MATERIALS & DESIGN
·
2019
·
IF 5.77
Pengbo Sun,Lijing Zhang,Shengyang Tao
The processing method of natural polymers is one of the critical factors affecting their application. As commonly used biomass, chitosan was usually shaped by a wet chemical method which dissolves chitosan in a solvent and then fabricated into the membrane, fiber or other forms. This process often needs a large number of solvents and acids, which are harmful to the environment. In this paper, we mixed chitosan powder and thermoplastic polyurethane to form membrane by selective laser sintering. This method has advantages of simple operation, fast membrane formation, and low preparation cost. No solvents were applied in the whole progress. The hybrid membrane had an adsorption performance for heavy metal ions, the maximum adsorption capacities to Cu(II) and Pb(II) reached 19.6 mg g −1 and 30.4 mg g −1 , respectively. Palladium ions could also be adsorbed by the membrane to form palladium-loaded composite materials, which could be used as a catalyst for reducing p-nitrophenol, and the conversion rate could reach 96% in 20 min.
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高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2015
·Vol. 15
·期 1
·600-605
·
IF 1.556
Jiang Ping,Li Duxin,Xiao Ya,Yang Xingxing,Liu Yuejun
The biodegradable microcapsules based on chitosan for a controlled delivery of clove oil were prepared by the single coagulation process. The effect of chitosan concentration, core to shell ratio, types of emulsifier, flocculating agent and hardening agent on the microcapsule diameter
and the particle size distribution of microcapsule were investigated. The optimized conditions for the preparation of microcapsules with well-defined structure and narrow dispersibility were under that (1) the concentration of chitosan was 1.0 wt%, (2) clove oil to chitosan ratio was 75:25,
(3) OP-10 and 10 wt% sodium sulfate were used as emulsifier and flocculating agent respectively, and (4) the concentration hardening agent glyoxal was 1 wt% based on the weight of chitosan. The uniform spherical structures with smooth surfaces with a particle size distribution of 1–15
μm were evidenced by SEM images of microcapsules. Core–shell, hetero-structures were confirmed by optical micrograph. The chemical component of the microcapsules was determined by FTIR. Thermal analysis showed the microcapsules were thermally stable below 150°C. It was
found that the pH value and temperature play important roles on the release rate of clove oil from the microcapsules. The release volume of clove oil from microcapsules at pH = 7, and pH = 10 were smaller than that at pH = 2. And the release volume of Clove oil from microcapsules at 60°C
was smaller than that at 20°C and 40°C, which showed a sustained and prolonged release.
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DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2015
·Vol. 31
·期 6
·1051-1055
·
IF 0.875
Fang Xiaoting,Guo Hongyu,Yang Fafu,Bai Xiaoyan
By the Schiff-base condensation of formacyl calix[4]crown( 2 ) with raw chitosan, a novel calix[4]crown-grafted chitosan chelating polymer( 3 ) was conveniently prepared in good yield. The structure of polymer 3 was confirmed by elemental analysis, infrared(IR) spectrometry and X-ray diffraction(XRD) analysis. The elemental analysis suggests that the grafting degree of calixcrown unit was 22% on the amino groups of chitosan. The morphological characteristic of polymer 3 was studied by scanning electron microscopy(SEM). Polymer 3 possessed loose porous and smooth morphology of surface. The dyes adsorption abilities of polymer 3 for a series of organic dyes[Orange I(OI), Neutral red(NR), Victoria blue B(VB) and Brilliant green(BG)] were studied by solid-liquid adsorption experiments. The adsorption percentages increased from 45%―60%(raw chitosan for dyes) to 75%―90%(polymer 3 for dyes). The highest adsorption percentage reached 89% for VB. The saturated adsorption capacities for OI, NR, VB and BG were as high as 622, 564, 854 and 781 mg/g, respectively. The adsorption abilities kept stable at 70%―90% in the scope of pH=5―9. The adsorption abilities for anionic dye(OI) decreased gradually with the increase of pH and the opposite trend was observed for cationic dyes(NR, BG, VB). The adsorption percentages were 70%―90% after five times’ cycles for adsorption.
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高影响因子
Frontiers of Materials Science
·
2014
·Vol. 8
·期 4
·373-382
·
IF 0
Zhou Hui-Yun,Cao Pei-Pei,Zhao Jie,Wang Zhi-Ying,Li Jun-Bo,Zhang Fa-Liang
Novel ethyl cellulose/chitosan microspheres (ECCMs) were prepared by the method of w/o/w emulsion and solvent evaporation. The microspheres were spherical, adhesive, and aggregated loosely with a size not bigger than 5 μm. The drug loading efficiency of berberine hydrochloride (BH) loaded in microspheres were affected by chitosan (CS) concentration, EC concentration and the volume ratio of V (CS)/ V (EC). ECCMs prepared had sustained release efficiency on BH which was changed with different preparation parameters. In addition, the pH value of release media had obvious effect on the release character of ECCMs. The release rate of BH from sample B was only a little more than 30% in diluted hydrochloric acid (dHCl) and that was almost 90% in PBS during 24 h. Furthermore, the drug release data were fitted to different kinetic models to analyze the release kinetics and the mechanism from the microspheres. The released results of BH indicated that ECCMs exhibited non-Fickian diffusion mechanism in dHCl and diffusion-controlled drug release based on Fickian diffusion in PBS. So the ECCMs might be an ideal sustained release system especially in dHCl and the drug release was governed by both diffusion of the drug and dissolution of the polymeric network.
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JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2021
·Vol. 21
·期 12
·5912-5919
·
IF 0
Feng Zhi-Yuan,Wang Chen-Di,Park Soo-Jin,Meng Wan,Meng Long-Yue
Chitosan (CS), the only alkaline polysaccharose available in nature, has always been a promising candidate for drug delivery owing to its excellent biodegradability and biocompatibility. However, inherent solubility and polycationic properties of CS largely hinder electrospinning, which
is an efficient method of fabricating nanofibers for drug carriers. To solve this problem and extend the applications of CS, polyamide/chitosan/tetraethyl orthosilicate (PA/CS/TEOS) composite nanofibers were successfully prepared as drug carriers in this study via electrospinning. The PA/CS/TEOS
ratios significantly influenced the nanofiber morphology. As the content of each was increased, the beads among the membranes increased initially and then decreased, determined by scanning electron microscopy (SEM). The morphology of the optimum membranes with the ratio of 1:0.13:0.67 was
smoother with less beads and uniform fiber diameter. Finally, the membranes with optimum ratios were used as carriers of ofloxacin in the study of drug release performance to identify their future feasibility, which revealed an initial fast release followed by a relatively stable release.
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PubMed
Jove-Journal of Visualized Experiments
·
2017
·
IF 1.232
Yongsan Li,Yaling Zhang,Yen Wei,Lei Tao
The protocol presents a facile, efficient, and versatile method to prepare chitosan-based hydrogels using dynamic imine chemistry. The hydrogel is prepared by mixing solutions of glycol chitosan with a synthesized benzaldehyde terminated polymer gelator, and hydrogels are efficiently obtained in several minutes at room temperature. By varying ratios between glycol chitosan, polymer gelator, and water contents, versatile hydrogels with different gelation times and stiffness are obtained. When damaged, the hydrogel can recover its appearances and modulus, due to the reversibility of the dynamic imine bonds as crosslinkages. This self-healable property enables the hydrogel to be injectable since it can be self-healed from squeezed pieces to an integral bulk hydrogel after the injection process. The hydrogel is also multi-responsive to many bio-active stimuli due to different equilibration statuses of the dynamic imine bonds. This hydrogel was confirmed as bio-compatible, and L929 mouse fibroblast cells were embedded following standard procedures and the cell proliferation was easily assessed by a 3D cell cultivation process. The hydrogel can offer an adjustable platform for different research where a physiological mimic of a 3D environment for cells is profited. Along with its multi-responsive, self-healable, and injectable properties, the hydrogels can potentially be applied as multiple carriers for drugs and cells in future bio-medical applications.
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 44
·20974-20986
·
IF 4.682
Hu Yong,Xu Yuan,Wang Bing,Chen Yun,Huang Chao
The methacrylated catechol-chitosan (MCCS) was facile prepared using chitosan (CS) sequential crosslinked with 2,3,4-trihydroxybenzaldehyde (THB) and methacrylic anhydride (MA) in mild conditions and then was induced into adhesive hydrogel by photopolymerization with photoinitiator. Structure and morphology of the MCCS adhesive hydrogel were characterized by FTIR, UV, XRD, 1 H NMR, and SEM. Physical properties of the MCCS adhesive hydrogel including swelling, degradation, rheology, and adhesive strength were also investigated. These results show that the MCCS adhesive hydrogel with ideal elasticity and good mechanical properties can be quickly obtained by UV (365 nm) irradiation, endowing the photocrosslinked hydrogel exhibits controllable degradation rate and improved adhesive strength. The ultimate adhesion strength of MCCS hydrogel is up to 62.33 kPa, which is more than twice that of hydrogel prepared by CCS. Additionally, the MCCS hydrogel has good cell compatibility and antibacterial activity. The MCCS hydrogel may be a promising candidate material for the development of medical bioadhesives.
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高影响因子
MINERALS ENGINEERING
·
2020
·
IF 3.795
Tao Wang,Bo Feng,Yutao Guo,Wenpu Zhang,Yibei Rao,Chunhui Zhong,Liangzhu Zhang,Chen Cheng,Huihui Wang,Xianping Luo
The separation of apatite from calcite has been recognized as one of the most difficult subjects in mineral processing owing to their similar surface properties, thus finding high-efficiency depressants become the key for the separation. In this paper, carboxymethyl chitosan was tested as a potential selective depressant in the separation of apatite and calcite using sodium oleate (NaOL) as a collector. Contact angle measurements, adsorption tests, zeta potential tests, FTIR analysis and XPS analysis were performed to explain the selective depression mechanism of carboxymethyl chitosan. The micro-flotation experiment indicated that carboxymethyl chitosan had significantly depression effect on calcite but had a little influence on apatite at pulp pH 9. A series of mechanism tests show that the carboxymethyl chitosan adsorption quantity on calcite surface more than that on apatite surface, which is due to that carboxymethyl chitosan adsorbed on apatite surface by hydrogen bonding, while absorbed on calcite surface mainly through chemical chelating between Ca on mineral surface and –COO − on the depressant. Moreover, both apatite and carboxymethyl chitosan are negatively charged, strong electrostatic repulsive force and steric hindrance between carboxymethyl chitosan and apatite also make the carboxymethyl chitosan adsorb on apatite surface more difficult. These adsorption differences lead to the flotation separation of the two minerals.
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高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 17
·9349-9359
·
IF 3.917
He Xiaomei,Song Peng,Shen Xiaoping,Sun Yiming,Ji Zhenyuan,Zhou Hu,Li Baolong
Through a facile “dipping and drying” process, reduced graphene oxide, here simply referred to as “graphene”, was successfully coated onto a commercial textile substrate, resulting in a high-performance supercapacitor electrode with excellent flexibility and stretchability. With the assistance of difunctional chitosan (for dispersing and gluing), a high graphene loading amount of 5.5 mg cm −2 was achieved on cotton textile within 10 soaking times. The graphene@cotton-10 had a low sheet resistance of 1.75 Ohm sq −1 , which merely increased 0.51 and 0.78 Ohm sq −1 when being bent at 180° and stretched with 100% strain, respectively. In a three-electrode configuration, the areal specific capacitance of the graphene@cotton-10 reached up to 232 mF cm −2 at the current density of 1 mA cm −2 , which was superior to most of the carbon@textile flexible electrodes reported so far. The resulting graphene@cotton-10 symmetrical supercapacitor had a decent energy density of 4.38 μWh cm −2 at 5 mW cm −2 . Cycling test revealed the supercapacitor had more than 80% retention of its initial capacitance after 5000 cycles at 5 mA cm −2 , demonstrating an outstanding long-term durability. Furthermore, the synthesis methodology established in this study is simple, efficient and environment-friendly, which possesses a great potential for large-scale practical applications.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 51
·期 3
·1344-1353
·
IF 2.371
Yang Xia,Meng Nannan,Zhu Yuanchao,Zhou Yifeng,Nie Wangyan,Chen Pengpeng
In this work, molybdenum disulfide (MoS 2 ) nanosheets were employed to enhance the mechanical and thermal properties of chitosan (CS), which was one of the most promising biomaterials. In order to promote a homogeneous dispersion of MoS 2 and improved interface interactions between CS and fillers, carboxyl functionalization was subjected to the exfoliated MoS 2 nanosheets by chemical conjugation with thioglycolic acid before compositing with CS. Afterward, the CS/MoS 2 – g –COOH composite films were prepared by a simple solution blending method. Micromorphology characterizations showed that MoS 2 – g –COOH nanosheets dispersed much better than unmodified MoS 2 nanosheets, which was considered to be quite beneficial for the enhanced properties of CS nanocomposites. DMA results indicated that the mechanical properties of CS were improved by incorporating with MoS 2 – g –COOH nanosheets compared with neat CS and unmodified MoS 2 -filled CS. The thermal stability of CS/MoS 2 – g –COOH was also improved. This work demonstrated a promising route to prepare MoS 2 -based polymer nanocomposites with excellent performances.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2022
·
IF 8.025
Zhe Li,Xiaoxia Jiang,Hao Huang,Ao Liu,Hongning Liu,Naeem Abid,Liangshan Ming
The purpose of this study was to prepare chitosan/zein (CS/Zein) edible films reinforced with Mosla chinensis essential oils (EOs) nanoemulsions (NEs) and nanoparticles (NPs) in order to compare their properties. NEs and NPs containing EOs could be used to fabricate films with functional properties, and the films were prepared using a casting method. The influence of EO concentration and mixing methods on the physical, mechanical, and functional properties of the films was investigated. The results indicated that the films formulated with EO NEs generated favorable fundamental and functional characteristics with excellent mechanical properties, moisture barrier capacity, and significant antioxidant and antibacterial activity . In addition, the use of NEs-based films improved the release of bioactive compounds, and the mechanism of EO release was found to follow a first order model. In summary, EO NEs were more effective in preserving the fundamental and functional properties of CS/Zein nanocomposite edible films than NP-based films. These differences may reflect different forms and methods of dispersing EOs in NEs and NPs. This study demonstrated that NEs reinforced films could be used to enhance the effectiveness of EOs in food products and develop new strategies for their delivery and application.
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高影响因子
Journal of the Mechanical Behavior of Biomedical Materials
·
2016
·
IF 2.876
Jingjing Wu,Jiaoyan Liu,Yanmei Shi,Ying Wan
Silk fibroin (SF) and hydroxyapatite (HA) were incorporated into chitosan/glycerophosphate (GP) system to prepare new types of hydrogels. The formulated chitosan/SF/GP and chitosan/SF/HA/GP solutions were found to be injectable at room temperature, and able to form into hydrogels at near-physiological temperature and pH. Rheological measurements showed that elastic modulus of certain chitosan/SF/GP and chitosan/SF/HA/GP gels could reach around 1.8 and 15 kPa, respectively, and was much higher than their respective viscous modulus. Compressive measurements revealed that some chitosan/SF/GP and chitosan/SF/HA/GP gels had 8 and 20-fold modulus and strength higher than the chitosan/GP gel, respectively, confirming that compressive properties of these gels were greatly improved. Results obtained from in vivo degradation demonstrated that degradation endurance of the optimized chitosan/SF/GP and chitosan/SF/HA/GP gels was significantly enhanced as compared to the chitosan/GP gel, and the degradation rate of the gels could be regulated by the SF component alone or by the combination of SF and HA components.
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高影响因子
危险品化学品经营许可证（带存储）