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Abstrak :
The gas diffusion layer (GDL) is one of the critical components of a proton exchange membrane fuel cell (PEMFC). It is generally made of a fossil-fuel-based carbon material. In this study, carbon composite paper (CCP) for GDL was prepared by using carbon material obtained from coconut coir. To obtain the CCP, 80 wt% carbon material from the coconut coir and 20 wt% polymer binder (ethylene vinyl acetate and polyethylene glycol) were mixed in xylene solvent at 100°C, cast on molded glass, and then rolled. The carbon material consists of a mixture of carbon fibers (length: 2 mm) and powders (size: 74 µm). Subsequently, the CCP was treated with polytetrafluoroethylene solution (10 wt%). The physical properties of the CCPs, such as through-plane electrical conductivity, porosity, density, and hydrophobic properties, were investigated. Scanning electron microscopy and energy-dispersive spectroscopy mapping were used to analyze the morphology and polytetrafluoroethylene (PTFE) distribution in the CCP. The through-plane conductivity test showed that CCP with 70 wt% carbon fiber, 10 wt% carbon powder, and 20 wt% polymer was the optimum sample, and it showed the highest electrical conductivity of 2.22 S cm-1. The physical properties of PTFE-treated CCP, such as porosity, density, and contact angle, were almost similar to that of commercial carbon paper used as a GDL. Therefore, the CCP prepared from coconut coir can be applied as a GDL in a PEMFC.

Abstrak :
The gas diffusion layer (GDL) is one of the critical components of a proton exchange membrane fuel cell (PEMFC). It is generally made of a fossil-fuel-based carbon material. In this study, carbon composite paper (CCP) for GDL was prepared by using carbon material obtained from coconut coir. To obtain the CCP, 80 wt% carbon material from the coconut coir and 20 wt% polymer binder (ethylene vinyl acetate and polyethylene glycol) were mixed in xylene solvent at 100°C, cast on molded glass, and then rolled. The carbon material consists of a mixture of carbon fibers (length: 2 mm) and powders (size: 74 µm). Subsequently, the CCP was treated with polytetrafluoroethylene solution (10 wt%). The physical properties of the CCPs, such as through-plane electrical conductivity, porosity, density, and hydrophobic properties, were investigated. Scanning electron microscopy and energy-dispersive spectroscopy mapping were used to analyze the morphology and polytetrafluoroethylene (PTFE) distribution in the CCP. The through-plane conductivity test showed that CCP with 70 wt% carbon fiber, 10 wt% carbon powder, and 20 wt% polymer was the optimum sample, and it showed the highest electrical conductivity of 2.22 S cm-1. The physical properties of PTFE-treated CCP, such as porosity, density, and contact angle, were almost similar to that of commercial carbon paper used as a GDL. Therefore, the CCP prepared from coconut coir can be applied as a GDL in a PEMFC.

Abstrak :
Sel tunam merupakan salah satu energi alternatif yang potensial untuk dikembangkan mengingat potensi dan jenis sumber energi yang terbarukan. Salah satu jenis sel tunam adalah Polymer Electrolyte Membrane Fuel Cell (PEMFC). Pada PEMFC terdapat komponen penting yang disebut dengan pelat bipolar. Pelat bipolar memiliki prosentase terbesar dalam berat dan biaya pembuatan sel tunam. Pada penelitian ini dibuat pelat bipolar karbon komposit dengan 80%wt matriks dan penguat yang terdiri dari 90-100% wt grafit dapur busur listrik (EAF) dan 0-10% wt carbon black FEF 550 dan 20%wt polimer sebagai pengikat yang terdiri dari epoksi resin dan pengeras dengan perbandingan 1:1. Pembuatan pelat bipolar ini dengan variabel penambahan 0-10%wt carbon black FEF 550 yaitu 0;2,5;5;7,5 dan 10%wt carbon black FEF. Proses pencampuran menggunakan pengaduk berkecepatan tinggi dengan kecepatan 28.000 rpm dan dicetak menggunakan metode cetak kompresi dengan tekanan 55 MPa, suhu 100°C, selama 4 jam. Hasil penelitian menunjukkan bahwa komposisi optimum terdapat pada 10%wt carbon black FEF 550 dimana dihasilkan nilai densitas sebesar 2,34 gr/cm3, porositas 2,39%, kekuatan fleksural 30,06 MPa, dan konduktivitas listrik 6,52 S/cm.

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Fuel cell is one of the potentially alternative energy to be developed due to its potential and kind as renewable energy sources. Fuel cell has many types and one of them is PEMFC (Polymer Electrolyte Membrane Fuel Cell). Bipolar plate is one of main components in PEMFC which have the largest percentage in fuel cell weight and production cost. In this study, the bipolar plate materials made from carbon composites. Constituent materials carbon composites are 80wt% matrix and reinforcement, consist of 95wt% Graphite EAF (Electric Arc Furnace) and 0-10%wt carbon black FEF 550 and 20% polymer as binder consist of epoxy resin and hardener with ratio 1:1. The addition variabels 0-10%wt of carbon black FEF 550 are 0;2,5;5;7,5 and 10%wt. The mixing process used high-speed mixer with mixing speeds 28.000 rpm and to form the plate used compression molding with pressure 55 MPa, 100°C, for 4 hours. The test results showed that the maximum composition was 10%wt carbon black FEF 550 which values are density 2,34 gr/cm3, porosity 2,39%, flexural strength 30,06 MPa and electric conductivity 5,52 S/cm.

Abstrak :
Pelat bipolar memiliki berat 60-80% dari berat berat total sel tunam dan berfungsi sebagai penghantar elektron serta menopang komponen sel tunam lainnya sehingga pelat bipolar diharapkan mempunyai konduktivitas dan sifat mekanis yang baik. Pelat bipolar dibuat dengan mencampurkan limbah grafit electric arc furnace (EAF), carbon black, dan resin epoksi sehingga tercipta suatu pelat dari karbon-karbon komposit. Grafit bertindak sebagai matriks sedangkan carbon black sebagai filler dan resin epoksi berfungsi sebagai binder. Grafit yang digunakan mempunyai ukuran partikel 53 μm, sedangkan untuk carbon black digunakan kombinasi antara ukuran partikel 44μm dan 37 μm dengan perbandingan 100:0; 90:10; 80:20; 70:30. Pelat bipolar dicetak dengan metode compression moulding pada tekanan 450 kg/cm2 dan temperatur 70°C selama empat jam. Penambahan carbon black 37 μm ke dalam campuran carbon black 44 μm dan grafit 53 μm terbukti mampu meningkatkan konduktivitas dan menurunkan porositas. Konduktivitas paling tinggi terdapat pada pelat bipolar dengan penambahan carbon black 37μm 30% sebesar 15,7 x 10-4 S/cm dan porositas paling rendah terdapat pada pelat bipolar dengan penambahan carbon black 37μm 20% yang menghasilkan porositas sebesar 0.71%. Namun untuk kekuatan fleksural, semakin banyak penambahan carbon black 37 μm kekuatan fleksural semakin menurun. Kekuatan fleksural optimum terdapat pada carbon black 37 μm 0% dengan kekuatan sebesar 20,85 MPa. Penambahan carbon black 37μm 30% meningkatkan densitas pelat hingga 1.73 g/cm3. ......The weight of bipolar plate has 60-80% of total fuel cell stack weight and also as the support of all the component in fuel stack, with the reason of that bipolar plate should has good conductivity dan better mechanical properties. Bipolar plate is made from the mixture of graphite, carbon black, and epoxy resin. The mixture is called carbon-carbon composite. The matrix is the graphite, carbon black as the reinforcement and resin epoxy as a binder. The size of graphite is 53 μm and carbon black are the combination of 44 μm and 37 μm particle size with the comparation 100:0; 90:10; 80:20; 70:30. Bipolar plate is made with compression moulding method, the pressure is 450 Kg/cm2 and 70°C temperature for four hours. The increasing of 37μm carbon black in the combination of 44μm carbon black and 53μm graphite can increase the conductivity and reduce porosity. The sampel with 30% carbon black 37μ has highest conductivity (15,7 x 10-4 S/cm) and the best porosity (0.71%) is sampel with 20% increasing of 37μm carbon black. But the flexural strength decrease with the increase 37μ carbon black and cannot reach the DOE standard. The increase of 37μm carbon black also raise the density of sample until 1,73 g/cm3 with increasing 30% of 37μm carbon black.

Abstrak :
ABSTRAK
Komposit karbon adalah material komposit yang matriks dan penguatnya adalah karbon. Material ini biasanya digunakan pada berbagai aplikasi tertentu yang membutuhkan sifat mekanis yang baik dan mampu stabil pada suhu tinggi. Komposit karbon ini dibuat dengan material penyusun coal tar pitch, batubara(BB) dan arang batok kelapa(ABK). Dalam pembuatan komposit karbon ini akan divariasikan jumlah dari bahan penguat BB:ABK yaitu 60:40, 70:30, 80:20. Proses pembuatan spesimen uji dilakukan dengan metode kompaksi serbuk panas dengan tekanan 78 Mpa, temperatur 1000C, waktu tahan 30 menit dan kemudian dikarbonisasi. Pengujian densitas dan porositas dilakukan untuk mengetahui kepadatan spesimen uji yang dihasilkan sedangkan pengujian kekerasan dan keausan bertujuan untuk mengetahui sifat mekanis spesimen uji. Nilai densitas tertinggi dan persentase porositas terendah didapat pada saat komposisi BB:ABK 80:20 yaitu 1.53 gr/cm3 dan 32.14 %. Nilai kekerasan tertinggi dan laju keausan terendah terdapat pada saat komposisi BB:ABK 60:40 yaitu 38.54 BHN dan 0.05838 mm3/Nm.

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ABSTRACT
Carbon composite is kind of composite that using carbon as the matrix and reinforcement. This material is commonly used for applications which requires excellent mechanical properties and dimensional stability at high temperatures. Carbon composite consisting of coal tar pitch, coal, and coconut shell charcoal. Ratio between coal:coconut shell charcoal as reinforcement in the process of making this composite carbon is 60:40, 70:30, and 80:20. Composite carbon are prepared by hot compaction method at pressure of 78 MPa, temperature of 1000C for half hour and then perform carbonization. Porosity and density testing performed to determine the density of sample. Hardness and wear testing also performed to determine mechanical properties of specimens. Maximum density obtain was 1.53 gr/cm3 (ratio 80:20). Lower density value was 32.14 %(ratio 80:20). Maximum hardness was 38.54 BHN (ratio 60:40) which also have lowest wear rate value (0.05838 mm3/Nm).

Abstrak :
ABSTRAK
Polymer Electrolyte Membrane Fuel Cell (PEMFC) merupakan salah satu energy alternative untuk mengatasi keterbatasan energi fosil, serta ramah lingkungan. Pelat bipolar merupakan komponen penting pada PEMFC sebagai pengumpul dan pentransfer elektron dari anoda menuju katoda. Pada penelitian ini pelat bipolar dibuat dari grafit komposit yang terdiri dari matriks grafit Electric Arc Furnace (EAF), carbon black dan multi-walled carbon nanotube sebagai filler, dan resin epoksi sebagai binder. Bahasan utama penelitian ini ialah pengaruh penambahan multi-walled carbon nanotube yaitu sebanyak 1%, 2%, 3%, 4% dan 5% terhadap konduktivitas karakteristik material pelat bipolar. Karakterisasi pelat bipolar dengan melakukan beberapa pengujian yaitu uji konduktivitas, uji flexural, uji densitas, uji porositas dan pengamatan dengan menggunakan FE SEM. Hasil dari peneltian ini, penambahan multi-walled carbon nanotube pelat bipolar dapat meningkatkan sifat konduktivitas hingga menjadi 8.95 S/Cm dan kekuatan flexural bipolar yaitu sebesar 59.11 Mpa. Namun, penambahan multi-walled carbon nanotube memiliki titik optimum pada penambahan 3%, penambahan multi-walled carbon nanotube diatas 3% dapat menurunkan kembali sifat konduktivitas dan flexural pelat bipolar akibat penggumpalan atau aglomerat dari multi-walled carbon nanotube

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Abstract
Polymer Electrolyte Membrane Fuel Cell (PEMFC) is one of the alternative energy to overcome the limitations of fossil energy, as well as environmental friendly. Bipolar plate in PEMFC is an important component as collector and transferor o f electron from anode to cathode. In this research the bipolar plate is made from graphite composite consisting of Electric Arc Furnace (EAF) graphite as matrice, carbon black and multi-walled carbon nanotube as filler, and opxy resin and hardener as binder. The main subject of this research is effect of addition multi-walled carbon nanotube that is as much as 1%, 2%, 3%, 4% and 5% to the characteristics of bipolar plate. Characterization of bipolar plate by doing some testing iare conductivity test, flexural test, density test, porosity test, and observation with FE SEM. Result from this research is addition of multiwalled carbon nanotube can improve the conductivity to be 8.95 S/cm and flexural properties of bipolar plate is 59.11 Mpa. However, the excessive addition of multiwalled carbon nanotube has an optimum point on the addition 3%, the addition multi-walled carbon nanotube over can return decreace the conductivity and flexural properties of bipolar plate because there is agglomeration multiwalled carbon nanotube.