In this work, we present novel trivalent lanthanide ions（Ln^3＋）-based luminescent hybrid materials, in which the organic ligands are covalently grafted on the hectorite templates and the Ln^3＋ ions can be well imm...In this work, we present novel trivalent lanthanide ions（Ln^3＋）-based luminescent hybrid materials, in which the organic ligands are covalently grafted on the hectorite templates and the Ln^3＋ ions can be well immobilized by the ligands through coordination bond. The hybrid materials exhibit tunable emission colors by varying the molar ratio of Eu^3＋ to Tb^3＋, and the one with Eu^3＋：Tb^3＋=1：1 exhibits excellent coordinate of（0.327, 0.328） located in the ＂white region＂ of the CIE 1931 chromaticity diagram（under300 nm UV illumination）. These properties make the hybrid composites suitable for fabricating optoelectronic devices such as full-color displays and white LED.展开更多
针对天然锂皂石矿物稀缺和钻井领域亟需抗高温水基钻井液增黏剂的现状,优选了微波辅助法合成锂皂石,利用粉末X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、粒径分析对合成锂皂石进行了表征,并研究了其作为水基钻井液增黏剂的效果。...针对天然锂皂石矿物稀缺和钻井领域亟需抗高温水基钻井液增黏剂的现状,优选了微波辅助法合成锂皂石,利用粉末X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、粒径分析对合成锂皂石进行了表征,并研究了其作为水基钻井液增黏剂的效果。结果表明,利用微波辅助法合成了纯度较高的纳米级锂皂石,其粒径尺寸主要分布在18.17～58.77 nm,平均粒径仅为29.72 nm;随着锂皂石浓度从0.3%增加到1.5%,4%膨润土基浆的黏度、切力以及动塑比均显著增大,滤失量也逐渐降低,说明锂皂石还具有一定的降滤失效果,加入1.2%锂皂石,基浆黏度可提高2.64倍,且切力和动塑比保持适中;1.5%的锂皂石能抵抗至少2.5%的钙侵和15%的盐侵;随着老化温度从80℃增加到220℃,4%基浆＋1.5%锂皂石的表观黏度先减小后增大,维持在20 m Pa s以上,动切力和动塑比同样先减小后增加,但是下降幅度较为明显;在200℃,常规的有机聚合物增黏剂均失效,而锂皂石增黏剂却仍能保持很好的增黏效果。因此,合成锂皂石是一种理想的抗高温型水基钻井液增黏剂,且具有良好的配伍性。展开更多
The rational design of green chemical,low-cost,and highly efficient solid-state electrolytes for Li-metal anode is a promising but still challenging strategy for preventing Li dendrite growth and developing safe and u...The rational design of green chemical,low-cost,and highly efficient solid-state electrolytes for Li-metal anode is a promising but still challenging strategy for preventing Li dendrite growth and developing safe and ultralong cycle life Li-metal batteries.Herein,a homogeneous composite solid polymer electrolyte(CSPE)is fabricated with water as the ideal dispersion medium,hectorite(Ht)as nanofiller,and poly(ethylene oxide)(PEO)as the matrix,to guide uniform Li plating/stripping.Benefiting from the merit of Ht can form uniformly dispersed nanosheets in water,the obtained CSPE inheres to a low melting point,robust mechanical property,and high Li^(+)transference number.Moreover,the fabricated Li symmetric battery using PEO-Ht-LiClO_(4)CSPE keeps cycling steadily for 4000 h.The well demonstrated water-based CSPE paves the way for developing low-cost,environmentally friendly,and safe solid-state electrolytes for Li-metal batteries.展开更多
Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted...Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,respectively.However,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous research.Here,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic resonance.Our results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic minerals.Within the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay minerals.Owing to the octahedral sites of Mg-smectite bounded in Li,it is referred to be hectorite.We interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt tuffdissolution.This conclusion can be supported by the coexistence of spherulitic calcite and hectorite.Overall,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.展开更多
The use of clay minerals in the synthesis of nanosized noble metal particles to give increased catalytic activity was investigated. Nanosized platinum and ruthenium catalysts intercalated in clay (montmorillonite/hect...The use of clay minerals in the synthesis of nanosized noble metal particles to give increased catalytic activity was investigated. Nanosized platinum and ruthenium catalysts intercalated in clay (montmorillonite/hectorite) were synthesised and their catalytic activity was evaluated for the selective hydrogenation of three different α,β-unsaturated aldehydes, namely, crotonaldehyde, cinnamaldehyde, and citral, in a gas phase microreactor. The metal nano-sol was prepared by the chemical reduction of its precursor by the micellar technique in the presence of cetyl trimethyl ammonium bromide (CTAB), and the micelle stabilized metal particles were intercalated in the clay mineral by ion exchange. TEM micrographs of the catalyst particles showed that the metal particles were in the nanometre range. The average diameters of the particles were 1-25 nm. The effects of temperature, metal loading, and hydrogen flow rate on the catalytic activity and selectivity for α,β- unsaturated alcohol were studied. The results were correlated with the structural properties of the catalysts. The products formed in each reaction over the different catalysts showed that the catalysts were very active for hydrogenation, and the selectivity for the desired product, namely, α,β-unsaturated alcohol, was good. The metal catalysts intercalated in montmorillonite showed better selectivity than that in hectorite because of its higher acidity. Increased selectivity for α,β-unsaturated alcohol was observed with increased flow rate of hydrogen.展开更多
The main objective of this study is to determine the structural characteristics of synthetic Na-Hectorite (H-Na) exchanged with heavy metals: Ni2+, Pb2+, Zn2+, Cd2+, Co2+ and Mg2+ using quantitative analysis based on ...The main objective of this study is to determine the structural characteristics of synthetic Na-Hectorite (H-Na) exchanged with heavy metals: Ni2+, Pb2+, Zn2+, Cd2+, Co2+ and Mg2+ using quantitative analysis based on the comparison between the theoretical and experimental XRD patterns. The different complexes are not homogenous. The hectorite saturated by the lead and cadmium present a segregation distribution of the layers, where as the others complexes present a random distribution.展开更多
基金the National Natural Science Foundation of China (Nos. 21171046, 21271060, and 21236001)the Tianjin Natural Science Foundation(No. 13JCYBJC18400)+1 种基金the Hebei Natural Science Foundation(No. B2016202147)Educational Committee of Hebei Province(Nos. 2011141,LJRC021)for financial support
文摘In this work, we present novel trivalent lanthanide ions（Ln^3＋）-based luminescent hybrid materials, in which the organic ligands are covalently grafted on the hectorite templates and the Ln^3＋ ions can be well immobilized by the ligands through coordination bond. The hybrid materials exhibit tunable emission colors by varying the molar ratio of Eu^3＋ to Tb^3＋, and the one with Eu^3＋：Tb^3＋=1：1 exhibits excellent coordinate of（0.327, 0.328） located in the ＂white region＂ of the CIE 1931 chromaticity diagram（under300 nm UV illumination）. These properties make the hybrid composites suitable for fabricating optoelectronic devices such as full-color displays and white LED.
文摘针对天然锂皂石矿物稀缺和钻井领域亟需抗高温水基钻井液增黏剂的现状,优选了微波辅助法合成锂皂石,利用粉末X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、粒径分析对合成锂皂石进行了表征,并研究了其作为水基钻井液增黏剂的效果。结果表明,利用微波辅助法合成了纯度较高的纳米级锂皂石,其粒径尺寸主要分布在18.17～58.77 nm,平均粒径仅为29.72 nm;随着锂皂石浓度从0.3%增加到1.5%,4%膨润土基浆的黏度、切力以及动塑比均显著增大,滤失量也逐渐降低,说明锂皂石还具有一定的降滤失效果,加入1.2%锂皂石,基浆黏度可提高2.64倍,且切力和动塑比保持适中;1.5%的锂皂石能抵抗至少2.5%的钙侵和15%的盐侵;随着老化温度从80℃增加到220℃,4%基浆＋1.5%锂皂石的表观黏度先减小后增大,维持在20 m Pa s以上,动切力和动塑比同样先减小后增加,但是下降幅度较为明显;在200℃,常规的有机聚合物增黏剂均失效,而锂皂石增黏剂却仍能保持很好的增黏效果。因此,合成锂皂石是一种理想的抗高温型水基钻井液增黏剂,且具有良好的配伍性。
基金supported by the National Natural Science Foundation of China(22205147).
文摘The rational design of green chemical,low-cost,and highly efficient solid-state electrolytes for Li-metal anode is a promising but still challenging strategy for preventing Li dendrite growth and developing safe and ultralong cycle life Li-metal batteries.Herein,a homogeneous composite solid polymer electrolyte(CSPE)is fabricated with water as the ideal dispersion medium,hectorite(Ht)as nanofiller,and poly(ethylene oxide)(PEO)as the matrix,to guide uniform Li plating/stripping.Benefiting from the merit of Ht can form uniformly dispersed nanosheets in water,the obtained CSPE inheres to a low melting point,robust mechanical property,and high Li^(+)transference number.Moreover,the fabricated Li symmetric battery using PEO-Ht-LiClO_(4)CSPE keeps cycling steadily for 4000 h.The well demonstrated water-based CSPE paves the way for developing low-cost,environmentally friendly,and safe solid-state electrolytes for Li-metal batteries.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.92162214,41773015,and U1812402)the Key Research and Development Program of Yunnan Province(202103AQ100003).
文摘Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,respectively.However,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous research.Here,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic resonance.Our results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic minerals.Within the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay minerals.Owing to the octahedral sites of Mg-smectite bounded in Li,it is referred to be hectorite.We interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt tuffdissolution.This conclusion can be supported by the coexistence of spherulitic calcite and hectorite.Overall,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.
基金Supported by FONDECYT, Chile-Post Doctorate-2010 Project (3100010)
文摘The use of clay minerals in the synthesis of nanosized noble metal particles to give increased catalytic activity was investigated. Nanosized platinum and ruthenium catalysts intercalated in clay (montmorillonite/hectorite) were synthesised and their catalytic activity was evaluated for the selective hydrogenation of three different α,β-unsaturated aldehydes, namely, crotonaldehyde, cinnamaldehyde, and citral, in a gas phase microreactor. The metal nano-sol was prepared by the chemical reduction of its precursor by the micellar technique in the presence of cetyl trimethyl ammonium bromide (CTAB), and the micelle stabilized metal particles were intercalated in the clay mineral by ion exchange. TEM micrographs of the catalyst particles showed that the metal particles were in the nanometre range. The average diameters of the particles were 1-25 nm. The effects of temperature, metal loading, and hydrogen flow rate on the catalytic activity and selectivity for α,β- unsaturated alcohol were studied. The results were correlated with the structural properties of the catalysts. The products formed in each reaction over the different catalysts showed that the catalysts were very active for hydrogenation, and the selectivity for the desired product, namely, α,β-unsaturated alcohol, was good. The metal catalysts intercalated in montmorillonite showed better selectivity than that in hectorite because of its higher acidity. Increased selectivity for α,β-unsaturated alcohol was observed with increased flow rate of hydrogen.
文摘The main objective of this study is to determine the structural characteristics of synthetic Na-Hectorite (H-Na) exchanged with heavy metals: Ni2+, Pb2+, Zn2+, Cd2+, Co2+ and Mg2+ using quantitative analysis based on the comparison between the theoretical and experimental XRD patterns. The different complexes are not homogenous. The hectorite saturated by the lead and cadmium present a segregation distribution of the layers, where as the others complexes present a random distribution.
