Cerium(IV) Oxidations Of Sulfated Polysaccharides In Aqueous Perchlorate Solutions: A Kinetic And Mechanistic Approach

Ahmed Fawzy1,2*, Refat M. Hassan2, Ismail Althagafi1, Moataz Morad

1Chemistry Department, Faculty of Applied Science, Umm Al-Qura University, 21955 Makkah, Saudi Arabia

2Chemistry Department, Faculty of Sciences, Assiut University, 71516 Assiut, Egypt

Adv. Mater. Lett., 2016, 7 (5), pp 376-382

DOI: 10.5185/amlett.2016.6327

Publication Date (Web): Apr 04, 2016

E-mail: afsaad13@yahoo.com


The kinetics of oxidation of iota- and lambda-carrageenans as sulfated polysaccharides by cerium(IV) was studied spectrophotometrically in aqueous perchlorate solutions at a fixed ionic strength of 2.0 mol dm-3 and a temperature of 25 oC. The reactions showed a first order dependence on [CeIV], whereas the orders with respect to each carrageenan concentration were less than unity. The reactions exhibited fractional-first order kinetics with respect to [H+]. Increasing ionic strength increased the oxidation rates. The oxidation products of carrageenans were characterized by elemental analysis and IR spectra as their diketo-acid derivatives. The oxidation products were found to have high tendencies to form coordination polymer complexes with some metal cations such as BaII, CdII, PbII and AgI. Kinetic evidences for the formation of 1:1 complexes were revealed. Plausible mechanistic scheme for cerium(IV) oxidations of carrageenans were proposed. The activation parameters with respect to the slow step of the reactions were evaluated and discussed. The rate laws have been derived and the reaction constants involved in the different steps of the mechanisms were calculated. The activation parameters associated with the rate-determining step of the mechanism along with thermodynamic quantities of the equilibrium constants were computed and discussed. 


Carrageenans, cerium(IV), oxidation, kinetics, mechanism.

Current Issue

Advanced Materials Congress Celebrating 10th Years of Establishment

Secure Management of Networked Batteries for Building Integrated Photovoltaics (BIPV) Systems  

The Cause of 100-year Low Carbonated Concrete of the Bridge 

Organic Montmorillonite Intercalated Nano-composites Prevent Post-Surgical Associated Infections

Morphology/tensile Performance Relationship for LLDPE/PP Double Gated Injected Blends

Preparation and Characterization of Nickel Ferrite Nanoparticles via Sol-gel Method

Nitrogen-doped Diamond Nanowire Gas Sensor for the Detection of Methane

Manufacture of Functional Open-cell Al Foams with Recycled Al Scraps using NaCl Ball Space Holder 

Vilsmeier-Haack Transformations under Non Classical Conditions

New Application of Highly Vesicular Basalt from Jabel Isbil Volcano (Dhamar-Rada'a Volcanic Field), Yemen

An Assessment of Tribological Characteristics under different Operating Condition

Functional Bi Coatings as A Perspective Material for Radiation Shields Production against Electron Radiation

Effects of Silica Modified NiFe2O4 on the Dielectric and Electrical Properties of NiFe2O4 filled Poly (methyl methacrylate) Composites

Previous issues
The Journey of a Decade to Advancing Materials Are the Electrospun Polymers Polymeric Fibers? Mechanical and Thermal Properties of Composite Material and Insulation for a Single Walled Tank for Cryogenic Liquids Prediction of Long-Term Behavior for Dynamically Loaded TPU Investigation of Doped Titanium Dioxide in Anatase Phase. Study ab initio using Density Functional Theory Comparison between Single Al2O3 or HfO2 Single Dielectric Layers and their Nanolaminated Systems Preparation of Stable and Optimized Antibody-gold Nanoparticle Conjugates for Point of Care Test Immunoassays Resonance-Based Temperature Sensors using a Wafer Level Vacuum Packaged SOI MEMS Process Integrated System Based on the Hall Sensors Incorporating Compensation of the Distortions The Efficacy of Cinnamomum Tamala as a Potential Antimicrobial Substance against the Multi-Drug Resistant Enterococcus Faecalis from Clinical Isolates The Effect of Complexing Reagent on Structural, Electrical and Optical Properties of CuS Thin Film Laser Cladding of Fluorapatite Nanopowders on Ti6Al4V Preparation and Evaluation of Sulfonate Polyethylene Glycol Borate Ester as a Modifier of Functional Properties of Complex Petroleum Lithium Grease

Upcoming Congress

Knowledge Experience at Sea TM