Processes
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2020
·Vol. 8
·期 7
·834
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IF 2.753
Hongxia Su,Chongxing Huang,Ying Liu,Song Kong,Jian Wang,Haohe Huang,Bobo Zhang
In this study, different amounts of cinnamomum essential oil (CEO) were encapsulated in chitosan nanoparticles (NPs) (CS-NPs) through oil-in-water emulsification and ionic gelation. An ultraviolet-visible spectrophotometer, Fourier-transform infrared spectroscopy, synchronous thermal analysis, and X-ray diffraction were employed to analyze the CEO encapsulation. As observed by field-emission scanning electron microscopy, NP size analysis and zeta potential, the prepared CS-NPs, containing CEO (CS-CEO), were spherical with uniformly distributed sizes (diameters: 190–340 nm). The ranges of encapsulation efficiency (EE) and loading capacity (LC) were 4.6–32.9% and 0.9–10.4%, with variations in the starting weight ratio of CEO to CS from 0.11 to 0.53 (w/w). It was also found that the antioxidant activity of the CS-NPs loaded with CEO increased as the EE increased. The active ingredients of the CEO were prevented from being volatilized, significantly improving the chemical stability. The antioxidant activity of CS-CEO was higher than that of the free CEO. These results indicate the promising potential of CS-CEO as an antioxidant for food processing, and packaging applications.Keywords:cinnamomum essential oil;chitosan;encapsulation;antioxidant activity
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Materials Today Communications
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2021
·
IF 3.383
Thanakorn Yeamsuksawat,Hui Zhao,Jun Liang
This work aimed to synthesize Fe 3 O 4 @Chitosan@Ag nanoparticles by employing the suspension technique with a crosslinking agent, producing the Ag nanoparticles (AgNPs) using glucose as a reducing agent and applying them to the surface of Fe3O4@Chitosan. The Fe 3 O 4 @Chitosan@Ag nanoparticles were characterised by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) to determine the existence of chitosan and Ag nanoparticles on the surface of the Fe 3 O 4 . The thermal stability, morphology, and magnetic behaviour were studied by comparing the results among Fe 3 O 4 , Fe 3 O 4 @Chitosan, and Fe 3 O 4 @Chitosan@Ag with thermogravimetric analyses (TGA), transmission electron microscopy (TEM), and a vibrating sample magnetometer (VSM), respectively. Moreover, the comparison of antimicrobial activity between Fe 3 O 4 @Chitosan and Fe 3 O 4 @Chitosan@Ag nanoparticles was conducted by the colony count method. Based on the results, both types of nanoparticles can inhibit the growth of microbes. However, the Fe 3 O 4 @Chitosan@Ag showed superior results of at least 99.5 % prevention of the growth of microorganisms. These developed antimicrobial nanoparticles could be the potential antimicrobial agent or additives in various medical, biological, food packaging, and textile applications.
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COMPOSITES PART B-ENGINEERING
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2021
·
IF 9.078
Qian Zhang,Yansha Qiao,Jianhua Zhu,Yimeng Li,Chaojing Li,Jing Lin,Xiaoli Li,Hui Han,Jifu Mao,Fujun Wang,Lu Wang
Surgical sutures pervade almost all surgeries; however, their clinical therapy effects are barely satisfactory due to the lack of physiological signal responsiveness and the prone surgical site infection (SSI). Herein, the functional sutures (PCGT@S) with electroactivity and antibacterial properties were fabricated by decorating the suture surfaces with chitosan-gelatin/tannic acid/polypyrrole (CS-GE/TA/PPy) composite coating . Thanks to the assistance of CS-GE/TA on the polymerization of PPy, the inherent brittleness of PPy was alleviated and ensured PCGT@S excellent conductivity even under knotted state, thereby providing stable physiological electrical signal transmission among cells and regulating cell behaviors actively. Meanwhile, the synergistic effects of CS-GE/TA and PPy offered PCGT@S outstanding antibacterial rates of over 99% against E. coli and S. aureus without involving any additional drugs. Furthermore, in vivo studies revealed that PCGT@S could enhance wound healing dramatically, as evidenced by less inflammatory reaction, better angiogenesis, cell proliferation , re-epithelization, granulation tissue, and collagen regeneration. This study successfully demonstrates the feasibility of the electroactive and antibacterial sutures for promoting tissue regeneration and provides a new idea for exploring the next generation bioactive suture.
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CARBOHYDRATE POLYMERS
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2020
·
IF 7.182
Cunli Pan,Junqing Qian,Changyan Zhao,Haiyang Yang,Xiaohua Zhao,Hui Guo
In order to reveal the relationship between the degree of crosslinking and the properties of chitosan nanoparticles, a potassium polyvinyl sulfate (PVSK) titration method was established for the determination of free amino group in chitosan, which showed that there was a window effect in the crosslinking degree and particle size of three kinds of molecular weight chitosan cross-linked by different content of tripolyphosphate (TPP), and the nanoparticles with moderate crosslinking degree were smaller. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) showed the moderate degree of cross-linking nanoparticles had strong antibacterial properties. IR analysis showed that the interaction between chitosan nanoparticles with different crosslinking degree and TPP were different. X-ray diffraction analysis showed that the cross-linked chitosan nanoparticles were amorphous. Above all, the crosslinking degree of TPP cross-linked chitosan nanoparticles was related to the particle size and antibacterial properties.
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ADSORPTION SCIENCE & TECHNOLOGY
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2020
·
IF 2.425
Qiaoling Xie,Gaojie Liang,Tao Lin,Fuming Chen,Dandan Wang,Bo Yang
A study on selective chelating precipitation of palladium metal from real electroplating wastewater using chitosan and its water-soluble derivative was conducted. The pH parameter, the concentrations of chitosan and its water-soluble derivative and the chelating precipitation time were experimentally investigated, and the optimum conditions were determined. The results revealed that both chitosan and its water-soluble derivative acted as chelating precipitation agents. Rapid chelating precipitation occurred when chitosan was added to real electroplating wastewater containing the chitosan derivative, thereby improving removal efficiency of palladium in different forms up to 95% under the optimum condition of 0.2 g/L chitosan and 0.16 mg/L derivative at pH 2.5. Then, dissolution experiments showed that chelating precipitation products could be dissolved in aqua regia. Additionally, selective chelating precipitation of palladium by chitosan and its derivative was characterized using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Thus, it can be concluded that the combined utilization of chitosan and its water-soluble derivative is a promising approach method for the removal of different forms of palladium from real electroplating wastewater.
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APPLIED ORGANOMETALLIC CHEMISTRY
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2020
·Vol. 34
·期 5
·e5619
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IF 3.14
Yijun Du,Sailong Wei,Minchao Tang,Miaoting Ye,Hongyu Tao,Chenze Qi,Linjun Shao
Palladium chloride doped chitosan composite nanofibers were prepared by electrospinning with sodium polyacrylate (PAAS) as the co-spinning agent. The composite nanofibers are subsequently treated at elevated temperature to improve their solvent resistance. The Pd (II) cations inside the composite nanofibers were reduced into uniform palladium nanoparticles (Pd NPs) with mean diameter of ~4.93 nm. These Pd NPs inside the chitosan composite nanofibers exhibited excellent catalytic activity for Heck reactions of aromatic iodides with alkenes with yields over 85%. Moreover, due to the fibrous structure, this novel fibrous palladium catalyst could be readily recovered by simple filtration and reused for 18 times without loss of initial catalytic activity. It was found that the reactants could readily diffuse from the reaction solution to the active Pd NPs inside the nanofibers and the products could departure from composite fibers into the reaction solution, while the Pd NPs were tightly restricted inside the chitosan composite nanofibers.
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E-POLYMERS
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2020
·Vol. 20
·期 1
·303-316
·
IF 1.675
Haihua Yu,Xiuhang Xu,Yunfei Xia,Mingzhen Pan,Nighat Zarshad,Bo Pang,Anis Ur Rahman,Min Wu,Henmei Ni
According to the concept of fire life cycle assessment (LCA), a new type of intumescent flame retardant was designed and synthesized by chemically bonding chitosan, phosphorus pentoxide and melamine. The resultant compound, chitosan ethoxyl melamine phosphate (CEMP), was characterized by FTIR, 1 H NMR, 31 P NMR, XRD and SEM. The performance of CEMP and organic montmorillonite (OMMT) was evaluated in the substrate of epoxy resin (EP) with limited oxygen index (LOI), UL-94, cone calorimetric test (CCT), TGA and TG-IR. As a result, intumescent flame retardant EP (EP3) containing 30.6% LOI and V-0 rating was prepared by adding 3 wt% OMMT and 15 wt% CEMP. The CCT results indicated that CEMP and OMMT reduced the peak of heat release rate (PHRR) to about one fourth that of pure EP and total heat release (THR), 1/2. Decomposition of EP and EP3 was traced from 100 to 600°C by TG-IR.
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PROGRESS IN ORGANIC COATINGS
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2020
·
IF 4.469
Zhidong Ma,Min Sun,Anhang Li,Guiyu Zhu,Yue Zhang
A novel environment-friendly composite coating (P/P'-Ch-P/P') was prepared by layer-by-layer assembly of polyvinyl butyral (PVB), polymethylhydrosiloxane (PMHS) and chitosan (Ch) on AA 2024 substrate to improve the corrosion resistance of AA 2024 sample. The properties of the coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and laser confocal microscope. The results showed that the addition of PMHS increased the hydrophobicity of composite coating；as the intermediate layer, Ch also crosslinked other components while forming the film. At the same time, the corrosion resistance of the coating in 3.5 wt.% NaCl solution was characterized by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. Compared with the bare aluminum substrates, the impedance modulus of the composite coating was increased by 3 orders of magnitude; the corrosion current density (Icorr) of the composite coating was reduced by 5 orders of magnitude. The results of long-term immersion test showed that the composite coating still had good anticorrosion ability after 60 days. This study provides a simple and environment-friendly method for corrosion protection of aluminum alloy in marine environment.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
·
IF 3.99
Yanqing Wang,Qianqian Han,Ying Wang,Dan Qin,Qiang Luo,Hongmei Zhang
In this study, aromatic amino acid-conjugated chitosan are designed and developed, as viewed by multi-spectral methods. The results from 1H NMR , FTIR, and UV–vis indicated the successful grafting of tryptophan (Trp) or phenylalanine (Phe) onto chitosan (CS) to form Trp-CS and Phe-CS nano-conjugates with 4.7 % and 6.8 % grafting ratio. The grafting induced some influences on the chiral structure and the symmetry and backbone structure of CS. The thermal stability of Trp-CS and Phe-CS nano-conjugates is less than that of CS. Trp-CS and Phe-CS conjugates were formed as spherical nanoparticles . The rheological studies show that Trp-CS and Phe-CS exhibit characteristic of an elastic material. In addition, Trp-CS and Phe-CS present well antioxidant activities and good biocompatibility.
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Jiayun Chen,Huali Xie,Xuejun Lai,Hongqiang Li,Jiefeng Gao,Xingrong Zeng
High fire-safe aerogel with multi-functionality is urgently desirable due to the frequent fire disasters. However, it is still a challenge to afford both excellent flame retardancy and sensitive fire-warning in combustible aerogels. Herein, we fabricated an ultrasensitive fire-warning and high fire-resistance chitosan/montmorillonite/carbon nanotube composite aerogel (CCA) via freeze-drying. Benefiting from the rapid decrease of the electrical resistance for amino-functionalized carbon nanotube when being burned, CCA achieved a hitherto shortest fire-warning response time (~0.25 s). Importantly, the aerogel exhibited excellent flame retardancy and self-extinguished in the vertical burning test. Besides, owing to the hierarchical porous structure of the aerogel and the excellent barrier effect of the montmorillonite nanosheet, CCA could resist a high-temperature flame up to 1200 °C and effectively prevent the temperature of the nonexposed side from increasing, exhibiting excellent thermal insulation. Furthermore, the mechanical resilience, anti-fatigue performance, electrical conductivity, and unique three-dimensional network endowed the aerogel with good piezoresistivity. This work provides a facile, environmentally-friendly, and cost-effective approach to fabricating multifunctional fire-safe aerogel, showing promising applications in exterior wall insulation, vehicle interior, firefighting, and wearable electronics.
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ACS Biomaterials Science & Engineering
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2020
·
IF 4.152
Lei Liu,Yali Miao,Xuetao Shi,Huichang Gao,Yingjun Wang
Phosphorous-containing biopolymers have been applied to expedite the regeneration of damaged bone tissue by stimulating the function of phosphorous groups in natural bones. However, the underlying mechanism of phosphorous-containing biopolymers in promoting osteogenic differentiation is unclarified. Herein, we synthesized phosphorylated chitosan hydrogels by incorporating phosphocreatine into chitosan molecular chains under mild conditions. The introduction of phosphate groups improved properties of protein adsorption and calcium deposition without affecting the morphology of hydrogels. Our results showed that phosphorylated chitosan hydrogels could not only promote alkaline phosphatase activity and mineralization but also upregulate the expression of osteogenic-related genes and proteins. Meanwhile, application of c-Jun N-terminal kinase inhibitor SP600125 and p38 mitogen-activated protein kinase inhibitor SB203580 repressed the expression of osteogenic-related markers in gene and protein levels. To the best of our knowledge, it is reported for the first time that phosphorous-containing biopolymers promote osteogenic differentiation of osteoblasts via JNK and p38 signaling pathways.
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ACS Biomaterials Science & Engineering
·
2020
·
IF 4.152
Shuang Yang,Xiaoming Li,Ping Liu,Maolan Zhang,Chao Wang,Bo Zhang
Electrospinning-based wound dressings with multifunctional properties, including hemostasis-promoting, antibacterial, drug release, and therapeutic effects, are of great interest in military and civilian trauma healthcare. Herein, we designed lidocaine hydrochloride (LID) and mupirocin-loaded chitosan/polycaprolactone (CSLD-PCLM) scaffolds with multiple functions as wound dressings. Through the dual spinneret electrospinning technique, the scaffolds achieved a nanofiber structure, which enhanced the interfacial interaction between the scaffold and blood cells and showed excellent blood coagulation capacity. In particular, the scaffolds loaded with LID and mupirocin exhibited rapid release of LID and sustained release of mupirocin. The CSLD-PCLM scaffold containing mupirocin exhibited outstanding antibacterial activity. Moreover, the scaffold significantly enhanced the wound healing process with complete re-epithelialization as well as collagen deposition in a full-thickness skin defect model. Thus, CSLD-PCLM nanofibrous scaffolds may ideally meet the various requirements of the wound healing process and are promising candidates for wound dressings in future clinical applications.
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