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RISS 인기검색어
- 검색키워드
- 저자 : Remi Ayu Pratika (검색결과 3 건)
- 무료
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Wijaya, Karna,Pratika, Remi Ayu,Fitri, Edhita Rahmawati,Prabani, Prisnu Fadilah,Candrasasi, Yufinta,Saputri, Wahyu Dita,Mulijani, Sri,Patah, Aep,Wibowo, Arief Cahyo Materials Research Society of Korea 2022 한국재료학회지 Vol.32 No.3
Effect of sulfation processes on the physicochemical properties of ZrO<sub>2</sub> and TiO<sub>2</sub> nanoparticles were thoroughly investigated. SO<sub>4</sub>/ZrO<sub>2</sub> and SO<sub>4</sub>/TiO<sub>2</sub> catalysts were synthesized to identify the acidity character of each. The wet impregnation method of ZrO<sub>2</sub> and TiO<sub>2</sub> nanoparticles was employed using H2SO<sub>4</sub> with various concentrations of 0.5, 0.75, and 1 M, followed by calcination at 400, 500, and 600 ℃ to obtain optimum conditions of the catalyst synthesis process. The highest total acidity was found when using 1 M SO<sub>4</sub>/ZrO<sub>2</sub>-500 and 1 M SO<sub>4</sub>/TiO<sub>2</sub>-500 catalysts, with total acidity values of 2.642 and 6.920 mmol/g, respectively. Sulfation increases titania particles via agglomeration. In contrast, sulfation did not practically change the size of zirconia particles. The sulfation process causes color of both catalyst particles to brighten due to the presence of sulfate. There was a decrease in surface area and pore volume of catalysts after sulfation; the materials' mesoporous structural properties were confirmed. The 1 M SO<sub>4</sub>/ZrO<sub>2</sub> and 1 M SO<sub>4</sub>/TiO<sub>2</sub> catalysts calcined at 500 ℃ are the best candidate heterogeneous acid catalysts synthesized in thus work.
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Nanosulfated Silica as a Potential Heterogeneous Catalyst for the Synthesis of Nitrobenzene
Khairul Amri,Aan Sabilladin,Remi Ayu Pratika,Ari Sudarmanto,Hilda Ismail,Budhijanto,Mega Fia Lestari,오원춘,Karna Wijaya 한국재료학회 2023 한국재료학회지 Vol.33 No.7
In this study, the synthesis of nitrobenzene was carried out using sulfated silica catalyst. The study delved into H2SO4/SiO2 as a solid acid catalyst and the effect of its weight variation, as well as the use of a microwave batch reactor in the synthesis of nitrobenzene. SiO2 was prepared using the sol-gel method from TEOS precursor. The formed gel was then refluxed with methanol and calcined at a temperature of 600 °C. SiO2 with a 200-mesh size was impregnated with 98 % H2SO4 by mixing for 1 h. The resulting 33 % (w/w) H2SO4/SiO2 catalyst was separated by centrifugation, dried, and calcined at 600 °C. The catalyst was then used as a solid acid catalyst in the synthesis of nitrobenzene. The weights of catalyst used were 0.5; 1; and 1.5 grams. The synthesis of nitrobenzene was carried out with a 1:3 ratio of benzene to nitric acid in a microwave batch reactor at 60 °C for 5 h. The resulting nitrobenzene liquid was analyzed using GC-MS to determine the selectivity of the catalyst. Likewise, the use of a microwave batch reactor was found to be appropriate and successful for the synthesis of nitrobenzene. The thermal energy produced by the microwave batch reactor was efficient enough to be used for the nitration reaction. Reactivity and selectivity tests demonstrated that 1 g of H2SO4/SiO2 could generate an average benzene conversion of 40.33 %.
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Iqmal Tahir,Karna Wijaya,Mudasir,Dita Krismayanti,Aldino Javier Saviola,Roswanira Abdul Wahab,Amalia Kurnia Amin,Wahyu Dita Saputri,Remi Ayu Pratika 한국재료학회 2024 한국재료학회지 Vol.34 No.2
The optimization of deacetylation process parameters for producing chitosan from isolated chitin shrimp shell waste was investigated using response surface methodology with central composite design (RSM-CCD). Three independent variables viz, NaOH concentration (X1), radiation power (X2), and reaction time (X3) were examined to determine their respective effects on the degree of deacetylation (DD). The DD of chitosan was also calculated using the baseline approach of the Fourier Transform Infrared (FTIR) spectra of the yields. RSM-CCD analysis showed that the optimal chitosan DD value of 96.45 % was obtained at an optimized condition of 63.41 % (w/v) NaOH concentration, 227.28 W radiation power, and 3.34 min deacetylation reaction. The DD was strongly controlled by NaOH concentration, irradiation power, and reaction duration. The coefficients of correlation were 0.257, 0.680, and 0.390, respectively. Because the procedure used microwave radiation absorption, radiation power had a substantial correlation of 0.600~0.800 compared to the two low variables, which were 0.200~0.400. This independently predicted robust quadratic model interaction has been validated for predicting the DD of chitin.
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