JKPK (Jurnal Kimia dan Pendidikan Kimia)
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Characterization of Biocomposites from Polylactic Acid and Cellulose of Oil Palm Empty Fruit Bunch
Get PDFBiocomposites are polymers reinforced with natural fibers, such as cellulose. This research aims to synthesize cellulose from Oil Palm Empty Fruit Bunch (OPEFB) and biocomposites from PLA and cellulose. In this study, cellulose was obtained through alkalization, hydrolysis, and bleaching of OPEFB. Biocomposites production was carried out by mixing PLA and cellulose using the extrusion method. In the extrusion method, PLA and cellulose of OPEFB were mixed using an extruder above the melting point of PLA of 170°C. The output product of an extruder was then pressed using a compression moulding machine to form biocomposites. The tensile strength of biocomposites had a smaller value than pure PLA, whereas the modulus young of biocomposites with 5% by weight of cellulose had a higher value than pure PLA. The decrease in the mechanical properties of biocomposites was caused by poor adhesion between PLA and cellulose. The water absorption of biocomposites was greater than pure PLA, which was influenced by cellulose's characteristics as hydrophilic and PLA is hydrophobic. Also, the higher water absorption in biocomposites accelerated the weight loss of biodegradability
Sonochemical Synthesis of Ethyl Cinnamate
Get PDFThis research aimed to determine the yield of ethyl cinnamate synthesized by the sonochemical method and its potency as a sunscreen agent. Ethyl cinnamate was synthesized from cinnamic acid and ethanol with concentrated sulfuric acid as catalysts assisted by ultrasonic waves. The Identification of compounds was carried out by infrared spectrophotometry and gas chromatography-mass spectroscopy. Synthesis of ethyl cinnamate resulted in the form of clear yellow liquid with a fragrant aroma of a cinnamon ester with a 96.61% yield. Identification by an infrared spectrophotometer showed many functional groups of ethyl cinnamate. Â Identification by GC-MS was given a relative abundance of 98.96%. The product of synthesis had SPF number 4.769 at 10 ppm used Mansur Equation. Based on this research, it concluded that it has potential as a sunscreen agent. The sonochemical method provides an excellent yield of ethyl cinnamate
Synthesis of Cinnamic Acid Based on Perkin Reaction Using Sonochemical Method and Its Potential as Photoprotective Agent
Get PDFCinnamic acid plays a vital role in the synthesis of other important compounds and as a precursor for the synthesis of commercial cinnamon esters used in perfumery, cosmetics, and pharmaceutical industries. The aim of this research is to synthesize cinnamic acid using sonochemical methods. Cinnamic acid was synthesized using Perkin reaction by reacting 0.05 mole of benzaldehyde with 0.073 mole of acetic acid anhydride and 0.03 mole of sodium acetate as a catalyst in the Erlenmeyer flask and then the mixture was put in a sonicator for 60 minutes at 70 oC. The synthesized compound was tested organoleptic properties, and the melting point was measured. The chemical structure was elucidated using FT-IR, H-NMR, and 13C-NMR. The photoprotective activity was examined from its antioxidant and SPF values. The synthesized compound was found in the form of a shiny white fine crystal which had distinctive odor with a yield of 4.98% and the melting point was found at 133 oC. In the structure elucidation using FT-IR (the aromatic ring absorption at the wave number 1580 cm-1 -1600 cm-1. The wave number 1625 cm-1is an aromatic conjugated alkene group, while wave number 1689.4 cm-1 is a carbonyl group. The wave number 2500 cm-1 – 3250 cm-1 is an OH carboxylic acid group) , H-NMR (7.410 (m, 5H, Ar-H); 7.425(t, 1H); 7.572 (d, 1H); 8.057 (d, 1H,C=CH) and 13C-NMR (129.309 ppm; 130.998 ppm; 134.58 ppm; 170.017 ppm) showed that when compared with the standard compound as the reference, the synthesized compound was confirmed to be cinnamic acid. The antioxidant activity test showed that at the concentration of 20 ppm the synthesized compound was able to reduce free radicals by 46.69%. This finding showed that the synthesized compound had antioxidant activity
Synthesis of Nano Silver using Bioreductor of Tristaniopsis merguensis Leaf Extracts and Its Antibacterial Activity Test
Get PDFSynthesis nanosilver from pelawan leaf extract (Tristaniopsis merguensis) has been carried out. The variables of this study were variations in the concentration of AgNO3 1 mM, 1.5 mM and 2 mM. Pelawan leaf extract acted as a bioreductor that converts Ag+ to Ag0. The synthesis was carried out in a ratio of 1: 4 (opposition leaf extract: AgNO3 solution) at 70 °C for 1.5 hours. The results of the UV-Vis analysis showed the maximum at the 1 mM; 1.5 mM; 2 mM AgNO3 concentration were 391 nm, 392 nm and 400 nm, respectively. XRD analysis explained that the resulting nanosilver was crystalline and according the Scherrer equation an average particle size was of 22.8 nm. The antibacterial activity test of nanosilver was carried out by disc method, nanosilver showed the existence of strong antibacterial activity against E. coli and S. aureus bacteria.
Synthesis and Characterization of Material LiNi0.8Co0.15Al0.05O2 Using One-Step Co-Precipitation Method for Li-Ion Batteries
Get PDFLi-ion battery is an energy storage device which could be applied as power source for electronic devices. The capacity of a battery is determined by the cathode material. Over this last decade, high nickel content cathode material is applied for electric vehicular technology. This study aims to synthesize a nickel-rich cathode material, LiNi0.8Co0.15Al0.05O2 (NCA) via one-step co-precipitation and study its characteristics. The Ni, Co and Al metal ion conversion during co-precipitation were analyzed using Atomic Adsorption Spectroscopy (AAS). Based on X-Ray diffraction analysis, NCA sample exhibited hexagonal-layered structure with high crystallinity. Based on Scherrer equation, the mean crystallite diameter of NCA sample is 40 nm. Scanning electron microscope (SEM) showed micron-sized homogenous particles with smooth surface. The final composition of Ni, Co and Al metal were confirmed using XRF. The capacity of the battery was determined using galvanostic test method with voltage range of 2.7-4.25 V using graphite as the counter anode. The initial specific discharge capacity of NCA is 60 mAh/g while the capacity loss per cycle is 1%
Socratic Questioning Method in The Colloid System Topics Using The Participatory Action Research (PAR)
Get PDFThe purpose of this research is to identify how lesson plans prepared based on socratic questions can improve critical thinking skills. Research method used is Participatory Action Research (PAR), data collection techniques through interviews and questionnaires. It is expected that the results of the research can be applied in schools specifically to produce lesson plans in colloidal learning integrated with TPACK (Technological Pedagogical Content Knowledge). The results showed the teacher gave a positive assessment of 85% on the socratic questions contained in the lesson plan. This will provide stimulants to students in order to able to argue and practice their critical thinking skills. Postgraduate student participants also gave a positive response of 87.5%. It can be concluded that both teacher participants and postgraduate students agree with the application of socrates questions to students because they have a positive impact on critical thinking skills. Thus, this initial stage of research can proceed to the next stage of PAR research
The Determination of Metals and Minerals Contains in The Water of Pucung River, Prehistoric Site Sangiran, Central of Java
Get PDFSangiran was an important prehistoric site heritage for Indonesia. Entire site area was living environment once pass by several rivers, one of them was Pucung river. This study was approaching study from water environment by measuring metals and minerals contained in the water from Pucung river and measured that Iron (Fe) containend was 0,01mg/L; Zink (Zn) 0,02mg/L; Nickel (Ni) 0,00mg/L; Mangan (Mn) 0,00mg/L; Chrom (VI) (Cr6+) 0,009mg/L; Aluminium (III) (Al3+) 0,00mg/L and Copper (Cu) 0,01mg/L. From the minerals containing measured that Phosphate (PO4) 0,37mg/L; Nitrate (NO3-) 0,8mg/L; Nitrite (NO2-) 0,001mg/L; Chloride (Cl-) 0,01mg/L; Fluoride (F-) 0,00mg/L; Sulphide (S2-) 0,0µg/L; Sulphate (SO42-) 6,00mg/L; and N as N-NH3 (Ammonia) 0,05mg/L. This studi continuing the study before wich are just limiting to studying the river stratigraphy.
Cinnamon Oil as an Antibacterial Agent on Natural Paper from Banana Peel (Musa paradisiaca Linn.)
Get PDFThe research about the use of cinnamon oil as an antibacterial agent on natural paper from Banana (musa paradisiaca Linn.) Peel has been conducted. The preparation of the paper using alkalization method, with the use of NaOH 4% at the temperature of 100oC for 1.5 hours. The paper is made in two variations, ie with additive cinnamon oil and without additive. The natural paper produced are tested for pH based on SNI ISO 6588-1.2010 and water content by dry-oven method based on SNI ISO 287:2010. The antibacterial activities were tested against Staphylococcus aureus and Escherichia coli using Kirby-Bauer disc diffusion method. The paper produced meet the standard of ISO 6519:2016 about Basic Paper for Laminated Plastic Wrapping Paper within the parameter of pH and water content. The results showed that the paper with additive cinnamon oil have antibacterial activity againts S. aureus and E. coli with inhibition diameter zone 15 mm and 13 mm respectively, whereas paper without cinnamon oil additives has no antibacterial activity against either S. aureus or E. coli. Â These result indicate that cinnamon oil can be used as an antibacterial agent on the natural paper from Banana peel (musa paradisiaca Linn.)
