WATER SCIENCE AND TECHNOLOGY
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2022
·Vol. 86
·期 5
·1017-1033
·
IF 2.43
Fu Chengbin,Li Ye,Zuo Yangyang,Li Bolin,Liu Chang,Liu Dongxue,Fu Yan,Yin Yixin
It is essential to solve the problem of phosphorus pollution in urban landscape water and reduce the degree of eutrophication. In this paper, lanthanum-modified bentonite (La-B) was prepared by high-temperature calcination and liquid-phase precipitation. Then La-B was modified with chitosan to prepare a low-cost environment-friendly functional material: lanthanum/chitosan co-modified bentonite (La-BC). It can reach the adsorption equilibrium within 30 min, and the maximum adsorption capacity is 15.5 mg/g (initial phosphate concentration 50 mg/L); when the target concentration is 2 mg/L, the removal rate can reach 98.5%. La-BC has a stronger anti-interference ability to common coexisting anions SO 4 2− , HCO 3 − , NO 3 − and Cl − in the urban landscape water body. La-BC has excellent performance in weakly acidic to neutral water, and its pH applicable range has been improved, making it possible to apply in practical water. The fitting results show that the adsorption behavior conforms to the pseudo-second-order kinetic model and the Freundlich model. After 5 regenerations, the removal efficiency remained around 80%. In the actual water test results, the phosphate concentration can be controlled below 0.1 mg/L and the removal rate is above 75%. Due to its low cost and reusability, it has great potential in the practical application of phosphate removal from landscape water. La-BC high-efficiency phosphorus removal agent was prepared by high temperature calcination and liquid phase precipitation. La-BC has shown excellent competitiveness in actual landscape water application and regeneration experiments. A possible mechanism of La-BC adsorption of phosphate has been studied and analyzed.
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EUROPEAN POLYMER JOURNAL
·
2012
·
IF 2.739
Wei Li,Xueyong Li,Wei Li,Ting Wang,Xiaoxia Li,Siyi Pan,Hongbing Deng
Negatively charged cellulose acetate (CA) and positively charged chitosan (CS) were layer-by-layer (LBL) assembled together by the electrospinning–electrospraying hybrid technique via physical deposition and electrostatic force for the first time. The morphology of the mats indicated that all of them were of a good fiber shape and a three-dimension structure. The X-ray photoelectron spectroscopy results verified the existence of CS on the surface of the as-spun mats. The thermogravimetric analysis and differential scanning calorimetry results illustrated that the thermal properties of the mats were affected by their compositions. In addition, the cell culture experiment demonstrated that the scaffolds with the LBL structured polysaccharide films were of good cell compatibility and no cytotoxicity for the mouse lung fibroblasts cells. Moreover, the ability of cell adhesion and spreading was affected by the number of deposition layers and the composition of outermost layer.
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CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Qing Li,Qian Mao,Min Li,Shengjie Zhang,Gaohong He,Wenjun Zhang
Radioactive iodine waste from nuclear plant became the severe environmental problem and led to the public health concern. The cross-linked chitosan adsorbed iodide anions through the electrical attraction, yet performing limited-efficiently. Targeting as the better adsorption, the modified chitosan sorbent as AgCl@CM (silver chloride entrapped in the cross-linked chitosan microspheres) for iodine adsorption was proposed and implemented by chemisorption from AgCl and physisorption from chitosan via the improved emulsion method (emulsions mixing-collision and polymerization). With the broad application from pH 2 to pH 10, the spherical AgCl@CM (from 0.20 g silver nitrate) performed the I 127 anions (instead of radioactive iodine) adsorption efficiency of higher than 90 % in 20 min, with the maximum adsorption capacity of 1.5267 mmol/g, well-fitting with the pseudo-first-order model and Sips isothermal model. AgCl@CM also performed I 127 adsorption with the significant selectivity relative to Cl − . The micro-spherical AgCl@CM sorbents were therefore prospective-effectively for iodine waste water treatment.
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JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Gang-Tian Zhu,Xiao-Li Hu,Sheng He,Xiao-Mei He,Shu-Kui Zhu,Yu-Qi Feng
Tailor-made chitosan fiber was prepared via hydrothermal treatment to serve as a micro-solid phase extraction (micro-SPE) sorbent for the analysis of petroleum acids (PAs) in crude oils. Chitosan fiber, which is commercial and cheap, has a diameter of about 10 μm and a length of a few centimeters. The fibrous property of the sorbent enables the micro-SPE to deal with viscous crude oil samples because of the low back-pressure during extraction, while the abundant hydroxyl groups and amino groups on the surface of chitosan fiber can provide high density of specific sites for adsorption of PAs. Moreover, it was found that hydrothermal treatment at certain conditions could tune the surface properties of chitosan fiber, leading to significant improvement of the capacity of the fiber in adsorption of PAs. Using hydrothermally treated chitosan fiber as sorbent, the micro-SPE was applied to the determination of PAs in crude oils, with the advantages of easy-operation, rapidness and high sensitivity (the limits of detection range from 0.7 ng/g to 5.4 ng/g). Furthermore, coupled with comprehensive two dimensional gas chromatography-mass spectrometry (GC × GC MS), the treated chitosan fiber packed micro-SPE method showed a great potential for comprehensive profiling of PAs in crude oils.
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Polymers
·
2017
·Vol. 9
·期 12
·633
·
IF 3.364
Junrong Li,Ying Ye,Huining Xiao,Beihai He,Liying Qian
Guanidinylated chitosan (GCS) was prepared by grafting guanidine oligomers onto chitosan under microwave irradiation. The structure of GCS characterized by FT-IR and1H NMR verified the covalent bonding between the guanidine oligomers and chitosan; the effects of molar ratio, reaction temperature, and time were investigated and the degree of substitution of GCS reached a maximum of 25.5% under optimized conditions in this work. The resulting GCS showed significantly enhanced antimicrobial activities. The results obtained from the dynamic UV absorption ofEscherichia coli(E. coli) and atomic force microscopy (AFM) revealed that the deactivation ofE. coliby GCS was due to the destructing of the cell membrane and the prompt release of cytoplasm from the bacterial cells. The adsorption of GCS onto cellulose fibers and the antimicrobial efficiency of the hygiene papers with GCS were also investigated. Microwave irradiation as a green assisted method was applied to promote this reaction. This facile approach allowed chitosan to be guanidinylated without tedious preparation procedures and thus broadened its application as a biocompatible antimicrobial agent.
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FOOD CONTROL
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2018
·
IF 3.667
Jianhua Liu,Jie Xiao,Feng Li,Ying Shi,Dapeng Li,Qingrong Huang
ε-Polylysine-loaded chitosan-sodium alginate nanoparticles (ε-PL NPs) were synthesized and characterized in terms of particle size distribution, surface morphology, thermal properties and structure, respectively. Their antibacterial activity on Escherichia coli, Bacillus subtilis , Staphylococcus aureus and Micrococcus luteus were studied. The ε-PL NPs were well dispersed as spherical particles within the range of 200–500 nm. In vitro release studies showed an initial burst release of ε-PL from the nanoparticles followed by a sustained release. The minimum inhibitory concentrations (MIC) of ε-PL NPs against four test bacteria were 7.81 μg/mL ( E. coli ), 31.25 μg/mL ( B. subtilis ), 15.63 μg/mL ( S. aureus ) and 38.67 μg/mL ( M. luteus ), respectively. The bacteriostatic activity of ε-PL NPs was three times higher ( P < 0.05) than that of free ε-PL in terms of inhibition zone diameter, suggesting that ε-PL NPs has stronger antibacterial activity. These findings may provide some basis for the application of ε-PL NPs as a promising food preservative.
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Science China-Chemistry
·
2013
·Vol. 56
·期 12
·1701-1709
·
IF 1.327
Chen ZhiPing,Wang Wei,Guo Lei,Yu YanYan,Yuan Zhi
For the requirement of preliminary vascularization, the scaffolds for thick tissue engineering should possess not only good cell affinity, but also anticoagulant ability. In this paper, an enzymatically crosslinked hydrogel scaffold based on sulfated chitosan (SCTS) was prepared. Firstly, sulfated chitosan-hydroxyphenylpionic acid (SCTS-HPA) conjugate was synthesized, and its structure was identified by FITR and 1 H NMR. And then an enzymatically crosslinked hydrogel was prepared in the presence of horseradish peroxidase (HRP) and hydrogen peroxide (H 2 O 2 ). The gelation time, mechanical property, morphology and cytotoxicity to human umbilical vein endothelial cells (HUVECs) of the hydrogel was evaluated in vitro , the tissue compatibility of SCTS scaffold was studied in vivo . The results showed that the gelation time, mechanical property, morphology of the dehydrated hydrogel could be controlled by the HRP and H 2 O 2 concentration. The cytotoxicity test showed that the hydrogel extracts had no cytotoxicity to HUVECs. The in vivo assay indicated that SCTS-HPA scaffold showed good tissue compatibility, and no thrombus formation. All these results indicated that the SCTS-HPA scaffold could be used as thick tissue engineering scaffold.
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CELLULOSE
·
2013
·Vol. 21
·期 1
·519-528
·
IF 3.476
Liu Kai,Lin Xinxing,Chen Lihui,Huang Liulian,Cao Shilin
In order to enhance the antibacterial and mechanical properties of agar films, the chitosan-methylisothiazolinone (C–MIT) complex was first prepared by the ionic gelation method, and the characterization of the C–MIT complex was carried out by Fourier transform infrared spectroscopy, transmission electron microscopy, and Thermo gravimetry. Chitosan was successfully crosslinked with tripolyphosphate for the nanoencapsulation of methylisothiazolinone, and the C–MIT complex was spherical in shape with a diameter of about 10 nm. The C–MIT/MFC biocomposites obtained through the adsorption of the C–MIT complex on the microfibrillated cellulose (MFC) was then incorporated into the agar films. In comparison with the pure agar films, the tensile strength of the agar composite films was increased by about 19 % at the loading of 10 wt% of C–MIT/MFC biocomposites, and antibacterial tests demonstrated that the agar composite films exhibited remarkable antibacterial activities against both Escherichia coli and Staphylococcus aureus . This work provides a new approach to utilizing multifunctional agar films in the medical field.
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GREEN CHEMISTRY
·
2020
·Vol. 22
·期 8
·2426-2433
·
IF 9.48
Guanglei Zhao,Yuanyuan Chen,Xiao-Feng Li,Sihan Zhang,Yuanqiu Situ
Chitosan-based membrane materials are promising biomaterials with excellent biodegradability, biocompatibility, high hydrophilicity, and cost efficiency. However, their low proton conductivity greatly limits their use as proton exchange membranes, and the previously reported methods to improve their proton conductivity generally introduced non-biodegradable groups and compounds, which caused this natural polymer to lose its basic advantage of biodegradability. In this work, a facile and efficient strategy has been developed for fabricating new chitosan-based whole-biopolymers to satisfy both sustainability and high-performance simultaneously. The modified chitosan with introduced purine groups has significantly improved proton conductivity up to 50 fold higher than that of chitosan itself, due to the unique structures of the grafted purine groups that produced a large number of proton-hopping sites, and the adenine monophosphate-grafted membrane materials exhibited higher proton conductivity (0.1867 S cm−1) at 100 °C than Nafion, indicating their capability for use in high-temperature fuel cells. Meanwhile their methanol permeability was much lower than that of Nafion (7.888 × 10−7 cm2 s−1vs. 1.550 × 10−6 cm2 s−1). Blending of NCC with modified chitosan further improves its mechanical properties and dimensional stability. This study paves a new way to prepare environmentally friendly membrane materials in the place of commonly used non-degradable membranes, highlighting the prospects of natural polymer-based membrane materials in the sustainable fields of fuel cells, supercapacitors and solid-state batteries.
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JOURNAL OF HAZARDOUS MATERIALS
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2013
·
IF 3.925
Shao-Ping Kuang,Zhao-Zhan Wang,Jie Liu,Zhan-Chao Wu
In this paper, a novel triethylene-tetramine grafted magnetic chitosan was synthesized. The chemical structure and the percentage content of each element of chitosan and its derivatives were characterized by elemental analysis, infrared spectroscopy, solid state 13 C NMR, X-ray diffraction analysis and thermogravimetric analysis, respectively. Their surface topography was observed by the transmission electron microscope. The results of adsorption kinetics and adsorption thermodynamics showed the adsorption mechanism could be better described by the pseudo-second-order equation ( R > 0.999). The adsorption isotherm was well fitted by the Langmuir equation ( R > 0.999), and 0 < R L < 1. The maximum adsorption capacity was 370.63 mg/g at the optimized adsorption conditions, which were pH = 6, T = 298 K, t = 1.5 h, C 0 = 200 mg/L and adsorbent dose is 500 mg/L. The rate-limiting step may be the chemical adsorption rather than mass transport. The adsorbent still exhibited very good adsorption performance after the fifth regeneration cycle. The mechanism for adsorption and desorption was discussed.
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JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2023
·
IF 5.3
Li Jing,Liu Wan,Jiang Ping
First, biocompatible temperature-responsive polymer chitosan- graft - N -isopropylacrylamide (CS- g -PNIPAm) synthesized via ATRP. Second, mugwort oil (MO) was encapsultated with CS- g -PNIPAm as shell materials to form long-term anti-bacterial agents and temperature responsive microcapsules. The CS- g -PNIPAm@MO (CSPN@MO) microcapsules were prepared via single coacervation method and solvent evaporation method. The chemical structures of CS 0.1 - g -PNIPAm 22 was confirmed by 1 H NMR and FTIR. And the copolymer micelles were characterized by UV, laser particle-size analysis, and TEM. The results indicated that the copolymer had temperature-responsive behaviors. The microcapsules were characterized by laser particle-size analyzers (LPSA), scanning electron microscopy (SEM), TG and anti-bacterial agents performance testing. The results showed that the average particle size of microcapsules was 0.28 μm, and the encapsulation efficiency and drug loading efficiency of MO reached 60.2 and 44.5%. After 48 h of release in media at different temperature (20, 40 and 60 °C) still sequestered 79.2, 92.2 and 96.1% of MO which approved the shell of microcapsules responded to different temperature. The morphology of CSPN@MO microcapsules revealed that the microcapsules presented smooth and firm structure. Antibacterial test for Artemisia argyi of CSPN@MO implied that the bacteriostatic rate reached 99.2 and 96.2% after 1 day and 10 days respectively. Bio-based macromolecular modification strategies can provide inspiration for the development of green microcapsules. Graphical Abstract
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RSC Advances
·
2019
·Vol. 9
·期 23
·13065-13076
·
IF 3.049
Yuzhe Zhang,Tingting Bian,Da Xia,Dandan Wang,Yi Zhang,Xudong Zheng,Zhongyu Li
Although bio-materials are widely used for the adsorption of heavy metal ions, they have low specific surface area, slow adsorption rates, and poor selectivity. To overcome these limitations, in this study, we report a 3D-ordered macroporous ion-imprinted chitosan film (3DOM-IICF); the 3DOM-IICF coupled with a colloidal crystal template and ion imprinting (IIP) technology has been used to absorb copper ions (Cu(II)) present in water. Moreover, polystyrene (PS) micro-spheres and copper templates were added to form a three-dimensional ordered macroporous structure and ion-imprinted sites, respectively. Finally, the film was formed by drying. Adsorption experiments showed the removal of Cu(II) from the 3DOM-IICF in an aqueous solution. The 3DOM-IICF exhibited good adsorption performance under neutral conditions of pH = 7.0, and the adsorption efficiency was high. The maximum adsorption capacity of the 3DOM-IICF was 261.31 mg g−1. The adsorption processes were more consistent with the pseudo-second-order kinetic model and the Langmuir isotherm. The 3DOM-IICF exhibits superior selective adsorption of Cu(II). Moreover, the 3DOM-IICF could be regenerated multiple times, reused as an adsorbent and maintained high adsorption capacity. This kind of imprinted template method has important significance in the selective adsorption of pollutants in bio-materials and is worthy of in-depth research.
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