Search results for "mesoporous material"

NO2-controlled cargo delivery from gated silica mesoporous nanoparticles

2017

[EN] Cargo delivery from mesoporous silica nanoparticles loaded with sulforhodamine B and capped with a difluoroboron-dipyrromethene (BODIPY) derivative was triggered by a NO2-induced oxidative process.

Formation of hierarchically ordered silicas prepared by spray drying of nanosized spheres

2002

We report on our strategy to synthesise defined arrangements of macro- and mesopores in one single material with spherical morphology using the spray drying technique. As starting materials, nano-sized silica spheres and colloidal suspensions were chosen. The intra-particle as well as inter-particle pore size was independently controlled which allowed to obtain materials with varied bimodal pore networks. The spherical agglomerates were characterised regarding their pore structural parameters and are potential adsorbents in liquid chromatographic separations.

A simple approach towards one-dimensional mesoporous carbon with superior electrochemical capacitive activity.

2009

One-dimensional (1D) mesoporous carbons with highly ordered 3D interconnected pore structure and large-diameter pore size (10–20 nm) have been synthesized by a simple precursor-controlled thermolysis approach; such unique carbonaceous frameworks show superior capacitive behavior in electrochemical double-layer capacitors.

Silica-based macrocellular foam monoliths with hierarchical trimodal pore systems

2005

Abstract Silica-based large monoliths exhibiting a trimodal hierarchical pore system have been successfully prepared through a nanotectonic approach starting from sub-micro/nanometric mesoporous particles (as building blocks), and using a polyurethane foam as macrotemplate. Large trimodal pieces with macrocellular like interconnected macropores in the micrometer range are a mineralized replica of the polyurethane foam. Textural large-mesopores/macropores (in the 20–70 nm range) have their origin in the inter-particle voids. The small intra-particle mesopore system (with pore diameters around 2–3 nm) is due to the supramolecular templating effect of the surfactant.

Aging of MCM41, MSU-H and MSU-F mesoporous systems investigated through the Raman spectroscopy

2014

Here we report an experimental investigation, based on the Raman spectroscopy, on the aging of some mesoporous silica based systems. In details, we studied the aging in air of the MCM41, the MSU-H and the MSU-F materials by acquiring the Raman spectra of as received and of mechanically pressed, at 0.2 and 0.45 GPa, powders. Our data evidenced that the starting powders of the MCM41 and of the MSU-H undergo structural modification when they are exposed to the ambient atmosphere, such modification consisting in the decrease of the D2 Raman band (originated by the three member rings). At variance the powders of the MSU-F appear to be stable. Furthermore, by pressing the starting powders to prod…

Caspase 3 Targeted Cargo Delivery in Apoptotic Cells Using Capped Mesoporous Silica Nanoparticles

2015

[EN] Excessive apoptotic cell death is at the origin of several pathologies, such as degenerative disorders, stroke or ischemia-reperfusion damage. In this context, strategies to improve inhibition of apoptosis and other types of cell death are of interest and may represent a pharmacological opportunity for the treatment of cell-death-related disorders. In this scenario new peptide-containing delivery systems (solids S1-P1and S1-P2) are described based on meso-porous silica nanoparticles (MSNs) loaded with a dye and capped with the KKGDEVDKKARDEVDK (P1) peptide that contains two repeats of the DEVD target sequence that are selectively hydrolyzed by caspase3 (C3). This enzyme plays a central…

Rational design, tailored synthesis and characterisation of ordered mesoporous silicas in the micron and submicron size range

2000

Ordered mesoporous hybrid materials containing cobalt(ii) Schiff base complex

2002

Immobilisation of Co-salen and Co-fluomine onto ordered mesoporous silica has been achieved through coordination of the cobalt to pyridine or imidazole groups covalently attached to the silica matrix. Two routes have been investigated to obtain mesoporous hybrid materials containing coordinating ligands: post synthesis grafting of 4-[2-(trimethoxysilyl)ethyl]pyridine 1 and N-trimethoxysilylpropylimidazole 2 on hexagonally ordered mesoporous silica via SiOH groups or direct synthesis method i.e. co-hydrolysis and polycondensation of the same functionalised organotrimethoxysilane with a number of equivalents of TEOS in the presence of n-hexadecylamine as structure directing agent. The first m…

Phosphorylation triggered growth of metal phosphate on halloysite and sepiolite nanoparticles: preparation, entrapment in chitosan hydrogels and appl…

2020

The rational design of porous, biomass-derived eco-friendly adsorbents instead of costly synthetic, petroleum-based resins stands as a promising approach to resolving the thorny issue of sewage treatment (for example, by supplying safe water for drinking and irrigation). Herein we explore a straightforward transformation of abundant clay and polysaccharides into highly-reactive water-cleaning adsorbents. Surface-functionalization of sepiolite and halloysite by phosphoryl chloride triggered metal dissolution from the framework (inside of the lumen for halloysite and on the external surface for sepiolite) and the concomitant growth of well-truncated crystalline metal phosphates. These unprece…

Enzyme-responsive intracellular-controlled release using silica mesoporous nanoparticles capped with ε-poly-L-lysine.

2014

The synthesis and characterization of two new capped silica mesoporous nanoparticles for controlled delivery purposes are described. Capped hybrid systems consist of MCM-41 nanoparticles functionalized on the outer surface with polymer epsilon-poly-L-lysine by two different anchoring strategies. In both cases, nanoparticles were loaded with model dye molecule [Ru(bipy)(3)](2+). An anchoring strategy involved the random formation of urea bonds by the treatment of propyl isocyanate-functionalized MCM-41 nanoparticles with the lysine amino groups located on the epsilon-poly-L-lysine backbone (solid Ru-rLys-S1). The second strategy involved a specific attachment through the carboxyl terminus of…