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All Journal Jurnal Pendidikan dan Pembelajaran Kimia (JPPK) Jurnal Pendidikan Kimia (JPKim) Jurnal Redoks JCRS (Journal of Community Research and Service) Journal of Educational Chemistry (JEC) Indonesian Journal of Chemical Science and Technology JURNAL KIMIA SAINTEK DAN PENDIDIKAN EINSTEIN (E-JOURNAL) JS (Jurnal Sekolah) Jurnal Sains dan Kesehatan
Muhammad Yusuf
Departement Of Chemistry Universitas Negeri Medan
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Languange, Linguistic, Communication & Media Materials Science & Nanotechnology Mechanical Engineering Medicine & Pharmacology Physics Social Sciences Other

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Mechanism Study of the Glycerol Oligomerization Reaction using Ab Initio Method Muhammad Yusuf
Jurnal Pendidikan Kimia (JPKim) Vol 9, No 1 (2017): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (727.744 KB) | DOI: 10.24114/jpkim.v9i1.6185

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Abstract: The mechanism study of the glycerol oligomerization reaction was performed to obtain the most possible diglycerol product based on its optimized energy. The mechanism study of the glycerol oligomerization reaction has been investigated regarding to SN2 type route with using HyperChem computer software, ab initio method, and 6-31G* basis set for all atom. Based on the computational calculation results, the energy level of the interaction between base catalyst (NaOH) with glycerol was similar in the α or β-anionic glycerol position (529.38kJ/mol). These results indicate the interaction of base catalyst (NaOH) with glycerol in the α or β-anionic glycerol position shows same possibility energetically favored. However, based on the computational calculation of diglycerol product, αα’-linear diglycerol more possible formed than αβ-branched diglycerol and ββ’-branched diglycerol due to its lowest energy (-0.19 kJ/mol). These results show that the fast attack of polarized glycerol to a carbon of a second glycerol will easier develop when the product is a αα'-linear diglycerol. The next step is formation of linear triglycerol from αα'-linear diglycerol which the difference of energy with glycerol is 6.83 kJ/mol. Keywords: ab initio, diglycerol, HyperChem, oligomerization
Computational calculation of acetalization of 2-chlorobenzaldehyde reaction mechanism using hydrochloric acid catalyst with ab initio method Muhammad Yusuf
Jurnal Pendidikan Kimia (JPKim) Vol 12, No 1 (2020): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (386.842 KB) | DOI: 10.24114/jpkim.v12i1.17707

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The aim of this research was to investigate the possible reaction mechanism steps in the formation of acetal from 2-chlorobenzaldehyde substrate. Asetal is a chemical compound that attracts the attention of the researchers because it has advantage in various fields of life. This study was conducted using Hyperchem software (OS Window’s) with the ab initio method using a 6-31G* basis set. In this study, the 3-21G basis set was also used as a comparison. The calculations were performed for each steps of the reaction mechanism including the substrate, the formation of hemiacetal intermediate, and the formation of acetal products. Based on the results of computational calculations, the acetalization of 2-chlorobenzaldehyde reaction can occur in the presence of an HCl catalyst. The HCl catalyst serves as an acid catalyst where hydrogen ions will be protonated by the substrate and hemiacetal. Hemiacetal compounds based on calculations have the highest formation energy compared to the benzaldehyde substrate and acetal products. This is because hemiacetal has a low stability and is easily transformed into other compounds. Keywords: Ab initio; 2-chlorobenzaldehyde; acetal
The Compatibility of Polyglycerol Acrylic as Plasticizer For Polyvinyl Chloride Matrix Muhammad Yusuf
Jurnal Pendidikan Kimia (JPKim) Vol 8, No 2 (2016): Agustus
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1000.524 KB) | DOI: 10.24114/jpkim.v8i2.4417

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Abstract- The aim of this research was to compare whether polyglycerol (PG) acrylic plasticizer is more compatible and has good thermal stability than PG acetate plasticizer or even DOP plasticizer. PG acrylic plasticizer producted from polymerization of glycerol and then esterification with acrylic acid and can used as a plasticizer for PVC. Based on tensile strength and elongation analysis can be concluded that PG acrylic-DOP plasticizer (tensile strength 37.33 MPa and elongation 277.2%) is more compatible for PVC than DOP plasticizer (tensile strength 5.4 MPa and elongation 230.33%) and PG acrylic plasticizer (tensile strength 18.67 MPa and elongation 89.7%). PG acrylic-DOP plasticizer also more compatible than PG acetate plasticizer for PVC. According to DTA analysis can be concluded that PG acrylic plasticizer has thermal stability alike with PG acrylic – DOP plasticizer in PVC matrix and better compared with DOP plasticizer. This can be proven by the increase of decomposition (exoterm) temperature PG –acrylic plasticizer in PVC (from 490 oC to 500 oC) alike with PG acrylic-DOP plasticizer (constant 490 oC) andhigher than DOP plastcizer (from 490 oC to 400 oC). According to tensile strength, elongation and DTA analysis can be concluded PG acrylic-DOP plasticizer is a better plasticizer in PVC matrix than PG acrylic, PG asetate, and DOP plasticizer.   Keyword: polyglycerol acrylic, PVC, compatibility, and DTA
An ab initio study of the reaction mechanism of 2-methylbenzaldehyde acetalization with methanol Muhammad Yusuf; Ahmad Kamil Nasution
Jurnal Pendidikan Kimia (JPKim) Vol 14, No 2 (2022): August
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (338.57 KB) | DOI: 10.24114/jpkim.v14i2.33756

Abstract

Acetalization of 2-methylbenzaldehyde is a type of reaction that occur by reacting 2-methylbenzaldehyde with methanol. Meanwhile, the catalyst used in the reaction is an acid catalyst. This research was conducted to determine the pathway of the intermediate reaction mechanism that is most likely to produce 2-methylbenzaldehyde acetal product. The software used in this research is HyperChem 8.0, 6-31G* basis sets, with the ab initio method. Before being calculated, the molecular structure is drawn with a 2-dimensional view. After that, the molecular structure is converted into a 3D view and geometry optimization is carried out. The results obtained are in the form of optimized energy from the structure of reactant 2-methylbenzaldehyde, several intermediate products, and product 2-methylbenzaldehyde acetal.Keywords:Ab initio, Acetal, 2-methylbenzaldehyde, Reaction mechanism
Development of Computer Based Test Instrument for Higher Order Thinking Skills (CBT-HOTS) on Chemical Bonding Materials Sulistiani Sulistiani; Muhammad Yusuf
Journal of Educational Chemistry (JEC) Vol 4, No 1 (2022)
Publisher : Chemistry Education Department

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21580/jec.2022.4.1.11709

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This study aimed to produce a computer-based test instrument for higher-order thinking skills (CBT-HOTS) on the chemical bonding materials and to determine the higher-order thinking skills of students in Class X MIA at MAN Binjai Academic Year 2021/2022. This research employed the ADDIE model of Research and Development (RD). The test instrument was created in the form of multiple-choice consisting of 30 questions measuring the cognitive domains of analyzing (C4), evaluating (C5), and creating (C6). Based on the findings, the developed instrument was declared feasible for use, considering that it had met the required content validity by expert assessments using the Aiken’s V index in the range of 0.97 to 1.00 and the reliability value of 0.93. The students' higher-order thinking skills on chemical bonding materials were included in the "high" category. It was shown from the percentages of answers to the HOTS questions in each involved domain; analyzing (C4) by 28%, evaluating (C5) by 44%, and creating (C6) by 28%. Additionally, the average score was 74.64, indicating that students' higher-order thinking skills were high.
STUDI PERHITUNGAN CELAH ENERGI SENYAWA KOMPLEKS BIS(BENZOILTRIFLUOROASETON)ZIRKONIUM DENGAN MENGGUNAKAN METODE SEMI-EMPIRIS PM3 Muhammad Yusuf; Putri Octaviani; Muhammad Baghery Rafsanzani
EINSTEIN (e-Journal) Vol 11, No 1 (2023): EINSTEIN (e-Journal)
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (343.138 KB) | DOI: 10.24114/einstein.v11i1.43302

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Salah satu pengaruh dari berkembangnya teknologi dan ilmu pengetahuan adalah munculnya bidang kimia baru yaitu kimia komputasi. Kimia komputasi adalah penggabungan antara unsur eksperimental dengan teori dalam suatu sistem kimia menggunakan perangkat komputer. Pada penelitian ini, digunakan software Hyperchem 8.0 (windows) dengan metode semi-empiris PM3 untuk menghitung celah energi senyawa kompleks bis(benzoiltrifluoroaseton)zirkonium (bis(btfa)2Zr). Selain itu, dilakukan juga analisis spektrum ultraviolet (UV) pada senyawa kompleks tersebut untuk menentukan panjang gelombang maksimumnya. Berdasarkan hasil perhitungan, diperoleh celah energi ligan btfa lebih besar dibandingkan senyawa kompleks bis(btfa)2Zr. Sebaliknya, berdasarkan analisis UV diperoleh panjang gelombang maksimum kompleks bis(btfa)2Zr lebih panjang dibandingkan ligan btfa. Hasil data ini menunjukkan bahwa celah energi senyawa kompleks bis(btfa)2Zr berbanding terbalik dengan panjang gelombang maksimumnya.
Theoretical study to determine the band gap of the bis(benzoylacetone)zirconium complex compound using the PM3 semi-empirical computational method Muhammad Yusuf
Jurnal Pendidikan Kimia (JPKIM) Vol 15, No 1 (2023): April
Publisher : Pascasarjana Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1591.027 KB) | DOI: 10.24114/jpkim.v15i1.41764

Abstract

TThe bis(benzoylacetone)zirconium (bis(bzac)2Zr) complex compound has been used as a catalyst in various chemical reactions. The aim of this study was to compare the band gap and maximum wavelength of the bis(bzac)2Zr complex with its ligands. The software used is HyperChem 8.0. Calculations begin by optimizing complex compounds. After that, the HOMO-LUMO energy is calculated so that the band gap is obtained. Meanwhile, the calculation of the maximum wavelength is carried out based on UV calculations by using the singly excited method. The addition of Zr atoms to the ligand is expected to reduce the band gap of the complex. On the other hand, the maximum wavelength of the resulting complex is expected to be higher than that of the ligand. Based on the calculation results, the band gap of the complex compounds is 6.128 eV, while the maximum wavelength produced is 383.54 nm. The band gap of the ligand is larger than that of the complex, which is 9.031 eV, while the maximum wavelength of the ligand is 261.25 nm.Keywords: Bis(benzoylacetone)zirconium; Band gap; Complex; Wavelength
PENGEMBANGAN INSTRUMEN TES BERBASIS HOTS (HIGHER ORDER THINKING SKILLS) PADA MATERI LAJU REAKSI KIMIA Nony MillaNium Napitupulu; Muhammad Yusuf
JS (JURNAL SEKOLAH) Vol 6, No 3 (2022): JUNI 2022
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (251.911 KB) | DOI: 10.24114/js.v6i3.36179

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Abstract : The Development of HOTS-Based Test Instrument On Reaction Rate Material. This study aims to produce a HOTS-based test instrument on the material reaction rate as well as to determine the higher order thinking ability of students in class XI IPA SMA Negeri 1 Dolok Batu Nanggar T.A 2021/2022. The research population is all Unimed chemistry lecturers, all chemistry teachers at SMA Negeri 1 Dolok Batu Nanggar, and all students of class XII IPA 1 and XI IPA 2. The sample used in the The research consisted of 4 Unimed chemistry lecturers, 1 chemistry teacher at SMA Negeri 1 Dolok Batu Nanggar and XII IPA 1 and XI IPA 2 selected by purposive technique sampling. This research uses the Research and Development model Development (R&D) type ADDIE. Based on the results of the research, the test instruments used developed in the form of a multiple choice test with 30 questions with each question measuring the cognitive domains of analyzing (C4), evaluating (C5) and creating (C6) declared that the HOTS-based test instrument  developed was declared feasible used with criteria that have met the content validity requirements obtained from expert assessment with the V Aiken index in the range 0.81 to 1.00 with the category very high and meet the reliability requirements with a reliability of 0.75 which is entered into the high category.  Students' higher order thinking skills on the subject matter reactions in class XI IPA are in the high category. It is shown from percentage of answers from HOTS  questions that include indicators analyzing (C4) is 26.66%, evaluating (C5) is 50% and creating (C6) that is equal to 23.23%. Overall students' higher order thinking skills has an average value of 68.68. So it can be concluded that the ability high-level thinking students are classified as high. Keywords: Higher Order Thinking Skills, HOTS-based Test Instruments, Reaction rate Abstrak : Pengembangan Instrumen Tes Berbasis HOTS (Higher Order Thinking Skills) Pada Materi Laju Reaksi. Penelitian ini bertujuan untuk menghasilkan instrumen tes berbasis HOTS pada materi laju reaksi serta untuk mengetahui kemampuan berpikir tingkat tinggi siswa di kelas XI IPA SMA Negeri 1 Dolok Batu Nanggar T.A 2021/2022. Populasi penelitian adalah seluruh dosen kimia Unimed, seluruh guru kimia SMA Negeri 1 Dolok Batu Nanggar, dan seluruh siswa kelas XII IPA 1 dan XI IPA 2. Sampel yang digunakan dalam penelitian adalah 4 orang dosen kimia Unimed, 1 orang guru Kimia SMA Negeri 1 Dolok Batu Nanggar dan XII IPA 1 dan XI IPA 2  yang dipilih dengan teknik purposive sampling. Penelitian ini menggunakan model pengembangan Research and Development (R&D) tipe ADDIE. Berdasarkan hasil penelitian instrumen tes yang dikembangkan berupa tes pilihan berganda dengan 30 soal dengan masing-masing soal mengukur ranah kognitif menganalisis (C4), mengevaluasi (C5) dan mencipta (C6) dinyatakan instrumen tes berbasis HOTS yang dikembangkan dinyatakan layak digunakan dengan kriteria telah memenuhi syarat validitas isi yang didapatkan dari penilaian ahli dengan indeks V Aiken pada rentang 0,81 sampai 1,00 dengan kategori sangat tinggi dan memenuhi syarat reliabilitas dengan reliabilitas 0,75 yang masuk kedalam kategori tinggi. Kemampuan berpikir tingkat tinggi siswa pada materi laju reaksi di kelas XI IPA termasuk pada kategori tinggi. Hal ini ditunjukkan dari persentase jawaban dari soal-soal HOTS yang mencakup pada indikator menganalisis (C4) sebesar 26,66%, mengevaluasi (C5) yaitu 50% dan mencipta (C6) yaitu sebesar 23,23%. Secara keseluruhan kemampuan berpikir tingkat tinggi siswa memiliki nilai rata-rata sebesar 68,68. Sehingga dapat disimpulkan kemampuan berpikir tingkat tinggi siswa tergolong tinggi.Kata Kunci: Higher Order Thinking Skills, Instrumen Tes berbasis HOTS, Laju reaksi
PERBAIKAN MUTU AROMA DAN CITA RASA KOPI DENGAN MENGGUNAKAN PROSES FERMENTASI PADA USAHA PUCAKO ROASTERY DI KELURAHAN AMPLAS, KECAMATAN MEDAN AMPLAS, KOTA MEDAN Yusuf, Muhammad; Siregar, Rudi Munzirwan; Daulay, Rabiah Afifah; Mukra, Rizal; Andayani, Widya
Journal of Community Research and Service Vol 8, No 2: JULY 2024
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/jcrs.v8i2.62221

Abstract

Program pengabdian kemitraan masyarakat (PKM) ini bertujuan untuk melakukan pendampingan kepada mitra dengan memanfaatkan buah nanas sebagai bahan fermentasi untuk memperbaiki mutu aroma dan cita rasa kopi. Hal ini dilakukan berdasarkan hasil observasi awal yang dilakukan oleh tim pengusul yaitu : 1) Proses pengeringan kopi yang tidak seragam, dan 2) Mutu aroma dan cita rasa yang masih kurang bagus. Penyebabnya karena bahan kopi robusta yang dibeli ke petani memiliki tingkat mutu yang berbeda. Dampaknya, harga kopi menjadi rendah. Mitra PKM ini adalah Usaha Pucako Roastery di Kelurahan Amplas, Kota Medan. Metode pelaksanaan PKM ini dilakukan melalui dua tahapan utama yaitu: 1) Pembuatan bubur buah nanas, dan 2) Fermentase kopi menggunakan bubur nanas. Melalui PKM ini diharapkan terjadi perbaikan mutu aroma dan cita rasa kopi serta dapat meningkatkan penjualan mitra. Adanya enzim bromelin pada bubur nanas akan dapat menurunkan kadar kafein karena enzim ini mampu memecahkan senyawa yang mirip protein pada kopi.
An Investigation of the Functional Groups and Structure Characteristics of a Polymer Blend of Polystyrene and Poly(ε-Caprolactone) Produced by Using Bis(Dibenzoylmethanato)Zirconium(IV) Chloride Catalyst Munzirwan, Rudi; Muhammad Yusuf, Muhammad Yusuf; Utama, Erwinsyah
Indonesian Journal of Chemical Science and Technology (IJCST) Vol 7, No 2 (2024): JULY 2024
Publisher : Universitas Negeri Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24114/ijcst.v7i2.62252

Abstract

Although polystyrene (PS) finds widespread use in household applications, its non-biodegradable nature raises concerns about its environmental impact. Therefore, modifying PS by blending it with a biodegradable polymer such as poly(ɛ-caprolactone) (PCL) is essential. This study focuses on investigating the functional groups and structural characteristics of PS/PCL blends. In this study, we produce polyblend using the solvent casting method. On the other hand, the PCL employed in this study was synthesized using the bis(dibenzoylmethanato)zirconium(IV)chloride (bis(dibzm)2Zr) catalyst. Next, the FTIR analysis indicates a Van Der Wall’s interaction between PS and PCL. Therefore, we did not find any absorption of new functional groups outside of the PS and PCL functional groups. Next, the XRD analysis revealed that polyblend has a more crystalline structure than PS. Meanwhile, PCL has a more crystalline structure than PS/PCL polyblend and pure PS.
Co-Authors Afrilita Harahap Ahmad Kamil Nasution Daulay, Rabiah Afifah Dedek Febbriani Dika Fahreza Ega Amalia Yuniar Harahap, Armita Sari Innayah Wulandari Lulu Arika Reka Mawaddatur Rahmah Muhammad Baghery Rafsanzani Muhammad Noufal Munzirwan, Rudi Nony MillaNium Napitupulu Putri Octaviani Rafsanzani, Muhammad Baghery Ramanda Fatwa Rizal Mukra Rudi Munzirwan Siregar, Rudi Munzirwan Salaisa Sasi Kirana Sulistiani Sulistiani Tembusai, Tariza Humaira Utama, Erwinsyah WIDYA ANDAYANI wulandari, innayah Zata Zahirah