Search results for "Mesoporous"

Impact of the post-treatment conditions of parent silica on the silanization of n-octadecyl bonded silica packings in reversed-phase high-performance…

2001

Native mesoporous silica beads were subjected to a sequence of post-treatment procedure including hydrochloric acid treatment, calcination and subsequent rehydroxylation. The post-treated silica beads were converted into RP-18 silica by silanization with monochloro- and dimethoxy-n-octadecylsilanes, respectively. The influence of post-treatments and silanization conditions on the physico-chemical characteristics and on the chromatographic behaviour of the RP-silicas was studied. Also the changes of the pore structural parameters and the silanol group densities during the post-treatment and silanization were assessed.

Nanoparticulated Silicas with Bimodal Porosity: Chemical Control of the Pore Sizes

2008

Nanoparticulated bimodal porous silicas (NBSs) with pore systems structured at two length scales (meso- and large-meso-/macropores) have been prepared through a one-pot surfactant-assisted procedure by using a simple template agent and starting from silicon atrane complexes as hydrolytic inorganic precursors. The final bulk materials are constructed by an aggregation of pseudospherical mesoporous primary nanoparticles process, over the course of which the interparticle (textural) large pore system is generated. A fine-tuning of the procedural variables allows not only an adjustment of the processes of nucleation and growth of the primary nanoparticles but also a modulation of their subseque…

Cisplatin derivative loaded in mesoporous MCM-41: preparation and characterization

2014

The aim of this study is to design and investigate a new material constituted by mesoporous silica MCM-41 and a new cisplatin derivative, cis-PtCl2(DMSO)HL]•2DMSO, where HL = 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid, having biological activity.[1] The high surface area and the tunable pore size of MCM-41 allow it for loading vast amounts of bioactive molecules, including biocides and drugs. Mesoporous silica MCM-41 was prepared in alkaline environment from tetraethoxysilane as Si source and cetyltrimethylammonium bromide (CTAB) as template. [2] Amino groups have been successfully grafted onto the pore surface with 3-aminopropyl triethoxysilane (APTES) in orde…

Overview of the Evolution of Silica-Based Chromo-Fluorogenic Nanosensors

2019

[EN] This review includes examples of silica-based, chromo-fluorogenic nanosensors with the aim of illustrating the evolution of the discipline in recent decades through relevant research developed in our group. Examples have been grouped according to the sensing strategies. A clear evolution from simply functionalized materials to new protocols involving molecular gates and the use of highly selective biomolecules such as antibodies and oligonucleotides is reported. Some final examples related to the evolution of chromogenic arrays and the possible use of nanoparticles to communicate with other nanoparticles or cells are also included. A total of 64 articles have been summarized, highlight…

Synthesis of large-pore ordered mesoporous silicas containing aminopropyl groups

2005

Ordered mesoporous silicas with large-pore diameters incorporating aminopropyl groups in variable quantity have been synthesized via the co-condensation of tetraethyl orthosilicate (TEOS) and 3-tert-butyloxycarbonylaminopropyltriethoxysilane templated with nonionic surfactant P123 under acidic conditions. The deprotection of amino groups was then quantitatively achieved either by thermal treatment or acid hydrolysis followed by Et3N treatment, both routes leading to exactly the same materials. We showed that the free amino centers are fully accessible, by using the condensation of the amine function with benzaldehyde.

Theoretical and Experimental Studies of Capillary Hysteresis in MCM-41

1996

Mesoporous materials of MCM-41 type are considered to be reference model adsorbents due to their regular pore structure. Nitrogen adsorption isotherms on MCM-41 are modeled using the Non-Local Density Functional Theory (NLDFT). The thermal dependence of the thermodynamic hysteresis predicted by the NLDFT is confirmed by experimental measurements. The nitrogen hysteresis on MCM-41 at temperatures below 77.4 K or in pores greater than 4 nm is associated with the metastability of the adsorption branch of the isotherm. In the hysteresis regime, the desorption branch is likely to be thermodynamically stable and is recommended for calculating pore size distributions.

A Highly Sensitive Hybrid Colorimetric and Fluorometric Molecular Probe for Cyanide Sensing Based on a Subphthalocyanine Dye

2006

A highly sensitive, selective colorimetric and fluorometric molecular probe based on a subphthalocyanine dye has been developed for cyanide-anion determination in aqueous solution. It has also been shown that a carboxysubphthalocyanine derivative can be covalently anchored to transparent mesoporous nanocrystalline high-surface-area metal oxide films to detect low concentrations of cyanide anion in pure water with no interference from other anionic or cationic species.

Selective Encapsulation and Enhancement of the Emission Properties of a Luminescent Cu(I) Complex in Mesoporous Silica

2018

Oligonucleotide-capped mesoporous silica nanoparticles as DNA-responsive dye delivery systems for genomic DNA detection

2015

[EN] New hybrid oligonucleotide-capped mesoporous silica nanoparticles able to detect genomic DNA were designed.

Selective, Highly Sensitive, and Rapid Detection of Genomic DNA by Using Gated Materials:MycoplasmaDetection

2013

The coupling of gated-indicator delivery with highly specific biochemical recognition is an innovative strategy for the detection of DNA sequences, able to compete with classical methods which need PCR amplification, in important areas such as point-of-care diagnostics or detection of specific biological contaminations with pathogens. Such comparatively simple and cheap yet highly selective and sensitive assays hold promise for use in less-developed areas of the world.