Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering （SPS）. Amorphous powders with the nominal composition of Nd_28.72Fe_balCo_5.66 Ga_0.59...Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering （SPS）. Amorphous powders with the nominal composition of Nd_28.72Fe_balCo_5.66 Ga_0.59B_0.92 （wt%） were used as the starting material. The results show that the amorphous powders would suffer varying degrees of crystallization even below the crystal- lization point during the SPS process under high pressure. And the pre-crystallized grains in precursors have great impacts on the microstructure and magnetic properties of the hot-deformed magnets. The final obtained anisotropic magnets exhibit homogeneous microstructure consisting of well-aligned and platelet-shaped Nd_2Fe_14B grains without abnormal growth. It can be found that a reasonable pro- portion of pre-crystallized gains could promote the pref- erential orientation in the magnet, leading to the achievement of optimal magnetic properties among the magnets with identical composition and best magnetic performance is achieved in the magnet hot deformed from the 490 ℃ high-pressure hot-pressed precursor.展开更多
Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the...Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the optimal integration of antibacterial characteristics.In this study,Sm-doped nano-hydroxylapatite(SmHAp)was synthesized by spontaneous mineralization of amorphous SmHAp precursors,which ensures a homogeneous distribution of Sm^(3+)within bulk SmHAp.Powder X-ray diffraction and its Pawley fitting results for SmHAp indicate the lattice substitution of Ca^(2+)with Sm^(3+),resulting in the lattice distortion in SmHAp compared to pure HAp.Meanwhile,polymer-encapsulated Sm-doped nano-hydroxylapatite composite(p_SmHAp)was synthesized by a dual-step polymerization involving UV curing of an outer crust and heat treatment for bulk reaction completion.Irgacure 2959 and a toluene solution of AIBN were used as catalysts for the radical polymerization process.The antibacterial property of p_SmHAp was evaluated by observing the growth of Sporosarcina pasteurii(ATCC 11859)both in the solid and the liquid medium,correlating with the Sm fraction and SmHAp's crystallinity in p_SmHAp.These bacteriostatic rings'diameters exceed 20 mm,demonstrating that p_SmHAp with a SmHAP/p_SmHAp mass ratio of 0.1 and Sm/(Ca+Sm)molar ratio of 0.05-0.1 effectively releases Sm^(3+),serving as a strong antibacterial agent.展开更多
Nanoporous Ag-Pt bi-metallic alloy was fabricated by free dealloying of amorphous Ag-based precursor with the nominal composition of Ag38.25Pt0.5Cu38.75Si22.5.The noble Ag and Pt were left after the less noble Cu and ...Nanoporous Ag-Pt bi-metallic alloy was fabricated by free dealloying of amorphous Ag-based precursor with the nominal composition of Ag38.25Pt0.5Cu38.75Si22.5.The noble Ag and Pt were left after the less noble Cu and Si dissolved in a certain acid solution.Bi-continuous nanoporous microstructure was formed with asymmetric ligaments and pores with typically 30-200 nm in width.The trace addition of Pt has refined the grains of the ligaments to the average size of less than 20 nm in the substrate and induced the formation of rods with nanopores.The morphologies of the rods were observed by scanning electron microscopy(SEM)and transmission electron microscopy(TEM)both in the form of clusters and as scattered individuals with characteristic length of several micrometers and diameter of tens of nanometers.The grains sizes in the rods were finer than those in the ligaments.The good mechanical integrity might be due to the combination of continuous ligaments and clusters of rods.展开更多
Bioinspired materials with excellent properties have attracted intense interests of scientists,and the methodology for rationally design of these materials is crucially important.This review briefly introduces our rec...Bioinspired materials with excellent properties have attracted intense interests of scientists,and the methodology for rationally design of these materials is crucially important.This review briefly introduces our recent achievements on inorganic ionic polymerization for bioinspired material preparation.The inorganic ionic polymerization realized the assembly of inorganic ions in a way similar to the polymerization in polymer chemistry,overcoming the limitation by classical nucleation pathway.It enabled the moldable construction of inorganic minerals and even the reconstruction of enamel tissue,which commonly only achieved by biomineralization.In the presence of organic molecules,the inorganic ionic polymerization could participate in the organic polymerization,resulting in hybrids with molecular-scaled organic-inorganic homogeneity.And furthermore,under the regulation of bio-inspired molecules,the condensed state of the assembled inorganic ions could show unusual behaviors:such as adding the flexibility to commonly fractal inorganic minerals,and flowability to solid mineral particles.It enabled the production of flexible mineral materials as plastic substitute,and the extrusion forming of moldable minerals under room temperature.The inorganic ionic polymerization demonstrated a promising way to synthesize inorganics in a more rational way,which may shed light on more advanced bio-inspired and biomimetic material.展开更多
基金supported by the National Natural Science Foundation of China (No. 51171122)the Sichuan Province Science and Technology Support Program (Nos. 2014GZ0090 and 2016GZ0262)
文摘Anisotropic magnets were obtained by hot deformation with the partial crystallized precursor prepared via spark-plasma sintering （SPS）. Amorphous powders with the nominal composition of Nd_28.72Fe_balCo_5.66 Ga_0.59B_0.92 （wt%） were used as the starting material. The results show that the amorphous powders would suffer varying degrees of crystallization even below the crystal- lization point during the SPS process under high pressure. And the pre-crystallized grains in precursors have great impacts on the microstructure and magnetic properties of the hot-deformed magnets. The final obtained anisotropic magnets exhibit homogeneous microstructure consisting of well-aligned and platelet-shaped Nd_2Fe_14B grains without abnormal growth. It can be found that a reasonable pro- portion of pre-crystallized gains could promote the pref- erential orientation in the magnet, leading to the achievement of optimal magnetic properties among the magnets with identical composition and best magnetic performance is achieved in the magnet hot deformed from the 490 ℃ high-pressure hot-pressed precursor.
基金Project supported by the Fundamental and Applied Fundamental Research Major Program of Guangdong Province,China(2019B030302013)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA0430205)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515011531)the Science and Technology Planning Project of Guangdong Province,China(2023B1212060044,2023B1212060048)the Market Readiness Assistance Grant of Singapore(04INS000458C15000E01)。
文摘Hydroxylapatite(HAp),owing to its excellent biocompatibility,is a promising carrier for lanthanide ions to encourage antibacterial activity.However,hydroxylapatite powder would still require modification to ensure the optimal integration of antibacterial characteristics.In this study,Sm-doped nano-hydroxylapatite(SmHAp)was synthesized by spontaneous mineralization of amorphous SmHAp precursors,which ensures a homogeneous distribution of Sm^(3+)within bulk SmHAp.Powder X-ray diffraction and its Pawley fitting results for SmHAp indicate the lattice substitution of Ca^(2+)with Sm^(3+),resulting in the lattice distortion in SmHAp compared to pure HAp.Meanwhile,polymer-encapsulated Sm-doped nano-hydroxylapatite composite(p_SmHAp)was synthesized by a dual-step polymerization involving UV curing of an outer crust and heat treatment for bulk reaction completion.Irgacure 2959 and a toluene solution of AIBN were used as catalysts for the radical polymerization process.The antibacterial property of p_SmHAp was evaluated by observing the growth of Sporosarcina pasteurii(ATCC 11859)both in the solid and the liquid medium,correlating with the Sm fraction and SmHAp's crystallinity in p_SmHAp.These bacteriostatic rings'diameters exceed 20 mm,demonstrating that p_SmHAp with a SmHAP/p_SmHAp mass ratio of 0.1 and Sm/(Ca+Sm)molar ratio of 0.05-0.1 effectively releases Sm^(3+),serving as a strong antibacterial agent.
基金financially supported by the China Postdoctoral Science Foundation(No.2015M570964)the National Key Research and Development Program of China(No.2017YFB0304504)。
文摘Nanoporous Ag-Pt bi-metallic alloy was fabricated by free dealloying of amorphous Ag-based precursor with the nominal composition of Ag38.25Pt0.5Cu38.75Si22.5.The noble Ag and Pt were left after the less noble Cu and Si dissolved in a certain acid solution.Bi-continuous nanoporous microstructure was formed with asymmetric ligaments and pores with typically 30-200 nm in width.The trace addition of Pt has refined the grains of the ligaments to the average size of less than 20 nm in the substrate and induced the formation of rods with nanopores.The morphologies of the rods were observed by scanning electron microscopy(SEM)and transmission electron microscopy(TEM)both in the form of clusters and as scattered individuals with characteristic length of several micrometers and diameter of tens of nanometers.The grains sizes in the rods were finer than those in the ligaments.The good mechanical integrity might be due to the combination of continuous ligaments and clusters of rods.
基金support from National Natural Science Foundation of China(22022511)the Fundamental Research Funds for the Central Universities(226-2022-00022,2021FZZX001-04).
文摘Bioinspired materials with excellent properties have attracted intense interests of scientists,and the methodology for rationally design of these materials is crucially important.This review briefly introduces our recent achievements on inorganic ionic polymerization for bioinspired material preparation.The inorganic ionic polymerization realized the assembly of inorganic ions in a way similar to the polymerization in polymer chemistry,overcoming the limitation by classical nucleation pathway.It enabled the moldable construction of inorganic minerals and even the reconstruction of enamel tissue,which commonly only achieved by biomineralization.In the presence of organic molecules,the inorganic ionic polymerization could participate in the organic polymerization,resulting in hybrids with molecular-scaled organic-inorganic homogeneity.And furthermore,under the regulation of bio-inspired molecules,the condensed state of the assembled inorganic ions could show unusual behaviors:such as adding the flexibility to commonly fractal inorganic minerals,and flowability to solid mineral particles.It enabled the production of flexible mineral materials as plastic substitute,and the extrusion forming of moldable minerals under room temperature.The inorganic ionic polymerization demonstrated a promising way to synthesize inorganics in a more rational way,which may shed light on more advanced bio-inspired and biomimetic material.
