Garuda - Garba Rujukan Digital

p-Index From 2020 - 2025

2.976

P-Index

This Author published in this journals

All Journal VALENSI SAINS DAN MATEMATIKA JURNAL KIMIA SAINS DAN APLIKASI Jurnal Sains Dasar Bulletin of Chemical Reaction Engineering & Catalysis Elkawnie Indonesian Journal of Chemistry ASEAN Journal of Chemical Engineering Jurnal Abdimas Perbanas Greensphere: Journal of Environmental Chemistry Bulletin of Chemical Reaction Engineering & Catalysis JURNAL REKAYASA KIMIA & LINGKUNGAN Jurnal Wicara Desa

Adi Darmawan

Chemistry Department, Faculty Of Sciences And Mathematics, Diponegoro University, Jl. Prof. Soedarto, SH., Tembalang, Semarang|Diponegoro University|Indonesia

Author-ID : 249994

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Economics, Econometrics & Finance Education Energy Engineering Languange, Linguistic, Communication & Media Mathematics Public Health Social Sciences

Published : 36 Documents Claim Missing Document

Claim Missing Document

Articles

1 2 3 4

The Characterization of Oyster Shell (Crassostrea gigas) as Adsorbent in The Removal of Cr(VI) Ions. A Study of NaOH and H2SO4 Activation Effect Lia Handayani; Cut Rahmawati; Nurhayati Nurhayati; Yayuk Astuti; Adi Darmawan
Elkawnie: Journal of Islamic Science and Technology Vol 6, No 1 (2020)
Publisher : Universitas Islam Negeri Ar-Raniry Banda Aceh

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22373/ekw.v6i1.5543

Abstract : Oyster shell as one of the highest bio-waste in Alue Naga Aceh Besar District, Indonesia, was used as an adsorbent to remove a heavy metal Cr (VI) ion. The study was started by calcinating oyster shells at a high temperature of 800 ºC for 3 hours. The effect of various acid (H2SO4) and base (NaOH) activator was studied using characterization and adsorption experiments. The characterization obtained the sample activated by 10% NaOH (Na10-ACT) and 10% H2SO4 (H10-ACT) had the highest surface area which had 14.23 m2/g, 10.77 m2/g, respectively. Furthermore, the adsorption experiments confirmed the highest surface area by showing the highest Cr (IV) ion removal of 57.66%, 70.7%, respectively. The further investigation using X-ray fluorescence (XRF) determined that the Na10-ACT adsorbent has a better composition compared to the H10-ACT due to its high purities.Abstrak : Cangkang tiram sebagai salah satu bio-limbah padat di Desa Alue Naga Kabupaten Aceh Besar, digunakan sebagai adsorben untuk menghilangkan ion logam berat Cr (IV). Penelitian ini diawali dengan mengkalsinasi cangkang tiram pada temperatur tinggi 800ºC selama tiga jam. Pengaruh penambahan aktivator asam (H2SO4) dan basa (NaOH) juga dipelajari melalui karakterisasi dan pengujian adsorpsi. Hasil karakterisasi menunjukkan sampel yang diaktivasi dengan 10% NaOH (Na10-ACT) dan 10% H2SO4 (H10-ACT) memiliki luas permukaan tertinggi yaitu 14,23 m2/g, 10,77 m2/g, masing-masing. Lebih lanjut, pengujian adsorpsi juga mendukung luas permukaan yang tinggi dengan menghilangkan ion Cr (IV) sebesar 57,66%, 70,7%, masing-masing. Investigasi melalui analisa XRF menyimpulkan bahwa Na10-ACT memiliki komposisi yang lebih baik dibanding H10-ACT karena memiliki kemurnian yang tinggi.

Effect of Polymer Concentration on the Photocatalytic Membrane Performance of PAN/TiO2/CNT Nanofiber for Methylene Blue Removal through Cross-Flow Membrane Reactor Lathifah Puji Hastuti; Ahmad Kusumaatmaja; Adi Darmawan; Indriana Kartini
Bulletin of Chemical Reaction Engineering & Catalysis 2022: BCREC Volume 17 Issue 2 Year 2022 (June 2022)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.17.2.13668.350-362

A photocatalytic membrane combining photocatalyst and membrane technology based on polyacrylonitrile (PAN) and TiO2/CNT has been developed. Such combination is to overcome fouling formation on the membrane, thus prolonging the membrane lifetime and enhancing the efficiency on the waste treatment. PAN nanofiber was prepared by electrospinning method. The precursor solution was dissolved PAN and dispersed TiO2/CNT in N,N-Dimethylformamide (DMF). PAN concentration in the precursor solution was varied at 4.5, 5.5, 6.5, 7.5, and 8.5%. The effect of PAN concentration on the fiber morphology and pore size was discussed. The performance of the resulted membrane on methylene blue (MB) removal was also investigated on a cross-flow system. SEM images of the resulted membrane identified that PAN nanofiber was successfully fabricated with random orientation. The PAN 6.5% showed the highest diffraction intensity of the anatase crystalline phase of TiO2. The additions of CNT and TiO2 lead to the formation of a cluster of beads as confirmed by TEM. Increasing the concentration of PAN increased the fiber diameter from 206 to 506 nm, slightly decreased the surface area and pore size, respectively, from 32.739 to 21.077 m2.g−1 and from 6.38 to 4.75 nm. The PAN/TiO2/CNT nanofibers show type IV of the adsorption-desorption N2 isotherms with the H1 hysteresis loops. Membrane PAN/TiO2/CNT at PAN concentration of 6.5% shows the optimum performance on the MB color removal by maintaining the percentage of rejection (%R) at 90% for 240 min and permeability of 750 LMH. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Bismuth Oxide Prepared by Sol-Gel Method: Variation of Physicochemical Characteristics and Photocatalytic Activity Due to Difference in Calcination Temperature Yayuk Astuti; Brigita Maria Listyani; Linda Suyati; Adi Darmawan
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.53144

Research on synthesis of bismuth oxide (Bi2O3) using sol-gel method with varying calcination temperatures at 500, 600, and 700 °C has been done. This study aims to determine the effect of calcination temperature on the characteristics of the obtained products which encompasses crystal structure, surface morphology, band-gap energy, and photocatalytic activity for the decolorization of methyl orange dyes through its kinetic study. Bismuth oxide prepared by sol-gel method was undertaken by dissolving Bi(NO3)3·5H2O and citric acid in HNO3. The mixture was stirred then heated at 100 °C. The gel formed was dried in the oven and then calcined at 500, 600, and 700 °C for 5 h. The obtained products were a pale yellow powder, indicating the formation of bismuth oxide. This is confirmed by the existence of Bi–O and Bi–O–Bi functional groups through FTIR analysis. All three products possess the same mixed crystal structures of α-Bi2O3 (monoclinic) and γ-Bi2O3 (body center cubic), but their morphologies and band gap values are different. The higher the calcination temperature, the larger the particle size and the smaller the band gap value. The accumulative differences in characteristics appoint SG700 to have the highest photocatalytic activity compared to SG600 and SG500 as indicated by its percent degradation value and decolorization rate constant.

Hydrocracking of Coconut Oil on the NiO/Silica-Rich Zeolite Synthesized Using a Quaternary Ammonium Surfactant Sriatun Sriatun; Heru Susanto; Widayat Widayat; Adi Darmawan
Indonesian Journal of Chemistry Vol 21, No 2 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.55522

NiO/silica-rich zeolite catalysts were used for coconut oil hydrocracking. The catalyst was prepared with a mixture of Na2SiO3, Al(OH)3, NaOH, and quaternary ammonium surfactants. The surfactant was varied of types like as tetrapropylammonium bromide (TPAB) and cetyltrimethylammonium bromide (CTAB). The acidity of the silica-rich sodalite zeolites enhances with the increase in nickel oxide added through a wet impregnation. The hydrocracking process was carried out by a semi-batch method. Liquid products were analyzed using GC-MS. The results showed that the addition of surfactants increased the catalyst surface area and acidity. Meanwhile, the presence of nickel oxide increases the acidity of the catalyst. The hydrocracking results showed an increase in gas products when the surface area was high, i.e., 23.781% in silica-rich sodalite zeolite without template (Z), 32.68% in silica-rich sodalite zeolite with tetrapropylammonium (ZTPA), and 39.673% in silica-rich sodalite zeolite with cetyltrimethylammonium (ZCTA). The presence of NiO increased the liquid product and the selectivity of the bioavtur fraction (C10-C15), where the highest percentage of liquid product was 60.07% at NiO/ZTPA.

Statistical Approaching for Superhydrophobic Coating Preparation using Silica Derived from Geothermal Solid Waste S Silviana; Adi Darmawan; Agus Subagio; Febio Dalanta
ASEAN Journal of Chemical Engineering Vol 19, No 2 (2019)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Material quality can be affected by humidity resulting in short durability. Many observations have been conducted to endure the durability of material, such as coating methods. However, recent methods are unaffordable. Therefore, this paper observes efficient and effective method to prepare superhydrophobic silica coatings derived from geothermal waste. The method was conducted by spraying. The objective of this paper is to observe optimum condition by using variables of silica concentration, TMCS (trimethylsilyl chloride) concentration, solvents and materials confirmed by contact angle of material based on statistical analysis. The study consisted of silica treatment for purification and preparation of superhydrophobic silica coatings. The study was carried out in factorial design of 81 experiments with one-time replication through Design Expert software (version 8.0.6). Based on previous research, the experiment was obtained optimum condition at 5.5 %w/v, 13 %v/v, isooctane, zinc coated for silica concentration, TMCS concentration, solvent and material, respectively, releasing contact angle by instrumentation of 180°. By ANOVA analysis, it was also complied the optimum condition of the superhydrophobic coating solution preparation achieved the same condition with experimental data releasing contact angle of 179.69°.

Silica-rich Sodalite Synthesis: The Effect of Variations in Ultrasound Treatment and Hydrothermal Temperature Sriatun Sriatun; Marta Chandra Anikke Putri; Hanifa Zakiyatul Urbach; Adi Darmawan; Widayat Widayat; Heru Susanto
Jurnal Kimia Sains dan Aplikasi Vol 25, No 4 (2022): Volume 25 Issue 4 Year 2022
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Silica-rich sodalite zeolite has been synthesized by ultrasound treatment and hydrothermal temperature variation. This study aimed to determine the effect of ultrasound treatment and hydrothermal temperature variations on the crystallinity, hydrophobicity, and structural properties of silica-rich sodalite zeolite. The synthesis was conducted by reacting a sodium aluminate and sodium silicate solution by varying Si/Al ratios of 20, 30, 40, 60, 80, and 90. The next step was to characterize the product. The product with the best crystallinity was used as a reference to determine the effect of ultrasound and hydrothermal temperature. The reaction gel was treated with and without ultrasound and hydrothermal using autoclave at 100, 150, and 200°C for 24 hours. The last step was the product characterization using XRD, FTIR, and GSA. The XRD showed similarity peaks at 2θ = 14.058°; 24.41°; 31.73°; 34.75°; 42.88°. The best crystallinity was silica-rich sodalite zeolite with a Si/Al ratio of 30. Meanwhile, silica-rich sodalite zeolite peaks were obtained at 2θ = 14.16°, 24.66°, 31.99°, 35.13°, and 43.39° by ultrasound treatment and hydrothermal temperature variation (100, 150, and 200°C). Ultrasound treatment revealed the presence of other peaks besides sodalite at 2θ = 19.05° and 27°, where these peaks were referred to as SAPO-56. In conclusion, the degree of crystallinity increased with increasing temperature, decreasing Si-OH/Si-O-Si showed increased hydrophobic properties. Increasing the hydrothermal temperature of 150 and 200°C with and without ultrasound treatment increased the surface area significantly to 114.137 m2/g and 160.717 m2/g, and the pore volume of sodalite with a Si/Al ratio of 30 to 0.318 cc/g and 0.274 cc/g.

Effect of pH on the Synthesis of Silica Sol-Gel Tetraethylorthosilicate-Trimethylchlorosilan (TEOS-TMCS) Artha Monica Andini; Choiril Azmiyawati; Adi Darmawan
Jurnal Kimia Sains dan Aplikasi Vol 25, No 11 (2022): Volume 25 Issue 11 Year 2022
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.25.11.394-398

Sol-gel synthesis of silica employing the co-precursor trimethylchlorosilane (TMCS) and the precursor tetraethylorthosilicate (TEOS) was accomplished. The purpose of this investigation was to ascertain how pH affected the properties of synthetic silica. The synthesized hydrophobic silica was characterized using FTIR, TGA, and GSA to determine the effect of pH adjustment on the functional group characters, thermal properties, and pore morphology. The ratio between TEOS/TMCS was fixed at 75:25 and varied the pH (4, 6, 7, 8, and 10) and the calcination temperature (without calcination, 300℃ and 500℃). FTIR analysis showed that the number of C-H and Si-OH groups in the xerogel decreased with increasing calcination temperature. Xerogel formed at pH 6 provides the highest thermal stability among other pHs. The results from the BET analysis revealed that changes in pH directly affect the physical characteristics of the surface, making the resulting gel network less rigid and more susceptible to shrinkage of pore volume and diameter in the atmosphere. Meanwhile, in an alkaline medium, continuous condensation will occur so that the pore diameter and volume decrease. The high pore diameter and volume imply that pH 7 is ideal for preparing xerogels.

Polyaniline Modified Natural Zeolite as Adsorbent for Chromium(III) Metal Ion Rina Nurianingsih; Sriatun Sriatun; Adi Darmawan
Jurnal Kimia Sains dan Aplikasi Vol 22, No 6 (2019): Volume 22 Issue 6 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Zeolite is an inorganic material whose surface has a permanent negative charge in its crystal structure. This material consists of tetrahedral [SiO4]-4 and [AlO4]-5, which are connected by oxygen atoms in such a way as to form an open three-dimensional framework containing canals and cavities, as well as alkali or alkali metals for balancing the negative charge. This structure makes zeolites have the ability to adsorb. The ability of natural zeolite adsorption can improve by modifying the surface by adding polyaniline cationic compounds (PANI), which have an amine group (: NH2). Moreover, environmental pollution by metals is the biggest problem in daily life, one of which is the metal ion Cr(III), which is a waste from industrial processes. Therefore, it is necessary to have an effort to reduce waste. This study aims to determine the effect of the addition of polyaniline on the adsorption ability of natural zeolites to metal ions Cr(III). The research was carried out in several stages, namely activation of natural zeolite using HF 1%, modification with polymer from aniline monomers, and ammonium peroxidisulphate (APS), and testing the ability of adsorption on Cr(III) metal ions. The study on the ability to adsorb Cr(III) metal ions by PANI-modified zeolites was carried out on variations in the concentration of Cr(III) metal ions and the system pH. The results showed that natural zeolite successfully modified with PANI. The FTIR absorption band at wavenumber 1303 -1319 cm-1 and 1597 cm-1 indicated the presence of NH functional groups. Meanwhile, adsorption capability test data showed that the best adsorbent for adsorption of Cr(III) metal ions was zeolite-PANI 0.01M. The best pH was 4, the initial concentration of Cr(III) metal ions was 1000 ppm, and the percentage of absorption is 48.13%.

Penggunaan Zeolit Alam Terdealuminasi Sebagai Adsorben Senyawa Aromatik Sriatun Sriatun; Adi Darmawan
Jurnal Kimia Sains dan Aplikasi Vol 10, No 1 (2007): Volume 10 Issue 1 Year 2007
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Sifat pembakaran bahan bakar sangat dipengaruhi oleh komponen senyawa yang terkandung didalamnya. Diketahui bahwa adanya senyawa hidrokarbon aromatik dapat memberikan asap yang berlebihan pada pembakaran. Tentu saja hal ini tidak menguntungkan karena menimbulkan polusi udara. Untuk mengurangi senyawa hidrokarbon aromatik dalam bahan bakar dapat menggunakan zeolit alam yang sudah didealuminasi karena zeolit mempunyai kelebihan dalam hal struktur, bentuk, ukuran rongga dan pori yang spesifik.Prosedur kerja dalam penelitian ini meliputi dealuminasi zeolit alam melalui pengasaman dengan HCl dan H2SO4 dan penambahan oksidator KMnO4.. Zeolit hasil dealuminasi digunakan untuk mengadsorpsi komponen hidrokarbon aromatik pada minyak bumi fraksi 200 – 300oC. Karakterisasi produk dilakukan dengan analisis titik anilinnya, kromatografi gas (GC) dan pemeriksaan warna.Hasil uji adsorpsi menunjukkan bahwa zeolit terdealuminasi mampu mengadsorp senyawa hidrokarbon aromatik tetapi tidak signifikan. Hal ini ditunjukkan oleh kenaikan titik anilin produk, perubahan kromatogram pada puncak-puncak tertentu dan warna produk lebih terang.

Pengaruh Substitusi Kaca terhadap Kuat Tekan dan Suhu Reaksi Semen Portland Adi Darmawan; Doddy Bestyan; Gunawan Gunawan
Jurnal Kimia Sains dan Aplikasi Vol 10, No 3 (2007): Volume 10 Issue 3 Year 2007
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dilakukan penelitian pengaruh substitusi kaca botol Coca Cola dan Pyrex terhadap kuat tekan dan suhu reaksi semen Portland. Penelitian dilakukan dengan mensubstitusi kaca pada semen portland Tiga Roda Indocement dengan variasi komposisi terhadap berat semen (5%,10%, 15%, 20%, 25%, 30%). Pengaruh substitusi dianalisis terhadap kuat tekan dan suhu reaksi. Analisis kuat tekan dilakukan dengan menggunakan compression test dan suhu reaksi dengan termometer.Hasil analisis menunjukkan bahwa kuat tekan semen meningkat dengan substitusi kaca. Substitusi kaca Pyrex menghasilkan kuat tekan yang lebih tinggi daripada substitusi kaca botol Coca Cola. Kuat tekan optimal yang didapat pada substitusi 10% kaca dan pada umur 28 hari. Dengan meningkatnya substitusi kaca maka suhu reaksi menurun.

Co-Authors . Widayat Agus Subagio Ahmad Kusumaatmaja Ahmad Suseno Al Aqad, Yuniar Rizki Rahmawati Amara, Nadya Amaryllis Kartika Ratri Andrew Pradana Putra Anna Sumardi Anna Sumardi Aptar Eka Lestari Aptar Eka Lestari Ari Kurniawan Artha Monica Andini Aulia Rahma Aulia Zahra Ekaningsih Azwar Thaib Brainy Happy Ana Tasiman Brigita Maria Listyani Choiril Azmiyawati Cut Rahmawati Dian Anggraini Dimas Buntarto Doddy Bestyan Dwi Rasy Mujiyanti Endang Sawitri Erdina Lulu Atika Rampun Evan Evan Faradina Azahra Zaqia Febio Dalanta Gunawan Gunawan Hakim, Muhamad Shaufil Hanifa Zakiyatul Urbach Hendri Widyandari Heru Susanto Indriana Kartini Isna Syauqiah Isna Syauqiah Khaerunnisa Khaerunnisa, Khaerunnisa Kristinawati, Leny Laksamana, Patria Lathifah Puji Hastuti Lia Handayani Lia Handayani Linda Selvianingrum Linda Suci Wati Linda Suciwati Linda Suyati Listiana Listiana Lusiana, RA. Maranti Sianita Marta Chandra Anikke Putri Muslimin Muthia Elma Nanik Sulistyowati Nurhayati Nurhayati Nurhayati Nurhayati Oktaffi Arina Manasikana P Siahaan Pardoyo Pardoyo Pulojuliadi Nababan Purnomo, Slamet Agus Putra, Muhammad Septian Dwi Putri, Aida Musyarrifah Hasri Rina Nurianingsih Rosmaliati, Rosmaliati Sani, Nabila Aulia Sari, Ainayya Amalia Saripudin Saripudin Silviana Silviana Sriatun Sriatun Sriyanti Sriyanti Suhartana Suhartana Suharyanto Susanto, Oki Novian Trie Nanda Mulyana Wasino Hadi Rahmanto Yanti Mawaddah Yanti Mawaddah Yayuk Astuti Zaini Lambri Assyaifi Zaini Lambri Assyaifi

Title

Found 36 Documents
Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title Search

Found 36 Documents Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 36 Documents
Search