Synthesis and characterization of chitosan citrate(CC), 2-sulfobenzoyl chitosan (SBC), and 2-sulfobenzoyl chitosan citrate (SBC-CC) for Cu2+ adsorption: Equilibrium and kinetics studies

Date of Publication

2007

Document Type

Master's Thesis

Degree Name

Master of Science in Chemistry

Subject Categories

Chemistry

College

College of Science

Department/Unit

Chemistry

Thesis Adviser

Eric Camilo R. Punzalan

Defense Panel Chair

Anamy Ma. C. Paano

Defense Panel Member

Nikko P. Quevada
Fortunato B. Sevilla III

Abstract/Summary

The study aimed to synthesize and characterize modified chitosan adsorbent and to use it to perform equilibrium and kinetic studies on the adsorption of copper (II) ions from aqueous solution. The three (3) modification procedures of chitosan are: (1) N-derivatization reaction of 2-sulfobenzoic acid cyclic anhydride with the amino group of chitosan; (2) O-crosslinking of chitosan with citric acid; and (3) two step modification: (a) the reaction of 2-sulfobenzoic acid cyclic anhydride with the amino group of chitosan; (b) O-cross-linking of the N-derivatized chitosan with citric acid. The changes in the molecular structures of chitosan after grafting and

cross-linking reactions were confirmed by FTIR (KBr disk method), DSC, SEM, and powder X- ray diffraction experiments. The solubility of chitosan was significantly reduced after the

modification procedures. Results showed that the adsorption of Cu (II) ions using chitosan, CC, SBC, and SBC-CC were dependent on pH of the solution. The percent Cu (II) ions removed from the aqueous solution decreases as the initial copper metal ion concentration increases. The best interpretation of the equilibrium data for chitosan is Dubinin-Radushkevich isotherm, Freundlich for SBC, Langmuir isotherm for CC and Temkin for SBC-CC. The adsorption kinetics followed the mechanism of pseudo-second order equation. The results showed that grafted chitosan (2-SBACA) followed by cross-linking (citric acid), SBC-CC presented higher adsorption capacity for Cu (II) (110.89 mg/g) compared with CC (89.59 mg/g), chitosan (82.66 mg/g) and SBC (79.28 mg/g).

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTG004159

Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall

Physical Description

vii, 68 leaves, 28 cm. ; Typescript

Keywords

Chitosan—Synthesis; Citrates; Copper —Absorption and adsorption

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2-8-2022

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