Jurnal Pendidikan Kimia
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Effect Concentrations of Polyethylene Glycol in Stability Structure of Blending Polymer Cholesteryl acrylate-ITO
Get PDFPolymer ChoAcry/ITO was added glycol is one of the material polymer liquid crystal modifications. In general polymer liquid crystal cholesteryl acrylate was made for many application usage in optoelectronics materials. This research want to study effect Polyethylene Glycol (PEG) in polymer choAcry/ITO for stability structure of blending choAcry/ITO. PEG 0.006 was added to mixed cholesteryl acrylate with ITO. Polymerizations that doing using UV curing photopolymerizations. Characterizations group functions using Fourier Transformed Infra Red (FTIR) and Nuclear Magnetic Resonance (NMR). Effect concentrations of PEG in PolyChoAcry-ITO shown from FTIR spectrum, shown not different. Peak in spectrum showed are C=C and C-H aliphatic, C=C aromatic, C-O ester, and para-benzene. Based on data FTIR that PE-b-PEG not change structures. Therefore, diffractogram of XRD, showed added ITO and PEG can be affect phisycal and chemistry properties of polymer cholestryl acrylate. This data showed PEG changed structures of polymer. Polyethilene glycol spreading into polymer cholesteryl acrylate. In the literatures told that PEG can be conjunctionc between that monomer or polymer cholesteryl acrylate-ITO
APLIKASI LIGNOSELULOSA SULFONAT AMPAS TEBU UNTUK ADSORPSI ZAT WARNA TEKSTIL KATIONIK BASIC VIOLET 10
Get PDFTelah dilakukan penelitian aplikasi lignoselulosa sulfonat ampas tebu untuk adsorpsi zat warna tekstil kationik basic violet 10. Lignoselulosa sulfonat disintesis dari limbah ampas tebu melalui proses ekstraksi dan sulfonasi menggunakan larutan induk yang terbuat dari 168 g Na2SO3 dan 1 g NaHCO3. Penelitian ini menggunakan metode eksperimen di laboratorium. Prosedur kerja yang dilakukan adalah dengan membuat adsorben alami, bebas ekstrak, dan lignoselulosa sulfonat kemudian mengidentifikasi gugus fungsi dengan metode spektrofotometri menggunakan spektrometer infra merah. Uji adsorpsi dilakukan pada berbagai variasi waktu interaksi 5, 10, 20, 40, 80, dan 160 menit pada pH 6,0. Untuk analisa kuantitatif dilakukan dengan metode spektrofotometri menggunakan spektrofotometer UV-Vis pada panjang gelombang 542,75 nm.Kandungan komponen ekstraktif total (total extractive content) dari ampas tebu yang diteliti adalah 15,2 %. Adsorben lignoselulosa sulfonat memiliki daya adsorpsi paling tinggi terhadap zat warna tekstil kationik basic violet 10 yaitu sebesar 87,42 %, sedangkan adsorben alami 66,3% dan adsorben bebas ekstrak 82,64%. Waktu optimum adsorpsi oleh adsorben alami adalah 40 menit, sedangkan untuk adsorben bebas ekstrak dan lignoselulosa sulfonat adalah 80 menit
Synthesis and Characterization of Fe3O4 Composites Embeded on Coconut Shell Activated Carbon
No full textSynthesis and characterization of Fe3O4-coconut shell activated carbon composites has been carried out to create a magnetic adsorbents. Composites were synthesized using the coprecipitation reflux method by mixing a solution of Fe3+/Fe2+ iron salt (mol ratio 2:1) and suspension of activated carbon in water followed by the addition of NaOH solution. The structure, functional groups, morphology and surface area of the composites were characterized using FTIR, XRD, SEM and GSA. The magnetic properties of composites are tested by response to magnetic fields. The characterization results showed that the embedment of Fe3O4 on coconut shell activated carbon was successfully carried out through the interaction of hydroxyl groups at wave numbers 601.79 and 416.62 cm-1. Diffraction peaks at 2θ 30.12° [220], 35.58° [311], 43.14° [400], 53.57° [422], 57.18° [511] and 62.83° [440] indicate the existence magnetite sized of 11.72 nm. Activated carbon has an average pore size of micropores with an average pore of 1.46 nm. Magnetite embedment reduced the surface area of activated carbon from 91.16 m2/g to 12.04 m2/g. The response of sample to the magnetic field indicates that composite has magnetic properties
Module Development with Problem Based Learning (PBL) Model Based on Environmental Wetland to Increase Students’ Learning Outcomes
Get PDFResearch has been carried out on the development of modules with the Problem Based Learning (PBL) model based on wetland environments on the topic of acid-base solutions. This study aims to determine: the validity, practicality and effectiveness of module development. This study used a research & development design of a 4-D development model that was modified into 3-D, the data collection techniques used a test of student learning outcomes and a questionnaire. The research was conducted at SMAN 3 Banjarmasin with a sample of 10 students of class of XI PMIA 3 for small-scale trials, 24 students of XI PMIA 3 for limited-scale trials, and class of XI PMIA 1 and XI PMIA 2 with total 74 students for testing in a wide scale. Validity can be seen based on the results of the validation, the practicality of the students’ responses, and the effectiveness of the students' learning outcomes. The results showed that the module was considered valid with an average score of 146.4 and a percentage of 91.58% (very valid), practical with a percentage of 82.90% (good), effective with an average N-gain score of 0.84 (high), the average score of N-gain is 0.87 (high) for class of XI PMIA 1 and 0.86 (high) for class of XI PMIA 2. The results of this study indicate that the module with the Problem Based Learning (PBL) model based on the wetland environment on the topic of acid-base solutions is declared valid, practical and effective for use as a learning resource for students.
The Science Learning Material Using PjBL Model Integrated with Science, Technology, Engineering, and Mathematics (STEM) Approaches to Enhance Students' Communication Skills
Get PDFThis study aims to develop a science learning material using PjBL model integrated STEM approaches to enhance students' communication skills. The method used is the 4D Research and Development (R&D) model and an experimental method for testing the effectiveness of the device. The study population was all VII class in one of the junior high schools in the South Tangerang region with samples taken using a random sampling technique of 76 people. The instrument used was a device feasibility test sheet and an observation skill communication sheet. The data obtained were then analyzed quantitatively and qualitatively. The results showed the components of the learning device in the form of syllabus, lesson plans, teaching materials and student worksheets, were very feasible to use with an average of 3.62. In addition, each item validity assessment instrument is also declared valid for use. The observed communication skills also increased from 1.59 to 3.15 with a gain value of 0.64 (medium category) for the experimental class. Meanwhile, the gain value for the control class is 0.005 (very low category). The difference in the gain value indicates that the learning device is effective in improving students' communication skills
Potential of Water Extract of The White Frangipani (Plumeria acuminate) and Hibiscus (Hibiscus tiliaceus) Leaves Powder as Textile Natural Dyes
Get PDFSynthetic dyes have a high environmental impact, especially on waters. The use of natural dyes for textiles provides new hope for ecological improvement. This article is to find out the yield of water extract of white frangipani (Plumeria acuminate) and hibiscus (Hibiscus tiliaceus) leaves-powder, as well as to find out whether the water extracts have potential as textile natural dyes. Natural dyes must have a good quality of fastness. For this reason, the color fastness tests for washing with a launder meter and colorfastness against rubbing with a crock meter are performed. Colorfastness is assessed by comparing color changes to washing with grayscale and color changes due to staining on fabric with staining scale. The rubbing test is carried out on the wet and dry cloth. Cotton and polyester fabrics are samples that will be colored. Fixers used to bind dyes are Al2(SO4)3, CaCO3, and FeSO4.H2O. The results show that the water extraction of hibiscus and white frangipani leaves powder gave a yield of 11% (w/w) and 27 % (w/w), respectively. The test of colorfastness against washing showed that both water extract of the white frangipani dan hibiscus leaves has a pretty good average quality in staining scale but less in grayscale. The test against rubbing shows that the type of fixer used affects the quality of the colorfastness, but in general, the water extract of white frangipani leaves gives better quality as a potential of natural dye than hibiscus leave
Gamma Irradiation for Preservation of Suruhan Herbs (Peperomia pellucida L. Kunth.) and its Bioactivity Against L1210 Leukemia Cells
Get PDFPeperomia pellucida includes the Piperaceae family that has anti-cancer, anti-inflammatory, antioxidant, and anti-microbial activities. Microbes easily contaminate dry herbs during storage, so special handling is needed. One of the preservation techniques is using irradiation technology. This technique can be used to extend the shelf life of herbal medicinal ingredients. This research aimed to study the effects of irradiation on the anti-cancer activity of P. pellucida leaves. P. pellucida leaves' dried powder was irradiated at doses of 5, 7.5, 10, and 15 kGy. The anti-cancer activity test was carried out against L1210 leukaemia cells. The un-irradiated irradiated samples were macerated successively with n-hexane, ethyl acetate, and ethanol, then be concentrated. The ethyl acetate extract was fractionated using silica gel column chromatography, obtained seven fractions. Their IC50 values < 20 mg/mL, with fraction F4 was the most active fraction (IC50 1.9 mg/mL). The result showed that gamma radiation at doses of 5 - 15 kGy reduced their cytotoxic activity significantly. However, the fractions were still in the active category as anti-cancer (IC50 values were < 20 mg/mL)
INFLUENCE OF TIME AND CONCENTRATION ON TEXTURAL PROPERTIES OF MESOPOROUS CARBONS OF GELATIN PREPARED BY HARD-TEMPLATING PROCESS
Get PDF Mesoporous carbons with different textural properties were prepared with gelatin by hard templating process. The effect silica removal condition (time and acid concentration) on the nanocomposite properties was studied during synthesis process. 1, 6, and 24 h silica removal times and 10%, 20%, 30% and 40% HF concentraton were chosen. Textural properties and microstructure of the nanocomposites were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectroscopy (EDAX), and N2 adsorption– desorption. Results showed that removal silica time process led to mesoporous nucleation and growth on the surface of mesoporous carbon. At decreasing of removal silica time and HF concentration the surface area and total pore volume increased from 410 to 760 m2/g and 0.14–0.99 cm3/g with almost same of the average pore diameter considerably at 4.1 nm. Furthermore, it was observed more homogeneous pore distribution with decreasing the silica removal time dan HF consentration. In conclusion, the silica removal time and acid concentration play an important role on textural properties of mesoporous carbon which could have a major effect on adsorption properties of sulfuric compound in the fuel
Hydroxiapatite (HAp) Bioceramics Made from The Caletaiya presclupta Snail Shells from Poso Lake
Get PDFBioceramic Hydroxyapatite (HAp) was a derivated chemical synthetic compound from calcium phosphate commonly used to care for hard tissue damage. Bioceramic Hydroxyapatite can be synthesized from the compounds rich with calcium contains. This study treated the synthesis and physicochemical Characterization of the HAp made from Celetaiya persclupta snail shells obtained from Poso lake. From the characterization of the sample C. presclupta shells obtained the water contains 0.50±0.00%; ash contains 0.9913±0.0017g/g; potassium 0.0005±0.00007g/g; calcium 0.0391±0.0059g/g; phosphate 0.0221±0.0009g/g; phosphorus 0.0111±0.0005 and the ratio of Ca/P 1.7382±0.1994%. The synthesis of HAp by base precipitation method showed the yield of synthesis 85.2891±4.2496% with the level of material reduction during synthesis 18.0442±1.1684%. The result of characterization of the HAp showed that the potassium contains 0.0002±0.00003g/g; calcium 0.0121±0.0031g/g; phosphate 0.0167±0.0013g/g; phosphorus 0.0084±0.0007g/g; ratio of Ca/P 1.3724±0.2736%; porosity 9.9929±0.7626%; swelling ability 24.8416±1.4989%; and biodegradability 10.8958±1.1781%. The overall results concluded that the C. presclupta snail shells could become a source of Bioceramic Hydroxyapatite (HAp).
Influence Comparison of Precursors on LiFePO4/C Cathode Structure for Lithium Ion Batteries
Get PDFElectricity is the most energy demanded in this era. Energy storage devices must be able to store long-term and portable. A lithium ion battery is a type of battery that has been occupied in a secondary battery market. Lithium iron phosphate / LiFePO4 is a type of cathode material in ion lithium batteries that is very well known for its environmental friendliness and low prices. LiFePO4/C powder can be obtained from the solid state method. In this study the variables used were the types of precursors : iron sulfate (FeSO4), iron oxalate (FeC2O4) and FeSO4+charcoal. Synthesis of LiFePO4/C powder using Li:Fe:P at 1:1:1 %mol. Based on the XRD results, LiFePO4/C from FeSO4+charcoal shows the LiFePO4/C peaks according to the JCPDS Card with slight impurities when compared to other precursors. XRD results of LiFePO4/C with precursors of FeSO4 or FeC2O4 shows more impurities peaks. This LiFePO4/C cathode is paired with lithium metal anode, activated by a separator, LiPF6 as electrolyte. Then this arrangement is assembled become a coin cell battery. Based on the electrochemical results, Initial discharge capacity of LiFePO4/C from the FeSO4 precursor is 19.72 mAh/g, while LiFePO4/C with the FeC2O4 precursor can obtain initial discharge capacity of 17.99 mAh/g, and LiFePO4/C with FeSO4+charcoal exhibit initial discharge capacity of 21.36 mAh/g. This means that the presence of charcoal helps glucose and nitrogen gas as reducing agents