Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan

Bulletin of Chemical Reaction Engineering & Catalysis. 2016;11(1):48-58 DOI 10.9767/bcrec.11.1.415.48-58

 

Journal Homepage

Journal Title: Bulletin of Chemical Reaction Engineering & Catalysis

ISSN: 1978-2993 (Print)

Publisher: Diponegoro University

Society/Institution: Indonesian Catalyst Society (Masyarakat Katalis Indonesia)

LCC Subject Category: Technology: Chemical technology: Chemical engineering

Country of publisher: Indonesia

Language of fulltext: Indonesian, English

Full-text formats available: PDF

 

AUTHORS

Ratnawati Ratnawati (Department of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto, Kampus Undip Tembalang, Semarang 50275,)
Aji Prasetyaningrum (Department of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto, Kampus Undip Tembalang, Semarang 50275,)
Dyah Hesti Wardhani (Department of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto, Kampus Undip Tembalang, Semarang 50275,)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 12 weeks

 

Abstract | Full Text

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. Copyright © 2016 BCREC GROUP. All rights reserved Received: 10th November 2015; Revised: 18th January 2016; Accepted: 19th January 2016 How to Cite: Ratnawati, R., Prasetyaningrum, A., Wardhani, D.H. (2016). Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan. Bulletin of Chemical Reaction Engineering & Catalysis, 11(1): 48-58. (doi:10.9767/bcrec.11.1.415.48-58) Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.415.48-58