Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retar...Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.展开更多
Magnesium alloy(MgA)has been extensively used as orthopedic and cardiovascular scaffolds in virtue of its good biocompatibility,unique biodegradability and excellent mechanical properties.However,poor corrosion resist...Magnesium alloy(MgA)has been extensively used as orthopedic and cardiovascular scaffolds in virtue of its good biocompatibility,unique biodegradability and excellent mechanical properties.However,poor corrosion resistance and easy infection after implantation seriously limit the potential applications of MgA in the biomedical field.Herein,we fabricated bilayered nanoarrays of hydroxyapatite nanorods(HANRs)and ZnO nanorods(ZnONRs)onto the surface of MgA(MgA-MgO-HANRs-ZnONRs)via micro-arc oxidation(MAO)treatment,microwave-assisted hydrothermal and hydrothermal methods.The morphology and chemical composition of MgA-MgO-HANRs-ZnONRs was characterized by FE-SEM,XRD and EDS,indicating that HANRs-ZnONRs bilayered nanoarrays were fabricated on the surface of MgA-MgO.The surface of MgA-MgO-HANRs-ZnONRs exhibited excellent hydrophilicity as evidenced by the low water contact angle of 3°.Compared with the original MgA,the corrosion resistance of MgA-MgO-HANRs-ZnONRs was obviously improved with decreasing the corrosive current density(icorr)of 2 orders of magnitude.The MgA-MgO-HANRs-ZnONRs performed excellent antibacterial properties with the bactericidal rate of 96.5%against S.aureus and 94.3%against E.coli.展开更多
文摘Paper packaging materials like cardboards are widely used to protect archives which are a major kind of cultural relics.Unfortunately,paper is a combustible material,and thus exploring environment-friendly flame retardant for paper-based archive packaging material plays an important role.Herein,boric acid,borax and disodium octaborate are used to modify the craft paper-based packaging materials for archive conservation to improve fire safety.The modified craft paper exhibits much higher flame retardancy than the pristine one dose based on vertical burning tests,without much influence on mechanical properties such as tensile strength and elongation at break.Thermogravimetric analysis(TGA),scanning electron microscope(SEM),and X-ray photoelectron spectroscopy(XPS)reveal that porous glass structure is formed during the combustion,because thermal decomposition of boric acid,borax and disodium octaborate will produce porous glassy matter as B_(2)O_(3).The porous glass covers the paper surface as an insulating layer which retards the further pyrolysis and combustion,resulting in a denser carbon layer.Our study provides a robust way to reduce the fire hazard of the archive packaging material by applying environment-friendly boron-based fire retardants.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.21773149,21273142 and 21703132)the Program for Changjiang Scholars and Innovative Research Team in University(IRT14R33)+2 种基金the Key Research and Development Project of Shaanxi Province of China(No.2018GY-117)the Natural Science Foundation of Shaanxi Province of China(2019JQ161)the Fundamental Research Funds for the Central Universities(GK201802001).
文摘Magnesium alloy(MgA)has been extensively used as orthopedic and cardiovascular scaffolds in virtue of its good biocompatibility,unique biodegradability and excellent mechanical properties.However,poor corrosion resistance and easy infection after implantation seriously limit the potential applications of MgA in the biomedical field.Herein,we fabricated bilayered nanoarrays of hydroxyapatite nanorods(HANRs)and ZnO nanorods(ZnONRs)onto the surface of MgA(MgA-MgO-HANRs-ZnONRs)via micro-arc oxidation(MAO)treatment,microwave-assisted hydrothermal and hydrothermal methods.The morphology and chemical composition of MgA-MgO-HANRs-ZnONRs was characterized by FE-SEM,XRD and EDS,indicating that HANRs-ZnONRs bilayered nanoarrays were fabricated on the surface of MgA-MgO.The surface of MgA-MgO-HANRs-ZnONRs exhibited excellent hydrophilicity as evidenced by the low water contact angle of 3°.Compared with the original MgA,the corrosion resistance of MgA-MgO-HANRs-ZnONRs was obviously improved with decreasing the corrosive current density(icorr)of 2 orders of magnitude.The MgA-MgO-HANRs-ZnONRs performed excellent antibacterial properties with the bactericidal rate of 96.5%against S.aureus and 94.3%against E.coli.
