生物表面活性剂为一种特定微生物代谢产生的具有表面活性的物质,通过在岩石表面的吸附来达到改变其润湿性的目的,而润湿改性机制对油藏提高采收率至关重要。通过接触角的测定、洗油砂评价、液-固界面自由能计算及分子动力学模拟等方法,...生物表面活性剂为一种特定微生物代谢产生的具有表面活性的物质,通过在岩石表面的吸附来达到改变其润湿性的目的,而润湿改性机制对油藏提高采收率至关重要。通过接触角的测定、洗油砂评价、液-固界面自由能计算及分子动力学模拟等方法,研究了鼠李糖脂表面活性剂与疏水Si O_(2)表面间的相互作用,并对其吸附特性和润湿改性机制进行了阐释。结果表明,鼠李糖脂可快速改善亲油玻片表面的润湿性。经10%鼠李糖脂溶液浸泡12 h后,亲油玻片的接触角从111.6°降至32.7°。鼠李糖脂溶液对油砂的最佳洗油有效加量为30%,洗油效率可达84.83%,原油黏附功降低了98.4%。通过液-固界面自由能计算得到去离子水与鼠李糖脂溶液作用后的亲油玻片间的自由能为-140.2 m J/m^(2),远低于去离子水与原始亲油玻片间的自由能(-52.1 m J/m^(2))。分子模拟计算结果表明,鼠李糖脂分子主要通过氢键这一强作用力吸附在亲水Si O_(2)表面,其与亲水界面的吸附结合能达到29.7 e V;而鼠李糖脂分子与疏水Si O_(2)表面的作用力为静电力和范德华力等弱作用力,导致其与疏水界面的吸附结合能仅为12.2 e V。结合液-固界面自由能和分子模拟计算结果推测,鼠李糖脂分子相较于原油极性分子具有更强的界面竞争吸附能力,从而使其易于锚定到亲水表面、最终替换油性分子,达到提高洗油效率的目的。研究结果可为构建以鼠李糖脂为主的生物润湿调控驱油体系提供理论支撑。展开更多
Metal carbides play significant roles in electronics and materials science due to their unique properties,high strength,and high melting points.Also,they are applied in various organometallic synthesis and catalytic r...Metal carbides play significant roles in electronics and materials science due to their unique properties,high strength,and high melting points.Also,they are applied in various organometallic synthesis and catalytic reactions,such as in the Fischer-Tropsch process and olefin metathesis[1,2],and they are able to adsorb small gas molecules such as hydrogen showing promising application for the hydrogen storage[3].Hydrogen is known as a sustainable solution for rising energy demands and an environmentally friendly option to replace fossil fuels.Enormous efforts have been made to develop hydrogen storage materials[4],with the aim to facilitate the application of hydrogen energy for achieving the future carbon–neutral goal set by governments.It has been recognized that the removal of the metal-bound terminal ligands and the doping of transition metals(TMs)on carbon substrates can improve the capacity of hydrogen adsorption[5,6].展开更多
Metal clusters that contain a small number of atoms usually present unique properties with dramatic dependence on their sizes,geometric structures,and compositions.The studies of naked metal clusters are devoted to de...Metal clusters that contain a small number of atoms usually present unique properties with dramatic dependence on their sizes,geometric structures,and compositions.The studies of naked metal clusters are devoted to develop new catalysts and functional materials of atomic precision,and enable to improve the fundamental theory of structure chemistry and to understand the basic reactions and properties bridging the gap between atoms and bulk materials.In particular,some interesting superatom clusters have received reasonable research interest indicative of materials gene of clusters.Here in this review,we simply summarize the preparation,stability,and reactivity of naked metal clusters with a few examples displayed.Hopefully it serves as a modest spur to stimulate more interest of related investigations in this field.展开更多
文摘生物表面活性剂为一种特定微生物代谢产生的具有表面活性的物质,通过在岩石表面的吸附来达到改变其润湿性的目的,而润湿改性机制对油藏提高采收率至关重要。通过接触角的测定、洗油砂评价、液-固界面自由能计算及分子动力学模拟等方法,研究了鼠李糖脂表面活性剂与疏水Si O_(2)表面间的相互作用,并对其吸附特性和润湿改性机制进行了阐释。结果表明,鼠李糖脂可快速改善亲油玻片表面的润湿性。经10%鼠李糖脂溶液浸泡12 h后,亲油玻片的接触角从111.6°降至32.7°。鼠李糖脂溶液对油砂的最佳洗油有效加量为30%,洗油效率可达84.83%,原油黏附功降低了98.4%。通过液-固界面自由能计算得到去离子水与鼠李糖脂溶液作用后的亲油玻片间的自由能为-140.2 m J/m^(2),远低于去离子水与原始亲油玻片间的自由能(-52.1 m J/m^(2))。分子模拟计算结果表明,鼠李糖脂分子主要通过氢键这一强作用力吸附在亲水Si O_(2)表面,其与亲水界面的吸附结合能达到29.7 e V;而鼠李糖脂分子与疏水Si O_(2)表面的作用力为静电力和范德华力等弱作用力,导致其与疏水界面的吸附结合能仅为12.2 e V。结合液-固界面自由能和分子模拟计算结果推测,鼠李糖脂分子相较于原油极性分子具有更强的界面竞争吸附能力,从而使其易于锚定到亲水表面、最终替换油性分子,达到提高洗油效率的目的。研究结果可为构建以鼠李糖脂为主的生物润湿调控驱油体系提供理论支撑。
基金supported by the National Key Research and Development Program of China(2020YFA0714602)the National Natural Science Foundation of China(21802146 and 21722308)+1 种基金National Project Development of Advanced Scientific Instruments Based on Deep Ultraviolet Laser Source(Y31M0112C1)CAS Key Research Project of Frontier Science(QYZDB-SSW-SLH024).
文摘Metal carbides play significant roles in electronics and materials science due to their unique properties,high strength,and high melting points.Also,they are applied in various organometallic synthesis and catalytic reactions,such as in the Fischer-Tropsch process and olefin metathesis[1,2],and they are able to adsorb small gas molecules such as hydrogen showing promising application for the hydrogen storage[3].Hydrogen is known as a sustainable solution for rising energy demands and an environmentally friendly option to replace fossil fuels.Enormous efforts have been made to develop hydrogen storage materials[4],with the aim to facilitate the application of hydrogen energy for achieving the future carbon–neutral goal set by governments.It has been recognized that the removal of the metal-bound terminal ligands and the doping of transition metals(TMs)on carbon substrates can improve the capacity of hydrogen adsorption[5,6].
基金financially supported by the National Natural Science Foundation of China (Nos. 21802146 and 21722308)CAS Key Research Project of Frontier Science (CAS Grant QYZDB-SSW-SLH024)Frontier Cross Project of National Laboratory for Molecular Sciences (051Z011BZ3)。
文摘Metal clusters that contain a small number of atoms usually present unique properties with dramatic dependence on their sizes,geometric structures,and compositions.The studies of naked metal clusters are devoted to develop new catalysts and functional materials of atomic precision,and enable to improve the fundamental theory of structure chemistry and to understand the basic reactions and properties bridging the gap between atoms and bulk materials.In particular,some interesting superatom clusters have received reasonable research interest indicative of materials gene of clusters.Here in this review,we simply summarize the preparation,stability,and reactivity of naked metal clusters with a few examples displayed.Hopefully it serves as a modest spur to stimulate more interest of related investigations in this field.
