scholarly journals Pengaruh Jumlah Siklum HEM (High Energy Milling) Pada Karakteristik MFC (Microfibrillated Cellulose) Dari Sekam Padi

2020 ◽  
Vol 21 (1) ◽  
pp. 29
Author(s):  
Anwar Maruf ◽  
Neni Damajanti
Keyword(s):  
Response Surface ◽  
High Energy ◽  
Microfibrillated Cellulose ◽  
High Energy Milling

MFC merupakan selulosa yang sudah mengalami proses lanjut yaitu refinerdan homogenizer sehingga ukurannya berskala nanometer (nm). Proses pembuatanMFC dapat dilakukan secara mekanik, yaitu dengan memanfaatkan refiner, highpressure homogenizer dan gelombang ultrasonic. Selain dengan metode mekanik,pembautan MFC juga dapat dilakukan dengan metode enzimatis. MFC dapatdigunakan sebagai komposit pada berbagai bidang seperti industri makanan, cat,kosmetik dan medis. Pemanfaatan selulosa sekam padi dalam pembuatan MFC belumbanyak dilakukan. Proses penting dalam pembuatan MFC sekam padi adalah prosesdelignifikasi untuk menghilangkan lignin dan silika, proses bleaching dan prosespenggilingan. Pada penelitian ini akan dikaji pengaruh konsentrasi hydrogenperoksida, temperature bleaching dan waktu penggilingan. Optimasi variabel dapatdilakukan dengan menggunakan Response Surface Metodology (RSM). Hasilpenelitian menunjukkan kondisi optimum untuk proses delignifikasi adalah padaperbandingan volume/berat sekam sebesar 9, konsentrasi H2O2 1,5% dan pH 11,5.Variabel yang signifikan terhadap kadar lignin adalah diketahui yang signifikanterhadap kadar lignin adalah pH (linier), rasio V/w (kuadratik), konsentrasi H2O2(kuadratik) dan pH (kuadratik). Proses HEM sangat berpengaruh pada karakteristikMFC. Semakin banyak siklus HEM, maka gugus aktif MFC akan semakin banyak.

scholarly journals Peningkatan Kuat Tarik Bioplastik dengan Filler Microfibrillated Cellulose dari Batang Sorgum

2020 ◽  
Vol 18 (2) ◽  
pp. 37
Author(s):  
Yuli Darni ◽  
Lia Lismeri ◽  
Muhammad Hanif ◽  
Sarkowi Sarkowi ◽  
Dita Synthauli Evaniya
Keyword(s):  
Tensile Strength ◽  
Mechanical Treatment ◽  
High Energy ◽  
Microfibrillated Cellulose ◽  
Weight Basis ◽  
Filler Concentration ◽  
Mechanical Method ◽  
High Energy Milling ◽  
Stirring Time ◽  
Disk Mill

Abstrak. Penelitian ini membahas tentang pengaruh rasio pati terhadap kitosan (dalam basis berat) dan konsentrasi microfibrillated cellulose sebagai filler dalam pembuatan bioplastik menggunakan pati sorgum, kitosan dan gliserol. Dalam penelitian ini, rasio pati terhadap kitosan yang divariasikan adalah 10:0, 9,5:0,5, 8,5:1,5, 7,5:2,5, 6,5:3,5, 5,5:4,5 (gr/gr). Microfibrillated cellulose sebagai filler disintesis dari batang sorgum dengan metode semimekanis. Perlakuan kimia diawali dengan delignifikasi batang sorgum dengan KOH 4% pada temperatur 80oC selama 1 jam untuk menghilangkan lignin. Setelah itu dicuci dan dipucatkan (bleaching) sebanyak dua kali menggunakan H2O2 6% pada suhu 70oC. Serbuk batang sorgum yang sudah kering dilanjutkan dengan perlakuan mekanis yaitu dimasukkan ke dalam disk mill  selama 90 menit dan dilanjutkan dengan high energy milling (HEM) untuk mengecilkan ukurannya sampai dengan rata-rata 4-8 µm. Filler ditambahkan, dan konsentrasinya (dalam basis berat) divariasikan dari 0, 1, 2, dan 3 %. Pati dan kitosan berukuran 63 mikron (lolos ayakan), waktu  pengadukan selama 35 menit pada kecepatan 375 rpm, dan penambahan 10% berat gliserol sebagai plasticizer dijaga konstan. Hasil terbaik pada penelitian ini diperoleh pada formulasi 8,5:1,5 (gr/gr). dan konsentrasi filler 3%. Produk bioplastik ini memiliki kuat tarik 11,64 MPa, persen perpanjangan 10,98%, modulus Young 105,96 MPa, densitas 0,915 gr/ml, dan penyerapan air  38,3%. Kata kunci: bioplastik, gliserol, kitosan, microfibrillated cellulose, sorgum. Abstract. The Improving of Bioplastic Tensile Strength with Microfibrillated Cellulose Filler from Sorghum Stem. This study discusses the effect of starch on chitosan ratio (in weight basis) and also the concentration of microfibrillated cellulose as a filler in the preparation of bioplastics using sorghum starch, chitosan, and glycerol. In this study, the ratio of starch to chitosan varied was 10:0, 9.5:0.5, 8.5:1.5, 7.5:2.5, 6.5:3.5, 5.5:4,5 (gr/gr). Microfibrillated cellulose as filler was encouraged from the sorghum stem by the semi-mechanical method. The delignification of sorghum stem initiated chemical treatment with a 4% KOH solution on 80oC for 1 hour to remove lignin. Bleaching is done after delignification using 6% H2O2 at 70oC. The dried sorghum powder is further followed by mechanical treatment that is put into disk mill for 90 minutes and continued with high energy milling (HEM) to reduce its size to an average of 4-8 µm. The filler is added, and the concentration (on a weight basis) varies from 0, 1, 2, and 3%. Starch and chitosan measuring 63 microns (sieve pass), stirring time for 35 minutes at a speed of 375 rpm, and the addition of 10% by weight of glycerol as a plasticizer is kept constant. The best results in this study were obtained in formulations 8.5:1.5 (gr/gr) and 3% filler concentration. This bioplastic product has 11.64 MPa tensile strength, 10.98% elongation, 105.96 MPa Young moduli, 0.915 gr/ml density, and 38.3% water uptake. Keywords: bioplastic, chitosan, glycerol, microfibrillated cellulose, sorghum.Graphical Abstract 

INFLUENCE OF ACETONE AND METHANOL PROCESS CONTROL AGENTS IN THE SIZE AND MORPHOLOGY OF THE PARTICLES IN THE HIGH ENERGY MILLING OF THE NB-25%AL ALLOY

2019 ◽  
Author(s):  
Ágata Pontes ◽  
EDWIN MEDINA ◽  
Fabiano Sangi de Oliveira ◽  
Gilbert Silva ◽  
Marcos Cirilo ◽  
...  
Keyword(s):  
Process Control ◽  
High Energy ◽  
Al Alloy ◽  
High Energy Milling ◽  
Size And Morphology

Impact of the SiC addition on the morphological, structural and mechanical properties of Cu-SiC composite powders prepared by high energy milling

2021 ◽  
Author(s):  
Nailton T. Câmara ◽  
Rafael A. Raimundo ◽  
Cleber S. Lourenço ◽  
Luís M.F. Morais ◽  
David D.S. Silva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Composite Powders ◽  
High Energy Milling

Effect of High-Energy Milling and Sintering Temperature on the Properties of Al2O3-WC-Co Composites

2021 ◽  
Author(s):  
Heytor V. S. B. Azevêdo ◽  
Rafael A. Raimundo ◽  
David D. S. Silva ◽  
Luís M. F. Morais ◽  
Franciné A. Costa ◽  
...  
Keyword(s):  
Sintering Temperature ◽  
High Energy ◽  
High Energy Milling

scholarly journals Optimization of Lutein Recovery from Tetraselmis suecica by Response Surface Methodology

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 182
Author(s):  
Kang Hyun Lee ◽  
Ye Won Jang ◽  
Hansol Kim ◽  
Jang-Seu Ki ◽  
Hah Young Yoo
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
High Energy ◽  
Solid Loading ◽  
Control Group ◽  
Energy Yield ◽  
Tetraselmis Suecica ◽  
Antioxidant Power

Microalgae have been attracting attention as feedstock for biorefinery because they have various advantages, such as carbon fixation, high growth rate and high energy yield. The bioactive compounds and lutein contained in microalgae are known to be beneficial for human health, especially eye and brain health. In this study, in order to improve the recovery of bioactive extracts including lutein from Tetraselmis suecica with higher efficiency, an effective solvent was selected, and the extraction parameters such as temperature, time and solid loading were optimized by response surface methodology. The most effective solvent for lutein recovery was identified as 100% methanol, and the optimum condition was determined (42.4 °C, 4.0 h and 125 g/L biomass loading) by calculation of the multiple regression model. The maximum content of recovered lutein was found to be 2.79 mg/mL, and the ABTS radical scavenging activity (IC50) and ferric reducing antioxidant power (FRAP) value were about 3.36 mg/mL and 561.9 μmol/L, respectively. Finally, the maximum lutein recovery from T. suecica through statistical optimization was estimated to be 22.3 mg/g biomass, which was 3.1-fold improved compared to the control group.

Fabrication of (Y2O3)n–ZnO nanocomposites by high-energy milling as potential photocatalysts

2021 ◽  
Author(s):  
A. Modwi ◽  
M. A. Ben Aissa ◽  
Kamal K. Taha ◽  
L. Khezami ◽  
J. El Ghoul ◽  
...  
Keyword(s):  
High Energy ◽  
High Energy Milling

Composite Ta–Cu powders prepared by high energy milling

2008 ◽  
Vol 26 (6) ◽  
pp. 499-503 ◽  
Author(s):  
F.A. Costa ◽  
A.G.P. Silva ◽  
J.F. Silva Júnior ◽  
U.U. Gomes
Keyword(s):  
High Energy ◽  
High Energy Milling

scholarly journals Sliding friction and wear performance of the nano-bioceramic α-Al2O3 prepared by high energy milling

2015 ◽  
Vol 91 ◽  
pp. 151-159 ◽  
Author(s):  
Mamoun Fellah ◽  
Mohammed Abdul Samad ◽  
Mohamed Labaiz ◽  
Omar Assala ◽  
Alain Iost
Keyword(s):  
Friction And Wear ◽  
Sliding Friction ◽  
High Energy ◽  
Wear Performance ◽  
High Energy Milling ◽  
Α Al2o3
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