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All Journal Alchemy : Journal of Chemistry The Journal of Pure and Applied Chemistry Research International Journal of Mechanical Engineering Technologies and Applications (MECHTA)
Rachmawati Ningsih
Jurusan Kimia Fakultas Sains dan Teknologi Universitas Islam Negeri (UIN) Maulana Malik Ibrahim Malang
Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Medicine & Pharmacology

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Potensi Ekstrak Kasar Teh Hitam (Camellia sinensis O.K. var. Assamica) sebagai Pewarna (Dye) pada Pembuatan Sela Surya Tersensitisasi (SSPT) Deskawi, Oki; Ningsih, Rachmawati; Avisena, Novi; Hastuti, Erna
ALCHEMY ALCHEMY (Vol.4, No.1
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (463.25 KB) | DOI: 10.18860/al.v4i1.3148

Abstract

Has done research on the manufacture of dye sensitized solar cells by utilizing the crude extract of black tea (Camellia sinensis var O.K. Assamica). This study aims to determine the potential of black tea extract as a dye in dye sensitized solar cell manufacturing. This study includes several stages: sample preparation of black tea, black tea sample extraction in a mixture of acetic acid: methanol: distilled water (4:25:21), analysis of the crude extract of black tea using UV-Vis, color density analysis using a color reader, testing DSSC obtained by measuring voltages and currents strong produced under conditions halogen lamp illuminated with a light intensity of 4.488 Watt/m2, the identification number of the crude extract of pigments by TLC analytical. The results of the characterization black tea extract is flavonoids. That it contains theaflavins shown with a maximum wavelength 273 nm. Color of black tea using a color reader testing showed reddish yellow (orange) with the color density reached 78,3%. Voltage maximum and maximum current strength produced by 107,3 mV and 2.13 x 10 -3 mA. The efficiency of the resulting solar cell system by 1,26 x 10 -2%. The results of the identification of the amount of pigment produced 8 spot with eluent ethyl acetate: formic acid: distilled water. Keywords: Dye sensitized solar cells, dye (dye), theaflavin
Syntheses, Characterization, Antioxidant Activity, and Toxicity Evaluation of Schiff Base Derivates from O-Vanillin Hanapi, Ahmad; Ningsih, Rachmawati; Nafiah, Sri Ani; Nadhiroh, Ainun; Oktavianti, Fatin
The Journal of Pure and Applied Chemistry Research Vol. 13 No. 1 (2024): Edition January-April 2024
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/ub.jpacr.2024.013.01.3321

Abstract

Three Schiff bases (1a, 1b, and 1c) have been prepared from the reaction of o-vanillin with primary amine (aniline, p-toluidine, and p-anisidine). Schiff base derivates from o-vanillin were synthesized using the grinding method for 20 minutes. Physical properties were observed based on color, melting point, and solubility. Synthesis products were also characterized using FTIR, GCMS, 1H-NMR, and 13C-NMR. The antioxidant activity of the Schiff base was tested using DPPH. While the toxicity test uses the BSLT method. The result of this synthesis and characterization Schiff base (1a, 1b, and 1c) showed that the Schiff base compound was formed into 2-methoxy-6 (phenyliminomethyl) phenol; 2-methoxy-6- (((4-methylphenyl) imino) methyl) phenol; and 2-methoxy-6-(((4-methoxyphenyl) imino) methyl) phenol. The result of NMR analysis, on 1H-NMR spectrum showed the shift chemical at 8,5-8,6 ppm which indicates the typical peak of proton (-HC=N-). Meanwhile, the 13C-NMR spectrum shown the shift chemical at 160-162 ppm which indicates the typical peak of carbon (-C=N-). The result of antioxidant activity showed that all Schiff base was antioxidant quite low ability with value of EC50 is 106.2-196.4 ppm. Meanwhile, the result of toxicity test showed that all Schiff base was anticancer with an LC50 value of 9.99-22.29 ppm.
Synthesis of Hematite Pigment (A-Fe2O3) from Iron Lathe Waste using Precipitation-Sonication Method as Anti-Swelling on Wood Rahmawati, Dewi Elok; Khoiroh, Lilik Miftahul; Ningsih, Rachmawati; Yusniyanti, Febi; Solawati, Wariatus; Sari, Puspa
International Journal of Mechanical Engineering Technologies and Applications Vol. 1 No. 2 (2020)
Publisher : Mechanical Engineering Department, Engineering Faculty, Brawijaya University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21776/MECHTA.2020.001.02.5

Abstract

Iron lathe waste powder has the potential as a raw material in the synthesis of hematite pigments. Hematite pigments have many advantages, one of which is anti-swelling properties that can maintain the dimensions of wood. Hematite pigment synthesis was carried out using the precipitation-sonication method. The precipitation stage uses an ammonium hydroxide solution as a precipitating agent. Stages of sonication using the PEG-6000 template were performed at different times were 30, 45, and 90 minutes then calcined at 750 ° C for 3 hours. The samples were characterized by X-ray diffraction (XRD), color reader, and scanning electron microscope-energy dispersive X-Ray (SEM-EDX). The result confirmed that a ferrihydrite phase obtained after the precipitation process and transform into hematite after the calcination process with the highest degree of crystallinity for 90-minute sonication. From a color reader, the brightness and redness degrees decrease with increasing time. Scanning electron microscope results illustrated that the morphology was not uniform with the particle size getting smaller with increasing sonication time. The EDX results show that hematite pigments still contain impurities such as carbon. The swelling test indicated that the highest stability in hematite-pigmented wood increased as increasing in the weight of pigment.
Co-Authors A. Ghanaim Fasya Ahmad Abtokhi Ahmad Hanapi Ahmad Nasichuddin, Ahmad Alfiyaturrohmah Alfiyaturrohmah, Alfiyaturrohmah Avin Ainur Fitrianingsih Dinasti, Anike Riska Elok Kamilah Hayati Eriyanto Yusnawan Erna Hastuti Handoko, Singgih Haris Nursyah Arifin, Haris Nursyah Latifah Latifah Lilik Miftahul Khoiroh Luky Adrianto Millati, Nuria Nadhiroh, Ainun Nafiah, Sri Ani Noer Mardlatillah Sharo, Noer Mardlatillah Novi Avisena Nur Jazilah, Nur Nurul Inayah Oki Deskawi, Oki Oktavianti, Fatin Puspa Sari, Puspa Rahmawati, Dewi Elok Rahmawati, Laili Maghfiroh Safitri, Dany Aulia Shofiyah, Muharromatus Sholeh Afif, Sholeh Solawati, Wariatus Tri Kustono Adi Yusniyanti, Febi