Chitin is a kind of natural macromolecule material which was first discovered in mushrooms and was widely found in the shells of crustaceans and arthropods,the cell walls of fungi(yeast and mold)and algae,and the moll...Chitin is a kind of natural macromolecule material which was first discovered in mushrooms and was widely found in the shells of crustaceans and arthropods,the cell walls of fungi(yeast and mold)and algae,and the mollusks.The original chitin in nature usually has an antiparallel molecular chain alignment forming nanofibers connected by inter-and intramolecular hydrogen bonds.These microfibers consist of nanofibers about 2-5 nm in diameter,and about 300 nm long,embedded by protein matrices.Due to their unique dimensional,optical,mechanical,and other characteristics,the preparation of nano-chitin materials is an important subject.It is possible to extract nano-chitins from their sources with various methods,including acid hydrolysis,mechanical disintegration,TEMPO-mediated oxidation,electrospinning,and others.In this article,the latest progress in recent years in the preparation and applications of nano-chitin were reviewed.The morphology of the nano-chitins obtained from the above methods was presented.The advantages and disadvantages of each method were analyzed.An overview of applications of nano-chitins was discussed,including biomedicine,food applications,water treatment,green electronic materials,enzyme immobilization carriers,cotton textile materials,cosmetics,and others.展开更多
In the present work, nanofibrous chitin microsphere （NCM） was prepared via sol-gel transition from a chitin solution dissolved in a NaOH/urea aqueous system at low temperatures. Ag nanoparticles （AgNPs） were synth...In the present work, nanofibrous chitin microsphere （NCM） was prepared via sol-gel transition from a chitin solution dissolved in a NaOH/urea aqueous system at low temperatures. Ag nanoparticles （AgNPs） were synthesized via an in situ reduction of silver nitrate using trisodium citrate dehydrate and were immobilized on chitin nanofibers to obtain composite microspheres that consist of nanofibers and AgNPs （NCM-Ag）. The size of AgNPs could be controlled in the range of 10 to 70 nm, depending on the concentration of AgNO3. X-ray photoelectron spectroscopy （XPS） and Fourier transform infrared （FT-IR） analyses showed that the chitin nanofibers have a strong affinity toward AgNPs, resulting from the interaction between the acetamino group of chitin and the AgNPs. The NCM-Ag exhibited a perfect nanoporous structure and high surface area, as well as high stability in organic solvents. Moreover, in the catalytic epoxidation of olefin （particularly, the conversion of styrene to styrene epoxide）, NCM-Ag exhibited an excellent selectivity of up to 90%. Converting chitin powder into chitin microspheres using an environmentally friendly technique is a green process, which is beneficial for the large-scale synthesis of industrial products. More importantly, this work provides a green synthetic pathway for the construction of size-controlled noble metal nanoparticles immobilized on nanofiber support, which have a wide range of potential applications.展开更多
Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we evaluated hydrophilicity of a new nano-hydroxyapatite/co...Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we evaluated hydrophilicity of a new nano-hydroxyapatite/collagen/PLLA (nHACP) scaffold optimized by chitin fibres for bone tissue engineering. The results show that with the CF content increase, hydrophilicity of nHACP/CF increases, which reflects from the side that the addition of the chitin fibres can improve the cytocompatibility of the nHACP. Moreover, crosslink does not take significant influences on the material hydrophilicity. The results suggest that nHACP/CF with the crosslink should be a kind of potential appropriate scaffold for tissue engineering.展开更多
基金supported by the National Natural Science Foundation of China[51473150,51603191,U1404509]sthe Education Department of Henan Province[17HASTIT009]
文摘Chitin is a kind of natural macromolecule material which was first discovered in mushrooms and was widely found in the shells of crustaceans and arthropods,the cell walls of fungi(yeast and mold)and algae,and the mollusks.The original chitin in nature usually has an antiparallel molecular chain alignment forming nanofibers connected by inter-and intramolecular hydrogen bonds.These microfibers consist of nanofibers about 2-5 nm in diameter,and about 300 nm long,embedded by protein matrices.Due to their unique dimensional,optical,mechanical,and other characteristics,the preparation of nano-chitin materials is an important subject.It is possible to extract nano-chitins from their sources with various methods,including acid hydrolysis,mechanical disintegration,TEMPO-mediated oxidation,electrospinning,and others.In this article,the latest progress in recent years in the preparation and applications of nano-chitin were reviewed.The morphology of the nano-chitins obtained from the above methods was presented.The advantages and disadvantages of each method were analyzed.An overview of applications of nano-chitins was discussed,including biomedicine,food applications,water treatment,green electronic materials,enzyme immobilization carriers,cotton textile materials,cosmetics,and others.
基金This work was supported by the Major Program of National Natural Science Foundation of China （No. 21334005） and the National Natural Science Foundation of China （No. 20874079）. We gratefully acknowledge Prof. Can Li in State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, for their discussion and kind help for instrument.
文摘In the present work, nanofibrous chitin microsphere （NCM） was prepared via sol-gel transition from a chitin solution dissolved in a NaOH/urea aqueous system at low temperatures. Ag nanoparticles （AgNPs） were synthesized via an in situ reduction of silver nitrate using trisodium citrate dehydrate and were immobilized on chitin nanofibers to obtain composite microspheres that consist of nanofibers and AgNPs （NCM-Ag）. The size of AgNPs could be controlled in the range of 10 to 70 nm, depending on the concentration of AgNO3. X-ray photoelectron spectroscopy （XPS） and Fourier transform infrared （FT-IR） analyses showed that the chitin nanofibers have a strong affinity toward AgNPs, resulting from the interaction between the acetamino group of chitin and the AgNPs. The NCM-Ag exhibited a perfect nanoporous structure and high surface area, as well as high stability in organic solvents. Moreover, in the catalytic epoxidation of olefin （particularly, the conversion of styrene to styrene epoxide）, NCM-Ag exhibited an excellent selectivity of up to 90%. Converting chitin powder into chitin microspheres using an environmentally friendly technique is a green process, which is beneficial for the large-scale synthesis of industrial products. More importantly, this work provides a green synthetic pathway for the construction of size-controlled noble metal nanoparticles immobilized on nanofiber support, which have a wide range of potential applications.
基金National Natural Science Foundation of Chinagrant number:31000431 and 10925208+1 种基金Bejing Nove Programgrant number:2010B011
文摘Chitin is a kind of seemly material to match PLLA for a scaffold, which may create an appropriate environment for the regeneration of tissues. In this study, we evaluated hydrophilicity of a new nano-hydroxyapatite/collagen/PLLA (nHACP) scaffold optimized by chitin fibres for bone tissue engineering. The results show that with the CF content increase, hydrophilicity of nHACP/CF increases, which reflects from the side that the addition of the chitin fibres can improve the cytocompatibility of the nHACP. Moreover, crosslink does not take significant influences on the material hydrophilicity. The results suggest that nHACP/CF with the crosslink should be a kind of potential appropriate scaffold for tissue engineering.
