JKPK (Jurnal Kimia dan Pendidikan Kimia)
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Synthesis and Photoluminescence Properties of Alkylbromoporphyrin
Get PDFThe usage of porphyrin as a light-harvesting chromophore is considered as one of the keys to obtaining low-cost and high-efficiency dye-sensitized solar cell (DSSC). In this paper, a novel porphyrin, 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin, having a long alkyl chain and three nitro groups was synthesized. The nitro groups serve as anchoring groups to TiO2 surfaces and long alkyl chain prevents unwanted dye aggregation. The porphyrin was synthesized by condensation of p-(12-Bromododecoxy)benzaldehyde and pyrrole in propionic acid according to an adaptation of the general Rothemund method [1]. p-(12-Bromododecoxy)benzaldehyde was synthesized by nucleophilic substitution reaction between 4-hydroxybenzaldehyde and 1,12-dibromododecane in acetone. The reaction products were analyzed by 1H-NMR and mass spectroscopy. The absorption and fluorescence spectra of the porphyrin were also recorded. As results, the absorption spectrum of the porphyrin consists of a strong Soret and four weak Q-band. Compared to 5,10,15-tris(nitrophenyl)-20-(p-(11-bromo)dodecoxyphenyl))porphyrin spectrum, there is no wavelength shifting because of the incorporation of the alkyl chain. The fluorescence spectrum of the porphyrin shows two characteristic emission bands and the intensity ratio of those emission bands is always constant when irradiated by different excitation wavelength related to Soret and Q-band
Fabrication and Characterization of Passive Sampler using Polymeric Inclusion Membrane (PIM) as Diffusion Layer for Phosphate Measurement
Get PDFThe PIM-passive sampler is a passive sampler using PIM as a diffusion layer. This research aimed to optimize the concentration of PIM plasticizer and the concentration of phosphate ions in bulk solution to produce a PIM-passive sampler for phosphate measurement with high accuracy. In this study, a passive sampler was made of a 15 ml glass bottle containing 0.2 M H2SO4 solution as the receiving phase and PIM as a diffusion membrane. PIM was prepared by mixing polyvinyl chloride (PVC) as the base membrane, Aliquat 336-Cl as a carrier, and 1-decanol as a plasticizer. Sampling was done by immersing the passive sampler in the bulk phase solution for three hours. The phosphate concentrations in bulk and receiving phases were determined regularly every 30 minutes using the visible spectrophotometric method at a wavelength of 690 nm. The results showed that the optimum concentration of 1-decanol for PIM was 15% w/w. The higher the plasticiser concentration, the PIM was oily, thus preventing the analyte from contacting the extractant. The range of phosphate ion concentrations in the sample that the PIM-passive sampler could detect was 0.1-1.3 mg P/L. The calibration curve for phosphate measurement was CTWA = 1.0664. Cs – 0.0088 with a correlation coefficient (R2) was 0.9998. This shows that the PIM-passive sampler can be used for the measurement of phosphate ions with high accuracy. Â
Virtual Practicum Guideline Development Based on 5E Learning Cycle
Get PDFThe research purpose was to develop chemistry practicum guidelines based on the 5 E (Engagement, Exploration, Explanation, Elaboration, Evaluation) learning cycle and determine the student's responses. This development research adapted from Borg and Gall model. Data were obtained from interviews, validation questionnaires from content and media experts, readability questionnaires, and student's responses after used the product. Results validation of the chemistry practicum guidelines shows that the content expert validation scores 4.42 while media expert validation scores 4.65 with a range> 4.2, classified as very good. The average readability test showed a score of 4.28. A product trial to determine the student's response toward developed guidelines had an average of 4.28, which was included in an exciting classification. There was an increase in student learning outcomes with average pretest scores of 50, average posttest scores of 85, and the N-gain value data obtained was 0,7 in the high category. Thus, the study concluded that the chemistry learning guidelines with salt hydrolysis topic based on the 5E learning cycle using the virtual program developed in this study were feasible to be applied in the learning process
Study of Virtual Molecular Docking of Avocados Compounds against Pseudomonas aeruginosa (5N5H) by Carbapenemase using DOCK 6 Algorithm
Get PDFAntimicrobial resistance from bacteria is a global health problem that can cause death, and the cause is the emergence of carbapenem resistance Pseudomonas aeruginosa through VIM (Verona integron-encode metallo-β-lactamase), which causes the carbapenem class of antibiotics not to work properly. This species is a gram-negative bacteria which is the main cause of nosocomial pneumonia infection. This study aims to determine in silico inhibitory activity of 50 compounds obtained from avocado (Persea Americana Mill) on VIM, preventing carbapenem antibiotic resistance. The molecular docking process was carried out to test carbapenem's antibiotic resistance control activity by 50 compounds. Docking using DOCK 6 software with a flexible and rigid method, Molecular docking on a protein with PDB ID 5N5H, The target protein was prepared using the Chimera application. Visualization of ligand-protein interactions was carried out with PyMOL and PLIP. The results of the native ligand grid score obtained by each method are -63.013 kcal/mol (Flexible) and -64.032 kcal/mol (Rigid). The best test ligands in the flexible method are 44257090, 14282775 and 44257819, and the grid score are -77.474, -75.274 and -73.219 kcal/mol. The best test ligands in the rigid method are 5280637, 14282775 and 5490064; the grid score is -62.191, -61.714, and -60.453 kcal/mol. The results of the test ligands can provide a better grid score than native ligands, namely in the flexible method. However, the rigid method of grid score results is no better than the native ligand. A good result is that the test ligand grid score is smaller than native ligands, so it has less energy to bind to the active site
Remazol Briliant Blue Uptake by Green and Low-Price Black Carbon from Ilalang Weeds (Imperata cylindrica) Activated by KOH Solution
Get PDFSynthesis of activated carbon (AC) from green, low-price, and renewable source as a pollutant adsorbent is growing interest of researcher. This work aims to synthesis of AC from Ilalang weed (Imperata cylindrica) (IW-AC) with KOH activator as a green and low price Remazol Brilliant Blue dye (RBB) adsorbent. The success IW-AC synthesis was evidently characterized by Fourier Transform-Infrared (FT-IR) and Scanning Electron Microscopy (SEM). The effects of initial solution pH, adsorbent dosage, initial RBB concentration, and contact time were systematically investigated. Results showed the optimum condition of RBB adsorption was occurred at low pH (2.0-4.0) and 75 mg of adsorbent dosage. Under the optimum condition, the equilibrium adsorption data fitted well to the Langmuir isotherm with the adsorption capacity of RBB uptake was 13.42 mg/g. Calculation of adsorption energy by Dubinin-Radushkevich (D-R) isotherm model (13.39 kJ/mol) showed that the electrostatic interaction was the main interaction of RBB adsorption on IW-AC. Adsorption kinetics showed that the adsorption behavior followed the Ho pseudo-second-order kinetic model. The experimental results of this work demonstrate that the IW-AC can be used as a promising green and low-cost adsorbent for removal of anionic dyes from aqueous solution
XRF and XRD Investigation for the Results of the Extraction of Mud Volcano from Napan Village into Silica
Get PDFSilica powder was obtained from the mud volcano of Napan Village following the co-precipitation method. This research aimed to determine the phase changes that occur in calcined silica with various temperatures. This research was carried out in three stages, there are the preparation of a mud volcano using the pre-treatment method, extraction of silica with sodium hydroxy solution, and calcination of silica with temperature variations. By analysis of XRF and XRD results, the mud volcano samples showed a high percentage of SiO2 minerals. The results of silica characterization using XRD showed that uncalcined and calcined silica at 600oC had an amorphous structure with broading peaks. Tridymite and cristobalite phases were detected in calcined silica at 800oC and 1000oC. Calcined silica at a temperature of 1000oC transformed the tridymite phase to cristobalite with a decrease in the intensity of the tridymite phase while the cristobalite phase increased
ZnO Nanoparticles and Its Interaction With Chitosan : Profile Spectra and Their Activity Against Bacterial
Get PDFThe biosynthesis of ZnO nanoparticles and synthesis of chitosan- ZnO nanoparticles were studied. The aims of this research were biosynthesis of ZnO nanoparticles, synthesis of chitosan-ZnO nanoparticles, its characterization and, used as an antibacterial agent of Escherichia coli. ZnO nanoparticles were biosynthesized by reacting with ethanolic extract of guava seeds leaves (Psidium guajava L.) and zinc acetate dihydrate solution. Chitosan-ZnO nanoparticles were synthesized by the heating method. ZnO nanoparticles and chitosan-ZnO nanoparticles were characterized by FTIR spectroscopy and X-ray diffraction, respectively. The suspension of chitosan-ZnO nanoparticles was used as an antibacterial agent with a paper disk method. The result showed that the Zn-O group at ZnO nanoparticles was detected at a wavenumber 615.29 and 673.16 cm-1 The crystallite size of ZnO nanoparticles was 1.43 nm. The wavenumber of 617-655 cm-1 is the Zn-O group at the structure of the chitosan-ZnO nanoparticle. The average of diameter inhibition zone of chitosan-ZnO nanoparticles (1:2) at concentration 0.25 and 0.5 % (w/v) to Escherichia coli was 15.7 ± 1.0 and 18.3 ± 0.4 mm respectively.Â
Biosorption of Fe (II) Ions from Aqueous Solution using Kepok Banana Peel (Musa acuminate)
Get PDFThe present study used adsorbents from Kepok banana peel to remove Fe (II) from an aqueous solution. The effect of adsorbent dose and initial metal concentration was investigated at room temperature to evaluate the maximum adsorption and adsorption capacity of Kepok banana peels. The adsorption parameters studied were adsorbent mass [0.5-2.5 g], and initial Fe (II) concentration [30-70 mg/L], where the operating conditions were 50 ml of Fe metal solution was added to each adsorbent, the pH value of the mixture was adjusted to 6. Then the mixture was stirred at 250 rpm for 30 minutes. In the adsorption process, it was found that 2.5 grams of mass adsorbent and 60 mg/L as initial metal concentration gave the highest adsorption and adsorption capacity, with 57.99% and 0.644 mg/g, respectively. FTIR spectra of adsorbent showed hydroxyl, carboxylic, and amine groups in Kepok banana peels. This study showed that Kepok banana peels had good potential for removing Fe (II) ions and could be used as a good adsorbent for removing the Fe (II) from water and wastewater at very little concentration
Preparation and Characterization of Adsorbent from Natural Zeolite Mixed Chicken Feather in Degradation of Batik Waste Dyes Based Green Chemistry
Get PDFThis research is the adsorption of dyestuffs from batik industry waste. The adsorption method was used chicken feather adsorbent with natural zeolite. Zeolite was activated by HF. Feather flour was activated with 0.2 M KOH. The main focus of this research is determine the potential for dye degradation with the batch method.Samples were analyzed by Atomic Absorption Spectroscopy (AAS), Fourier Transform Infra Red Spectrophotometer (FTIR), and Surface Area Analyzer (SAA). Measurement of dye degradation includes the effect of adsorbent concentration, pH, contact time and particle size of adsorbent. The results showed that the optimum pH in the degradation of dyestuffs from the batik industry waste was pH 8.5. The optimum contact times by activated and unactivated adsorbents were 65 minutes and 120 minutes, respectively. The reaction kinetics analysis showed the Freundlich adsorption model based on the  experimental data. This indicates that the surface pores of the adsorbent are very influential in the degradation of the dye. Adsorption capacity of degradation dyestuffs with adsorbents has an efficiency of 94%. In the laboratory, it  has been proven that adsorbents are able to degrade dyes in batik waste before being discharged into the water disposal system
Biofilm Chitosan as Modern Dressing for Ulcers
Get PDFModern dressing techniques as open wound dressings are still effective and suitable for use, especially for people with open wounds such as ulcers, but they still have disadvantages, such as the high prices and need for other antibiotics to prevent inflammation. Previous studies reported an increase in the number of antibiotic resistance, which sparked the idea of producing new dressing materials that have strong antimicrobial and biocompatible properties. The material suitable for the idea of a wound dressing is chitosan biofilm because it has strong antibacterial properties and has a similar structure to the skin tissue. This study aims to produce chitosan biofilm using the deacetylation method using a strong base. The physicochemical characterization results of biofilms showed a deacetylation degree of 87.13 with a voltage of 1.15 ± 0.00 and a polycationic group of biofilms that appeared at a wavenumber of 2.1714 ± 0.0000 nm. From the measurement of the antibacterial power of chitosan biofilm against skin surface bacteria, the inhibition zone diameter was 18.93 ± 0.12; 19.50 ± 0.17; 20.20 ± 0.23; 20.13 ± 0.03 and 22.53 ± 0.09 against S. aureus, S. epidermidis, P. aeruginosa, E. colli, Bacillus sp. Overall, it can be concluded that biofilm chitosan has the opportunity to be applied as a dressing in wound care