Jurnal Kimia Valensi
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Structure Prediction and Ultrasonic Assisted Synthesis of Coordination Compound Cadmium (II) Bromide with N,N’-diethylthiourea Ligand
Full text linkCadmium (II) halides with N,N\u27-diethylthiourea (detu) ligands at a stoichiometry of 1: 2 tend to form molecular complexes [Cd(detu)2X2] with a distorted tetrahedral geometry at the central atom. Generally, these complex compounds are prepared by the conventional method of reflux for 4 hour. The use of ultrasonic waves for complex synthesis can be an alternative to make the reaction time more efficient and environmentally friendly. The aim of this study was to synthesize and characterize complex compounds from CdBr2 and detu ligands using the ultrasonication method that have not previously reported. The synthesis of complex compounds was carried out by reacting CdBr2 and detu (1:2) in methanol solvent. In the synthesized compounds, a melting point test, electrical conductivity test, Fourier Transform Infrared (FTIR), Scanning Electron Microscope-Energy Dispersive Xray (SEM-EDX), qualitative test of bromide ion and calculation of free energy using Spartan\u2714 software were carried out for the complex structure prediction. The complex compound resulted has colorless needle crystals with a melting point of 93-94°C. The results of the EDX analysis provide the empirical formula C10H24CdBr2N4S2. The electrical conductivity test data and the bromide ion qualitative test proved that the synthesized complex compound was a molecular complex compound with the molecular formula [Cd(detu)2Br2]. The complex compound has two possible structures, namely a distorted tetrahedral and a square planar. Free energy calculations showed that complex compounds with a distorted tetrahedral structure and a square planar have free energies of -527.5574 kJ/mol and -408.7424 kJ/mol, respectively
Synthesis and Characterization of Bioplastic from Macroalgae Padina australis
Full text linkSynthetic plastics are one of the more significant contributors to waste in the environment. Bioplastic is a type of plastic that is environmentally friendly because it is made from biomass. In this study. brown macroalgae. Padina australis. is one of the potential raw materials found in large quantities in Indonesian waters and used to produce bioplastics with filtration technique. The aim of this study was to synthesis bioplastics using P. australis alginate with glycerol plasticizer.The alginate macroalgae were mixed with glycerol as a plasticizer in the following proportions: 1:15. 1:25. 2:15. and 2:25. with the quality determined through tensile strength measurements. water solubility. and degradation time. On day 12. the tensile strength of P. australis bioplastic was 3.24-7.33 MPa. the water solubility was 61.79-65.19%. and the biodegradability rate was 0.1-20.0%. When the macroalgae alginate and glycerol formulation was 2:25. the best bioplastic film produced had a tensile strength of 7.33 MPa and a water solubility of 61.79%. which was lower than the Indonesia National Standard number 7818/2016 for bioplastic products. P. australis. however. has the potential to be a promising alternative bioplastic product that contributes to the reduction of petroleum-based plastic pollution in the environment. Furthermore. as a preliminary study. it will be improved to meet industrial standards or find the products that match these characteristics
Synthesis of Green Diesel from Palm Oil Using Nickel-based Catalyst: A Review
Full text linkPetroleum is the primary energy that is generally used throughout the world. Its non-renewable nature and exhaust gas emissions that can damage the environment are a concern for developing environmentally friendly renewable energy. Green diesel is an alternative energy to replace diesel fuel (diesel) from petroleum which has the potential to be developed. The raw material in palm oil has great potential for development due to its relatively high production. Green diesel synthesis can be carried out using the catalytic deoxygenation method. The type of raw material, catalyst, and process conditions influences this method. The catalyst is the most influential factor in catalytic deoxygenation. Transition metal catalysts like nickel are inexpensive and have good catalytic activity like precious metals. Catalytic activity can be increased by modifying the catalyst components and optimizing the process. Modification of the catalyst can increase the surface area, Lewis and Bronsted sites, and crystal size so that the resulting green diesel can be maximized, such as Ni-Co, Ni-Zn, and Ni-Mo bimetallic catalysts
Isolation and Identification of Lactic Acid Bacteria form Chinese Cabbage Waste by 16s rRNA Amplification using The Polymerase Chain Reaction (PCR) Method
Full text linkWaste is material that is disposed of from sources of human and natural activities that do not yet have economic value. Physically, vegetable waste is perishable due to its high-water content, especially Chinese Cabbage waste. The purpose of this study was the isolation and identification of lactic acid bacteria from Chinese Cabbage waste. Isolation was carried out to obtain isolates of lactic acid bacteria from Chinese Cabbage waste. Then it was amplified using a Polymerase Chain Reaction (PCR) instrument. The results of chromosomal DNA amplification of bacterial isolates from mustard 1, mustard 2 and mustard 3 waste showed DNA bands with a size of ± 1200 bp, so it can be concluded that the process of amplification of the 16s rRNA gene fragment in mustard 1, mustard 2 and mustard 3 isolates was successful. The results of the 16s rRNA base sequence analysis showed that the mustard 1 isolate had a similarity index of 84.65% with Bacillus sp, the gene for the mustard 2 isolate had a similarity index of 84.09% with the Uncultured bacterium clone, and the mustard 3 isolate gene had a similarity index of 85.42% with Environmental 16s rDNA sequence
Exploring The Potential of Mango Seed as A Bioadsorbent for Pb(II) Removal in Aqueous Solution
Full text linkVarious industrial activities produce heavy metals as by-products or wastes. Lead is a metal trace element from sewage disposal, vehicle fumes, and atmospheric emissions from industrial activities. Mango seeds are composed of cellulose, lignin, and hemicellulose, which have many potential binding groups. Mango seeds, which are often considered waste, can be utilized as a low-cost biosorbent due to their various functional groups, such as hydroxyl, carboxyl, carbonyl, alcohol, amide, and aromatic groups. Mango seed are organic waste with potential as low-cost biosorbent for heavy metals removal. The purposes of the study are: (1) to explore the optimum condition of biosorbent in absorbing heavy metal species (Pb (II)), and (2) to analyze the adsorption model of synthetic waste containing Pb(II). Mango seeds have a considerable potential to be used as a biosorbent to absorb heavy metal ions. The optimum conditions for Pb2+ ion adsorption is at pH 6 with contact time 70 minutes, and concentration of biosorbent 2.0 g/L. Adsorbate adsorption follows the Freundlich model, and adsorption occurs only in a few surface layers. The kinetic parameters of adsorbent satisfied pseudo-second-order reaction. The optimum adsorption capacity (qm) of mango seed biosorbent in absorbing Pb ions is 43.86 mg/g
Synthesis and Cytotoxic Evaluation of 3-Dimethyl Carbamoyl Emodin
Full text linkEmodin (6-methyl-1,3,8-trihydroxyanthraquinone) is a natural anthraquinone derivative with potential pharmacological such as cytotoxic effects. The structure modification could be performed to determine the functional groups that have the role of substance activities. In this study, we modified one hydroxy group in the emodin structure to become dimethyl carbamoyl moiety. Emodin was reacted with dimethyl carbamoyl chloride and potassium carbonate to create 3-dimethyl carbamoyl emodin. The structure of the product was elucidated using mass spectrophotometer (MS), Fourier transform infrared (FTIR), proton and carbon nuclear magnetic resonance (H-NMR and C-NMR). These substances were tested for cytotoxicity against HepG2 cell lines using the MTT assay. According to the evaluation, 3-dimethyl carbamoyl emodin is less cytotoxic than emodin. As a result, the hydroxy group at the C3 position of emodin has been identified as a functional component that contributes to its cytotoxic effect
Comparison of Maceration and Soxhletation Methods on the Antioxidant Activity of the Bouea macrophylla Griff Plant
Full text linkThe impact of extraction methods on the potency of plant extracts is crucial. Bouea macrophylla Griff., a tropical fruit plant rich in phenolic and flavonoid compounds, exhibits strong antioxidant activity. This study aimed to evaluate the effect of maceration and soxhletation extraction techniques on B. macrophylla plants on antioxidant activity in vitro using the method of inhibiting DPPH radical compounds. Ethyl acetate and ethanol solvents were utilized to macerate and soxhlet all parts of the plant. Subsequently, each extract was subjected to quantitative analysis for antioxidant activity, total phenolic, and flavonoid content through UV-Vis spectrophotometry. Quantitative analysis revealed substantial antioxidant activity and notable levels of total phenolic and flavonoid content across all plant parts. The result indicated that although both maceration and soxhletation showed a significant impact on yield (p=0.009) and total flavonoids (p=0.038), significant differences in antioxidant activity (p=0.409) or total phenolics (p=0.874) within the plant extracts of B. macrophylla were not observed at a significance level of 5%
Application of PAN/α-Fe2O3-Bentonite as A Photocatalytic Membrane for The Photodegradation of Methylene Blue
Full text linkThe intricate molecular structure of the dyes in wastewater makes it difficult to biodegrade, which could harm the environment. Currently, semiconductor-based photocatalytic methods are being developed to remove dyes from water. In this study, the α-Fe2O3-bentonite photocatalyst was synthesized by mechanical milling and immobilized in polyacrylonitrile (PAN) membrane by phase inversion. Analysis of the composition and surface morphology of the synthesized samples was carried out by FTIR, XRD, and EDX. The performance of the photocatalytic membrane was studied by investigating the removal of methylene blue (MB). Photocatalytic membrane with 2% α-Fe2O3-bentonite had the best performance in removing MB (10 ppm) that reached 99.84% at pH 11.5 with an irradiation time of 300 minutes under direct sunlight. The reuse cycle of the photocatalytic membrane was also carried out and the results showed that there is no significant change in the photodegradation efficiency after 3 cycles. Photocatalyst immobilization on PAN membranes is proven to overcome the post-recovery problem of photocatalysts and making easier to reuse. The photocatalyst membrane synthesized in this study can be used as an alternative for removing dyes from water
Synthesis of Carboxylated Chitosan Amide Using Some Cyclic Anhydride and Their Activities as Antifungal
Full text linkChitosan is a natural polymer that has antifungal activity. It is necessary to modify chitosan into its derivatives to increase its activity. One modification of chitosan that has the potential to be developed as an antifungal is carboxylated chitosan amide because this chitosan derivative contains a carboxylic group and is more hydrophilic. This research aims to synthesize chitosan amide carboxylate using several cyclic anhydride compounds and test its antifungal activity against Aspergillus flavus. The cyclic anhydrides used in this research are maleic anhydride and phthalic anhydride. In the initial stage of chitosan amide carboxylate synthesis, reaction optimization was carried out at varying temperatures of 25, 50, and 72oC for 7 hours. Compound characterization was carried out using FTIR and UV-Vis spectrophotometry. The disc diffusion method tested the chitosan amide carboxylate product for its antifungal activity against Aspergillus flavus. The optimal MCA (Maleoyl Chitosan Amide) product is (MCA_50), synthesized at a reaction temperature of 50oC. Under these optimal reaction conditions, PCA_50 (Pthaloyl Chitosan Amide) was successfully synthesized to produce a brownish-yellow solid with a yield of 46.1% (w/w) and a degree of substitution (DS) of 41.93%. The diameter of the inhibition zone against Aspergillus flavus for PCA_50 was 30 mm at the 12th hour of observation. The product (PCA_50) has better antifungal activity than chitosan and MCA_50
The Potential of Nanocellulose Acetate as Surfactant for Water-Vegetable Oil Systems
Full text linkIndonesia, as an agricultural country, has a variety of abundant plants. Cellulose is a component in plants that can be modified to increase its economic value. Resizing cellulose to nanocellulose and modification of nanocellulose to nanocellulose acetate can increase its potential as a surfactant. Resizing cellulose can be done using the strong acid hydrolysis method. An acetic anhydride reagent was utilized to convert the surface hydroxyl functional group into acetyl. The successful production and modification of nanocellulose were confirmed using fourier transform infrared and particle size analysis characterization. The infrared absorption spectrum of cellulose and nanocellulose showed no difference in peaks. Particle size distribution showed that nanocellulose I (CNC I) and nanocellulose II (CNC II) has sizes of 142 nm and 319 nm, respectively. The property of nanocellulose molecules in an oil-water system was simulated using molecular dynamics with GROMACS 2020.6 software. Appropriate trends can be seen in the interfacial tension of water-vegetable oil systems. The value of interfacial tension decreases with the addition of nanocellulose acetate compared to the addition of nanocellulose. With the agreement between the experimental and computational results, nanocellulose acetate can act as a surfactant