Preparation of amino terminated polyamidoamine functionalized chitosan beads and its Cr(VI) uptake studies
Highlights
► Zr4+ loaded polyamidoamine chitosan beads used to remove Cr(VI) for first time. ► Maximum sorption capacity with the minimum 2 h contact time. ► The Cr(VI) removal is via adsorption/electrostatic attraction. ► Polyamidoamine chitosan beads is a promising sorbent for enhanced removal of Cr(VI).
Introduction
Chitosan, a deacetylated derivative of chitin, is a natural polymer, highly hydrophilic, nontoxic, abundant, biocompatible, and biodegradable polymer (Muzzarelli et al., 2012). Chemical modifications of a large numbers of hydroxyl and amino groups present in chitosan, can obviously improve the physical and chemical properties of chitosan and will open ways to various applications in different fields like biomedical, food ingredients and water treatment (Jayakumar et al., 2010, Tsubokawa and Takayama, 2000). In recent years, hyperbranched polymers, represented as dendrimer, have received great attention because of their multifunctional properties, morphological features and potential use in medical applications, host–guest chemistry, cosmetics, dendritic catalysts (Ravi Kumar et al., 2004, Sashiwa et al., 2002a, Sashiwa et al., 2002b, Sashiwa et al., 2002c). Modification of terminal groups with different functionalities, such as acetamido, hydroxyl, carboxyl, quaternary ammonium leads to the versatile applicability of chitosan as well as dentrimeric materials. Presently, a dendrimer like hyperbranched polyamidoamine was grafted onto the surface of chitosan and used for heavy metal removal (Ma et al., 2009, Qu et al., 2008). Our previous study shows that the Cr(VI) sorption capacity of amino terminated hyperbranched dendritic polyamidoamine was very high when compare to protonated, carboxylated and amine grafted chitosan beads (Kousalya, Rajiv Gandhi, & Meenakshi, 2010). To increase the amino group in chitosan, dendritic chitosan was prepared. Further protonation of amino groups and rare earth metal ion loading increases the Cr(VI) removal than the aminated chitosan beads. The higher Cr(VI) sorption capacity of Zr(IV) loaded chitosan beads is due to its higher positive charge. Chitosan beads functionalized by Zr4+ loaded amino terminated hyperbranched dendritic polyamidoamine have not been reported for chromium removal. The probable mechanism of chromium sorption onto the sorbents was established.
Section snippets
Materials
Chitosan (85% deactetylated) was supplied by Pelican Biotech and Chemicals Labs, Kerala (India). Ethylenediamine, methyl acrylate, acetic acid and K2Cr2O7 were purchased from Merck (India) and all other chemicals used were of analytical grade.
Instrumentation
The FT-IR samples were prepared by mixing 0.01 g of the crushed chitosan beads with 0.1 g of spectroscopy grade KBr and pressing the mixture under higher pressure. Under pressure, the KBr melts and seals the chitosan beads into a matrix. The FT-IR spectra
FT-IR analysis
Fig. 1a shows the FT-IR spectra obtained for 3ACB and 3ACBZr. 3ACB showed a broad band around 3419 cm−1 corresponding to both primary amine and OH stretching groups of the chitosan moiety. Generally, primary amines will show two stretching bands around 3400–3300 cm−1 and 3330–3250 cm−1. In contrast, this was not observed in the present case even though there was primary amine functionality in 3ACB. Instead a very broad band was observed. This may be due to the overlapping of the stretching bands
Conclusions
3ACBZr possess higher SC than the other modified chitosan beads. This is because of the presence of more amine groups and Zr4+ loading. The amount of Cr(VI) ions, adsorbed per unit mass of adsorbents at 303 K from 200 mg/L of Cr(VI), by chitosan beads and 3ACBZr were 21 and 185 mg/g, respectively. All the sorbents need 200 min as the contact time for maximum SC. The SC of the sorbents was influenced by the pH of the medium. The maximum sorption capacity was at 2–4 pH. The sorption data follows
Acknowledgements
The corresponding author is grateful to the DRDO (No. ERIP/ER/0703670/M/01/1066), New Delhi, India for the financial support to carry out this research work. The first author likes to thank CSIR, New Delhi, India for awarding the SRF.
References (21)
Selection of optimum sorption isotherm
Carbon
(2004)- et al.
Novel carboxymethyl derivatives of chitin and chitosan materials and their biomedical applications
Progress in Polymer Science
(2010) - et al.
Chemical modification of chitosan and equilibrium study for mercury ion removal
Water Research
(2003) - et al.
Removal of boron from aqueous solution by clays and modified clays
Journal of Colloid Interface Science
(2006) - et al.
Adsorption thermodynamics of carbofuran on Sn(IV) arsenosilicate in H+, Na+ and Ca2+ forms
Colloids and Surfaces
(1987) - et al.
Sorption of chromium(VI) using modified forms of chitosan beads
International Journal of Biological Macromolecules
(2010) - et al.
On the characterization of acidic and basic surface sites on carbons by various techniques
Carbon
(1999) - et al.
Adsorption behaviors of Hg(II) on chitosan functionalized by amino-terminated hyperbranched polyamidoamine polymers
Journal of Hazardous Materials
(2009) - et al.
Current views on fungal chitin/chitosan, human chitinases, food preservation, glucans, pectins and inulin: A tribute to Henri Braconnot, precursor of the carbohydrate polymers science on the chitin bicentennial
Carbohydrate Polymers
(2012) - et al.
Preparation and metal-binding behaviour of chitosan functionalized by ester and amino-terminated hyperbranched polyamidoamine polymers
Carbohydrate Research
(2008)
Cited by (64)
Effective arsenite adsorption from aqueous solution using N- and S-functionalized tetragonal nano-zirconia on chitosan-derived carbon
2023, Separation and Purification TechnologyWater-soluble amino functionalized chitosan: Preparation, characterization, antioxidant and antibacterial activities
2022, International Journal of Biological MacromoleculesCitation Excerpt :However, these bioactivities of pristine chitosan are considerable weak compared with the commercial chemicals, which has restricted its broad application prospects in food and biomedicine fields. The structural modification of chitosan proves to be an effective way to improve its biological activities and the chitosan derivatives with excellent bioactivities can be used as promising candidates to replace the chemical antioxidant and biocides and further expand the application and development in the related fields [8,9]. Meanwhile, given the vital function of amino groups for performing the bioactivities and interesting properties of chitosan molecule, the primary amino functionalized modification of chitosan at the C-6 position and the simultaneous reservation of the free amino groups at C-2 position are particular interest in the current study.
Rational modification of chitosan biopolymer for remediation of Cr(VI) from water
2022, Journal of Hazardous Materials AdvancesAdsorption of tetracycline antibiotics using metal and clay embedded cross-linked chitosan
2022, Materials Chemistry and PhysicsRecent trends of carbon nanotubes and chitosan composites for hexavalent chromium removal from aqueous samples
2022, Separation Science and Technology (New York)