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Rahmat GUnawan
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Chemistry

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PEMANFAATAN ABU DAUN JAGUNG (Zea Mays) SEBAGAI SUMBER SILIKA PADA PEMBUATAN KATALIS Na/ SBA- 15 UNTUK REAKSI TRANSESTERIFIKASI MINYAK JELANTAH Drajat Bangun Utomo; R R Dirgarini Julia Nurlianti Subagyono; Rahmat GUnawan
JURNAL KIMIA MULAWARMAN Vol 16 No 1 (2018)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v16i1.621

Abstract

Preparation of Na / SBA-15 from corn leaves ash (Zea mays) as a substitute for TEOS (Tetraethyl Orthosilicate) applied as a heterogeneous catalyst in the transesterification reaction of used palm oil and methanol has been performed. The preparation of SBA-15 was conducted by surfactant template method and modification with Na was conducted by impregnation method. SBA-15 from corn leaves ash has a pore size ranging from 4.9 nm to 9.3 nm, a surface area of ​​595 m2/ g, a pore diameter of 3.95 nm and a pore volume of 0.99 cm3/ g. The yeild obtained from the first transesterification process was 96.46% with the free fatty acid content of the product 0.16 mg KOH/ g. The two most prominent methyl ester based on the chromatogram of the transesterification product, the two most prominent methyl ester in the product were methyl palmitate (36,32%) and methyl oleat (36,15%). Keywords : Maize, SBA-15, TEOS (Tetraethyl Orthosilicate), Transesterification of used palm oil
KAJIAN PERUBAHAN UKURAN RONGGA ZEOLIT RHO BERDASARKAN VARIASI RASIO Si/Al DAN VARIASI KATION ALKALI MENGGUNAKAN METODE MEKANIKA MOLEKULER Wahdana Kusuma Sari; Rahmat Gunawan; Erwin Erwin
JURNAL KIMIA MULAWARMAN Vol 14 No 1 (2016)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

The structure modeling of zeolite RHO with variation of Si/Al ratio (5; 4.33; 3.8; 3.36; 3; 2.69; 2.43; 2.2; 2) and variation of alkaline cations (Li+, Na+, K+, Rb+, Cs+, Fr+) calculated by the molecular mechanics method has been investigated. The result shows that the structure of zeolite RHO with Si/Al ratio 3.36 has the most stable structure with a minimum energy 2652.0308 kcal/mol. The most stable structures of zeolite RHO impregnated with cation is that impregnated with Fr+ (alkaline) with a minimum energy 3006.6587 kcal/mol. The result shows that the zeolite RHO structure with cations Fr+ (alkaline) has the largest pore diameter which potentially has the best adsorption capacity.
STUDI KOMPUTASI SEMIBUCKMINSTERFULLERENE SEBAGAI PENYIMPAN HIDROGEN MENGGUNAKAN METODE PERHITUNGAN DENSITY FUNCTIONAL THEORY. Digva Willyan; Rahmat Gunawan; Veliyana Londong Allo
JURNAL KIMIA MULAWARMAN Vol 17 No 2 (2020)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v17i2.716

Abstract

Hydrogen is an alternative energy source for fossil fuels. One of molecules that have an ability to store hydrogen is Semibuckminsterfullerene. This study was conducted to find out the optimum distance in adding hydrogen and the phenomenon of energy produced when adding hydrogen from 10 molecules to 100 molecules. Semibuckminsterfullerene was calculated using Density Functional Theory method, B3LYP with a basis set of 6-31G*. The optimum distance of Semibuckminsterfullerene with hydrogen was 3 ? Furthermore, the results of adding hydrogen from 10 to 100 molecules showed a decrease in energy due to the bowl-shaped structure of Semibuckminsterfullerene
PENURUNAN KADAR ION LOGAM TEMBAGA (CU) PADA LIMBAH CAIR INDUSTRI ELEKTROPLATING MENGGUNAKAN METODE ELEKTRODEPOSISI Tangke Veronika; Bohari Yusuf; Rahmat Gunawan
JURNAL KIMIA MULAWARMAN Vol 16 No 1 (2018)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v16i1.415

Abstract

The reduction of copper concentration in the electroplating industry wastewater by electrodeposition method by means of Atomic Absorption Spectrophotometer (AAS). The result of research showed that degradation and is big of elimination percent of copper metal have with the effect of time contact and voltage at optimum hence in getting results of final concentration of iron (Fe) successive plate 4,02 ppm and 2,84 ppm of concentration early 35,86 ppm and elimination percent of exclusion at optimum parameter in getting result successive 88,403 % and 92,069 %. While the results of the final concentration of Aluminium (Al) successive plate 2,38 ppm dan 2,22 ppm of concentration early 35,86 ppm and elimination percent of exclusion at optimum parameter in getting result successive 93,363 % dan 93,814%.
Co-Authors Bohari Yusuf Digva Willyan Drajat Bangun Utomo Erwin Erwin R R Dirgarini Julia Nurlianti Subagyono Tangke Veronika Veliyana Londong Allo Wahdana Kusuma Sari