Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules t...Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules though silane chemistry or electrostatic interactions,while retaining open access to MOF porosity.Silica coating would be highly beneficial for employing MOFs in a wide range of applications such as catalysis or drug delivery.However,obtaining a stable,controlled core–shell structure using MOF nanoparticles as seeds is challenging because of their intrinsic chemically labile nature.Here we analyze the factors that destabilize the core of the Zeolitic Imidazolate Framework-8(ZIF-8)MOFs during the sol–gel deposition of a mesoporous silica shell causing a partial or total etching of the MOF material.Silicates in solution are found to scavenge Zn^(2+)ions removing them from the ZIF structure and causing a partial or complete dissolution of the ZIF seed.By carefully tuning the silicate concentration in solution simultaneous control can be obtained over both the ZIF-8 dissolution and the silica condensation kinetics,resulting in the growth of a uniform mesoporous silica shell while preserving the integrity of ZIF-8.The core–shell nanoparticles obtained show a compact core shell structure with no gap between the MOF core and the silica shell,even after calcination,while the crystalline ZIF-8 structure is retained.Overall,a general synthetic approach is presented for producing nanocomposite core–shell materials which can be applied to other MOF labile seeds to design new hierarchical materials.展开更多
Artificial skins are essential for bridging sensory gaps between robots and environments,enabling natural and intuitive interactions.While artificial skins can sense stimuli like pressure and stretchability,their capa...Artificial skins are essential for bridging sensory gaps between robots and environments,enabling natural and intuitive interactions.While artificial skins can sense stimuli like pressure and stretchability,their capabilities need to be expanded into chemical sensing for specific applications.Here,we introduce optical/electronic artificial skins(oe-skins),advancing robotic sensing from physical perception to chemical sensation.Our design integrates optical fibers into a carbon nanotube(CNT)-based haptic electronic skin.This empowers the skin to sense force and temperature,while detecting near-infrared(NIR)optical signals from molecules,giving dual modalities of physical and chemical sensing.We successfully implement the oe-skin into robots,enabling intraocular pressure and glucose level detection for diagnosing glaucoma and diabetes.Additionally,we demonstrated their effectiveness in delicately harvesting fruits and grading them by ripeness,firmness,and sugar levels.We present a blueprint for next-generation intelligent electronics where technological progress aligns with sustainable development and societal well-being.展开更多
基金the Ministry of Research and Innovation of Spain for support through the PID2020-114356RB-I00 Retos projectthe Maria de Maeztu Units of Excellence Program from the Spanish State Research Agency-Grant No.MDM-2017-0720.
文摘Surface engineering of metal–organic frameworks(MOFs)with a mesoporous silica coating can improve MOF mechanical properties and provide an easy way to decorate MOF nanoparticles with organic or biological molecules though silane chemistry or electrostatic interactions,while retaining open access to MOF porosity.Silica coating would be highly beneficial for employing MOFs in a wide range of applications such as catalysis or drug delivery.However,obtaining a stable,controlled core–shell structure using MOF nanoparticles as seeds is challenging because of their intrinsic chemically labile nature.Here we analyze the factors that destabilize the core of the Zeolitic Imidazolate Framework-8(ZIF-8)MOFs during the sol–gel deposition of a mesoporous silica shell causing a partial or total etching of the MOF material.Silicates in solution are found to scavenge Zn^(2+)ions removing them from the ZIF structure and causing a partial or complete dissolution of the ZIF seed.By carefully tuning the silicate concentration in solution simultaneous control can be obtained over both the ZIF-8 dissolution and the silica condensation kinetics,resulting in the growth of a uniform mesoporous silica shell while preserving the integrity of ZIF-8.The core–shell nanoparticles obtained show a compact core shell structure with no gap between the MOF core and the silica shell,even after calcination,while the crystalline ZIF-8 structure is retained.Overall,a general synthetic approach is presented for producing nanocomposite core–shell materials which can be applied to other MOF labile seeds to design new hierarchical materials.
基金supported by the Joint Fund of the National Natural Science Foundation of China(Grant No.U20A2019)the Natural Key R&D Program of China(Grant No.2024YFD2000900)+2 种基金the Major Science and Technology Special Projects of Xinjiang Uygur Autonomous Region(2022A02011-1)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2022D01E48)supported by the CREATE Lab of EPFL.
文摘Artificial skins are essential for bridging sensory gaps between robots and environments,enabling natural and intuitive interactions.While artificial skins can sense stimuli like pressure and stretchability,their capabilities need to be expanded into chemical sensing for specific applications.Here,we introduce optical/electronic artificial skins(oe-skins),advancing robotic sensing from physical perception to chemical sensation.Our design integrates optical fibers into a carbon nanotube(CNT)-based haptic electronic skin.This empowers the skin to sense force and temperature,while detecting near-infrared(NIR)optical signals from molecules,giving dual modalities of physical and chemical sensing.We successfully implement the oe-skin into robots,enabling intraocular pressure and glucose level detection for diagnosing glaucoma and diabetes.Additionally,we demonstrated their effectiveness in delicately harvesting fruits and grading them by ripeness,firmness,and sugar levels.We present a blueprint for next-generation intelligent electronics where technological progress aligns with sustainable development and societal well-being.
