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PERANAN KATALIS TiO2/SiO2-MONTMORILLONIT PADA REAKSI KONVERSI SITRONELAL MENJADI ISOPULEGOL

REAKTOR Volume 12, Nomor 2, Desember 2008
Publisher : Dept. of Chemical Engineering, Diponegoro University

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Abstract

Catalytic conversion of citronellal to isopulegol over TiO2/SiO2-montmorillonite catalyst was studied for citronellal isolated from Cymbopogon leaf oil. The role of physico-chemical characteristics of montmorillonite and SiO2-montmorillonit catalyst on total conversion, activity and selectivity to produce isopulegol was studied. Activity test was conducted for citronellal cyclication for 4 hour. The total conversion, catalyst activity and catalyst selectivity to produce isopulegol were evaluated based on product composition obtained by GC-MS analysis. The experimental result showed that TiO2/SiO2-montmorillonite plays role in the increase of total conversion significantly from 87.80% over SiO2-montmorillonit and 85.38% over natural montmorillonite become 95.53%. Total conversion and selectivity of the catalyst to produce isopulegol increase could be related to Lewis acidity of TiO2/SiO2-montmorillonite, and also specific surface area enhancement. However, in the range of 1:1.25 to 1:5.0 catalyst to citronellal mass ratio, there was no influence on total conversion and selectivity to produce isopulegol. This may be caused by dominant influence of Lewis acidity compared to other physico-chemical characteristic of material. Kinetics study of the reaction showed that TiO2 dispersion on SiO2-montmorillonite almost doubles the reaction rate constant with the factor of 1.955. Konversi katalitik sitronelal menjadi isopulegol menggunakan katalis TiO2/SiO2-montmorillonit dipelajari terhadap sitronelal hasil isolasi minyak daun sereh. Peranan karakter fisikokimiawi material katalis montmorillonit alam dan SiO2-montmorillonit terhadap konversi total, aktivitas dan selektivitas dalam pembentukan isopulegol dipelajari. Uji aktivitas katalis dilakukan pada reaksi siklisasi sitronelal selama 4 jam. Konversi total, aktivitas katalis dan selektivitas terhadap isopulegol dihitung berdasar perubahan komposisi hasil reaksi yang ditentukan menggunakan GC-MS. Hasil penelitian menunjukkan bahwa katalis TiO2/SiO2-montmorillonit berperanan meningkatkan konversi total reaksi secara signifikan dari sebesar 87,80% pada penggunaan SiO2-montmorillonit dan 85,38% dengan menggunakan montmorillonit alam menjadi sebesar 95,53%. Peningkatan konversi total dan selektivitas terhadap isopulegol berkaitan dengan keasaman Lewis yang dimiliki oleh TiO2/SiO2-montmorillonit serta peningkatan luas permukaan spesifik material. Namun pada rentang perbandingan massa katalis terhadap sitronelal 1:1,25 hingga 1:5,0 tidak berpengaruh signifikan terhadap konversi total dan selektivitas produk isopulegol. Hal ini mungkin disebabkan peranan keasaman Lewis lebih dominan terhadap sifat-sifat fisikokimiawi material katalis. Studi kinetika reaksi menunjukkan bahwa dispersi TiO2 pada SiO2-montmorillonit meningkatkan konstanta laju reaksi dengan faktor sebesar 1,955. 

Analysis of Quantitative Structure and Solubility Relationship for Organophospate Active Compounds Linear Model and Cluster Model Approach

Jurnal ILMU DASAR Vol 8, No 1 (2007)
Publisher : Fakultas MIPA Universitas Jember

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Abstract

Study on quantitative solubility and structure relationship of organophospate pesticide has been conducted. Aim of this research is to analyze relationship between characteristic physical properties (water solubility) of pesticide with molecular structure by a model that can be used to predict physical properties of new compound proposed to be pesticide compound. Analysis was done for 52 organopospate compounds and its water solubility data. The model predicted by 39 fagmental descriptor based on spesific structure of organophospate compound. Analysis used in modeling are cluster analysis, one way analysis of variance (ANOVA) and regression analysis. Result show water solubility of the pesticide compound positive effect by functional group of P=O, N-primer and C=O in the structure. Functional group of S (sulphur), fen (phenil) , C-aromatic, C1-C2, C3-C4, C5-C6, Ortho Aromatic, P=S, C-Cl and log(Mr) decrease water solubility. The model resulted by regression analysis using stepwise and best subset method is : Ln(1+watsol) = 11.0 - 0.352 n C (aromatic) - 5.41 n (P=S) - 1.55 n (C-Cl), F-value = 32.43 (sign. 0,000) , R2 = 0.67 dan S=2.643. The model can be used to predict the organoposphate water solubility.Keywords : QSPR, ANOVA, regression analysis, organophospate pesticide

PREPARASI Fe3+/TiO2-MONTMORILLONIT SEBAGAI KATALIS PADA DEGRADASI ZAT WARNA AZO

REAKTOR Volume 14, No. 4, OKTOBER 2013
Publisher : REAKTOR

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Abstract

PREPARATION OF Fe3+/TiO2- MONTMORILLONITE AS CATALYST IN AZO DYEDEGRADATION. Preparation of Fe3+/TiO2-Montmorillonite and its activity test on azo dyesdegradation has been performed. The succeed of material preparation was examined byphysicochemical characterization by using X-ray Diffraction, BET surface area analyzer and DiffuseReflectance UV-Visible. The role of physicochemical character to catalytic activity was evaluated inthe degradation reaction of two azo dyes: metil jingga and metilena biru by examination of its kineticsstudy in the Photo-Fenton like mechanism. Result of research showed the success of Fe3+/TiO2-Montmorillonit preparation and its fulfillment of goals as a catalyst in dye degradation via photo-Fenton mechanism. Kinetics data simulation demonstrates that degradation reaction for both dyesobey the Langmuir-Hinshelwood kinetics model with the values of k and K for MO are 8.83x10-7M/sec dan 328.29 and for MB are 4.56x10-5 M and 555.60 respectively. The values of rate constantand adsorption-desorption constant from both dyes describe the role of surface interaction incatalysis.

TANDEM SIKLISASI-HIDROGENASI SITRONELAL BERKATALIS ZrO2 - MONTMORILLONIT DENGAN VARIASI METODE REAKSI

Jurnal Penelitian Saintek Vol 18, No 2 (2013): OKTOBER 2013
Publisher : Jurnal Penelitian Saintek

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Abstract

Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu tahap dengan variasi metode berkatalis ZrO2   montmorillonite (Zr-MMT). Tujuan penelitian adalah untuk menentukan keefektifan katalis Zr-MMTdengan dua metode: metode dengan sistem flow terhadap campuran sitronellal-katalis setelah refluks dengan tekanan H2  sebesar 3 kPa dan metode yang lain sistem flow terhadap campuran sitronellal- katalis pada 200oC dengan tekanan H2  2kPa. Hasil reaksi dianalisis menggunakan GC-MS dengan  menentukan  total  konversi  dan  rendemen  mentol.  Hasil  menunjukkan  bahwa metode yang berbeda memberikan mekanisme reaksi yang signifikan. Metode pertama memberikan konversi sebesar 99% dengan produk utama isomenthon dan isopulegol sedangkan metode ke dua memberikan nilai konversi 5,18% dengan selektifitas sebesar 0,39% terhadap menthol. Dibandingkan dengan montmorillonit alam, kedua proses memberikan nilai  konversi  lebih  besar  dimana  konversi  menggunakan  montmorillonit kurang dari 5%. Ketercukupan laju H2  sebagai reaktan adalah faktor penting dalam menentukan mekanisme.

PREPARASI Fe3+/TiO2- MONTMORILLONIT SEBAGAI KATALIS PADA DEGRADASI ZAT WARNA AZO

REAKTOR Volume 14, No. 4, OKTOBER 2013
Publisher : Dept. of Chemical Engineering, Diponegoro University

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Abstract

Dalam penelitian ini dilakukan preparasi material Fe3+/TiO2-Montmorillonit dan uji aktivitasnya sebagai katalis pada degradasi senyawa azo. Keberhasilan preparasi material dipelajari melalui karakterisasi menggunakan X-ray Diffraction, BET surface area analyzer dan Diffuse Reflectance UV-Visible. Peranan katalitik material hasil preparasi pada degradasi senyawa azo: metil jingga(MO) dan metilena biru(MB) dipelajari melalui studi kinetika reaksi dengan mekanisme mirip foto-Fenton (Photo-Fenton like mechanism). Hasil penelitian menunjukkan keberhasilan preparasi material Fe3+/TiO2-Montmorillonit serta tercapainya tujuan penggunaannya sebagai katalis untuk degradasi zat warna azo melalui mekanisme Photo-Fenton like. Simulasi terhadap data kinetika menunjukkan bahwa degradasi kedua zat warna azo dengan katalis hasil preparasi mengikuti  model kinetika Langmuir-Hinshelwood dengan nilai k dan K untuk MO berturut-turut adalah sebesar 8,83x10-7 M/detik dan 328,29 dan untuk MB sebesar 4,56x10-5 M dan 555,60. Nilai konstanta laju reaksi dan konstanta adsorpsi-desorpsi reaksi degradasi kedua zat warna menjelaskan peranan mekanisme interaksi permukaan dalam proses katalisis.

UTILISASI TiO2-ZEOLIT DAN SINAR UV UNTUK FOTODEGRADASI ZAT WARNA CONGO RED

Berkala Ilmiah MIPA Vol 16, No 3 (2006)
Publisher : FMIPA UGM

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Abstract

An investigation of Congo Red photodegradation using TiO2-zeolite and uv radiation was performed. TiO2-zeolite was prepared by dispersing of pillaring solution (in form oligocations of titanium) into suspension of zeolite. The suspension was stirred and then filtered to separate the solid phase from the filtrate. The solid phase was calcined by microwave oven at 800 Watt for 5 minutes to convert the oligocations into its oxide forms. The calcined product and unmodified zeolite were characterized using x-ray diffractometry, FT-IR spectrophotometry, X-ray fluorescence and gas sorption analysis to determine their physicochemical properties. Photocatalytic activity of TiO2-zeolite was tested on Congo Red using following method: 50 mg of zeolite was dispersed into 25 mL of 10-4 M Congo Red. The dispersion was irradiated using 365 nm uv light at room temperature on various irradiation times, i.e. 10,20,30,40 and 60 minutes. At certain irradiation time, the dispersion was filtered and the filtrate was then analyzed its concentration using uv-vis spectrophotometry method. Characterization results exhibited that the formation of TiO2 on internal as well as external surfaces of zeolite could not be detected with x-ray diffractometry and FT-IR spectrophotometry, however determination of titanium using x-ray fluorescence analysis on the calcined product showed that the concentration of titanium was much higher than zeolite (0.22% on zeolite and 12.08% on TiO2-zeolite). Gas sorption surface area (16,31 m2/g on zeolite and 100,96 m2/g on tiO2-zeolite) as well as total pore volume of calcined product (13,34 mL/A/g on zeolite and 57,54 mL/A/g on TiO2-zeolite). Photocalytic activity test result conducted on that dye showed that ca 99% of Congo Red was degraded by the system TiO2-zeolite after uv irradiation for 60 minutes. Keywords : TiO2-zeolite, Photocatalytic, UV-irradiation, Congo Red

Analysis of Quantitative Structure and Solubility Relationship for Organophospate Active Compounds Linear Model and Cluster Model Approach

Jurnal ILMU DASAR Vol 8 No 1 (2007)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

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Abstract

Study on quantitative solubility and structure relationship of organophospate pesticide has been conducted. Aim of this research is to analyze relationship between characteristic physical properties (water solubility) of pesticide with molecular structure by a model that can be used to predict physical properties of new compound proposed to be pesticide compound. Analysis was done for 52 organopospate compounds and its water solubility data. The model predicted by 39 fagmental descriptor based on spesific structure of organophospate compound. Analysis used in modeling are cluster analysis, one way analysis of variance (ANOVA) and regression analysis. Result show water solubility of the pesticide compound positive effect by functional group of P=O, N-primer and C=O in the structure. Functional group of S (sulphur), fen (phenil) , C-aromatic, C1-C2, C3-C4, C5-C6, Ortho Aromatic, P=S, C-Cl and log(Mr) decrease water solubility. The model resulted by regression analysis using stepwise and best subset method is : Ln(1+watsol) = 11.0 - 0.352 n C (aromatic) - 5.41 n (P=S) - 1.55 n (C-Cl), F-value = 32.43 (sign. 0,000) , R2 = 0.67 dan S=2.643. The model can be used to predict the organoposphate water solubility.Keywords : QSPR, ANOVA, regression analysis, organophospate pesticide

IMPROVEMENT OF THE PRODUCT AND QUALITY OF POGOSTEMON CABLIN BENTH

Eksakta: Jurnal Ilmu-Ilmu MIPA VOLUME 14, ISSUE 1, February 2014
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

Pogostemon cablin benth is an economic source of farmer communities which are presence in several provinces in Indonesia. In general, the production and quality of the Pogostemon cablin benth produced by the farmers are still low or under the standard ISO. The chelating method, the influence of pH and adsorption method with activated carbon and montmorilonite  were carried out to improve the production and quality of Pogostemon cablin benth. The results show that the production and the quality tends to be better proved by the color changes to yellow bright, reduced metal contents and an increase in Pogostemon cablin benth

Synthesis of Metal and Metal Oxide Nanoparticles Using Plant Extract: a Review

Eksakta: Jurnal Ilmu-Ilmu MIPA VOLUME 17, ISSUE 1, February 2017
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

Nanotechnology is an emerging technology and it is related to various applications. Related to nanotechnology development, the use of green chemistry concept, low cost technology and sustainability is a must. Synthesis of nanoparticles using plant extract is a developing technique within the scheme. In this paper, study on metal/metal oxide synthesis and its aspects is presented for describing the potency of natural resources for nanoparticle synthesis within green chemistry approach.

The Effect of CaO Weight from Snail Shell (Pilla Ampullacea) On Its Activity As Heterogeneous Catalyst on Biodiesel Conversion Of Bran Oil

Eksakta: Jurnal Ilmu-Ilmu MIPA VOLUME 18, ISSUE 1, February 2018
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

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Abstract

Research on utilization of snail (Pilla ampullacea) shell as CaO source for biodiesel conversion from rice bran oil has been investigated. CaO was derived by calcining the shell at pada 900oC for 2 h. The powder obtained from the process was characterized using x-ray diffraction (XRD),  energy dispersive x-ray (EDX), Fourier-Transform Infra-red (FTIR) and surface basicity test. In order to test the activity of catalyst, effect of catalyst weight on the yield of conversion as studied. Results show that the derived material is composed from dominantly CaO and the material demonstrates activity in rice bran conversion into biodiesel. Compared to  NaOH, the CaO catalyst exhibits more effectively active as shown by the higher yield. From varied catalyst weight, it is obtained that at the range of 2.5-10% catalyst weight does not affect significantly to the increasing yield.