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PEMBUATAN DAN KARAKTERISASI NANOKOMPOSIT MFe2O4 DAN MFe2O4-SiO2 (M = Cu, Ni) -, Rahmayeni; Arief, Syukri; Stiadi, Yeni; Oktavani, Herlin
Jurnal Riset Kimia Vol 4, No 1 (2010): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i1.84

Abstract

 Nanocomposites of MFe2O4 and MFe2O4-SiO2 (M= Cu, Ni) were prepared by complexation and complexs polymerization methods using citric acid as complexing agent, tetraethylorthosilicate (TEOS), metal (Cu, Ni) nitrate and iron chloride as precursors. FT-IR spectroscopy was used to analysis the complexation and polymerization process. The decomposition of material was investigated by TG-DTA. Microstructure characterization was carried out by XRD and SEM. Peaks in XRD pattern indicate that the nanocomposites products consist of copper iron oxide (CuFe2O4) and (NiFe2O4) crystals, copper iron oxide crystal distributed in silica (CuFe2O4-SiO2) and nickel iron oxide crystal distributed in silica (NiFe2O4-SiO2). SEM images of CuFe2O4 and NiFe2O4 show that the composites have porous and spherical texture. The surface texture of CuFe2O4-SiO2 composite is triangel like and has porous but NiFe2O4-SiO2 is not regulated texture and has porous.  Keywords: MFe2O4, MFe2O4/SiO2, citric acid and complexs polymerization method   
INHIBISI KOROSI BAJA RINGAN MENGGUNAKAN BAHAN ALAMI DALAM MEDIUM ASAM KLORIDA: Review Stiadi, Yeni; Arief, Syukri; Aziz, Hermansyah; Efdi, Mai; Emriadi, E.
Jurnal Riset Kimia Vol 10, No 1 (2019): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.321

Abstract

The corrosion of steel and its alloys is an important problem in industry, especially in acidic environments. Mild steel is one of the important alloys of iron which has many industrial applications because of its excellent mechanical properties, but mild steel is susceptible to corrosion. Corrosion problems need to be a concern and must be handled properly. Hydrochloric acid is widely used for pickling, cleansing, decomposition and metal etching, on the other hand also contributes to corrosion of metal surfaces. Plant extracts investigated the properties, mechanisms of adsorption and efficiency of inhibition as environmentally friendly corrosion inhibitors for various steel materials in different acidic media. The efficiency of corrosion inhibition of steel from plant extracts analyzed ranged from 72-98% and generally as a mixed-type inhibitor. Most of the inhibitors are adsorbed on the steel surface through a physisorption mechanism.
PEMBUATAN DAN KARAKTERISASI NANOKOMPOSIT MFe2O4 DAN MFe2O4-SiO2 (M = Cu, Ni) Rahmayeni -; Syukri Arief; Yeni Stiadi; Herlin Oktavani
Jurnal Riset Kimia Vol. 4 No. 1 (2010): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i1.84

Abstract

 Nanocomposites of MFe2O4 and MFe2O4-SiO2 (M= Cu, Ni) were prepared by complexation and complexs polymerization methods using citric acid as complexing agent, tetraethylorthosilicate (TEOS), metal (Cu, Ni) nitrate and iron chloride as precursors. FT-IR spectroscopy was used to analysis the complexation and polymerization process. The decomposition of material was investigated by TG-DTA. Microstructure characterization was carried out by XRD and SEM. Peaks in XRD pattern indicate that the nanocomposites products consist of copper iron oxide (CuFe2O4) and (NiFe2O4) crystals, copper iron oxide crystal distributed in silica (CuFe2O4-SiO2) and nickel iron oxide crystal distributed in silica (NiFe2O4-SiO2). SEM images of CuFe2O4 and NiFe2O4 show that the composites have porous and spherical texture. The surface texture of CuFe2O4-SiO2 composite is triangel like and has porous but NiFe2O4-SiO2 is not regulated texture and has porous.  Keywords: MFe2O4, MFe2O4/SiO2, citric acid and complexs polymerization method   
INHIBISI KOROSI BAJA RINGAN MENGGUNAKAN BAHAN ALAMI DALAM MEDIUM ASAM KLORIDA: Review Yeni Stiadi; Syukri Arief; Hermansyah Aziz; Mai Efdi; E. Emriadi
Jurnal Riset Kimia Vol. 10 No. 1 (2019): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.321

Abstract

The corrosion of steel and its alloys is an important problem in industry, especially in acidic environments. Mild steel is one of the important alloys of iron which has many industrial applications because of its excellent mechanical properties, but mild steel is susceptible to corrosion. Corrosion problems need to be a concern and must be handled properly. Hydrochloric acid is widely used for pickling, cleansing, decomposition and metal etching, on the other hand also contributes to corrosion of metal surfaces. Plant extracts investigated the properties, mechanisms of adsorption and efficiency of inhibition as environmentally friendly corrosion inhibitors for various steel materials in different acidic media. The efficiency of corrosion inhibition of steel from plant extracts analyzed ranged from 72-98% and generally as a mixed-type inhibitor. Most of the inhibitors are adsorbed on the steel surface through a physisorption mechanism.
SYNTHESIS OF MAGNETIC NANOPARTICLES OF TiO2-NiFe2O4: CHARACTERIZATION AND PHOTOCATALYTIC ACTIVITY ON DEGRADATION OF RHODAMINE B Rahmayeni Rahmayeni; Syukri Arief; Yeni Stiadi; Rianda Rizal; Zulhadjri Zulhadjri
Indonesian Journal of Chemistry Vol 12, No 3 (2012)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (418.312 KB) | DOI: 10.22146/ijc.21335

Abstract

Magnetic nanoparticles of TiO2-(x)NiFe2O4 with x = 0.01, 0.1, and 0.3have been synthesized by mixture of titanium isopropoxide (TIP) and nitric metal as precursors. The particles were characterized by XRD, SEM-EDX, and VSM. XRD pattern show the peaks at 2q = 25.3°, 38.4° and 47.9° which are referred as anatase phase of TiO2. Meanwhile NiFe2O4 phase was observed clearly for x = 0.3. The present of NiFe2O4 can prevent the transformation of TiO2 from anatase to rutile when the calcination temperature increased. Microstructure analyses by SEM show the homogeneous form and size of particles. The magnetic properties analysis by VSM indicates that TiO2-NiFe2O4 is paramagnetic behavior. TiO2 doped NiFe2O4 has higher photocatalytic activity than TiO2 synthesized for degradation of Rhodamine B in aqueous solution under solar light irradiation.
Bimbingan dan Pelatihan Fermentasi Pakan untuk Budidaya Ikan Lele dengan Probiotik sebagai Upaya Peningkatan Hasil Produksi Masyarakat di Koto Luar, Kecamatan Pauh, Padang Syafrizayanti Syafrizayanti; Rahmayeni Rahmayeni; Mai Efdi; Yeni Stiadi; Syukri Syukri; Yulia Eka Putri; Diana Vanda Wellia; Tio Putra Wendari; Admi Admi; Emil Salim; Geliz Luh Titisari; Famella Azhara
Warta Pengabdian Andalas Vol 30 No 1 (2023)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat (LPPM) Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jwa.30.1.40-46.2023

Abstract

The use of feed in fish farming is often inefficient because fish only partially consume the feed spread in ponds, so it becomes waste for the aquatic environment and, even worse, will trigger new diseases. The Department of Chemistry's of Universitas Andalas team was trying to overcome this problem by increasing the efficiency of fish feed. For the feed to work optimally and produce good quality fish weight, it is necessary to modify the nutrition of the fish feed, one of which is by adding probiotics through a fermentation process. The method used in this activity includes training, mentoring, and demonstration plots in feed fermentation and counselling regarding the right time to feed. This activity targets fish farmers in the Koto Luar area, Pauh District, Padang, with a fish culturing group, "Family Sepakat", as the partner. Feed fermentation was carried out with probiotic starters such as Bacillus sp., saccharomyces cerevisiae, L. fermentum, L. plantarum, and W. paramesenteroides. This activity improved catfish growth, and the death rate was lower than in catfish farming without feed fermentation treatment.
Studi Komputasi Daidzein, Galangin, Genistein, Naringenin sebagai Inhibitor Korosi Besi dengan Metode DFT dan Membandingkannya dengan Luteolin Yeni Stiadi; Muhammad Ilham; Emriadi
Jurnal Kimia Unand Vol. 11 No. 1 (2022): May 2022
Publisher : Departemen Kimia Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jku.11.1.12-18.2022

Abstract

Corrosion inhibitors of daidzein, galangin, genistein, naringenin and luteolin compounds have been studied using the Density Functional Theory (DFT) method with the basis set B3LYP/6-31G using the Gaussian program. To prevent corrosion, organic inhibitors are needed which are safe for the environment. Therefore, researchers are looking for other organic inhibitors that have the potential to prevent corrosion. The calculated quantum chemical parameters are EHOMO, ELUMO, gap energy (∆E), ionization potential (I), electron affinity (A), electronegativity (X), hardness (ɳ), softness (σ), electrophilicity (ω), nucleophilicity (ε), mulliken charge density, back-donation energy (Eb-d), electron transfer (∆N), adsorption energy (Eads), and bond energy (Ebinding). Theoretical calculations show that naringenin is a good inhibitor compared to other compounds so that it can be used as an alternative organic inhibitor to replace luteolin. In this research, naringenin is a compound that has the potential as an inhibitor as seen from the structure and parameter calculations that have been carried out, so that naringenin can be used as an organic inhibitor to replace luteolin. The theoretical order of increasing inhibition is naringenin > genistein > galangin > daidzein. This theoretical study will greatly contribute to the experimental research of organic inhibitors because the theoretical increase in inhibition is already known.
Pemanfaatan Ekstrak Lignin Dari Kulit Jengkol (Pithecellobium jiringa) Sebagai Inhibitor Korosi Baja Lunak Dalam Medium HCl Emriadi Emriadi; Savira Nurul Hayuni; Yeni Stiadi
Jurnal Kimia Unand Vol. 11 No. 2 (2022): November 2022
Publisher : Departemen Kimia Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jku.11.2.14-21.2022

Abstract

Lignin extract from jengkol peel (Pithecellobium jiringa) as a mild steel corrosion inhibitor in 1 M HCl solution was studied using weight loss method, characterization Fourier Transform Infra Red (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, and optical microscopy. The inhibition efficiency increased with increasing temperature and the concentration of lignin extract in 1 M HCl solution. The highest efficiency value was 90,1% with the addition of 10 g/L extracts at 60°C. The adsorption of lignin extract from jengkol peel followed the Langmuir adsorption isotherm. Thermodynamic parameters such as Gibbs energy (ΔG), enthalpy (ΔH), entropy (ΔS), and activation energy were calculated to determine the mechanism of corrosion inhibition. FTIR analysis and UV-Vis spectroscopy showed an interaction between lignin extract from jengkol peel and mild steel surface. Optical microscopy analysis showed that lignin extract from jengkol peel could reduce the formation of rust on the steel surface.
Sifat Adsorptif dan Termodinamika Ekstrak Lignin dari Pelepah Nipah (Nypa fruticans Wurmb) untuk Korosi Baja Lunak dalam Medium HCl Hilda Sartika; Emriadi; Yeni Stiadi; Suryati Suryati
Jurnal Fisika Unand Vol 13 No 6 (2024)
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jfu.13.6.784-791.2024

Abstract

Research on the adsorptive and thermodynamic properties of lignin extract from Nipah fronds (Nypa fruticans Wurmb) for mild steel corrosion in hydrochloric acid medium has been conducted. The inhibititon effect of lignin extract from Nipah (Nypa fruticans Wurmb) fronds (LENF) on the corrosion of mild steel in HCl solution was studied by weight loss and optical microscopy methods. The results show that LENF was a good inhibitor in 1.0 M HCl, and the inhibition efficiency increases with increasing concentration of the extract and temperature. Inhibitive effect was afforded by the adsorption of the extract on the steel surface, which was found to accord with Langmuir adsorption isotherm. Adsorption and activation parameters such as activation energy (Ea), enthalpy (∆Η), free Gibbs energy (∆G), and entropy (∆S) were evaluated on the corrosion and inhibition process.
Synergistic Effect of Cinnamon (Cinnamomum burmannii) Leaves Extract and Potassium Iodide on Mild Steel in HCl Rohil; Stiadi, Yeni; Emriadi
Chempublish Journal Vol. 9 No. 1 (2025): Chempublish Journal
Publisher : Department of Chemistry, Faculty of Science and Technology Universitas Jambi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22437/chp.v9i1.42334

Abstract

The synergistic impact of potassium iodide with cinnamon leaf extract (CLE) on hindering gentle steel corrosion in a HCl arrangement was examined utilizing weight loss measurement, UV-Vis spectroscopy, and X-ray diffraction (XRD) analysis. At an inhibitor concentration of 10 g/L CLE coupled with 0.04 g/L potassium iodide, the inhibition efficiency increased from 92.8% to 97.06% as the temperature and concentration increased. The Langmuir adsorption isotherm was followed by the inhibitor's adsorption on the mild steel surface. The synergistic interaction between CLE and potassium iodide was validated when the synergistic parameter (S) was greater than 1. The inhibitor components and the steel surface formed a coordination complex, according to UV-Vis analysis. When CLE was present, a defensive layer formed on the mild steel surface that prevented the corrosive medium from interacting with the metal, as confirmed by XRD analysis. These results imply that potassium iodide and CLE may be useful and sustainable corrosion inhibitors for mild steel in acidic environments