Optical, morphological and photocatalytic properties of biobased tractable films of chitosan/donor-acceptor polymer blends (original) (raw)
Related papers
Fabrication of chitosan/titanium dioxide composites film for the photocatalytic degradation of dye
Journal of metals, materials and minerals, 2013
The investigation of the chitosan film as a polymer matrix for titanium dioxide (TiO 2) dispersion was carried out. Chitosan-titanium dioxide composite films were prepared by solution casting, using Chitosan, TiO 2 , Arquad T50 HFP as surfactant. The mixture of 1.0 g chitosan in 100 mL acetic acid was prepared, subsequently with the addition of TiO 2. The solution was then cast onto an acrylic mold and allowed to air-dry. The external morphology of the composite film revealed the high dispersion of TiO 2 in the polymer matrix. Three types of crosslinking agent; glutaraldehyde, citric acid, and itaconic acid were studied. It was found that chitosan film crosslinked with 1.12 mM citric acid for 5 min exhibited the highest tensile strength about 150.4 MPa. X-ray diffraction patterns of the dried film revealed the minor change in the theta of the crystalline region of chitosan. The diffraction line shift was likely due to the change in its chain orientation caused by the covalent interactions between chitosan and the crosslinking agent. The noncrosslinked chitosan-TiO 2 composite film exhibited the higher tensile stress at maximum load with TiO 2 content of 1 wt%, whereas the high content of TiO 2 revealed the poor tensile stress at maximum load due to an aggregation of nanoparticles. The spent film for dye removal had the lower tensile stress at maximum load than that of the original film. Three reactive dyes of RR 120, RY 17, and RB 220 were selected as a representative contaminant. The optimal TiO 2 amount for dye removal in both UV and dark conditions was 1 wt.% of chitosan. The chitosan-TiO 2 composite films without crosslinking had the higher efficiency in dye removal than the crosslinked films. Dye removal in UV condition had the higher efficiency than without UV for all initial dyes concentrations in the range of 10 to 100 mg. L-1. The ratio of sorption to photocatalysis of RR120, RY17, and RB220 were 70.7:29.3, 78.5:21.5, and 92.2:7.8, respectively. Langmuir isotherm was used for data analysis for dark condition and the results showed that q max of RR120, RY17, and RB220 were 46.8, 427.1, and 229.1 mg-dye. g-1-chitosan-TiO 2 film, respectively. The analysis of dye removal in UV condition followed satisfactorilly a Langmuir-Hinshelwood model in dye removal efficiencies. This indicated that photocatalysis process occurred on the surface of TiO 2 and in the solution.
Chitosan based nanocomposite materials as Photocatalyst – A review
Heterogeneous photocatalysis is a significant technology for environmental application. Moreover, immobilising an appropriate catalyst on the surface of a natural organic polymer presents a number of additional advantages including low-cost, high catalytic activity and extensive potential reuse for the application of pharmaceutical, biomedical and industrial activities. This review mainly focuses on the role of chitosan based material as photocatalyst on the environmental remediation.
2011
Simple bilayer systems consisting of TiO2 as a top layer and chitosan (CS), cross-linked chitosan-glutaraldehyde (CS-GLA) and chitosan-epichlorohydrin (CS-ECH) as sub-layers were successfully fabricated and immobilized onto a glass plate. The deposition and adhesive properties of TiO2 were improved by adding organic binders like epoxidized natural rubber (ENR50) and phenol-formaldehyde resin (PF) in the coating formulation. Exposing these bilayer systems in aerated aqueous solution to 45-W fluorescent lamp caused significant changes in content of both ENR50 and PF of TiO2 top layer, in addition to the remarkable physico-chemical changes of CS, CS-GLA and CS-ECH sub-layers
Photo-active chitosan-based hybrid films
European Polymer Journal, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
PHOTOCATALYTIC DECOLORIZATION STUDY OF METHYL ORANGE BY TiO 2 -CHITOSAN NANOCOMPOSITES
The photocatalytic decolorization of methyl orange (MO) by TiO 2 -chitosan nanocomposite has been studied. This study was started by synthesizing TiO 2 -chitosan nanocomposites using sol-gel method with various concentrations of Titanium(IV) isopropoxide (TTIP) as the TiO 2 precursor. The structure, surface morphology, thermal and optical property of TiO 2 -chitosan nanocomposite were characterized by X-ray diffraction (XRD), fourier transform infra red (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and diffuse reflectance ultra violet (DRUV) spectroscopy. The photocatalytic activity of TiO 2 -chitosan nanocomposite was evaluated by photocatalytic decolorization of methyl orange as a model pollutant. The results indicate that the particle size of TiO 2 increases with increasing of the concentration of TTIP, in which TiO 2 with smallest particle size exhibit the highest photocatalytic activity. The highest photocatalytic decolorization was ...
Preparation and Photoactivity of the Immobilized TiO2/chitosan Layer
Chemical Engineering Transactions, 2015
Heterogeneous photocatalytic oxidation processes employing semiconducting oxides such as TiO2, ZnO, etc. and appropriate irradiation sources have demonstrated promising results for the degradation of many persistent organic pollutants, producing more biologically degradable and less toxic substances. Recent advances in photocatalysis have focused on improving current photoreactor performance to make the process economically feasible. The immobilization of the photocatalyst in the form of a thin film significantly reduces some of the drawbacks of practical application of heterogeneous photocatalysis with nanoparticles. The photolytic and photocatalytic activity was investigated in the photocatalytic batch annular reactor system with recirculation, using different sources of irradiation. Terbuthylazine (N-tert-buthyl-6-cloro-N'-ethyl-1,3,5-triazine- 2,4-diamine), a substitute for atrazine, was used as model pollutant. The influence of various operating conditions on degradation of...
Photosensitive chitosan for visible-light water pollutant degradation
Chemical Engineering Journal, 2017
This study presents the potential application of photosensitive chitosan (chitosan with immobilized phthalocyanine) as singlet oxygen (1 O 2) generating structure for water pollutant degradation. The scientific goal of the studies was to determine process parameters of degradation through photosensitized oxidation using phthalocyanines immobilized on chitosan carrier particles. The influence of the pH, oxygen concentration, quantity of immobilized photosensitizer, irradiation intensity and multiple reuse of photoactive chitosan beans during benzylparaben (BeP) and 2,4dichlorophenol (2,4DCP) photodegradation were investigated. The degradation occurs via the reaction of the xenobiotics with 1 O 2. It was demonstrated that photoactive chitosan beans can be used several times without losing photosensitizing properties. Moreover, the possibility of solar irradiation applicability was proved. The acute ecotoxicity was evaluated using bioluminescence inhibition assay with the marine bacterium Vibrio fischeri as the test organism. The results of ecotoxicity investigation showed that the ecotoxicity decreased with irradiation time, which indicates a lower environmental impact of the photodegradation products.
Photoactive Chitosan: A Step Toward a Green Strategy for Pollutant Degradation
Photochemistry and Photobiology, 2014
This article is a highlight of the paper by Ferrari et al. in this issue of Photochemistry and Photobiology. It describes the innovative use of rose bengal-conjugated chitosan as a reusable green catalyst that photo-degrades phenolic compounds in aqueous media, and thereby has decontamination potential of polluted waters. Whether a next-generation photoactive polymer that produces singlet oxygen is a solution to pollutant degradation can be argued. It is as yet unclear what polymeric sensitizer would be practical on a large scale. Nonetheless pursuing this goal is worthwhile.
Urea modified TiO2 nanoparticles were synthesized at different TiO2: urea ratios and 60 (%wt) named UTiO2-10, 30 and 60) by sol-gel method and annealing at 400 °C during 1h. Characterization revealed the presence of TiO2 nanoparticles with visible light absorption (between 400 and 500 nm) probably due by the formation of thermolysis urea byproducts such as melon, which may induce a TiO2/melon heterojunction. Then, modified nanoparticles were immobilized on chitosan films by adding 30% (70QS/30UTiO2) and 50% 50QS/50UTiO2) of UTiO2 nanoparticles. Functionalized films were characterized by SEM-EDS, DRS and AFM. Photo-induced degradation of malachite green stains was evaluated on these films under different wavelengths. Upon UV-A+visible light irradiation, films showed good activity even slightly better than those containing Evonik P-25 (70QS/30P-25). Upon visible light between 450 and 800 nm, films evidenced a satisfactory performance but slower than under UV-A+visible light irradiation whereas the photobleaching activity of 70QS/30P-25 was very poor. When visible light irradiation with wavelengths higher than 590 nm was used, a slight photobleaching was also observed. DRS spectra taken at different irradiation times showed that dye underwent N-demethylated oxidative reactions either upon UV-Visible or visible light irradiation. ATR-FTIR measurements revealed the generation of benzophenones after 6 h of irradiation probably suggesting the formation of singlet oxygen under visible light. 70QS/30UTiO2-10 films showed a good photo-bleaching activity after 18 h of continuous UV-A+visible light irradiation.
Urea modified TiO 2 nanoparticles were synthesized at different TiO 2 : urea ratios (10, 30 and 60 (%wt) named UTiO 2-10, 30 and 60) by sol-gel method and annealing at 400 °C during 1 h. Characterization revealed the presence of TiO 2 nanoparticles with visible light absorption (between 400 and 500 nm) probably due by the formation of thermolysis urea byproducts such as melon, which may induce a TiO 2 /melon heterojunction. Then, modified nanoparticles were immobilized on chitosan films by adding 30% (70QS/30UTiO 2) and 50% 50QS/ 50UTiO 2) of UTiO 2 nanoparticles. Functionalized films were characterized by SEM-EDS, DRS and AFM. Photo-induced degradation of malachite green stains was evaluated on these films under different wavelengths. Upon UV-A + visible light irradiation, films showed good activity even slightly better than those containing Evonik P-25 (70QS/30P-25). Upon visible light between 450 and 800 nm, films evidenced a satisfactory performance but slower than under UV-A + visible light irradiation whereas the photobleaching activity of 70QS/30P-25 was very poor. When visible light irradiation with wavelengths higher than 590 nm was used, a slight photobleaching was also observed. DRS spectra taken at different irradiation times showed that dye underwent N-demethylated oxidative reactions either upon UV–vis or visible light irradiation. ATR-FTIR measurements revealed the generation of benzophenones after 6 h of irradiation probably suggesting the formation of singlet oxygen under visible light. 70QS/30UTiO 2-10 films showed a good photo-bleaching activity after 18 h of continuous UV-A + visible light irradiation.