Search results for "Nanoporous"
showing 10 items of 70 documents
Mass Transport in Nanoporous Gold and Correlation with Surface Pores for EC 1 Mechanism: Case of Ascorbic Acid
2021
International audience; Entry for the Table of Contents Playing with the pores: Surface pores size in nanoporous gold modulates the electrode reactions pathways of ascorbic acid. The reaction is largely driven by diffusion when pores are smaller (nanometer). On the contrary, adsorption holds the key role when pores are bigger (micrometer), allowing permeation of molecules in the film volume.
Obtaining of the Modified NH4NO3 Granules with 3-D Nanoporous Structure: Impact of Humidifier Type on the Granule’s Structure
2018
The article deals with the study of the porous ammonium nitrate granules’ (PAN) nanoporous structure of surface and surface layers. The research results, presented in the article, show that the suggested way to generate PAN allows to provide the granule porous structure without destruction of core and disposal of air from the granules. Analysis of experiments results has shown that various types of humidifiers can form various kinds of pores after drying – “mechanical” pores and “modification” pores. Various types of humidifiers have significant effect on the ratio of values of “mechanical” and “modification” pores. The obtained results allow to select the optimal humidifier composition, wh…
Characterization of materials toward toluene traces detection for air quality monitoring and lung cancer diagnosis
2017
International audience; The aim of this work was to identify a nanoporous material able to trap toluene traces in order to develop a gas detection device for indoor air quality monitoring or biomedical diagnosis. A set of various adsorbents such as zeolites and activated carbon microspheres was studied here. First a detailed characterization of their porous properties was performed by nitrogen adsorption. Then adsorption of toluene and other interfering compounds which can selectively adsorbed with it, such as water and carbon dioxide, was studied in order to select the most suitable material. Results revealed that the activatedcarbon microspheres W5 and the zeolite NaY, which exhibit high …
Not always what closes best opens better: mesoporous nanoparticles capped with organic gates
2019
ABSTRACT Four types of calcined MCM-41 silica nanoparticles, loaded with dyes and capped with different gating ensembles are prepared and characterized. N1 and N2 nanoparticles are loaded with rhodamine 6G and capped with bulky poly(ethylene glycol) derivatives bearing ester groups (1 and 2). N3-N4 nanoparticles are loaded with sulforhodamine B and capped with self-immolative derivatives bearing ester moieties. In the absence of esterase enzyme negligible cargo release from N1, N3 and N4 nanoparticles is observed whereas a remarkable release for N2 is obtained most likely due to the formation of an irregular coating on the outer surface of the nanoparticles. In contrast, a marked delivery i…
Electrochemically etched sharp aluminium probes with nanoporous aluminium oxide coatings: demonstration of addressed DNA delivery
2014
Electrochemical etching of metal wires is widely used to fabricate sharp probes for use in scanning tunnelling microscopy. In this work an electrochemical fabrication method for sharp aluminium probes coated with nanoporous anodised aluminium oxide (AAO) layer is described. The method presented here involves simultaneous anodisation and etching of aluminium wires. The probe apex radius as well as the nanopore length and diameter depend on the etching mode, which could be direct current (DC), alternating current (AC), or pulsed voltage mode (PVM). The probes, coated with a nanoporous AAO layer, were used to demonstrate addressed DNA delivery.
Physicochemical characterization and photoelectrochemical analysis of iron oxide films
2013
Iron oxide films with a nanoporous structure were grown by anodizing sputter-deposited Fe in a fluoride containing ethylene glycol solution and annealed under air exposure at different temperatures. X-ray diffraction and Raman spectroscopy allowed to identify the presence of hematite and/or magnetite after thermal treatment for films annealed at T ≥ 400 °C under air exposure. According to GDOES compositional depth profiles, the thermal treatment sensitively reduced the amount of fluoride species incorporated into the film during the anodizing process. A band gap value of ~2.0 eV was estimated for all the investigated layers, while a flat band potential dependent on both the growth condition…
High-Density Plasmonic Nanoparticle Arrays Deposited on Nanoporous Anodic Alumina Templates for Optical Sensor Applications
2019
This study demonstrates a new, robust, and accessible deposition technique of metal nanoparticle arrays (NPAs), which uses nanoporous anodic alumina (NAA) as a template for capillary force-assisted convective colloid (40, 60, and 80 nm diameter Au) assembly. The NPA density and nanoparticle size can be independently tuned by the anodization conditions and colloid synthesis protocols. This enables production of non-touching variable-density NPAs with controllable gaps in the 20&ndash
Wood and Black Liquor-Based N-Doped Activated Carbon for Energy Application
2021
The research was funded by the Latvian Council of Science project “Nanostructured Nitrogenated Carbon Materials as Promoters in Energy Harvesting and Storage Technologies”, project No LZP-2018/1-0194, “New biomass origin materials hybrid carbon composites for energy storage” project No LZP-2020/2-0019 and postdoc project “Nitrogen and phosphorus-containing biomass based activated carbons for fuel cells and supercapacitors” project No 1.1.1.2/VIAA/4/20/596.
New Generation of Zeolite Materials for Environmental Applications.
2016
International audience; The influence of the morphology (microcrystals, nanocrystals, nanosponges and nanosheets) of MFI and *BEA-type zeolites on their adsorption capacities and adsorption rate of n-hexane at 25 ˚C has been investigated. The capacity of n-hexane adsorption sensitive to micro- and mesopore volume is enhanced by the use of zeolite nanocrystals or hierar-chical nanoporous materials (nanosheets and nanosponges). In the case of hierarchical zeolites MFI and *BEA nano-sponges, the n-hexane adsorption capacities reached values of about 790 and 693 mg/g, respectively, that are much higher than those in the corresponding microcrystals (130 and 103 mg/g, respectively). On the opposi…
Application of metal coatings for functionalization of technical fibers and fabrics
2011
The metal coatings in combination with sonochemical and leaching processes are used for nanostructuring and functionalization of glass, flax and hemp fabrics. The leaching is used for nanostructuring sodium alumosilicate K-glass fabrics to obtained silica like fibre with nanoporous structure on surface and in volume. The natural fibres as well as fabrics themselves are porous media. The porous media adsorbs water and content of moisture in fabrics have to be controlled. The metal-coated fabric characterization is an actual problem. Application of metal coatings for the functionalization of technical fibres and fabrics faced with influence of moisture on functional properties, e.g., the impe…