The oriented and patterned growth of fluorescent metal–organic frameworks onto functionalized surfaces

A metal–organic framework (MOF) material, [Zn2(adc)2(dabco)] (adc = anthracene-9,10-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]­octane), the fluorescence of which depends on the loading of its nanopores, was synthesized in two forms: as free-flowing nanocrystals with different shapes and as surface-attached MOFs (SURMOFs). For the latter, we used self-assembled monolayers (SAMs) bearing functional groups, such as carboxylate and pyridyl groups, capable of coordinating to the constituents of the MOF. It could be demonstrated that this directed coordination also orients the nanocrystals deposited at the surface. Using two different patterning methods, i.e., microcontact printing and electron-beam lithography, the lateral distribution of the functional groups could be determined in such a way that the highly localized deposition of the SURMOF films became possible

Microcontact electrochemical etching technique for rapid fabrication of glass-based microfluidic chips

NSFC of China [20675066]; Project of National Basic Research Program of China (973 Program) [2007CB935603]A simple and rapid microfabrication method for glass-based microfluidic chips is presented. In this method, a microcontact electrochemical etching technique is used to pattern the masking metal layer. By applying an anodic potential in the presence of KCl solution, a stamp's configuration can be precisely transferred to the masking layer within 2 min. In contrast to photolithography, the new method does not require clean room facilities and a photolithography machine, and the chemical reagent used is harmless to the environment and the human body. Combined with wet etching and thermal bonding, a microfludic device was fabricated and successfully used for electrophoretic separation of FITC. We anticipate that this fabrication method will bring glass microfluidic chips within the reach of any routine laboratory with minimal facilities. This low cost and high throughput process may also be suitable for mass production of microfluidic devices

China’s 10-year progress in DC gas-insulated equipment: From basic research to industry perspective

The construction of the future energy structure of China under the 2050 carbon-neutral vision requires compact direct current (DC) gas-insulation equipment as important nodes and solutions to support electric power transmission and distribution of long-distance and large-capacity. This paper reviews China's 10-year progress in DC gas-insulated equipment. Important progresses in basic research and industry perspective are presented, with related scientific issues and technical bottlenecks being discussed. The progress in DC gas-insulated equipment worldwide (Europe, Japan, America) is also reported briefly

Controlled synthesis of metal-organic framework particles and growth of surface-attached metal-organic frameworks

Metal-organic frameworks (MOFs) as a new class of micro/mesoporous materials have shown a wide range of applications. The aim of this work is the syntheses of MOF micro/nanoparticles and the growth of surface-attached metal-organic frameworks (SURMOFs). MOF particles with controllable morphology and size were synthesized under mild conditions. In order to use MOFs as sensors, smart membranes, and many other nanotechnological devices, the integration of MOFs onto specific surfaces is important. Thus, the main part of this work deals with the controlled deposition of SURMOFs onto various substrates. Several interesting properties (i.e. guest-molecule dependent fluorescence emission, dynamic gas adsorption capacity) of SURMOFs were investigated.Metallorganische Netzwerke (engl. metal-organic frameworks, MOFs) sind eine neuartige Klasse mikro/mesoporöser Materialien, für die eine Vielzahl von möglichen Anwendungen demonstriert werden konnte. Das Ziel dieser Arbeit besteht in der Synthese von MOF Mikro/Nanopartikeln sowie der Herstellung von sogenannten Oberflächen-deponierten MOFs (engl. surface-attached metal-organic frameworks, SURMOFs). MOF Partikel mit kontrollierbarer Morphologie und Größe wurden unter milden Bedingungen synthetisiert. Um MOFs als Sensoren, intelligente Membrane, oder in nanotechnologischen Bauelementen verwenden zu können, ist die Integration auf der jeweiligen Oberfläche wichtig. Daher beschäftigt sich der Großteil dieser Arbeit mit der kontrollierten Abscheidung von SURMOFs auf verschiedenartigen Trägermaterialien. Etliche interessante Eigenschaften (z.B. die Fluoreszenz in Abhängigkeit von der Gegenwart von Gastmolekülen und die dynamische Gasadsorptionskapazität) der SURMOFs wurden untersucht

Synthesis of 2D Ce-MOFs nanosheets and visiblelight-mediated decarboxylation performance

Two-dimensional Ce-MOFs nanosheets were successfully constructed by using ceric ammonium nitrate as metal salt and 1, 3, 5-tris(4-carboxyphenyl)benzene (H3BTB) as organic ligand, together with the use of acetic acid as modulator.Acetic acid modulator shows significant effects on the morphology and crystallinity of Ce-MOFs. Ce-MOFs microspheres synthesized without acetic acid as modulator (named Ce-BTB-H0) are composed of highly cross-linked small nanosheets with low crystallinity and surface areas. On the contrary, Ce-MOFs synthesized with acetic acid (named Ce-BTB-H60) consist of dispersed nanosheets, and show improved crystallinity and higher surface areas than that of Ce-BTB-H0. Using blue LED as light source and oxygen as oxidant, two-dimensional Ce-MOFs nanosheets enable decarboxylation oxygenation of a variety of substituted phenylacetic acid to their corresponding benzaldehydes and benzyl alcoholsunder irradiation of blue LED in oxygen atmosphere at room temperature.Moreover, Ce-BTB-H60nanosheets show better photocatalytic performance due to their higher crystallinity, larger specific surface area and improved dispersity than that of Ce-BTB-H0

Microcontact electrochemical etching technique for rapid fabrication of glass-based microfluidic chips

NSFC of China [20675066]; Project of National Basic Research Program of China (973 Program) [2007CB935603]A simple and rapid microfabrication method for glass-based microfluidic chips is presented. In this method, a microcontact electrochemical etching technique is used to pattern the masking metal layer. By applying an anodic potential in the presence of KCl solution, a stamp's configuration can be precisely transferred to the masking layer within 2 min. In contrast to photolithography, the new method does not require clean room facilities and a photolithography machine, and the chemical reagent used is harmless to the environment and the human body. Combined with wet etching and thermal bonding, a microfludic device was fabricated and successfully used for electrophoretic separation of FITC. We anticipate that this fabrication method will bring glass microfluidic chips within the reach of any routine laboratory with minimal facilities. This low cost and high throughput process may also be suitable for mass production of microfluidic devices