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Acid Isolation Techniques for Silica isolation from Rice Husk and Determination of Its Physicochemical Properties Siti Mutrofin; Leo Krisna; Diah Mardiana; Rachmat Triandi T
The Journal of Pure and Applied Chemistry Research Vol 11, No 1 (2022): Edition January-April 2022
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2022.011.01.641

Abstract

Previous research showed that rice husk has a high silica content so it becomes an alternative for processing rice waste. The acid leaching method is a technique to isolate silica by adding an acid solution. The research aim is to obtain the optimum silica yield and determine the chemical ash content of rice husks (rice IR-64,). Rice husks were first calcined at two various temperatures and times. The average yields obtained were 19.54% (500oC / 1 hr), 18.42% (500oC / 2 hrs), 25.03% (700oC /1 hr), and 22.4% (700oC/2 hrs). The physical appearance of ash was grains and white (700 oC/1hr), that were rinsed with 1 M HCl solution to remove impurities. Added 1 M NaOH was to form sodium silicate. The last step was to isolate silica using different concentrations of HCl and HNO3 (3 M, 2 M, and 1 M). The highest result was 99.87% of silica under HNO3 1 M solution. An infrared study supports that the isolated product was silica, with the presence of prominent peaks at 1102 cm-1 (stretching Si-O) and 471 cm-1 (bending Si-O). A unique peak at 958 cm-1 for Si-O-Ca present at the isolated silica using HCl 3 M, gives information on inosilicate type structure. X-ray diffraction analysis with QualX application showed that silica had cristobalite and wollastonite peaks, and the value of crystallinity index was about 63.91%.
Pelatihan Pewarnaan Tahu Malang Dengan Pewarna Alam Menggunakan Metode Door-to-Door dan Whatsapp Tutik Setianingsih; Danar Purwonugroho; Sri Wardhani; Siti Mutrofin; Yoandra Nadya Yoniansyah; Afif Eka Rahma Setiyanto
CARADDE: Jurnal Pengabdian Kepada Masyarakat Vol. 4 No. 1 (2021): Agustus
Publisher : Ilin Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31960/caradde.v4i1.870

Abstract

Pelatihan pewarnaan tahu Malang dengan pewarna alam kemangi dan rossela telah dilakukan. Kegiatan ini merupakan program Pengabdian Kepada masyarakat DPP SPP 2020. Kegiatan ini penting dilakukan karena kuliner tahu cukup populer di kota Malang, serta untuk peningkatan nilai gizi tahu dan penambahan zat aktif antioksidan dari pewarna alam agar lebih menyehatkan. Mengingat masa pandemi COVID 19, maka metode pelatihan yang dipilih adalah dor to door (penyelenggara mendatangi peserta) dan sharing video di grup WA. Penyiapan tahu warna dilakukan dengan menggunakan prinsip adsorpsi zat warna ekstrak kemangi dan bunga rosella oleh tahu yang dididihkan secara bersama. Pelatihan door to door dilakukan oleh mahasiswa dan dosen ketua pelaksana, sharing video penyuluhan yang dilakukan oleh semua dosen yang terlibat dalam kegiatan, dan video praktek pewarnaan tahu oleh mahasiswa. Hasil evaluasi menunjukkan bahwa kemangi mendapat penilaian lebih baik (67% menyatakan lebih enak dan 75% lebih menarik) oleh peserta dibanding rosella (62% menyatakan rasa tahu lebih masam). Sebanyak 71% peserta menyatakan metode door to door sangat baik, 94% menyatakan topik pewarnaan tahu menarik, serta 35% peserta memiliki rencana untuk melakukan pewarnaan tahu.
Anion Effect and Ligand Preference in the Precipitation of Ni(II) Complex from Methanolic Solution: Case of Tartrate vs Pyrazine Yenni Finisia; Siti Mutrofin; Yuniar Ponco Prananto
The Journal of Pure and Applied Chemistry Research Vol 11, No 2 (2022): Edition May-August 2022
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2022.011.02.670

Abstract

This research aims to incorporate pyrazine in the synthesis of Ni(II)-tartrate-pyrazine metal-organic frameworks or Ni(II)-T-P MOF as candidates of porous material. Synthesis of the targeted MOF was conducted at room temperature in a methanolic solution by mixing Ni(II) solution, L-tartaric acid (T), and pyrazine (P) solutions sequentially in various molar ratios (Ni(II):T:P = 1:1:0; 1:0:2; 1:2:2; and 1:2:4) using two different Ni(II) salts (chloride and nitrate). Solid products were characterized by infrared spectroscopy, qualitative anion identification test, melting point test, and scanning electron microscopy. The result shows that type of nickel salt affects the precipitation of Ni(II) complex, in which pale blue solids were precipitated out only from the chloride reactions (1:0:2, 1:2:2, and 1:2:4). IR and SEM analyses from the 1:2:2 and 1:2:4 reactions show the identical result as also shown by the 1:0:2 reaction, whereas qualitative anion identification test result suggests that the chloride is uncoordinated to the Ni(II). The targeted Ni(II)-T-P is unsuccessfully obtained, instead, the product is proposed to be [Ni(pyrazine)x(H2O)(6-x)]Cl2. although the tartaric acid was doubled and firstly reacted with the Ni(II), the pyrazine still has a higher preference to coordinate to the Ni(II) center than the tartrate ligand.