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All Journal Reaktor International Journal of Science and Engineering (IJSE) JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Bulletin of Chemical Reaction Engineering & Catalysis Jurnal Aplikasi Teknologi Pangan Indonesian Journal of Chemistry ASEAN Journal of Chemical Engineering Jurnal Pasopati : Pengabdian Masyarakat dan Inovasi Pengembangan Teknologi International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis
Aji Prasetyaningrum
Chemical Engineering Department, Faculty Of Engineering, Diponegoro University, Jl. Prof. Sudarto, Tembalang-Semarang, 50275, Telp/fax: (024)7460058/(024)76480675
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Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan Ratnawati Ratnawati; Aji Prasetyaningrum; Dyah Hesti Wardhani
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 1 Year 2016 (April 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.1.415.48-58

Abstract

The ultrasound-assisted depolymerization of κ-carrageenan has been studied at various temperatures and times. The κ-carrageenan with initial molecular weight of 545 kDa was dispersed in water to form a 5 g/L solution, which was then depolymerized in an ultrasound device at various temperatures and times. The viscosity of the solution was measured using Brookfield viscometer, which was then used to find the number-average molecular weight by Mark-Houwink equation. To obtain the kinetics of κ-carrageenan depolymerization, the number-average molecular weight data was treated using midpoint-chain scission kinetics model. The pre-exponential factor and activation energies for the reaction are 2.683×10-7 mol g-1 min-1 and 6.43 kJ mol-1, respectively. The limiting molecular weight varies from 160 kDa to 240 kDa, and it is linearly correlated to temperature. The results are compared to the result of thermal depolymerization by calculating the half life. It is revealed that ultrasound assisted depolymerization of κ-carrageenan is faster than thermal depolymerization at temperatures below 72.2°C. Compared to thermal depolymerization, the ultrasound-assisted process has lower values of Ea, ΔG‡, ΔH‡, and ΔS‡, which can be attributed to the ultrasonically induced breakage of non-covalent bonds in κ-carrageenan molecules. 
Co-Authors . Widayat Aat Zaki Mubarok Al Farrel A. Raemas Alwi Meidianto Andri Cahyo Kumoro Bakti Jos Denni Kartika Sari Dessy Ariyanti Dessy Ariyanti Diah Susetyo Retnowati Dyah Arum Kusumaningtyas Dyah Hesti Wardhani Fadlillah Fani Fatoni Nugroho Fauzia Dara Qonita Fitri Lafifa Gian Restu Prinanda Indrawati Dwi Paramita Inggrid K. Wardhani M. Djaeni Muqsit Bramantiya Nadia Sevi Ardiana Nita Aryanti Noer Abyor Handayani Novianto D K Nur Rokhati Nurfiningsih Nurfiningsih Nurul Asiah Pajar Saputra Purbo Suseno Ratnawati Ratnawati Ressa Puspita Dewi Sadam Arrois Samir Badres Teguh Riyanto Widayat Widayat Y. Dinarianasari Yudhy Dharmawan