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KAJIAN TEORITIS KEMAMPUAN CAPPING KATEKIN, KATEKU TANAT DAN QUARSETIN TERHADAP NANOPARTIKEL PERAK DENGAN MENGGUNAKAN METODA DFT-B Arief, Syukri; -, Emriadi; Saputra, Ade
Jurnal Riset Kimia Vol 9, No 1 (2015): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i1.256

Abstract

Interdiffusion mechanism of catechin, catechutannic acid and quercetin are studied by using DFT-B method. But before conducting these experiment, we perform molecular dynamic simulations to find adsorption models probability of each compound. Two models adsorption of quarcetin, four models for catechin and three models for catechutannic acid have been obtained from molecular dynamic simulations. Quantum parameter of each compound, energy and properties adsorption models have been calculated and discussed. The theoretical results were found to be consistent with the experimental data reported. Futhermore, optimization adsorption model samples show that all of adsorbents have weak bonds on the surface of silver nanoparticles. The mechanism can be classified as strong physisorption, so that catechin, catechutannic acid and quercetin can be categorized as good capping agent in synthesis of silver nanoparticles.
Bark Characteristics of Acacia auriculiformis A. Cunn. ex Benth. and Acacia mangium Willd. From Industrial Plantation Forest Sri Mutiar; Anwar Kasim; Emriadi -; Alfi Asben
Jurnal Penelitian Kehutanan Wallacea Vol 9, No 1 (2020): Jurnal Penelitian Kehutanan Wallacea
Publisher : Environment and Forestry Research and Development Institute of Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18330/jwallacea.2020.vol9iss1pp43-49

Abstract

Increasing the value of bark can be known through the characteristics of the bark such as physical properties, the grade of fiber quality and the chemical composition of the bark. The purpose of this study is to find out the characteristics of the bark of the acacia plant species (i.e. Acacia auriculiformis and Acacia mangium) of Industrial Plantation Forest. The characteristics of the bark observed includes physical properties, quality grade of fiber and chemical composition. The results of this study showed that the bark density, thickness and water content of A. auriculiformis were 1.18g/cm3, 1.55 mm and 35.27% respectively, while, the bark density, thickness and water content of A. mangium were  0.95 g/cm3, 1.23 mm and 48.21% respectively. The fiber qualities of both plants are classified as grade III.  The extractive substance levels of A. auriculiformis and A. mangium were 23.06% and 20.63%, respectively. Based on the analysis with GCMS it can be seen that the main compounds dissolve-hexane from species A. auriculiformis were 2-phenyl phenol 33.6% and palmitic acid 13.5%. In the species A. mangium the main compounds soluble n-hexane were palmitic acid 28.97% and oleic acid 21.43%. The results of the analysis showed that these two bark species could potentially to be adhesives materials, tanning agent, particle boards, and inhibitors at the rate of corrosion of steel.
Karboksimetil Kitosan sebagai Inhibitor Korosi pada Baja Lunak dalam Media Air Gambut Maria Erna; Emriadi Emriadi; Admin Alif; Syukri Arief
Jurnal Matematika & Sains Vol 16, No 2 (2011)
Publisher : Institut Teknologi Bandung

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Abstract

Telah dites efek karboksimetil kitosan (KMK) sebagai inhibitor korosi pada baja lunak dalam air gambut menggunakan metode berat hilang. Efisiensi inhibisi juga  dikarakterisasi berdasarkan energi aktivasi reaksi korosi dengan dan tanpa KMK dan pembentukan lapisan film pasif pada permukaan logam dipelajari menggunakan Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) dengan dan tanpa menggunakan KMK. Hasil menunjukkan bahwa efisiensi inhibisi korosi dipengaruhi oleh pH air gambut, waktu perendaman dan konsentrasi KMK. Inhibisi optimum yaitu  93,66%. terjadi pada pH 7 dan waktu perendaman 3 hari. Efisiensi inhibisi inhibitor ini meningkat dengan naiknya konsentrasi KMK. Inhibisi KMK pada permukaan baja mematuhi modifikasi persamaan isoterm adsorpsi  Langmuir dan  diasumsikan terjadi melalui adsorpsi kimia pada permukaan logam dengan nilai DGoads -35,413 kJ mol-1. Nilai negatif DGoads menunjukkan bahwa adsorpsi KMK terjadi secara spontan pada permukaan baja lunak. Kata kunci: Air gambut, Baja lunak, Inhibitor korosi, Karboksimetil kitosan.   Carboxymethyl Chitosan as a Corrosion Inhibitor for Mild Steel in Peak Water Abstract Carboxymethyl chitosan (CMC) had been tested as a corrosion inhibitor for mild steel in peat water using weight loss method. The inhibition efficiency is also characterized based  on activation energies of corrosion reaction and the formation of passive film on the surface of the metal was studied using Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) in the presence and absence  of CMC. Result showed that the inhibition was influenced by the peat water pH, immersion time and CMC concentration. The optimum inhibition i.e. 93,66%  obtained at pH 7 and immersion time 3 days. The inhibition efficiency of this inhibitor increased with the increasing of CMC  concentration. The inhibition of CMC on the steel surface followed modified Langmuir isotherm equation and assumed to occur through chemical adsorption  on the metal surface with DGoads -35.413 kJ mol-1 . The negative value of DGoads  indicated that the adsorption of CMC  onto the mild steel surface occured spontaneously. Keywords: Carboxymethyl chitosan, Corrosion inhibitor, Mild steel, Peat water.
PEMBUATAN LAPISAN TIPIS DAN SERBUK TIMBAL TITANAT DENGAN METODA SOL GEL -, Rahmayeni; -, Emriadi; Susanti, Eli; Silvia, Delfi
Jurnal Riset Kimia Vol 1, No 1 (2007): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v1i1.62

Abstract

 ABSTRACT Thin layer and powder of lead titanate had been prepared using lead acetate and tetraethylorthotitanate as precursor by sol gel process. The thin layer of composite was obtain through layering the composite on glass substrate. Both thin layer and powder were calcined between 100-700°C and were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), UV and Fourier Transform Infra Red (FTIR). The diffraction pattern show that the structure of composite on glass substrate is amorf at 500°C and could not identified at 700°C while the powder is crystalline at 500 and 700°C. FTIR spectra shown the Ti-O peak at 1407 cm-1, the Pb-O and Pb-O-Ti peaks at 718 and 600 cm-1, respectively. 
Sintesis dan Aplikasi Karboksimetil Kitosan sebagai Inhibitor Korosi pada Baja Karbon dalam Air Erna, Maria; Emriadi, Emriadi; Alif, Admin; Arief, Syukri; Noordin, Mohd Jain
Jurnal Natur Indonesia Vol 12, No 1 (2009)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (351.132 KB) | DOI: 10.31258/jnat.12.1.87-92

Abstract

Carboxymethyl chitosan (CMC) was synthesized with different methods by reacting chitosan with monochloroaceticacid in the presence of sodium hydroxide under variation conditions. The above samples were characterized byFourier transform infrared spectroscopy (FTIR) and soluble in water in range of pH. The CMc were soluble in watera wide range of pH and applied as corrosion inhibitor for steel in water. The inhibiting influence of CMC was studiedby potentiodynamic polarization method. It was found thad corrosion rate was dependent on water pH and CMCconcentration. The results show that optimum the inhibition efficiency at pH 5 and 1 ppm concentration CMC, i.e.,77%. The adsorption of used compound on the steel surface obeys modified Langmuir isotherm. Polarizationmeasurement show that the CMC acts essentially as a anodic-type inhibitor.
Efektifitas Kitosan sebagai Inhibitor Korosi pada Baja Lunak dalam Air Gambut Erna, Maria; Emriadi, Emriadi; Alif, Admin; Arief, Syukri
Jurnal Natur Indonesia Vol 13, No 2 (2011)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (70.13 KB) | DOI: 10.31258/jnat.13.2.118-122

Abstract

This research is intended to learn inhibition efficiency of mild steel corrosion in peat water using two type ofchitosan. First chitosan is without treatment and the second one is synthesized by ionotropic gelation method andthen is characterized by Fourier transform Infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM).Diameter of chitosan porous is about 500 nm which is measured based on morphological photo using SEM withinhomogeneous porous shape and porous distribution is unsmooth . Effect of chitin and chitosan on the corrosionof mild steel in peat water is studied using weight loss method. It is found that corrosion inhibition efficiencydepends on peat water pH, inhibition technique and interaction time. The results show that inhibition efficiency ofchitosan without treatment and with treatment are 88.73% and 93.32% respectively. The inhibition is assumed tooccur via physicsorption of the chitin and chitosan molecules on the metal surface. The Langmuir adsorptionisotherm is tested for their fit to the experimental data.
EKSTRAK METANOL DARI DAUN MAHKOTA DEWA (Phaleria macrocarpa) SEBAGAI INHIBITOR KOROSI BAJA DALAM ASAM KLORIDA Rahmi, Azimatur; -, Emriadi; Alif, Admin
Jurnal Riset Kimia Vol 7, No 2 (2014): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v7i2.168

Abstract

Vol 7 No 2ABSTRACTExtract of Phaleria macrocarpa leaves have been studied as corrosion inhibitor for mild steel ofhydrochloric acid solution 2.0 N. The efficiency of inhibition was evaluated by gasometric methodand electrochemical analysis. The temperature and concentration effects on the inhibitorsperformance were also investigated. The result obtained showed that the extract is one of promisingcandidate as an inhibitors for the corrotions of mild steel in HCl media, inhibition efficiencyincrease as the extract concentration is evaluated. The activation energy (Ea) increase with theaddition of the extract. Where inhibition of extract on the steel surface obey modified Langmuirisotherm equation. Potentiodynamic polarization curve indicated the Phaleria macrocarpa leavesextract play role as the anodic type inhibitor.Keywords : Corrosion inhibition, mild steel, Phaleria macrocarpa, hydrochloric acid.
TRANSPOR ION TEMBAGA (II) MELALUI TEKNIK MEMBRAN CAIR FASA RUAH Tetra, Olly Norita; Alif, Admin; A, Hermansyah; -, Emriadi
Jurnal Riset Kimia Vol 1, No 1 (2007): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v1i1.57

Abstract

 ABSTRACT Bulk liquid membrane methode have been used to study transport  of  Cu(II) ion containing oxine as carrier. It was found that total Cu(II) ion 20 ppm was transported from source phase to receiving phase after 360 min reached 97.3 % in optimum conditions source phase pH is 3, oxine concentration as carier in membrane phase is 17.5 x 10-4 M, membrane volume is 20 mL, sulfur acid concentration in receiving phase 0.15 M and time of balance is 15 minute. Thus a pH gradient is utilized to drive the Cu(II) transport.
PENGARUH INHIBITOR EKSTRAK DAUN INAI (lawsonia inermis) TERHADAP LAJU KOROSI BAJA ST. 37 DIUKUR DENGAN METODE PENGURANGAN MASSA Handani, Sri; Wildani, Sri; -, Emriadi
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.v4i1.148

Abstract

 Vol. 4, No. 1ABSTRACT The corrosion tests and micro structure analysis of St. 37 steel had been investigated. These investigation were conducted in nitric acid (HNO3). The range of concentration added was from 0-0.5 N with extract of henna leaves as inhibitors. The method used was losing mass by measuring loss mass of steel before and after corrosion. The boiling method was used to get the extract of henna leaves. Optical photo Carton Stereo Trinokuler were used for micro structure. Corrosion rate can be reduced by adding inhibitor and inhibition efficiency is measured if its ability to suppress corrosion. The result of the immersion tests show that the inhibition efficiencies are different on 0-0.5 N concentration are 81.96 %, 78.92 %, 53.74 %, 44.85 %, 44.45 % and 39.65 %. Addition of 50 g/1000 mL extrac of henna leaves results in the highest efficiency for HNO3 environment. The photo showed the surface structure of steel before corrosion, in layer with extract of henna leaves and after corrosion in medium nitric acid. Keywords: Corrosion rate, Inhibition efficiency, Extract of henna leaves, Nitric acid.   
SINTESIS DAN KARAKTERISASI PARTIKEL NANOSPERIK TIO2 MELALUI METODE HIDROTERMAL GELOMBANG MIKRO Amir, Amelia; -, Emriadi; Arief, Syukri; Manseki, Kazuhiro; Sugiura, Takashi
Jurnal Riset Kimia Vol 7, No 2 (2014): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v7i2.166

Abstract

 ABSTRACTSimple synthesis of nanospherical TiO2 by microwave hydrothermal method has beeninvestigated. Titanium tetra isopropoxide (TTIP) and tetra methyl ammonium hydroxide(TMAOH) were used as precursor. The crystal phase and microstructure were characterized byX-Ray Diffraction (XRD) and transmission electron microscopy (TEM) including selected areadiffraction (SAED). The presence of intense peak in the XRD patterns confirmed to anatase andin good agreement with SAED patterns. Nanospherical of particles were clearly seen in theTEM image and the size of particles was approximately 4-5 nm.Keywords : microwave hydrothermal, colloidal titanates, structure directing agent,nanospherical TiO2