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X-RAY DIFFRACTION PHASE ANALYSES OF MULLITE DERIVED FROM RICE HUSK SILICA Simon Sembiring; Wasinton Simanjuntak
Makara Journal of Science Vol 16, No 2 (2012): Agustus
Publisher : Directorate of Research and Community Engagement, Universitas Indonesia

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Abstract

In this study, mullite synthesized from aluminum nitrate hydrate [(Al(NO3)3.9H2O] and silica sol from rice husk was subjected to sintering treatment at temperatures of 900, 1000, 1100, 1200 and 1300 °C, and characterized using x-ray diffraction (XRD), followed by Rietveld refinement, and differential thermal analysis (DTA). The results indicate that in the sample sintered at 900 °C, no mullite phase was identified, but crystoballite and alumina were well detected. The formation of mullite started at temperature of 1000 °C and continued to grow at higher temperatures, resulted in increased weight percentage (wt%) from 62.62 to 92.29%, while crystoballite and alumina decreased from 22.42 to 1.25% and from 77.58 to 6.46 % respectively. A good correlation was found between the calculated and observed unit cells. For mullite phase, the unit cell dimensions are a = 7.545 nm, b = 7.689 nm and c = 2.884 nm, for crystoballite a = b = 0.5531 nm and c = 0.6923 nm, and for alumina a= b = 0.5026 nm, and c = 1.2808 nm. The DTA analyses revealed that in the untreated sample, only alumina and silica were detected, while in the sintered samples, the existence of mullite, alumina, and crystoballite are evident. Keywords: mullite, rice husk, Rietveld, structure, sintering
THE USE OF THE RIETVELD METHOD TO STUDY THE PHASE COMPOSITION OF CORDIERITE (Mg2Al4Si5O18) CERAMICS PREPARED FROM RICE HUSK SILICA Wasinton Simanjuntak; Simon Sembiring
Makara Journal of Science Vol 15, No 1 (2011): April
Publisher : Directorate of Research and Community Engagement, Universitas Indonesia

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Abstract

This research presents the use of the Rietveld method to study the phase composition of cordierite (MG2AL4SI5O18) ceramics prepared from rice husk silica, after the samples were sintered at 1300, 1400 and 1500 °C. The formation of cordierite is temperature-dependent as indicated by the relative phase composition obtained from x-ray diffraction patterns for the cordierite and spinel increased markedly with increasing temperature, i.e, from 38.98 to 54.15 wt% and from 11.81 to 17.99 wt % following the increase in temperature from 1300-1500 °C, respectively. The above values were obtained with the aid of the Rietveld method, carried out until the goodness of fit values (GoF) reached below 2, which is considered a satisfactory value to reveal the real phase composition. Different plots produced by refinement using the Rietveld method also reveal a reasonable fit between the observed and the calculated plot, demonstrating the usefulness of the method for calculating the quantity of phase composition in the sintering process.Keywords: cordierite ceramics, rice husk, Rietveld phase analysis, sintering
The Use of Carbon Dioxide Released from Coconut Shell Combustion to Produce Na2CO3 Wasinton Simanjuntak; Simon Sembiring; Wan Abbas Zakaria; Kamisah D Pandiangan
Makara Journal of Science Vol 18, No 3 (2014): September
Publisher : Directorate of Research and Community Engagement, Universitas Indonesia

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Abstract

In this investigation, sodium carbonate (Na2CO3) was produced by reacting the CO2 released from coconut shell combustion with NaOH solution with molar concentrations of 6.5, 7.0, 7.5, and 8.0 M. The main purpose of the study was to assess the potential of the proposed method for mitigation of the CO2 gas released into the atmosphere by the coconut shell industry. The Na2CO3 powder produced was oven-dried at 110 oC and subsequently characterized using FTIR, XRD, and SEM/EDS techniques. Thermal analysis was also carried out using DTA/TGA to investigate the thermal mechanisms of sodium carbonate formation. The experimental results show that the concentration of NaOH influences the mass of sodium carbonate produced, with the highest mass of 190.6 g obtained using 7.0 M NaOH solution. The FTIR analyses show the existence of O-H, C-O, C=O, and CO3-2, confirming the formation of Na2CO3. The C-S functional group was also detected most likely due to the presence of the sulfur that naturally exists in the coconut shell. The formation of Na2CO3 is also supported by the presence of C, Na, and O on the EDS results and the presence of the thermonatrite (Na2CO3.H2O) phase, as seen by the XRD. The XRD analysis of the sintered sample at 450 oC indicates the transformation of thermonatrite into sodium carbonate and sodium oxide, which is in accordance with the results of DTA/TGA analysis. Based on the results obtained, it is concluded that the proposed method can be applied to mitigation of CO2 gas released by the coconut shell industry.
Pembuatan Membran Polimer Elektrolit Berbasis Polistiren Akrilonitril (SAN) untuk Aplikasi Direct Methanol Fuel Cell Suka, Irwan Ginting; Simanjuntak, Wasinton; Dewi, Eniya Listiani
Jurnal Natur Indonesia Vol 13, No 1 (2010)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (309.762 KB) | DOI: 10.31258/jnat.13.1.1-6

Abstract

In this study, electrolyte membranes based on polystyrene acrylonitrile (SAN) for Direct Methanol Fuel Cell applicationwere prepared. The preparation was carried out in two steps. The first step was introduction of additives, silicaand zeolite, as reinforcing agent on SAN, to obtain silica-reinforced SAN membrane, specified as SAN-Si, andzeolite-reinforced SAN membranae, specified as SAN-Z. The two reinforced membranes were then subjected tosulphonation using sulphuric acid, and the sulphonated membranes are specified as S-SAN-Si and S-SAN-Z,respectively. The characteristics of the membrane were described in terms of the degree of sulphonation, ionicconductivity, methanol permeability, and percentage of swelling in water and methanol. The results obtaineddemonstrated that additives result in significant reduction of methanol crossover, as reflected by lower values ofmethanol permeability than that obtained for the membrane without additive. It was also found that zeolite functionsrelatively better than silica. For zeolite-modified membrane (S-SAN-Z) the ionic conductivity of 10.05 x 10 -6 S/cmwas achieved. The membrane also marked by methanol permeability of 0.52 x 10 -6, percentage of swelling of 5.12%in water and 2.58% in methanol. Thermal analysis using DSC technique revealed changes in glass transition fromthe original sample, in which the glass transition of the original sample, SAN, (55 0C), sulphonated SAN, S-SAN,(83.360C), silica-modified membrane S-SAN-Si (79.860C), and zeolite-modified membrane S-SAN-Z (79.290C). Additionof additive was also found to influence the surface characteristics of the membranes as revealed by SEM analysis,in which the surface changed from smooth for the original sample into rough for the reinforced samples with bothadditives.
Pengaruh Penambahan Alumina (Al2O3) 0, 10, dan 15 wt% terhadap Karakteristik Konduktivitas Listrik dan Mikrostruktur Cordierite (2MgO.2Al2O3.5SiO2) Berbasis Silika Sekam Padi Oktivianty, Shella Windi; Sembiring, Simon; Simanjuntak, Wasinton; Karo-Karo, Pulung
Jurnal Teori dan Aplikasi Fisika Vol 4, No 2 (2016): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v4i2.1339

Abstract

Penelitian ini dilakukan untuk mengetahui pengaruh penambahan alumina terhadap karakteristik fisis, mikrostruktur, dan konduktivitas listrik cordierite. Silika diperoleh dari sekam padi melalui metode sol-gel sedangkan alumina dan magnesium berasal dari MERCK. Cordierite disintesis melalui metode padatan dengan suhu sintering 1200oC. Hasil Pengukuran menunjukkan bahwa penambahan alumina mengurangi densitas, menambah porositas, dan menurunkan nilai konduktivitas listrik sampel. Karakterisasi dengan Scanning Electron Microscopy (SEM) menunjukkan adanya bentuk yang tidak beraturan, pori yang semakin banyak dan aglomerasi yang semakin besar pada sampel dengan penambahan alumina.
Peningkatan Karakteristik Listrik Sel Elektrokimia Cu(Ag)-Zn dengan Penggunaan AnodaTumbal Mgpada Accumulator Berbahan Air Laut Ahmad Pauzi, Gurum; Nisa, Mia Abi; Samosir, Ahmad Saudi; Sulistiyanti, Sri Ratna; Simanjuntak, Wasinton
Jurnal Teori dan Aplikasi Fisika Vol 8, No 1 (2020): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v8i1.2448

Abstract

Penelitian ini dilakukan untuk mempelajari penggunaan magnesium (Mg) sebagai anoda tumbal untuk melindungi Zn yang digunakan sebagai anoda dalam sel elektrokimia untuk menghasilkan energi listrik dari air laut. Sebagai katoda digunakan Cu yang dilapisi dengan logam Ag untuk melindunginya dari korosi katodik. Sel elektrikimia dirangkai terdiri dari 20 sel yang disusun secara seri, dan masing-masing sel diisi air sebanyak 300 mL. Sel elektrokimia dihubungkan dengan beban LED 3 watt 12 volt selama 72 jam dan pengambilan data karakteristik listrik meliputi tegangan, arus, dan intensitas cahaya, setiap 1 jam. Dari data tegangan dan arus, dihitung besarnya hambatan dalam. Hasil penelitian menunjukkan bahwa penggunaan Mg sebagai anoda tumbal menghasilkan data karaktersitik listrik yang lebih besar dibanding dengan sel elektrokimia tanpa penggunaan anoda tumbal.
Pembuatan Serbuk Pewarna Alami Dari Berbagai Tanaman Tropis Dengan Metode Oven Drying Rinawati Rinawati; Zipora Sembiring; Wasinton Simanjuntak; Emantis Rosa
Jurnal Pengabdian Kepada Masyarakat (JPKM) TABIKPUN Vol. 2 No. 2 (2021)
Publisher : Faculty of Mathematics and Natural Sciences - Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jpkmt.v2i2.20

Abstract

Pewarna alami yang bersifat tidak beracun, aman bagi kesehatan dan ramah lingkungan sangat berpotensi untuk menggantikan pewarna sintetik. Selama ini pewarna sintetik banyak digunakan untuk membuat makanan menjadi lebih menarik namun memiliki dampak negatif pada kesehatan. Kegiatan pengabdian ini bertujuan untuk meningkatkan pengetahuan dan kesadaran masyarakat terhadap pewarna alami dan bagaimana pembuatannya. Format kegiatan adalah penyuluhan, diskusi dan pelatihan pembuatan bahan pewarna alami. Hasil pre-test dan post-test menunjukkan peningkatkan pengetahuan dan pemahaman sebesar 34% terhadap bahaya penggunaan bahan aditif sintetis dan keunggulan bahan aditif alami pada makanan dan minuman. Masyarakat juga telah memiliki keterampilan untuk membuat bahan pewarna alami dengan metode oven drying dari berbagai tanaman tropis sehingga dapat digunakan sebagai pengganti pewarna sintetik yang selama ini digunakan.
Diseminasi Teknologi Pengolahan Cangkang Biji Karet Menjadi Arang Aktif Berpotensi Industri Kamisah Delilawati Pandiangan; Wasinton Simanjuntak; Mita Rilyanti; Ilim Ilim
Jurnal Pengabdian Kepada Masyarakat (JPKM) TABIKPUN Vol. 2 No. 2 (2021)
Publisher : Faculty of Mathematics and Natural Sciences - Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jpkmt.v2i2.43

Abstract

Latar belakang kegiatan PKM ini adalah belum tergalinya potensi tanaman karet di lingkungan petani, khususnya pemanfaatan cangkang biji karet sebagai bahan baku pembuatan arang aktif berpotensi industri. Pembuatan arang aktif dengan teknologi pirolisis dan karakterisasi arang meliputi kadar abu, kadar air, dan daya serap terhadap metilen biru dilakukan di Jurusan Kimia Universitas Lampung.  Semua kegiatan didokumentasikan dalam bentuk video tutorial dan didiseminasikan kepada aparat dan petani karet di Desa Bumiayu, Provinsi Lampung. Tim pelaksana menjelaskan tentang  program PKM,  tujuan, luaran dan target  kegiatan yakni meningkatkan pengetahuan  masyarakat  mitra  untuk mengolah cangkang biji karet menjadi arang aktif. Video tutorial  digunakan sebagai panduan bagi petani yang tertarik untuk mengolah cangkang biji karet menjadi arang aktif dengan pendampingan dan pembinaan secara langsung oleh tim pelaksana.
Implementasi Green Chemistry Menggunakan Teknologi Pirolisis Untuk Pengolahan Limbah Plastik Di Kelurahan Way Urang Kalianda Zipora Sembiring; Nurhasanah Nurhasanah; Rinawati Rinawati; Wasinton Simanjuntak
Jurnal Pengabdian Kepada Masyarakat (JPKM) TABIKPUN Vol. 3 No. 1 (2022)
Publisher : Faculty of Mathematics and Natural Sciences - Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jpkmt.v3i1.67

Abstract

Kelurahan Way Urang merupakan salah satu destinasi wisata pantai yang berpotensi menyumbang limbah plastik berlimpah. Salah satu metode pengolahan limbah plastik yang menerapkan prinsip Green Chemistry serta sederhana adalah metode pirolisis. Metode pirolisis dapat mengubah limbah atau sampah plastik menjadi bahan bakar yang dapat digunakan dalam keperluan sehari-hari. Pada kegiatan ini dilakukan pre-test dan post-test yang didasari pada pemaparan dan edukasi tentang prinsip-prinsip Green Chemistry, metode pirolisis serta jenis dan sifat bahan plastik yang dilanjutkan dengan demonstrasi pengolahan limbah plastik dengan metode pirolisis. Hasil evaluasi kegiatan menunjukkan peningkatan pengetahuan dan wawasan masyarakat terkait jenis plastik dan pengolahannya sebesar 51% sesudah penyampaian materi oleh narasumber. Melalui kegiatan pengabdian ini juga diharapkan Pemda dan masyarakat setempat saling sinergi menanggulangi limbah yang ada di daerah wisata agar dapat menunjang perekonomian daerah.