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All Journal Jurnal Pengolahan Hasil Perikanan Indonesia VALENSI JURNAL KIMIA SAINS DAN APLIKASI Jurnal Sains Materi Indonesia Jurnal Penelitian Hasil Hutan Jurnal Riset Kimia IJFAC (Indonesian Journal of Fundamental and Applied Chemistry) Indonesian Journal of Chemical Science Science and Technology Indonesia Al-Kimia Jurnal Kartika Kimia Jurnal Penelitian Hasil Hutan JURNAL REKAYASA KIMIA & LINGKUNGAN Jurnal Penelitian Hasil Hutan
Tetty Kemala
Departemen Kimia, FMIPA - IPB Kampus IPB Darmaga, Gedung Fakultas Peternakan, Bogor-16680
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Decision Sciences, Operations Research & Management Education Energy Engineering Environmental Science Materials Science & Nanotechnology Physics

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Decolorization of Synthetic Dyes by Laccase of Phellinus noxius BRB 11 Immobilized with Halloysite Nanotubes Naser, Inda Hastuti N; Kemala, Tetty; Yanto, Dede Heri Yuli; Purwaningsih, Henny; Nurhayat, Oktan Dwi; Ardiati, Fenny Clara; Bakar, N.H.H Abu; Iqbal, Anwar
Science and Technology Indonesia Vol. 10 No. 2 (2025): April
Publisher : Research Center of Inorganic Materials and Coordination Complexes, FMIPA Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26554/sti.2025.10.2.644-659

Abstract

Halloysite nanotubes (HNTs) have been proposed as promising supports for enzyme immobilization. Developing an effective technique for enzyme immobilization on HNTs is crucial for their practical application. In this study, we present a method for immobilizing laccase enzymes on HNTs using various amino acids as green cross-linkers for eco-friendly decolorization of synthetic dye. The modified HNTs were characterized using FT-IR, FE-SEM, and HR-TEM analyses. Furthermore, the effects of various parameters—including pH (ranging from 3 to 8), temperature (30-70°C), toxicity, and reusability—on the activity of both free and immobilized laccase were investigated. The results indicated that glycine (Gly) provided the most effective support for laccase immobilization on HNTs. The modified HNTs/Gly-Lac achieved an immobilization yield of 98.45% and successfully decolorized 94.60% of Acid Blue 129 (AB129) within 2 h. The successful immobilization of laccase onto functionalized HNTs was confirmed through FT-IR, FE-SEM, and HR-TEM analyses. Morphological observations of HNTs/Gly for laccase immobilization showed a thickened and roughened appearance with a thin, light gray layer on the outer surface. Additionally, the presence of an imine (-C=N-) bond peak and a peak at 1410 cm-1, corresponding to the (-NH) bond, suggested successful covalent immobilization. The toxicity analysis revealed a reduction in the toxicity of laccase after immobilization onto modified HNTs. A reusability assessment conducted over five cycles demonstrated that decolorization efficiency remained above 45%. These findings suggest that HNTs/GlyLac could serve as an effective material for textile dye wastewater treatment.
Impact of Modifying Filler into Porous on Hydrophobicity Behaviour of The Silica-HDPE Composite Defrizal, Muhammad; Kemala, Tetty; Khotib, Mohammad
Jurnal Kimia Sains dan Aplikasi Vol 28, No 4 (2025): Volume 28 Issue 4 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.4.168-175

Abstract

Even though the approach is relatively simple and does not require additional treatment, the porous filler method has not been widely utilized to boost the composite’s hydrophobicity. Therefore, this study wants to show that silica’s porosity as a filler material affects the surface roughness and hydrophobicity of its composite (in this case, silica-HDPE). Pore formation in silica uses the soft-template method with Tween-80 as the mould. The amount of surfactant was varied by 0, 5, and 10 g. The particles are then physically composited into the HDPE matrix. Surface characterization of silica particles analyzed by Brunauer-Emmett-Teller (BET) shows enhancement in particle porosity as the amount of surfactant added is increased. When it is inserted into HDPE, the silica particles with the highest porosity have the greatest surface roughness. It is confirmed by the wavy surface texture of this composite when it is characterized using an Atomic Force Microscope (AFM). These results are accompanied by a significant enhancement in the contact angle value at each concentration. From the contact angle and AFM data, porous silica has the role of surface texture provider in raising its roughness. It affects the improvement of the hydrophobicity according to the Cassie-Baxter equation, which states that the more air fraction formed on a surface, the higher the contact angle obtained.
The Heat Resistant Capabilities of Bioplastic Composites on Sago Hampas Starch-Al2O3 Amatullah, Afra Najiyah; Kemala, Tetty; Irawadi, Tun Tedja
Jurnal Rekayasa Kimia & Lingkungan Vol 17, No 2 (2022): Jurnal Rekayasa Kimia & Lingkungan (December, 2022)
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v17i2.25520

Abstract

Sago hampas are a waste with a high starch content. The starch from sago hampas can be used as a raw material for bioplastics. However, because bioplastics have a lower heat resistance than conventional plastics, additives are required to increase heat resistance. Aluminum oxide can be used as a metal compound that acts as an additive to increase heat resistance. Bioplastics were created using a weight percentage of 0, 1, 3, and 5% Al2O3. DTA was used to determine the melting point of bioplastics, as well as their mechanical properties, density, and water resistance. The best results were identified using FTIR and SEM. The results showed that adding Al2O3 at 1, 3, and 5% increased the heat resistance of bioplastics with melting points of 270, 274, and 280 oC. Except for mechanical properties, the best results were obtained with a melting point of 280 oC, tensile strength of 3.41 Mpa, elongation of 38.66%, density of 5.52 g cm-3, and 80.28% water resistance for bioplastics with 5% Al2O3 that suitable on Indonesian National Standard 7188.7:2016. The FTIR analysis revealed that bioplastics containing Al2O3 experienced physical interactions. Morphological analysis revealed that Al2O3 was evenly distributed on the bioplastic's surface.
Physical, Mechanical, and Antioxidant Properties of Edible Film from Jackfruit Seed Starch and Microcellulose with Addition of Green Tea Extract Kemala, Tetty; Nada, Nida Kotrun; Arifin, Budi
Jurnal Riset Kimia Vol. 16 No. 1 (2025): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v16i1.709

Abstract

Edible films are gaining popularity as biodegradable alternatives to plastic packaging. Starch-microcellulose-based edible films are known to exhibit favorable physical and mechanical properties. However, enhancing their resistance to deterioration as food packaging is essential for extending shelf life of the product. This study aimed to develop edible films from jackfruit seed starch and microcellulose with the incorporation of green tea extract and to evaluate its effects on the films’ antioxidant activity, physical, and mechanical properties. Edible films were prepared with green tea extract at concentrations of 2.5%, 5%, 7.5%, and 10% (w/w of total starch). The produced films exhibited a smooth and elastic texture. The addition of green tea extract enhanced antioxidant properties, as indicated by an increase in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, with the highest activity observed at 10% extract concentration. Furthermore, the extract improved the films' thickness, density, tensile strength, and elongation while reducing water absorption and water vapor transmission rate. However, the mechanical properties did not yet meet the Indonesian National Standard for packaging materials.
Modified Natural Rubber Based on the Sulphur Curing System as Rubber Compound Formulation on Basic Design of Seismic Bearing Cifriadi, Adi; Sugita, Purwantiningsih; Kemala, Tetty; Nikmatin, Siti; Puspitasari, Santi; Falaah, Asron Ferdian; Wijaya, Usman
Jurnal Kimia Valensi Jurnal Kimia VALENSI, Volume 10, No. 2, November 2024
Publisher : Department of Chemistry, Faculty of Science and Technology Syarif Hidayatullah Jakarta State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v10i2.39963

Abstract

Indonesia is highly susceptible to earthquakes, with the southern and western coasts of Java and Sumatra being the most vulnerable regions. Due to this vulnerability, it is necessary to establish a culture of disaster mitigation in the most fertile and heavily populated islands to reduce the number of fatalities and economic losses caused by earthquakes. One of the promising real-world seismic base isolation methods is using a rubber seismic bearing constructed of rubber and metal layers. This study aimed to examine the typical behavior of natural rubber compounds subjected to various sulfur-curing processes as basic designs in the manufacture of rubber seismic bearings. The experiment was carried out by arranging the sulfur curing system into three categories, namely an efficient which applied N-cyclohexyl-2-benzothiazole sulfonamide (CBS)/Sulfur (S) ratio as 1.4/0.15 and 1.4/0.25, semi-efficient with CBS/S ratio of 1.4/1.4 and 1.4/1.7, and conventional with CBS/S ratio of 1.4/3.0 and 1.4/3.5. The results showed that the ideal modification condition for NR macromolecule chain found in seismic-bearing rubber compound was a semi-efficient sulfur curing system with a CBS/S ratio of 1.4/1.4. It suggested that a semi-efficient sulfur curing system was appropriate for developing rubber compound formulation for seismic rubber bearings, mainly for low-damping types.
PERAN GLUKOMANAN-ARANG AKTIF SEBAGAI HIPOKOLESTEROLEMIK PADA TIKUS SPRAGUE DAWLEY Agus Malik Ibrahim; Irma Herawati Suparto; Tetty Kemala; Gustan Pari
Jurnal Penelitian Hasil Hutan Vol. 34 No. 4 (2016): Jurnal Penelitian Hasil Hutan
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/jphh.2016.34.4.359-371

Abstract

Cholesterol is a metabolite which contains sterol fat, which is important to support cell functions and generate vitamin D, cortisol and reproduction hormones. Higher cholesterol content known as hypercholesterolemia is a predisposing towards cardiovascular disease. Previous study reported that glucommanan and activated charcoal individually can lower cholesterol levels, however combination both of them for lowering the cholesterol level has not been studied intensively. This paper examines the ability of glucommannan derived from Amorphophallus flour and activated charcoal in reducing cholesterol level of Sprague Dawley rat. Firstly, glucommanan was isolated from Amorphophallus flour and activated charcoal was produced from teak sawdust and coconut fiber. Both component were formulated and characterized using Fourier Transform Infra Red (FTIR), x-ray diffractometer and scanning electron microscope. Thirty five adult male Sprague Dawley rat with body weight of 160 to 200 g were divided into seven treatment groups: high-fat diet (DTL) and glucommanan, DTL and teak's activated charcoal (TC), DTL and cocout fiber's activated charcoal (CC), DTL and glucommanan and CC (1:1), DTL and glucommanan and CC (2:1), DTL and glucommanan and CC (1:2) and DTL without treatment as control. Initial rat cholesterol level was measured and it was compared with those after five weeks. Results show that the greatest cholesterol reduction (37.4%) is recorded from rat with DTL and glucommanan and CC (1:1) and low density lipoprotein reduction by about 49.7% and triglyceride reduction by 18.3%.
Development of Bioplastic Films from Cassava Peel Starch Reinforced with Banana Midrib Nanocellulose and the Effect of Sorbitol on Mechanical Strength Albarkah, Anita Maharani; Soebrata, Betty Marita; Kemala, Tetty
Jurnal Kimia Sains dan Aplikasi Vol 28, No 8 (2025): Volume 28 Issue 8 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.8.426-435

Abstract

Cassava peel and banana midrib, two abundant agricultural wastes, were utilized as sources of starch and cellulose to develop environmentally friendly bioplastic films. Cellulose was isolated through delignification and bleaching, followed by ultrasonication to produce nanocellulose. The obtained nanocellulose was characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and a Particle Size Analyzer (PSA), which confirmed distinct cellulose functional groups, a crystallinity index of 58.7%, and an average particle size of 326.44 nm. Bioplastic films were prepared by blending cassava peel starch with banana midrib nanocellulose and varying concentrations of sorbitol as a plasticizer. The incorporation of nanocellulose increased thickness, density, and tensile strength, while reducing water absorption and water vapor transmission rate (WVTR), likely due to the reinforcing effect of nanocellulose within the polymer matrix. The addition of sorbitol at different concentrations influenced the mechanical properties of the bioplastics, with the composition containing 0.89 g sorbitol exhibiting favorable tensile strength and elongation. The optimal formulation consisted of 2.85 g cassava peel starch, 0.15 g nanocellulose, and 0.89 g sorbitol, yielding a tensile strength of 2.76 MPa and an elongation of 11.19%. These findings demonstrate that incorporating sorbitol and nanocellulose significantly enhances the performance of starch-based bioplastics, highlighting their potential application in sustainable packaging materials.
Co-Authors Achmad Sjahriza Adi Cifriadi Adi Cifriadi, Adi Afra Najiyah Amatullah Agus Malik Ibrahim Ahmad Sjahriza Aisy, Laaili Azti Rohaadatul Albarkah, Anita Maharani Aloma Karo Karo Amatullah, Afra Najiyah Andi Nursanti Anjarsari Anjarsari Ardiati, Fenny Clara Armi Wulanawati Asron Ferdian Falaah, Asron Ferdian Bakar, N.H.H Abu Budi Arifin Charlena Dede Heri Yuli YANTO Deden Saprudin Defrizal, Muhammad Finaldin, Muhammad Alhas Gustan Pari Gustan Pari Harahap, Muslim Arfanshah Hendra Adijuwana Henny Purwaningsih Ibrahim, Agus Malik Iqbal, Anwar Irma Herawati Suparto Karim, Wouda Fiorendita Kiagus Dahlan Komar Sutriah M. Syaeful Fahmi Mardiana Hardianti Mohammad Khotib Nada, Nida Kotrun Naser, Inda Hastuti N Nina Hartati Nor Pana Yupa Noviyan Darmawan Nur Inayatullah Nurhayat, Oktan Dwi Obie Farobie Permana, Ifri Surya Pipih Suptijah Prakoso, Mochamad Galih Purwantiningsih Sugita Purwantiningsih Sugita Ravena Ravena Santi Puspitasari Siti Komariah Siti Nikmatin Sitompul, Dina Wardani Soebrata, Betty Marita Sudirman Sudirman Suminar S. Achmadi Suryanegara, Lisman Susi Nurdayat Tun Tedja Irawadi Tun Tedja Irawadi