Carboxymethyl chitosan/clay nanocomposites and their copper complexes: Fabrication and property
Introduction
In the process of the development of marine antifouling paints, the self-polishing antifouling paint with the function group of organotin (TBT) acrylic resin was praised as special weapons of marine antifouling. However, TBT caused serious damage to marine ecological environment (Antizar-Ladislao, 2008), therefore it is urgent to find a non-toxicity antifouling paint.
Chitosan is natural, biocompatible, biodegradable, non-toxic and multifunctional resource, which is regarded as environmentally friendly antifoulant by chemists (He, Davis, & Illum, 1999; Khan, Badshah, & Airoldi, 2015; Kurmaev et al., 2002; Rhazi et al., 2002). Chitosan is the only kind of alkaline natural amino polysaccharide which is composed of β-(1,4)-2-acetamino-2-deoxy-d-glucose binary linear copolymer (Ling, Li, Zhou, Wang, & Sun, 2015; Li, Liu, Ye, Wang & Sun, 2015). Carboxymethyl chitosan (CMC) is water-soluble chitosan derivative with remaining excellent antibacterial properties (Liu, Wang, Li et al., 2012, Liu, Wang et al., 2012; Sun, Du, Fan, Chen, & Yang, 2006), which can chelate effectively with metal salts (Paradossi, Chiessi, Venanzi, Pispisa, & Palleschi, 1992), and the self-polishing antifouling paint can be simulated by chelating CMC with metal ion such as copper ion that is widely considered as a broad antibacterial material and used to kill algae (Heuser, Rivera, Nunez, & Cardenas, 2009; Muzzarelli & Tubertini, 1970). But the thermal stability and the antimicrobial activity of CMC–Cu complex are still not satisfactory.
From this point, it is noted that chitosan-based layered silicate nanocomposites have drawn people's attention for coupling of numerous merits of chitosan and layered silicate (Deng et al., 2012, Liu, Wang, Yang, Sun, 2011; Liu, Wang, Yang, Wang & Sun, 2011; Wang et al., 2009, Wang et al., 2006). Montmorillonite (MMT) is a 2:1 typed layered silicate with high thermal stability, and more interestingly, the previous study demonstrated that MMT had no antibacterial activity itself, but it showed dual performance of adsorbing bacteria and killing bacteria when the cationic material with antibacterial activity was intercalated into the interlayer of MMT (Guo, Ma, Guo, & Xu, 2005; Yao-Zong, Shi-Rong, & Delvaux, 2004). OMMT is modified MMT with surfactant, compared with pure MMT, OMMT owns a higher interlayer spacing and a larger specific surface area, and it even shows stronger antimicrobial activity. So the addition of OMMT may improve the possibility for CMC–Cu complex as the antifouling agent. However, there is still no report about preparing the composite of CMC, MMT and copper ions in order to combine their thermostability and antibacterial advantages.
In this work, CMC and CMC–Cu complexes were firstly obtained, and organic montmorillonite (OMMT) was prepared to make the insertion of CMC into the interlayer of MMT easier. Afterwards, CMC/OMMT and CMC/OMMT–Cu nanocomposites were prepared. Their structures were characterized by XRD, TEM and FT-IR, and TGA was used to investigate the thermal stability. Furthermore, the inhibition ability against Escherichia coli was evaluated.
Section snippets
Materials
Chitosan (CS) was purchased from Haidebei Ocean Biochemical Co., Ltd. (Jinan, China). Its degree of deacetylation was 85%, and its weight average molecular weight (Mw) was 2.0 × 105. Chloroacetic acid was purchased from Kelong Chemical Reagent Factory (Chengdu, China). Sodium based montmorillonite (Na–MMT) was purchased from Josiah reagent factory, its cation exchange capacity was 87 mmol/100 g, Cetyltrimethyl Ammonium Bromide (CTAB) was purchased by Henan Titaning Chemical Technology Co., Ltd.
Mw and DS of CMC
Table 1 presents the weight average molecular weight (Mw) and degree of substitution (DS) of CMC. The DS of CMC increased as the mass ratios of chloroacetic acid to chitosan increased. It could be explained that the increase of chloroacetic acid would largely destroy the internal structure and crystalline region of chitosan, which ensured the further infiltration and proliferation of carboxymethyle groups.
FT-IR analysis
Fig. 1a shows FT-IR spectra of chitosan, CMC and CMC–Cu. Compared to chitosan, CMC
Conclusions
Based on the inherent environmentally friendly characteristics and biological activity of chitosan compounds, CMC/OMMT–Cu nanocomposites were prepared. There were strong hydrogen bonding and covalent bonding interaction in CMC/OMMT–Cu nanocomposites. And the nanocomposites showed high thermal stability and excellent antibacterial activity because of the combinative advantages of CMC, OMMT and copper ions, which were related to the interlayer distance and content of OMMT.
Acknowledgement
This work was financially supported by Natural Science Foundation of Guangdong Province (No. 2014A030313142).
References (38)
Environmental levels, toxicity and human exposure to tributyltin (TBT)-contaminated marine environment. A review
Environment International
(2008)- et al.
Quaternized chitosan-layered silicate intercalated composites based nanofibrous mats and their antibacterial activity
Carbohydrate Polymers
(2012) - et al.
In vitro adsorption of zearalenone by cetyltrimethyl ammonium bromide-modified montmorillonite nanocomposites
Microporous and Mesoporous Materials
(2008) - et al.
Polymer-clay nanocomposites: exfoliation of organophilic montmorillonite nanolayers in polystyrene
Polymer
(2001) - et al.
Antimicrobial activity of chitosan against Campylobacter spp. and other microorganisms and its mechanism of action
Journal of Food Protection
(2009) - et al.
Chitosan microspheres prepared by spray drying
International Journal of Pharmaceutics
(1999) - et al.
Protein adsorption, fibroblast activity and antibacterial properties of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) grafted with chitosan and chitooligosaccharide after immobilized with hyaluronic acid
Biomaterials
(2003) - et al.
Poly(etherimide)/montmorillonite nanocomposites prepared by melt intercalation: morphology, solvent resistance properties and thermal properties
Polymer
(2001) - et al.
Probing oxygen and nitrogen bonding sites in chitosan by X-ray emission
Journal of Electron Spectroscopy and Related Phenomena
(2002) - et al.
Rapid exfoliation of rectorite in quaternized carboxymethyl chitosan
Carbohydrate Polymers
(2012)
Preparation and antimicrobial property of chitosan oligosaccharide derivative/rectorite nanocomposite
Carbohydrate Polymers
Rapid modification of montmorillonite with novel cationic Gemini surfactants and its adsorption for methyl orange
Materials Chemistry and Physics
Chitosan kills bacteria through cell membrane damage
International Journal of Food Microbiology
Effect of rectorite on the synthesis of Ag NP and its catalytic activity
Materials Chemistry and Physics
Branched-chain analogues of linear polysaccharides: a spectroscopic and conformational investigation of chitosan derivatives
International Journal of Biological Macromolecules
Effect of hydrogen peroxide treatment on the molecular weight and structure of chitosan
Polymer Degradation And Stability
Influence of the nature of the metal ions on the complexation with chitosan. Application to the treatment of liquid waste
European Polymer Journal
Preparation, characterization and antimicrobial activity of quaternized carboxymethyl chitosan and application as pulp-cap
Polymer
Alginate/starch blend fibers and their properties for drug controlled release
Carbohydrate Polymers
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