enhance PVDF membranes' selectivity and antifouling properties through chitosan modification, thereby optimizing protein filtration. PVDF and PVDF/Chitosan membranes were fabricated using the phase inversion technique, followed by a comprehensive characterization of their surface properties, thermal attributes, and performance in bovine serum albumin (BSA) protein filtration. The collected data revealed notable increases in membrane hydrophilicity, porosity, and pure water flux due to the incorporation of chitosan. The membrane protein rejection capabilities were significantly enhanced to levels exceeding 90% with the introduction of 0.5% chitosan. Moreover, as the chitosan concentration increased, the membrane exhibited superior antifouling characteristics, with the 0.5% chitosan concentration yielding the highest Flux Recovery Ratio (FRR) value of 85.35%. Considering the significant improvement selectivity and antifouling properties in the combined system, the chitosan-modified PVDF membrane holds substantial promise in protein purification applications.
Pemanfaatan Silika dari Abu Sekam Padi untuk Pembuatan Material Imprinted Ionic sebagai Adsorben Ion Logam Pb(II) Sri Hastuti; Tri Martini; Agustina Tri Utami
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.70373.162-169

Abstract

Sintesis material imprinted ionic Pb(II) (SiO2-TMPDT-Pb-Imp) menggunakan natrium silikat dari abu sekam padi (Na­2SiO3(ASP)) telah berhasil dilakukan pada penelitian ini dengan memanfaatkan abu sekam padi sebagai sumber silika untuk pembuatan natrium silikat (Na­2SiO3(ASP)). Modifier yang digunakan adalah N1-(3-trimethoxysilylpropyl)diethylentriamine (TMPDT) dan ion logam Pb(II) berfungsi sebagai templat. Uji kapasitas adsorpsi SiO2‒TMPDT‒Pb‒Imp terhadap ion logam Pb(II) dilakukan pada variasi pH (1 ‒ 6) dan waktu kontak (0 ‒ 120) menit dengan sistem batch. Karakterisasi material SiO2‒TMPDT‒Pb-Imp dilakukan dengan menggunakan Fourier Transform Infrared (FTIR), Scanning Electron Microscope and Energy Dispersive X-ray (SEM-EDX), dan Surface Area Analyzer (SAA).  Berdasarkan data FTIR dan SEM-EDX menunjukkan bahwa material SiO2‒TMPDT‒Pb‒Imp memiliki gugus silanol (Si‒OH); siloksan (Si‒O‒Si); alkana dan gugus amin dengan morfologi material yang halus serta terdapat unsur karbon (C) dan nitrogen (N) sebanyak 44,4% dan 8,3% secara berurutan. Hasil karakterisasi dengan SAA menunjukkan bahwa material SiO2‒TMPDT‒Pb‒Imp memiliki luas permukaan sebesar 7,418 m2/g, volume pori total sebesar 0,012 cc/g dan jari-jari pori sebesar 16,670 Å. Kondisi terbaik adsorpsi ion logam Pb(II) terjadi pada pH 5 dan waktu kontak 60 menit yang mengikuti model kinetika adsorpsi Pseudo Orde 2 dengan kapasitas adsorpsi sebesar 1,2418 mg/g.Utilization of Silica from Rice Husk Ash for Preparing Imprinted Ionic Materials as Pb(II) Metal Ion Adsorbent. Imprinted ionic Pb(II) (SiO2-TMPDT-Pb-Imp) material was synthesized using a solution of sodium silicate from rice husk ash (Na­2SiO3(RHA)) in this study using rice husk ash as a source of silica for sodium silicate (Na2SiO3(ASP)). The modifier used is N1-(3-trimethoxysilylpropyl) diethylenetriamine (TMPDT) and Pb(II) metal ion as a template. The SiO2‒TMPDT‒Pb‒Imp adsorption capacity of Pb(II) metal ion was performed on solution pH (1 ‒ 6) and contact time of (0 ‒ 120) minutes by the batch system. Material characterization was performed by Fourier Transform Infrared (FTIR), Scanning Electron Microscope and Energy Dispersive X-ray (SEM-EDX), and Surface Area Analyzer (SAA). Based on FTIR and SEM-EDX showed that SiO2‒TMPDT‒Pb‒Imp had a silanol group (Si‒OH), siloxane group (Si‒O‒Si), alkane and amine group with finer material morphology and presence of carbon (C) and nitrogen (N) element of 44.4% and 8.3% respectively. SAA characterization indicated that SiO2‒TMPDT‒Pb‒Imp had a surface area of 7.418 m2/g, total pore volume of 0.012 cc/g, and pore radius of 16.670 Å. The optimum condition of Pb(II) metal ion adsorption was obtained at pH 5 and a contact time of 60 min that followed the Pseudo Orde 2 adsorption kinetic model with an adsorption capacity of 1.2418 mg/g.
Simulasi Inhibisi Aktivitas Enzim α-Amilase dan α-Glukosidase oleh Senyawa Bioaktif Mikroalga Spirulina platensis Syafrizayanti Syafrizayanti; Adetya Putri; Marniati Salim; Arif Juliari Kusnanda
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.73120.223-233

Abstract

Diabetes Melitus (DM) Tipe 2 merupakan penyakit dengan gejala hiperglikemia dengan jumlah kasus yang meningkat setiap harinya pada populasi dunia. Enzim yang berperan terkait DM Tipe 2 yaitu α-amilase dan α-glukosidase yang bertindak dalam menghidrolisis pati pada pankreas. Target terapi dalam pengobatan DM Tipe 2 yaitu penurunan reabsorpsi glukosa di usus dengan melakukan penghambatan enzim α-amilase dan α-glukosidase. Tujuan penelitian ini adalah untuk mencari senyawa bioaktif yang terkandung dalam ekstrak Spirulina platensis yang berpotensi menjadi inhibitor α-amilase dan α-glukosidase sebagai antidiabetes secara in silico. Metode yang digunakan berupa skrining senyawa aktif dari literatur, farmakokinetika dengan prediksi ADMET, Lipinski’s Rule of Five dan simulasi penambatan molekul dengan program MOE. Berdasarkan hasil skrining dan simulasi penambatan molekul menunjukkan bahwa senyawa 4-amino-benzoat dapat berikatan dengan enzim α-amilase dengan afinitas pengikatan sebesar -4,16 kcal.mol-1 dengan situs pengikatan dengan asam amino His 299 dan Asp 195, dan berikatan dengan enzim α-glukosidase dengan afinitas pengikatan sebesar -4,08 kcal.mol-1 dengan situs pengikatan dengan asam amino Asn 58 dan Arg 17. Hasil ini menunjukkan senyawa 4-amino-benzoat dari mikroalga Spirulina platensis dapat dijadikan sebagai kandidat bahan alami dalam pengobatan antidiabetes.Inhibition Activity Simulation of α-Amylase and α-Glucosidase Enzyme by Bioactive Compounds of Microalgae Spirulina platensis. Diabetes Mellitus (DM) Type 2 is a disease with symptoms of hyperglycemia, in which its case number is increasing daily in the world population. Enzymes playing a role related to Type 2 DM, namely α-amylase and α-glucosidase, act in hydrolyzing starch in the pancreas. The therapeutic target in treating Type 2 DM is to decrease glucose reabsorption in the intestine by inhibiting the enzymes α-amylase and α-glucosidase. This study aimed to find bioactive compounds in Spirulina platensis extracts that can become α-amylase and α-glucosidase inhibitors as in silico antidiabetics. The method used was screening active compounds from the literature, pharmacokinetics with ADMET predictions, Lipinski’s Rule of Five, and molecular docking simulations with the MOE program. Based on the screening results and molecular docking simulations, it was shown that the 4-amino-benzoic compound could bind to the α-amylase enzyme with a binding affinity of -4.16 kcal.mol-1 with a binding site with the amino acids His 299 and Asp 195, and bind with the α-glucosidase enzyme with a binding affinity of -4.08 kcal.mol-1 with a binding site with the amino acids Asn 58 and Arg 17. These results show that the 4-amino-benzoic compound from Spirulina platensis microalgae can be a candidate for natural ingredients in antidiabetic treatment.
Deoksigenasi Katalitik Metil Ester Asam Lemak Menjadi Biohidrokarbon Menggunakan Katalis Cr2O3/Zeolit Isalmi Aziz; Nanda Saridewi; Fitri Febriyani; Lisa Adhani
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.72521.170-176

Abstract

Deoksigenasi katalitik merupakan proses yang dapat mengkonversi metil ester asam lemak (fatty acid methyl esters, FAME) menjadi biohidrokarbon seperti gasolin, kerosin dan diesel. Katalis yang digunakan berupa Cr2O3 dengan penyangga zeolit alam. Penelitian ini bertujuan untuk menentukan pengaruh konsentrasi Cr2O3 terhadap karakteristik dan aktivitas katalitik katalis pada deoksigenasi katalitik FAME menjadi biohidrokarbon. Katalis dikarakterisasi menggunakan XRD, FTIR DAN SAA. Semua katalis menunjukkan puncak Cr2O3 pada 2θ 24,5°; 33,6°; 36,2°;54,8° dan ukuran kristal 19 ‒ 21 nm. Serapan pada bilangan gelombang 470 ‒ 900 cm-1 mengindikasikan adanya peregangan Cr‒O. Peningkatan konsentrasi Cr2O3 menyebabkan luas permukaan menjadi turun. Katalis Cr2O3/zeolit 1% menunjukkan aktivitas terbesar dengan konversi 60,36% dan selektivitas biohidrokarbon 43,15% yang terdiri dari gasolin 7,23%, kerosin 15,08% dan diesel 20,84%.Catalytic Deoxygenation of Fatty Acid Methyl Esters into Biohydrocarbons using Cr2O3/Zeolite Catalysts. Catalytic deoxygenation is a process that can convert fatty acid methyl esters (FAME) into biohydrocarbons such as gasoline, kerosene, and diesel. The catalyst used is Cr2O3 with natural zeolite as support. This study aims to determine the effect of Cr2O3 concentration on the characteristics and catalytic activity in the catalytic deoxygenation of FAME into biohydrocarbons. The catalysts were characterized using XRD, FTIR, and SAA. All catalysts show a Cr2O3 peak at 2θ 24.5°, 33.6°, 36.2°, 54.8° and a crystal size of 19 ‒ 21 nm. The Cr‒O stretching is observable at wavenumbers 470 ‒ 900 cm-1. Increasing the concentration of Cr2O3 causes the surface area to decrease. Cr2O3/zeolite 1% catalyst showed the most excellent activity with 60.36% conversion and 43.15% selectivity for biohydrocarbons consisting of 7.23% gasoline, 15.08% kerosene, and 20.84% diesel.
Facile Synthesis of Composite Chitosan and Durio zibethinus Seed and Its Applications as Adsorbent of Metal Ion Ni(II) Silvia Devi Eka Putri; Sri Mulijani; Komar Sutriah
ALCHEMY Jurnal Penelitian Kimia Vol 19, No 2 (2023): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.19.2.65948.197-209

Abstract

Nickel is one of the most dangerous heavy metals that impact water ecosystems and human health. In the study, natural and harmless composite materials such as biochar and chitosan were modified to build adsorbent composites and form optimal conditions for the adsorption of nickel heavy metal ions from contaminated wastewater. Biochar was prepared from Durio zibethinus seeds by hydrothermal method to form nanopowder. It was treated with acid, while chitosan was designed as nanopowder by hydrothermal method, also without acid treatment. Composite adsorbents were prepared by mixing biochar and chitosan with a ratio of 4:3 (w/w). Fourier Transform Infrared characterizes composite materials as adsorbents, biochar, and chitosan. The surface morphology of the adsorbent was evaluated by scanning electron microscopy. Furthermore, Langmuir, Freundlich, and Temkin isotherms determine the adsorbent's performance. In addition, batch adsorption experiments were carried out to measure the effect of solution pH, adsorbent dosage, and initial concentration of metal ions. Nickel ion adsorption by the composite adsorbent showed an adsorption capacity of 26.69 mg/g, a maximum removal efficiency of 89.39% at optimum conditions of pH 6, an adsorbent dose of 0.5 g, and a contact time of 200 minutes. This adsorption capacity was better than chitosan and durian seed adsorbents. The nickel ion adsorption process by composite adsorbent shows a pattern in the Temkin isotherm model. In contrast, the chitosan and Durio zibethinus seed adsorbents tended to follow the Langmuir and Freundlich isotherm models. In addition, the adsorption kinetics of the composite material showed pseudo-second-order kinetics, and the reaction was exothermic.

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