Nurul Widiastuti, Nurul
Department of Chemistry, Sepuluh Nopember Institute of Technology (ITS), Jl. Arief Rahman Hakim, Sukolilo, Surabaya 60111

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IMPREGNATION NICKEL ON MESOPOROUS ZSM-5 TEMPLATED CARBONS AS A CANDIDATE MATERIAL FOR HYDROGEN STORAGE Ediati, Ratna; Mukminin, Amirul; Widiastuti, Nurul
Indonesian Journal of Chemistry Vol 17, No 1 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.23563

Abstract

A series of carbon with ZSM-5 mesoporous (ZMC) and Ni/ZMC ZSM-5 templates were synthesized and gravimetrically known its adsorption capacity to H2 gases. ZMC carbon was synthesized using a hard template method at a carbonation temperature of 900 oC with sucrose as a source of carbon. A mesoporous ZSM-5 template was synthesized by using a hydrothermal method at an aging and crystallization temperature of respectively 60oC and 150oC for as long as 24 hours. The characterized result of ZMC carbon using XRD powder has shown a diffracted pattern of amorphous carbon. Impregnating Ni with ZMC carbon each resulted in 5%, 15% and 25% of weight, which in turn also resulted in a diffractogram pattern of Ni/ZMC-5, Ni/ZMC-15, and Ni/ZMC-25, where each patterns were uniform and had no additional peaks. The results of SEM-EDAX showed that Ni had been successfully impregnated on the surface of ZMC carbon with a random morphology surface of ZMC carbon. The isothermal results of adsorption ? desorption of N2 showed that the larger the Ni loading on the supporting ZMC carbon, the smaller the surface area of the ZMC specific carbon. The distribution of the pore size that was counted by using the BJH method, which was applied to all the samples, was as big as 3,8 nm. The adsorption capacity of H2 was measured by using the gravimetry method at ambient temperature for Ni/ZMC-5, Ni/ZMC-15, and Ni/ZMC-25, which each gave a weight percentage of 0,331%; 0,663% and 0,649% respectively, whilst the ZMC carbon has a weight of 2,18%.
HYDROGEN ADSORPTION CHARACTERISTICS FOR ZEOLITE-Y TEMPLATED CARBON Wijiyanti, Rika; Gunawan, Triyanda; Nasri, Noor Shawal; Karim, Zulhairun Abdul; Ismail, Ahmad Fauzi; Widiastuti, Nurul
Indonesian Journal of Chemistry Vol 20, No 1 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.38978

Abstract

The hydrogen adsorption, kinetic and thermodynamic of adsorption onto the zeolite templated carbon (ZTC) were examined at the temperature range of 30-50 °C and ambient pressure. The ZTC was prepared from zeolite-Y template and sucrose carbon precursor by impregnation method and showed its specific surface area of 932 m2/g as well as 0.97 cm3/g for total pore volume. Analysis of physical and chemical characteristics for materials were performed using XRD, SEM, TEM and N2 isotherm. The results indicated that the ZTC has some ordered network structure of carbon and also exhibits the formation of carbon layer outside the zeolite micropore. We observed the ZTC for hydrogen adsorption both gravimetric and volumetric method up to 1.72 and 1.16 wt.% at the lowest temperature, respectively. The kinetic process at all studied temperature was best approximated by pseudo second order kinetic model. The aspects of thermodynamic such as heat of adsorption and the entropy change were -14.41 kJ/mol and -40.93 J/K mol, respectively. Both values was negative, indicating an exothermic reaction and low disorder at the hydrogen and ZTC interface, when the adsorption process took place. While, the enthalpy change value exhibits characteristic of physical process. The Gibbs energy change calculated at 30, 40 and 50 °C were -1.99, -1.59 and -1.19 kJ/mol, respectively, indicating a spontaneous adsorption process.
UKURAN PARTIKEL DAN KONFORMASI KRISTAL ZEOLIT-A HASIL SINTESIS DENGAN PENAMBAHAN TETRAPROPILAMMONIUM HIDROKSIDA (TPAOH) Widiastuti, Nurul; Thalib, Farhanah; Prasetyoko, Didik; Fansuri, Hamzah
Reaktor Volume 15, No.2, OKTOBER 2014
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (684.131 KB) | DOI: 10.14710/reaktor.15.2.132-138

Abstract

Abstract PARTICLE SIZE AND CRYSTAL CONFORMATION OF SYNTHESIZED ZEOLITE-A WITH TETRAPROPYLAMMONIUM HYDROXIDE (TPAOH) ADDITION. The aims of this research is to study the effect of tetrapropylammonium hydroxide (TPAOH) concentration in the synthesis of zeolite A to its physical characteristics such as crystallinity, crystal conformation and average crystal size. The zeolite A was synthesized with composition 3.165 Na2O : 1.000 Al2O3: 1.926 SiO2: 128 H2O : x TPAOH where x was 0; 0.0385; 0.0577; 0.0770; 0.1540 and 4.1602. The zeolite was crystalized under hydrothermal condition in a stainless steel autoclave at 100°C for 5 hours. The resulting crystal was washed with distilled water until pH 8 and then dried in an oven at 80oC for 24 hours. FT-IR and XRD analysis results show that the synthesized zeolite A at x = 4.1602 has the lowest crystallinity. It is estimated due to the mass of TPAOH was four times higger than the mass of zeolite framework components (Si and Al). SEM and PSD (Particle Size Distribution) analysis results show that TPAOH concentration affected the crystal conformation and the average size of zeolite A particles. The formation of chained crystal conformation was caused by the electrostatic interactions between TPA+ and negatively charge of zeolite framework. In addition, the particel size of the synthesized zeolite A at x = 0.1540 was 2.024 µm which was smaller than the particel size of the synthesized zeolite A without TPAOH, which was 3.534 µm.  Keywords: average size of particles; crystal conformation; TPAOH; zeolite A  Abstrak Penelitian ini bertujuan untuk mempelajari pengaruh konsentrasi TPAOH (Tetrapropilamonium hidroksida) dalam sintesis zeolit A terhadap sifat fisikanya yang meliputi kekristalan, konformasi kristal dan ukuran rata-rata kristal yang terbentuk. Pada penelitian   ini   zeolit A   disintesis    dengan komposisi 3,165 Na2O : 1 Al2O3 : 1,926 SiO2 :128 H2O: x TPAOH. Konsentrasi TPAOH divariasikan dengan nilai x adalah 0; 0,0385; 0,0577; 0,0770; 0,1540 dan 4,1602. Metode hidrotermal digunakan dalam penelitian ini dengan kondisi suhu  hidrotermal 100°C dan waktu kristalisasi selama 5 jam dengan pH pencucian 8. Hasil karakterisasi menggunakan FT-IR (Fourier Transform ? Infrared Spectroscopy) dan XRD (X-Ray Diffraction)  menunjukkan bahwa zeolit A yang disintesis dengan x = 4,1602 memiliki kekristalan terendah. Hal ini diperkirakan terjadi karena masa TPAOH yang digunakan empat kali lebih besar daripada masa penyusun zeolit (Si dan Al). Berdasarkan hasil karakterisasi menggunakan SEM (Scanning Electron Microscopy) dan PSD (Particle Size Distribution), dapat diketahui bahwa TPAOH berpengaruh terhadap konformasi kristal dan rata-rata ukuran kristalnya.  Terbentuknya konformasi kristal seperti rantai disebabkan oleh adanya interaksi elektrostatik antara muatan positif pada TPA+ dan muatan negatif dari kerangka zeolit. Zeolit A yang disintesis dengan x = 0,1540 memiliki ukuran partikel rata-rata 2,024 µm yang lebih kecil dari daripada zeolit A tanpa TPAOH yaitu sebesar 3,534 µm. Kata kunci : ukuran partakel rata-rata; konformasi kristal; TPAOH; zeolite A  
ADSORPTION OF Cu(II) ON ZEOLITE A SYNTHESIZED FROM COAL BOTTOM ASH OF PT. IPMOMI PAITON Said, Nurul Faradilah; Widiastuti, Nurul
Jurnal Zeolit Indonesia Vol 7, No 1 (2008)
Publisher : Jurnal Zeolit Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (586.259 KB)

Abstract

The study aimed to utilizing coal bottom-ash into zeolite A that was used as absorber metal ion of Cu(II). Zeolite A is made from bottom-ash using alkali fusion followed by hydrothermal processes. Melting temperature of Alkali conducted at 750°C during 12 h ours and hydrothermal processes at 100°C with molar ratio of SiO2/Al2O3 1,9. The result XRD showed that zeolite was formed is zeolite A. Product of Zeolite A was examined the ability of adsorption metal ions of Cu (II). In this test conducted several parameter variations that influences are period, concentration, pH, and temperature. The result showed that zeolite A can adsorbing Cu(II) up to 83,35% with the concentration of Cu(II) 50mg/l at pH 8 for 360 minutes. This study was learning some aspects of adsorption process were kinetic adsorption and isothermal adsorption. The result indicate that the kinetics adsorption of Cu(II) at zeolit A was following model of pseudo-first order, while isothermal adsorption is following model of Freundlich.
INFLUENCES OF TIME AND RATIO OF Si/Al ON FORMATION ZEOLITE A FROM BOTTOM ASH CARBON FREE PLTU PT. IPMOMI WITH HYDROTHERMAL METHODS Syukuri Nikmah, R. A.; Widiastuti, Nurul; Fansuri, Hamzah
Jurnal Zeolit Indonesia Vol 7, No 1 (2008)
Publisher : Jurnal Zeolit Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1271.659 KB)

Abstract

This study aimed to utilize bottom-ash PLTU PT. IPMOMI, Probolinggo. Synthesis zeolite A conducted with directly method of hydrothermal. Initially, bottom-ash calcined at temperature of 800oC during 4 hours for eliminating residu of carbon from baking of coal, then it was dissolved with alkali NaOH, NaAlO2 and water deionization with comparison molar of 3.165 Na2O: Al2O3: 1.926 SiO2: 128 H2O. Crystallization of hydrothermal conducted by variation time (12-144 hours) and ratio molar of Si/Al (1; 1.2 and 1.4). The result XRD analysis showed that kinds form of zeolite is mixture of zeolite A, X, P and sodalite. The most form dominant of Zeolite with various variations condition hydrothermal is zeolite A with orthorombik structure which was formed at hydrothermal temperature of 160°C during 24 hours.
SISTEM PENGAMBILAN KEPUTUSAN SELEKSI SISWA BERPRESTASI PADA SEKOLAH MENENGAH KEJURUAN (SMK) MA’ARIF 1 KALIREJO MENGGUNAKAN METODE AHP Haryani, Evi; Widiastuti, Nurul
Jurnal TAM (Technology Acceptance Model) Vol 5 (2015): Jurnal TAM (Technology Acceptance Model)
Publisher : LPPM STMIK Pringsewu

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (511.819 KB)

Abstract

Sekolah menengah kejuruan (SMK) ma’arif 1 Kalirejo, merupakan sekolahan yang memiliki visi dan misi menciptakan siswa berprestasi yang kelak setelah lulus nanti dapat membanggakan. Sehingga para siswa dituntut memiliki keterampilan khusus disertai dengan prestasi yang baik. Sebuah instansi harus mengmbil keputusan yang tepat, bila hal ini dilakukan dengan baik dan benar maka akan menghasilkan pemilihan siswa yang berkualitas dan dapat dipertanggungjawabkan kelak nanti. Untuk melakukan proses seleksi tersebut maka perlu di bentuk suatu sistem pendukung keputusan guna menyelesaikan masalah yang ada yaitu menggunakan Analitycal Hierachy Proses (AHP) sebagai metode pengambilan keputusan. Metode AHP adalah metode sintesa dari perhitungan eigen vector berbasis pada matriks pebandingan berpasangan dari prameter kriteria dan alternatif yang berasal langsung dari responden. Pada metode ini peneliti menggunakan empat faktor kriteria yaitu : Prestasi , Kehadiran (absensi), sikap dan bakat. Hasil dari penelitan ini memudahkan pengambilan keputusan dalam menentukan siswa berprestasi dengan kriteria-kriteria yang telah disusun dengan menggunaka metode AHP.
Crystal Phase and Surface Morphology of Zeolite-Y Templated Carbon with K2CO3 and ZnCl2 Activation Anggarini, Ufafa; Agustina, Eva; Widiastuti, Nurul
Indonesian Journal of Chemistry Vol 15, No 3 (2015)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (308.369 KB) | DOI: 10.22146/ijc.21201

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Zeolite-Y templated carbon (ZTC) has been activated with K2CO3 and ZnCl2. This research aims to compare the characteristics of ZTC with K2CO3 and ZnCl2 activation. ZTC was synthesized via impregnation method followed by carbonization. In this research, activation process was conducted at variation of activator/carbon weight ratio of 1 and 1.50. The activation was carried out by heating up impregnated carbon at 800 °C for 1 h followed by washing to remove inorganic salt. XRD and SEM results indicate that the use of different activator produce ZTC with varied structure and morphology. Diffractogram results showed that the graphitic peak decreased due to K2CO3 activation, whereas graphitic peak increased owing to ZnCl2 activation. Decreasing the graphitic peak indicates that ZTCs have higher pore structure formation. In addition, surface formation of ZTC activated by K2CO3 was higher than by ZnCl2 activation. The higher pore structure formation means the amount of carbon deposited on external surface material was decreased.
Synthesis of Zeolite-X Supported on Kapok Fiber for CO2 Capture Material: Variation of Immersion Time during Fiber Activation Lakapu, Mada Mariana; Widiastuti, Nurul
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (246.832 KB) | DOI: 10.22146/ijc.25162

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Zeolite-X is a potential material for CO2 adsorption. To increase the performance of zeolite-X, kapok fiber was used as a support material. The growth of zeolite-X on the surface of kapok was affected by activation of the surface. This research aims to optimize the immersion time of kapok fiber using NaOH in order to achieve high crystallinity of the zeolite-X. The Zeolite-X supported on kapok fiber was synthesized by the simple hydrothermal method at immersion time variation of 12 to 36 h. XRD results show that zeolite-X on kapok surface has the highest crystallinity at immersion time of 24 h. The topography of kapok surface from AFM indicates that the surface was damaged due to peeling reaction of NaOH. SEM results show that zeolite-X has grown on the kapok surface in considerable amounts. From TGA analysis, it was shown that the thermal stability of zeolite-X supported on kapok surface was up to 300 °C. Adsorption of CO2 measured by gravimetric method shows that CO2 adsorption capacitywas up to 15.097 wt.% at room temperature.
Synthesis of Zeolite-X Supported On Glasswool for CO2 Capture Material: Variation of Immersion Time and NaOH Concentration at Glasswool Activation Wardani, Anggita R.K.; Widiastuti, Nurul
Indonesian Journal of Chemistry Vol 16, No 1 (2016)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (494.942 KB) | DOI: 10.22146/ijc.21169

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Zeolite X supported on fiber material (glasswool) was successfully synthesized using a simple hydrothermal method. Variation of immersion time and NaOH concentration were used for glasswool activation. Activation process of glasswool has effects toward crystallinity and growth of zeolite X on glasswool surface. The results of characterization using XRD, SEM and AFM showed that zeolite X crystal grew on glasswool surface with high crystallinity using NaOH concentration 4M for 24 h. BET surface area and pore characteristics were analyzed by N2 isothermal adsorption. Carbon dioxide adsorption measurement using gravimetric method showed that zeolite X supported on glasswool has capability to capture carbon dioxide at room temperature up to 2.83 weight %.
The Modification of PVDF Membrane via Crosslinking with Chitosan and Glutaraldehyde as the Crosslinking Agent Silitonga, Romaya Sitha; Widiastuti, Nurul; Jaafar, Juhana; Ismail, Ahmad Fauzi; Abidin, Muhammad Nidzhom Zainol; Azelee, Ihsan Wan; Naidu, Mahesan
Indonesian Journal of Chemistry Vol 18, No 1 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (536.85 KB) | DOI: 10.22146/ijc.25127

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Poly(vinylidene fluoride) (PVDF) has outstanding properties such as high thermal stability, resistance to acid solvents and good mechanical strength. Due to its properties, PVDF is widely used as a membrane matrix. However, PVDF membrane is hydrophobic properties, so as for specific applications, the surface of membrane needs to be modified to become hydrophilic. This research aims to modify PVDF membrane surface with chitosan and glutaraldehyde as a crosslinker agent. The FTIR spectra showed that the modified membrane has a peak at 1655 cm-1, indicating the imine group (–N=C)- that was formed due to the crosslink between amine group from chitosan and aldehyde group from glutaraldehyde. Results showed that the contact angle of the modified membrane decreases to 77.22° indicated that the membrane hydrophilic properties (< 90°) were enhanced. Prior to the modification, the contact angle of the PVDF membrane was 90.24°, which shows hydrophobic properties (> 90°). The results of porosity, Ɛ (%) for unmodified PVDF membrane was 55.39%, while the modified PVDF membrane has a porosity of 81.99%. Similarly, by modifying the PVDF membrane, pure water flux increased from 0.9867 L/m2h to 1.1253 L/m2h. The enhancement of porosity and pure water flux for the modified PVDF membrane was due to the improved surface hydrophilicity of PVDF membrane.