Silvester Tursiloadi
Research Center for Chemistry, Indonesian Institute of Science, Kawasan Puspiptek Serpong, Tangerang Selatan 15314, Banten

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PERFORMANCE OF MODIFIED NATURAL ZEOLITES BY SODIUM HYDROXIDE TREATMENTS IN THE ESTERIFICATION OF GLYCEROL AND OLEIC ACID Fauzi, Rizky Achmad; Tursiloadi, Silvester; Dwiatmoko, Adid Adep; Sukandar, Dede; Aulia, Fauzan; Rinaldi, Nino; Sudiyarmanto, Sudiyarmanto
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 5, No. 2, November 2019
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat Syarif Hidayatullah State Islamic Uni

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (841.828 KB) | DOI: 10.15408/jkv.v5i2.9976

Abstract

Esterification is the reaction of the formation of an ester compound by reacting an alcohol compound and carboxylic acid. In this study, the performance of zeolite-based catalysts has been studied for esterification reactions. Modification of zeolite pore size was done to be hierarchical zeolite, with the aim of increasing the catalytic properties of zeolite. The modification was carried out by desilication by sodium hydroxide treatment with a variation of 0.1; 0.3; 0.5 M. The resulting catalyst was then characterized using BET and XRD. Furthermore, the catalyst was tested for activity for esterification of fatty acids and glycerol and the product was analyzed using GC-MS. Zeolite modification with sodium hydroxide has been proven to improve catalyst performance, without changing their crystal structure. The best catalytic activity was obtained on the catalyst with sodium hydroxide treatment of 0.3 M, resulting glycerol conversion of 92% and selectivity to monoglycerides of 74%.
SOLID ACID CATALYST OF MESOPOROUS ALUMINA-TITANIA MODIFIED GEL AND AEROGEL FOR ESTERIFICATION OF OF FATTY ACID. Tursiloadi, Silvester; Sondari, Dewi
Alchemy Jurnal Penelitian Kimia Vol 3, No 2 (2004)
Publisher : Alchemy Jurnal Penelitian Kimia

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Abstract

Three types of TiO2.Al2O3 gels ([TiO2]/[ Al2O3]=1/4 in mol) wre prepared by hydrolysis of Al(OC4H9sec)3and Ti(OC3H7iso)4 in an n-propanol solution with acid catalyst. Their physical properties and catalytic on the formation of polyethylene glycol ester were investigated. The wet gels were dried (Xerogel), immersed in surfactant solution before dying (Modified Gel), or supercritically extracted with CO2 at 60oC and 24 Mpa for 2h (Aerogel). The pore size and pore volume of these gels hardly decreased after calcinations at 800oC, atlhough those values of the xerogel remarkably decreased after calcination up to 800oC. The thermal stability of the microstructure of mesoporous titania-alumina is improved by surfactant immersion of supercritical extraction. The aerogel had the highest catalytic activity for the reaction of polyethylene glycol and stearic acid. The effects preparation methods on the microstructure and catalytic activity of the gels were disccussed.
PREPARATION OF LEAD MAGNESIUM NIOBATE-LEAD ZIRCONATE TITANATE FILMS AND THEIR CRYSTALLIZATION BEHAVIORS Tursiloadi, Silvester
Jurnal Sains Materi Indonesia Vol 3, No 3: JUNI 2002
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (103.284 KB) | DOI: 10.17146/jsmi.2002.3.3.5058

Abstract

PREPARATION OF LEAD MAGNESIUM NIOBATE-LEAD ZIRCONATE TITANATE FILMS AND THEIR CRYSTALLIZATION BEHAVIORS. The thin films with composition near morpotropic phase boundary (MPB) of the system xPb(Mg1/3, Nb2/3)O3-yPbTiO3-zPbZrO3 (x = 0 – 0.35, y = 0.47 and z = 0.53), were prepared by sol-gel method. The starting materials were consisted of Pb(iso-OC3H7)2, Zr(n-OC4H9)4, Ti(iso-OC3H7)4, Mg(CH3COO)2 4H2O and Nb(OC2H5)5. The 1-propanol was used as solvent. The concentration of PMN-PT-PZ in coating solution was 0.7 M, and the pH of the solution was 4.5. The thin films were prepared by dipcoating and spincoating. The crystallization behaviors of the PMN-PT-PZ thin films showed that the formation of perovskite phase at low temperature becomes difficult with increasing the content of PMN. The amounts of pyrochlore and perovskite phase in PMN-PT-PZ films depended on the heating temperatures, and PMN contents. Single-phase perovskite was found for the coated films containing 0 and 12.5 mol% after calcinating at 600 oC, 21 mol% after calcinating at 700oC, and 30 mol% after calcinating at 750oC. Single-phase perovskite of coated films will never be found when the content of PMN was 35 mol%.
PREPARATION OF POROUS TITANIA AEROGEL BY CO2 SUPERCRITICAL EXTRACTION TECHNIQUE. Tursiloadi, Silvester
Jurnal Sains Materi Indonesia Vol 5, No 3: JUNI 2004
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1197.273 KB) | DOI: 10.17146/jsmi.2004.5.3.5096

Abstract

PREPARATION OF POROUS TITANIA AEROGEL BY CO2 SUPERCRITICAL EXTRACTION TECHNIQUE. Porous anatase titania that is attractive to its notable functions for photo catalysis and photon-electron transfer. A method for producing the porous anatase titania at low temperature is with dissolving of a titanium alkoxide in a methanol to give a titanium alkoxide solution, adding a mixed solution containing water, nitric acid catalyst and a methanol to the titanium alkoxide solution to perform hydrolysis and simultaneous polymerization to give a polymer solution (gel). The solvent in wet gels was super-critically extracted in CO2 at 60°C and 22 Mpa. Thermal evolution ofthe microstructure ofthe gels were evaluated by TGA—DTA, N2 adsorption, TEM and XRD. A porous titania, which has an anatase-form crystalline structure, an anatase-form particle diameter about 4 nm, average pore diameter of 13 nm, a BET specific surface area of 195 m2/g and a total pore volume of 0.55 cm2/g was obtained as prepared condition. The transformation of anatase phase to rutile phase occurred at 600 °C.
STUDI AWAL PENGARUH METODE EKSTRAKSI TERHADAP RENDEMEN DAN KADAR ASIATICOSIDE DARI CENTELLA ASIATICA (L) URB Sondari, Dewi; Irawadi, Tun Tedja; Setyaningsih, Dwi; Tursiloadi, Silvester
Jurnal Sains Materi Indonesia Vol 17, No 3: APRIL 2016
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (224.213 KB) | DOI: 10.17146/jsmi.2016.17.3.4193

Abstract

STUDI AWAL PENGARUH METODE EKSTRAKSI TERHADAP RENDEMEN DAN KADAR ASIATICOSIDE DARI CENTELLA ASIATICA (L) URB. Proses ekstraksi Centella asiatica (L) Urb dengan metode maserasi, sonikasi, sokletasi dan CO2 superkritik telah dilakukan. Pengaruh proses ekstraksi terhadap rendemen dan kadar asiaticoside dari Centella asiatica (L) Urb (pegagan) telah dipelajari. Hasil dari perhitungan rendemen asiaticoside terlihat bahwa kandungan asiaticoside (% berat) dari proses ekstraksimaserasi, sonikasi, sokletasi dan CO2 superkritik berturut-turut sebagai berikut: 6,723%; 0,187%; 3.648%dan 9,24%. Rendemen asiaticoside paling tinggi diperoleh dari teknologi ekstraksi CO2 superkritik, karena teknologi ini dilakukan pada tekanan dan suhu tertentu sehingga kualitas hasil ekstraksi ditentukan oleh seberapa kritis penggunaan tekanan dan suhunya. Karena pada kondisi ini, selain mengubah densitas CO2, juga berpengaruh terhadap kelarutan dan selektivitas dari zat yang akan terekstrak. Semakin tinggi tekanan dan kelarutan, total hasil ekstraksi akan semakin tinggi. Untukmengetahui adanya senyawa asiaticoside dalam Centella asiatica (L) Urb (pegagan) digunakan analisis HPLC. Dari hasil analisis kromatogram bahwa ada dua puncak yang terdeteksi, dan secara kualitatif senyawa asiaticoside yang diperoleh denganmenggunakan ekstraksi CO2 superkritik lebih tinggi kadarnya dibanding metode ekstraksi lainnya, karena teknologi proses ekstraksi CO2 superkritik memanfaatkan kekuatan pelarut dan sifat fisik dari komponenmurni atau campuran, sehinggamudahmelakukan penetrasi ke dalam dinding material yang di ekstrak dan melarutkan komponen senyawa aktif secara selektif dengan kualitas produk tinggi dan tidakmengandung residu pelarut sehingga lebih murni.
SOL-GEL PROCESS FOR THE MANUFACTURING OF TRANSLUCENT LEAD ZIRCONATE TITANATE GEL-MONOLITH Tursiloadi, Silvester; Imai, Hiroaki; Hirashima, Hiroshi
Jurnal Kimia Terapan Indonesia Vol 6, No 1-2 (1996)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5234.829 KB) | DOI: 10.14203/jkti.v6i1-2.231

Abstract

Translucent Lead Zirconate Titanate (PZT) gel-monolith was prepared by partially hydrolyzing metal alkoxides solution which modified with acetylacetone(acacH). Metal alkoxides, lead di-i-propoxide, zirconium tetra-nbutoxide and titanium tetra-i-propoxide were used as starting materials. In Infrared spectra for the translucent monolithic gel after aging at room temperature for several days or drying at 90C for 18h, the most significant feature is the presence of band at around 1554 cm-1 which can be assigned to the v (C-O) and v (C-C) vibrati-ons of acetylacetanate group coordinated to the metal cations Ti and Zr. The diffraction peaks of PbO were found after heating at 300C for 2h. After heating at 450 C for 2 h, diffraction peaks of pyrochlore Pb2 Ti206 and perovskite PZT phase were observed. The diffraction peaks of PbO and pyrochlore phase disappeared after heating at 600C, and tetragonal perovskite phase was stable up to 1000 C. The diffraction peaks of perovskite phase were also found after heating at 430 for 24 h. The density of the compacted pulverizedgel after heating at 1000C for 30 min. was 6.9 g/cm3 , about 86% of the theoretical value.
Proses Dekomposisi untuk Pembuatan Serbuk Alumina dari Aluminium Format Tursiloadi, Silvester
Jurnal Kimia Terapan Indonesia Vol 9, No 1-2 (1999)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2254.842 KB) | DOI: 10.14203/jkti.v9i1-2.187

Abstract

The high purity excellent chemical stability and mechanical properties, is quite important for alumina ceramic products. The alumina ceramic products was made from aluminium formate in this study. Decomposition of organic salts is a useful method for preparation of pure and fine ceramic powder without using of expensive metal alkoxides and without producing air pollution. The aluminium formate alt was prepared from reagent grade AlCl3.6H2O,AlCl3.6H2O was dissolved in H2O and then NH4OH was added to the solution. The white precipitates formed were washed with distilled water repeatedly, then dissolved in formic acid solution. Alumina powders prepared by decomposition of aluminium formate had high chemical purity and had small size of agglomerates with a narrow size distribution. The spesific surface area and the equivalent spherical diameter calculated from the value of spesific surface area were 60 m2/gr and 0.03um. The value of equivalent spherical diameter of Al2O3 powder in cumulative mass percent for finer particle were diameter (10%) of 1.7um and diameter (50%) of 5,5um. The average diameter of particles was 5.5um. For the alumina powders which was prepared by docomposition of aluminium formate, the x- Al2O3 and x- Al2O3 did not appear as intermediate phase between y- Al2O3 and a- Al2O3 when calcinated from 800C to 900C .However a- Al2O3 phase appeared at 800C, so that this could reduce the transition temperature from y- Al2O3 to a- Al2O3. The single phase of a- Al2O3 was obtained after calcinating at 1100C or more for 2 hours.
Pembuatan dan Karakteristik Serbuk Piezoelektrik Pb(Zr,Ti)03 tanpa subtitusi dan dengan Nb substitusi Tursiloadi, Silvester
Jurnal Kimia Terapan Indonesia Vol 8, No 1-2 (1998)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4909.51 KB) | DOI: 10.14203/jkti.v8i1-2.202

Abstract

The characteristics of chemically prepared piezoelectric PZT and doped PZT with niobium (PNZT) were investigated. PZT 55/45, both unmodified and doped with Nb2O5 were prepared by the hydrolysis of metal alkoxides and solid state reaction from PbO, ZrO, and TiO,. The average particle size was 0.45 um. X-ray diffraction results indicated that transformation of the amorphous precipitate be came well crystallized PZT after heating at 500 C for 6 hours. DTA results suggested theformation of an intermediate PbTiO3 phase at 490 C. Using X-ray diffractton can be investigated occurring of both tetragonal and rombohedral ferroelectric PZT phases. That case depends on the initial mixing of chemical composition. The PZT powders which prepared from alkoxides were agglomerated easly at low temperature calcining. Poor sintered bodies will he resulted it was calcinated above 600C. Powders calcined at 500 C for 6 hours and sintered at 1200 C produced high body densities approaching 95% of theoretical density.The experimental results suggest that intimate mixing of constit uents during the hdrolyt ic decomposition produces a homogeneous powder. However, differences in the rate hydrolysis or polymerization of the respective metal alkoxides fend to couse the stoichiometric results difficult to be found.
Nickel Supported Natural Zeolite as a Bifunctional Catalysts for Conversion of Citronella Oil Crude to Menthols Pertiwi, Ralentri; Tursiloadi, Silvester; Adilina, Indri Badria; Sembiring, Kiky Corneliasari; Oaki, Yuya
Jurnal Kimia Terapan Indonesia (Indonesian Journal of Applied Chemistry) Vol 18, No 02 (2016)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (230.308 KB) | DOI: 10.14203/jkti.v18i02.78

Abstract

Characterization and catalytic activity of modified natural zeolite for the conversion of citronella oil to menthol was investigated. In this research, natural zeolite was prepared by acid activation with HCl and impregnated with Ni metal. The addition of Ni metal of around 12.5 nm in diameter provided a bifunctional catalyst for two steps of citronella oil conversion i.e. cyclization and hydrogenation. The process was performed in a one-pot reaction system by stirring at 200oC with pressure of 20 bar H2 for 3h. The reaction products changed slightly with varieties of reaction temperature and amount of catalysts employed. Results showed that Ni/NZB-HT catalyst was the best catalyst which was able to convert citronella oil to menthol with a selectivity of 50% menthol and 100% conversion of citronellal.
PREPARATION OF LEAD ZIRCONATE TITANATE FILM BY SOL-GEL METHOD AND ITS CHARACTERIZATION Tursiloadi, Silvester; Imai, Hiroaki; Hirashima, Hiroshi
Jurnal Kimia Terapan Indonesia Vol 6, No 1-2 (1996)
Publisher : Research Center for Chemistry - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5139.688 KB) | DOI: 10.14203/jkti.v6i1-2.232

Abstract

A ferroelectric material film of Lead Zirconate Titanate, Pb(Zr,Ti)O3 (PZT), was produced by sol-gel method from alkoxide and acetate precursors in a normal propanol solvent system. The excess amount of Pb was 10 mole % more than stoichiometrically used for preparing the solution. The concentration of PZT in coating solution was 0.7 M, and pH of the solution was 4.5. The films was prepared by dip-coating onto slide glass, silica glass and Pt/Ti/SiO2/Si substrate. In order to avoid cracking TiO2 was coated on the glasses as a barrier layer. The asdried PZT film was amorphous from X-ray diffraction. The amount of pyrochlore and perovskite phase depended on the heating temperature and kind of barrier layer. Single perovskite phase was found for coated films on TiO2/SiO2 and Pt/Ti/SiO2/Si heated at 600 C or higher, but it was never found for coated films on SiO2 substrate without barrier layers. Crystallization of perovskite PZT film was retarded when deposited on amorphous substrates as compared to crystalline substrate. The coated film on Pt/Til/SiO2/Si was thicker and smaller in particle size than that of coated film on Ti02/SiO2. A columnar structure with a diameter around 6.5 nm, was observed and no boundary was observed between layers in 9 time dipcoated film on Pt/Ti/SiO2/Si.