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All Journal Jurnal Sains Materi Indonesia Jurnal Riset Industri Indonesian Journal of Chemistry Mesin JURNAL SELULOSA Jurnal Teknologi Bahan dan Barang Teknik Automotive Experiences Teknologika

Mardiyati, Mardiyati

Fakultas Teknik Mesin Dan Dirgantara, Institut Teknologi Bandung

Author-ID : 1214936

Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Education Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Other

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Pembuatan dan Karakterisasi Bioplastik Pati-Kitosan Dengan Menggunakan Metode Dialisis-Solution Casting Steven Steven; Mardiyati Mardiyati; Bambang Widyanto
Mesin Vol. 27 No. 1 (2018)
Publisher : Mesin

Show Abstract | Download Original | Original Source | Check in Google Scholar

Bioplastik pati merupakan salah satu solusi yang ditawarkan untuk mengatasi permasalahan yang ditimbulkan oleh material plastik konvensional. Namun dikarenakan ketahanan airnya yang buruk, bioplastik pati umumnya digabungkan dengan material yang memiliki ketahanan air yang lebih baik, seperti kitosan. Didalam pembuatan bioplastik pati-kitosan umumnya melibatkan asam asetat yang dapat membuat bioplastik yang dihasilkan menjadi asam dan kurang baik untuk dimanfaatkan pada beberapa aplikasi. Untuk mengatasi hal tersebut, pada penelitian ini dilakukan pembuatan bioplastik pati-kitosan dengan metode dialisis-solution casting. Tujuan dari penelitian ini adalah mempelajari pengaruh penambahan kitosan didalam bioplastik pati-kitosan. Didalam penelitian ini pembuatan bioplastik pati-kitosan dilakukan dengan menggunakan metode dialisis-solution casting. Untuk mengukur peforma dari bioplastik pati-kitosan dilakukan pengujian tarik, pengujian ketahanan air serta pengujian degradasi tanah. Pengujian tarik dilakukan dengan mengacu pada ASTM D882. Berdasarkan hasil pengujian yang telah dilakukan dapat disimpulkan bahwa seiring peningkatan konsentrasi kitosan didalam bioplastik pati-kitosan akan meningkatkan kekuatan tarik, kekakuan tarik, dan ketahanan air namun menurunkan perpanjangan dan kemampuan degradasi dari bioplastik pati-kitosan.

Serat Bambu Petung (Dendrocalamus asper) Teralkalisasi sebagai Penguat Komposit Polimer Gunawan Refiadi; Novan Bayu; Hermawan Judawisastra; Mardiyati Mardiyati
JURNAL SELULOSA Vol 8, No 01 (2018): JURNAL SELULOSA
Publisher : Center for Pulp and Paper

The alkalized of petung bamboo fiber (Dendrocalamus asper) as reinforcement of polymer compositeAbstractPetung bamboo (Dendrocalamus asper) has good fiber characteristic and it has potential to substitute glass fiber as reinforcement in polymeric composite. However, like other natural based materials, bamboo fiber has a high variability in mechanical properties and inherently hygroscopic characteristic. Therefore it is required to optimize the petung bamboo qualities. The fiber optimization was carried out by alkalization process using NaOH solution with varying concentration of 0, 3, 5, and 10% v/v. Bamboo fiber processed in chemomechanical was used in this investigation. Characterization of density, mechanical and chemicals was conducted by pycnometry method, tensile strength testing, Fourier Transform Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The data variability was analyzed by Weibull distribution. Result indicates that the optimum condition of alkalization process of bamboo fiber using NaOH solution of 5% v/v which has fiber diameter of 175.098 ± 58.017 mm, tensile strength of 384 MPa, and characteristics strength of 390.5 MPa.Keywords: petung bamboo; alkalization; characteristics AbstractBambu petung memiliki karakteristik serat yang baik sehingga berpotensi sebagai pengganti serat gelas untuk penguat komposit polimer. Namun, seperti umumnya serat alam, serat bambu memiliki variabilitas sifat mekanis tinggi dan sifat higroskopik yang inheren. Oleh karena itu diperlukan upaya optimalisasi kinerja serat bambu petung. Optimalisasi kinerja serat dilakukan melalui proses alkalisasi dengan variasi larutan NaOH pada konsentrasi 0, 3, 5, dan 10% v/v. Serat bambu hasil dari proses kimia-mekanik digunakan dalam penelitian ini. Karakterisasi densitas, sifat mekanik, dan sifat kimia serat masing-masing dilakukan dengan metode piknometri, uji tarik, Fourier Transform Spectroscopy (FTIR), Scanning Electron Microscopy (SEM). Analisis variabilitas data menggunakan distribusi Weibull. Hasil menunjukkan bahwa kondisi optimum alkalisasi serat bambu petung yaitu menggunakan larutan NaOH 5% v/v yang menghasilkan serat berdiameter 175,098 ± 58,017 mm, kekuatan Tarik 384 MPa, dan kekuatan karakteristik 390,5 MPa.Kata kunci: bambu petung; alkalisasi; karakteristik

Dispersibility of Multiwall Carbon Nanotube in a Polyanionic Surfactant Based on UV-Vis Analysis Yuyun Irmawati; Deni Shidqi Khaerudini; Indriyati Indriyati; Mardiyati Mardiyati; Rike Yudianti
Indonesian Journal of Chemistry Vol 20, No 5 (2020)
Publisher : Universitas Gadjah Mada

The degree of carbon nanotube (CNT) dispersion in an ink solution plays a critical role in the performance of CNT based devices. This is a challenging task in the CNT utilization due to strong van der Waals interaction affecting the CNT bundles. A good dispersion degree can be achieved, for instance, by lowering the van der Waals interaction with the strategy of non-covalent interaction between polyanionic surfactant and the CNT surface. Herein, a simple and quick technique to disperse multiwall CNT (MWCNT) by using a polyanionic dispersant, carboxymethyl cellulose (CMC), is reported. The dispersion degree of MWCNT in aqueous solution during the sonication process was studied using UV-Vis analysis. Transmission electron microscope (TEM) was also applied to further investigate the interaction between CMC and MWCNT. The result shows that the maximum dispersion of MWCNT was achieved with a maximum absorbance in the UV-Vis spectra. Higher CMC concentration resulted in a higher viscosity of the solution, thus it increased the sonication duration in obtaining the maximum dispersion. By varying the MWCNT concentration at a constant CMC concentration of 0.25 wt.%, a homogenous MWCNT dispersion was obtained up to 0.2 wt.%. The encapsulation of a thin CMC layer on the MWCNT surface with a thickness of 1.5–3 nm was evidenced by TEM micrograph analysis.

Potensi Pemanfaatan Serat Selulosa sebagai Material Bahan Baku dalam Sintesis Filter Udara Non-Woven sesuai Standar TAPPI T 205 Irwan Suriaman; Mardiyati; Jooned Hendrarsakti; Ari Darmawan Pasek
Jurnal Teknologika Vol 10 No 2 (2020): Jurnal Teknologika
Publisher : Sekolah Tinggi Teknologi Wastukancana

Industry 4.0 era materials used by entrepreneurs should be recycled, environmentally friendly, renewable with less chemical content. Indonesia as a tropical country has a large land area with the potential to produce the largest natural fiber in the world. One opportunity that can be applied to the utilization of natural fibers in air filters that currently use dominant materials is synthetic fibers. natural fiber has the advantage because it does not contain toxic chemicals, local raw materials, and is easily produced. This research will analyze the mechanical and morphological characteristics of biological fibers that have great potential as pre-filter raw material. Analysis of mechanical properties through tensile strength testing for single fibers and morphological analysis through scanning electron microscopy (SEM). Tensile testing was the results are; palm oil has a tensile strength of 620 MPa; 998 MPa and 213 MPa flax coconut fiber. For the morphological test results from SEM analysis for ramie fiber, it looks solid without fiber holes; The fibers appear to be many small fibers bound to one another while coir fibers have many pore holes in one observed fiber.

Multi-objective Optimization of Sansevieria Trifasciata Fiber Reinforced Vinyl Ester (STF/VE) Bio-composites for the Sustainable Automotive Industry Apang Djafar Shieddieque; Mardiyati Mardiyati; Sukarman Sukarman; Bambang Widyanto; Yulfian Aminanda
Automotive Experiences Vol 5 No 3 (2022)
Publisher : Automotive Laboratory of Universitas Muhammadiyah Magelang in collaboration with Association of Indonesian Vocational Educators (AIVE)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31603/ae.7002

Bio-composite materials have taken an extensive interest in research over the years due to their excellent properties, such as excellent mechanical and physical properties, stiffness, and low density/lightweight. The exceptional properties of bio-composite materials have had a widespread application in several industries, such as; the packaging industry, construction, automotive, and other related engineering fields. This research investigates mechanical, physical, and microstructure properties of Sansevieria Trifasciata (STE) natural fiber, -reinforced Vinyl Ester (STF/VE) bio-composite. The mechanical and physical properties of STF/VE bio-composites, including the tensile strength and density, are investigated through fibre preparation, orientation, and fibre volume fraction parameters. The STF/VE bio-composite tensile strength coupon is manufactured using the bio-composite transfer moulding (BTM) process and with pressure moulding. The Taguchi experimental design and analysis of variance (ANOVA) are selected to investigate the effect of variables on the mechanical properties model. The alkali preparation of STF, unidirectional fibre orientation, and fibre volume fraction improve tensile strength. Non-alkali treatment and random fibre orientatio, on the other hand, result in a reduction of density. The results of the ANOVA analysis show that the fibre volume fraction (wt.%) is the variable that most significantly affects the tensile strength and density responses, with contributions of 50.57% of tensile strength and 51.34% of density, respectively. Based on the optimization results, the STF/VE with alkali treatment, unidirectional, and 15 w.t.% is chosen as the best bio-composite formulation, with the best tensile strength-density balance. It indicates that the optimum parameter was successfully achieved among the samples examined in this work.

Pembuatan Prekursor Serat Karbon dari Lignin Limbah Black Liquor Silvia Mar’atus Shoimah; Mardiyati Mardiyati; Steven Steven; Arif Basuki
Jurnal Teknologi Bahan dan Barang Teknik Vol 9, No 2 (2019)
Publisher : Balai Besar Bahan dan Barang Teknik

Carbon fiber precursor is a raw material required to produce carbon fiber and it spends around 51% of the manufacturing total cost of carbon fiber. Lignin is the second most abundant natural polymer in the world and has the potential to be utilized as a precursor of carbon fiber due to its high amount of carbon content, which reaches 68%. In this research, lignin which was extracted from black liquor waste was then utilized for the preparation of carbon fiber precursor. Extracted lignin was blended with polyvinyl alcohol (PVA) with varied concentration of 0%, 10%, 20%, 30%, 40%, 50% (wt%) and prepared as fiber using wet spinning method. Tensile strength of lignin fiber was determined based on ASTM D-3882 standard. SEM characterization was conducted to evaluate the morphology of lignin fiber. Moreover, TGA characterization was conducted to evaluate the thermal properties and carbon yield of lignin/PVA fiber, respectively. The result showed that the highest tensile strength of 633.29 MPa was achieved at 50% of lignin/PVA concentration. The thermal resistance of lignin fiber tended to improve with the increase of lignin concentration. This result showed that the lignin/PVA fiber has a great potential to be used as a carbon fiber precursor.Prekursor serat karbon merupakan bahan baku yang digunakan dalam pembuatan serat karbon dan menghabiskan sekitar 51% dari total biaya produksi serat karbon. Lignin merupakan polimer hayati paling melimpah kedua di bumi dan sangat potensial untuk dimanfaatkan menjadi prekursor serat karbon karena memiliki kandungan karbon yang tinggi mencapai 68%. Pada penelitian ini, dilakukan pembuatan prekursor serat karbon yang berbahan dasar lignin hasil pengolahan limbah black liquor. Lignin diekstraksi dari limbah black liquor dengan menggunakan metode asidifikasi. Lignin yang telah diekstraksi selanjutnya dicampur dengan polivinil alkohol (PVA) dengan variasi konsentrasi sebesar 0%, 10%, 20%, 30%, 40%, 50% (w/w) menggunakan metode wet spinning. Pengujian tarik serat lignin/PVA dilakukan dengan mengacu pada standar ASTM D-3882. Karakterisasi SEM dilakukan untuk mengetahui morfologi serat yang dihasilkan. Karakterisasi TGA dilakukan untuk mengetahui sifat termal dan carbon yield dari serat lignin/PVA. Berdasarkan hasil pengujian yang dilakukan, kekuatan serat lignin tertinggi yang dihasilkan adalah sebesar 633,29 MPa yang diperoleh oleh serat lignin/PVA dengan konsentrasi lignin sebesar 50%. Makin tinggi kandungan lignin akan menghasilkan serat lignin dengan kekuatan tarik dan ketahanan termal yang makin tinggi pula. Berdasarkan hasil pengujian yang telah dilakukan dapat disimpulkan bahwa serat lignin/PVA yang dihasilkan sangat berpotensi untuk dimanfaatkan sebagai prekursor serat karbon.

Pembuatan dan Karakterisasi Separator Baterai Berbahan Selulosa Alga Cladophora Anna Niska Fauza; Mardiyati Mardiyati; Steven Steven
Jurnal Teknologi Bahan dan Barang Teknik Vol 9, No 2 (2019)
Publisher : Balai Besar Bahan dan Barang Teknik

Separator membrane is one of the important components that serves as a separator between two electrodes for ionic transfer in the electrolyte, as well as to ensure the safety and capacitance performance of the battery. Recently, research on environmentally friendly materials for separator has been developed in order to substitute polyolefin-based separator, one of them is cellulose. Cellulose has excellent properties, such as good wettability, low cost of processing, good mechanical properties, and renewable. In this research, the separator was prepared by using cellulose extracted from Cladophora algae. Cellulose was extracted by performed alkalization, acid treatment and bleaching with 17.5% of NaOH, H2SO4 1M and 5% of H2O2 respectively. The separator membrane was prepared by using solution casting with concentration of cellulose varied in 0,011; 0,008; 0,006; 0,004 dan 0,003 gr/cm2. The porosity and thermal stability were determined by using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Chemical stability and contact angle characterization were conducted to determine chemical retention of the separator membrane toward electrolyte and wettability of the membrane. Based on the result, the extracted cellulose from Cladophora algae has the potential to be utilized as a material for the separator membrane of battery.Membran separator merupakan salah satu komponen penting yang berfungsi sebagai pemisah antara dua elektroda untuk transfer ion didalam elektrolit, serta memastikan keselamatan dan performa kapasitansi pada baterai. Pengembangan material separator baterai yang ramah lingkungan saat ini banyak dilakukan dengan tujuan untuk mencari material alternatif selain poliolefin. Salah satu material yang cukup menjanjikan adalah selulosa. Selulosa memiliki sifat wettability yang baik, biaya pemrosesan yang rendah, sifat mekanik yang baik dan merupakan material yang dapat diperbaharui. Pada penelitian ini dilakukan pembuatan separator baterai dari bahan selulosa yang diekstrak dari alga Cladophora. Selulosa diperoleh melalui tiga perlakuan yaitu alkalisasi dengan menggunakan NaOH 17,5%, perlakuan asam dengan menggunakan H2SO4 1M dan bleaching dengan menggunakan H2O2 5%. Membran separator dibuat dengan menggunakan metode solution casting dengan konsentrasi selulosa sebesar 0,011; 0,008; 0,006; 0,004 dan 0,003 gr/cm2. Pengukuran porositas dan stabilitas termal dilakukan dengan menggunakan scannning electron microscopy (SEM) dan thermogravimetric analysis (TGA). Pengujian stabilitas kimia dan sudut kontak dilakukan untuk menentukan ketahanan kimia membran separator terhadap elektrolit dan sifat wettability. Dari penelitian ini dapat disimpulkan bahwa selulosa yang diekstrak dari alga Cladophora memiliki potensi yang besar untuk dimanfaatkan sebagai bahan baku pembuatan membran separator baterai.

Kajian Material Komposit Sandwich pada Floor Panel Pesawat Terbang Muhammad Labib Adyavit; Larasati Irischa Ramadhani; Mardiyati Mardiyati; Steven Steven
Mesin Vol 29 No 1 (2023)
Publisher : Faculty of Mechanical and Aerospace Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/MESIN.2023.29.1.4

Sandwich composites have been used as lightweight materials in aircraft manufacturing for a long time, from balsa wood sandwich in the 1930s to honeycomb and fiber-reinforced polymers sandwich. Its characteristics are considered as a 'perfect' material for aircraft, which has high strength with low density. Sandwich composites are the common materials for aircraft floor panels. The core is usually made of Nomex or aluminum honeycomb, while the skin is made of 1 "“ 2 ply of carbon/glass fiber in epoxy resin composite. The core is usually constructed using the corrugating or expansion method, whilst the skins are usually constructed using the prepreg lay-up method. Both materials are combined together by a simple adhesive bonding. Being the most strictly regulated transportation method on the planet, floor panel manufacturers must abide by aircraft manufacturing companies and local aviation authority standards and specifications to ensure the product's safety. The purpose of this study is to determine the most used materials for aircraft floor panels and why is it widely used, to understand the manufacturing process, and to know the specifications and standards that need to be fulfilled.

Kajian Penggunaan Baja Tahan Karat 316L sebagai Implan Sendi Panggul Muhammad Aldy Hassan; Luhadi Satriawan; Jhonsen Taharuddin; Mardiyati Mardiyati; Steven Steven
Mesin Vol 29 No 1 (2023)
Publisher : Faculty of Mechanical and Aerospace Engineering

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/MESIN.2023.29.1.6

Implant is one of the most important innovations in medical devices to help people with disabilities or injuries, one of them is the hip-joint implant. The hip-joint implant must-have properties such as good corrosion resistance, good biocompatibility, and good wear resistance. These properties are important for maintaining safety during surgery and future use. Nickel-free 316L stainless steel is one of the materials that is commonly used as implants and meets all the requirements for a material to be used as an implant. 316L stainless steel also has an advantage, a lower price than titanium and cobalt. However, 316L stainless steel has low wear resistance and needs to be coated in order to improve its wear resistance. Recent research reported that the metallic glass FeCrMoCB was able to cover cronidur30 and improved its wear resistance. This study discussed the properties of 316L stainless steel implants, the testing process, the manufacturing process, and the sustainability aspects of the manufacturing process.

Co-Authors Ari Darmawan Pasek Arif Basuki Arif Basuki Bambang Widyanto Bambang Widyanto Deni Shidqi Khaerudini Djamaludin, Octianne Fauza, Anna Niska Gunawan Refiadi Hendrarsakti, Jooned Hermawan Judawisastra Indriyati Indriyati Irwan Suriaman Jhonsen Taharuddin Komalasari, Maya Larasati Irischa Ramadhani Luhadi Satriawan Maemonah, Maemonah Mauliza, Ika Natalia Muhammad Aldy Hassan Muhammad Labib Adyavit Novan Bayu Purnomo, Ikhsan R. Suratman R. Suratman, R. Raden Reza Rizkiansyah Raden Reza Rizkiansyah Rike Yudianti Rizkiansyah, Raden Reza Rochim Suratman Santosa, Sigit Puji Shieddique, Apang Djafar Silvia Mar’atus Shoimah Srahputri, Nurdesri Steven . Steven Steven Steven Steven Steven Steven Steven Steven Sukarman Sukarman Widyanto, Bambang Yulfian Aminanda Yuyun Irmawati

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