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All Journal EKSAKTA: Journal of Sciences and Data Analysis JURNAL ILMU PERTANIAN Elkawnie Chimica et Natura Acta Abdimas Talenta : Jurnal Pengabdian Kepada Masyarakat Jurnal Pendidikan Kimia (JPKim) JURNAL KIMIA SAINTEK DAN PENDIDIKAN JOURNAL OF CHEMICAL NATURAL RESOURCES (JCNaR) Jurnal Natural Jurnal Akademika Kimia
Marpongahtun
Department Of Chemistry, Faculty Of Mathematics And Natural Sciences, Universitas Sumatera Utara, Medan
Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Education Energy Engineering Environmental Science Immunology & microbiology Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Neuroscience Physics Social Sciences

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Synthesis and characterization nitrogen-doped carbon dots from candlenut shells using hydrothermal and solvothermal methods Riska Riska; Marpongahtun Marpongahtun; Saharman Gea
Jurnal Pendidikan Kimia Vol. 16 No. 1 (2024): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jpkim.v16i1.56957

Abstract

Candlenut shells can be utilized as precursors for Carbon Dots (CDs) since new nanoscale materials have been proven using lignin, cellulose, hemicellulose, and carbon present in candlenut shells. A carbon substance smaller than 10 nm in size, CDs have special optical properties. This research focuses on the synthesis of CDs and Nitrogen Carbon Dot (NCDs) from hazelnut shell using urea passivation agent by hydrothermal and solvothermal methods, to determine the effect of solvent on the emission produced by CDs and NCDs. Hazelnut shell was carbonized at 300°C for 6 hours. The synthesis of CDs and NCDs was carried out at 220°C for 8 hours, then sonicated at 75°C for 30 minutes. The synthesis results were centrifuged at 5000 rpm for 30 minutes, filtered using Whatman No.42 filter paper. Analysis with a 365 nm UV lamp produced bluish green luminescence, brighter luminescence was shown in NCDs by solvothermal method. UV-Vis spectra showed absorbance peaks of 289-309 nm for CDs and 335-350 nm for NCDs. FTIR spectra of CDs and NCDs produced OH, CH, C=C, C=O, C-N, CO, and C-O-C functional groups. Photoluminescence analysis showed emission peaks of CDs and NCDs at 494 nm and 496 nm for hydrothermal method, for solvothermal method at 418 nm and 432 nm. CDs and NCDs with hydrothermal method showed higher intensity than with solvothermal method. The quantum yield values obtained were 11.4226% and 25.7419% and 10.2555% and 11.7473% for hydrothermal and solvothermal methods, respectively. Solvothermal method was effective for the synthesis of CDs and NCDs with brighter luminescence.
Coconut oil effect on the hygroscopic properties of Simalambuo wood (Lophopetalum spp.) LIVER IMAN PUTRA ZAI; SAHARMAN GEA; MARPONGAHTUN MARPONGAHTUN; EDDYANTO EDDYANTO; NUR AZIZAH; APRI H SISWANTO
Jurnal Natural Volume 22 Number 2, June 2022
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jn.v22i2.24158

Abstract

Simalambuo (Lophopetalum spp) trees are endemic to Southeast Asia and widely grow in the natural forests in Nias island. Local people whose experience of utilizing the simalambuo wood have claimed that the wood easily absorbs water. Throughout our searches, not many efforts to modify the physical properties of the simalambuo woods have been carried out yet. Therefore, in this study, we modified simalambuo wood by thermal treatment in coconut oil-ambient conditions. The heat treatment became an option to support the efforts in reducing the use of non-environmental-friendly materials and methods. The simalambuo wood was treated under coconut oil at 130-210oC for 6 hours. Coconut oil uptake was up to 174%, while the leaching test (AWPA E-06 standard) showed the uneasily permeate out from the wood and high retention differently in terms of treatment and cooling temperature. Heat treatment with coconut oil affected water absorption ability and improved dimensional stability of simalambuo wood. Water absorption reduced from 162% to 16%, and dimensional stability increased from 8.4% to 4.2% at 192 hours after being soaked in water. The higher the difference between treatment and cooling temperature, the better-affected water absorption ability was and the higher dimensional ability could be achieved.
Education on community empowerment in prevention of Covid-19 to the community Laut Dendang village, Percut Sei Tuan district Deli Serdang regency Mardiningsih; Saib Suwilo; Herman Mawengkang; Sutarman; Marpongahtun
ABDIMAS TALENTA: Jurnal Pengabdian Kepada Masyarakat Vol. 5 No. 2 (2020): ABDIMAS TALENTA : Jurnal Pengabdian Kepada Masyarakat
Publisher : Talenta Publisher

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (167.727 KB) | DOI: 10.32734/abdimastalenta.v5i2.5069

Abstract

Community Service Activities carried out by the Service Team are intended to achieve the output target of reducing the spread of covid-19 in the people of Laut Dendang Village. The community service team conducts outreach regarding improving the quality of health and education in this village, in this case the Village Head, Hamlet Head, and PKK women become participants in this outreach, so that further all participants can socialize the issue of the importance of preventing Covid-19 and how to do it. prevention. It is hoped that the improvement of the quality of health in this village can be a lesson for the village community to understand and implement all knowledge or rules in reducing or stopping the spread of this deadly virus. This service is aimed at Community Service for the 2020 USU Lecturer Service Scheme is to solve problems together with the community through observation, problem identification, problem formulation, preparation of alternative solutions and evaluation of their implementation.
Impact of the Concentration Ethylenediamine on Optical Properties of Carbon Dots from Jengkol Peel (Archinendron pauciflorum) Aniza S. Prayugo; Marpongahtun Marpongahtun; Saharman Gea
Jurnal Akademika Kimia Vol. 12 No. 1 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i1.pp20-25

Abstract

Carbon dots (CDs) are a new member of fluorescent nano carbons that have attracted attention because of their potential applications derived from their optical, chemical, and electrical properties. CDs from jengkol peel via the solvothermal method at 200 oC for 7 h with the addition of ethylenediamine (EDA) as a heteroatom dopant have been successfully carried out. This study aims to determine the effect of concentration EDA on the optical properties of CDs for the possible reason. The results revealed that the CDs solution has fluorescence properties; that bluish-green glow can be observed under ultraviolet radiation (365 nm). The UV - Vis absorption peaks did not depend on the CDs concentration, but the absorbance intensity decreased with increasing EDA concentration. The best fluorescence properties were possessed by 10 % EDA in CDs which produced λex/λem of 370 nm/518 nm, respectively, with a quantum yield of 42 %. The FTIR spectra of all samples showed that the CDs surface had functional groups such as carboxylic acids, hydroxyl, and amines. The obtained CDs have the potential to be used as heavy metal ion detectors, bioimaging, and antibacterial agents.
Degradation of Natural Rubber as Asphalt Mixes Modifier using UV-Ozone Light Irene I. C. Ritonga; Tamrin Tamrin; Marpongahtun Marpongahtun
Jurnal Akademika Kimia Vol. 12 No. 2 (2023)
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/j24775185.2023.v12.i2.pp78-85

Abstract

The elastic properties of natural rubber are indispensable in improving the physical properties of asphalt mixtures. However, the long natural rubber molecule chains make it difficult to modify with other polymeric materials, so it needs to be degraded. In this study, the authors succeeded in degrading natural rubber using a combination of UV light and ozone with the addition of an H2O2 initiator; from the FTIR data, it appears that there are peaks indicating vibrations of the C=O and –OH groups indicating that natural rubber chain termination has occurred. The addition of natural rubber to asphalt was carried out with several variations, namely 8; 10; 12; 14; 16 % (to asphalt content), from the results of the softening point and ductility test of the asphalt mixture explained that the addition of 12 % natural rubber was the most optimum mixture. This result explains that efforts to degrade natural rubber using the UV - ozone combination method can increase the optimum insertion of natural rubber into asphalt mixtures by up to 100 % from previous studies.
Co-Authors Adiansyah , Agung Pratama Amru Daulay Amru Daulay Andriayani Aniza S. Prayugo Aniza Salviana Prayugo APRI H SISWANTO APRI H SISWANTO APRI H SISWANTO Ayu Syufiatun Cut Fatimah Zuhra Cut Fatimah Zuhra Darwin Yunus EDDYANTO EDDYANTO Ginting, Mimping Herman Mawengkang Irene I. C. Ritonga Khairul Amri LIVER IMAN PUTRA ZAI Mardiningsih Mimping Ginting NUR AZIZAH Riska Riska Rufina Pramudita Saharman Gea SAHARMAN GEA Saharman Gea SAHARMAN GEA Saharman Gea Saib Suwilo Sembiring, Helmina Br. Sutarman Sutarman Syufiatun, Ayu Tamrin Tamrin