Search results for "HYBRID MATERIALS"

Low-temperature molecular layer deposition using monifunctional aromatic precursors and ozone-based ring-opening reactions

2017

Molecular layer deposition (MLD) is an increasingly used deposition technique for producing thin coatings consisting of purely organic or hybrid inorganic-organic materials. When organic materials are prepared, low deposition temperatures are often required to avoid decomposition, thus causing problems with low vapor pressure precursors. Monofunctional compounds have higher vapor pressures than traditional bi- or trifunctional MLD precursors, but do not offer the required functional groups for continuing the MLD growth in subsequent deposition cycles. In this study, we have used high vapor pressure monofunctional aromatic precursors in combination with ozone-triggered ring-opening reactions…

Polyamines and applications. A look at the first workshop in linear and cyclic polyamines chemistry

2008

Given their versatile coordination properties, cyclic and linear polyamines are the subject of numerous worksin many research groups. This great interest is mainly related to their use in diverse fields such as removalof metals from liquids, purification of gases, application in catalysis, in sensors, as well as in various probesfor medical applications. This paper summarizes recent results obtained by the French research groupswhich attended the first ìworkshop in linear and cyclic polyamines chemistryî.

Chromogenic Detection of Aqueous Formaldehyde Using Functionalized Silica Nanoparticles

2016

Silica nanoparticles functionalized with thiol reactive units and bulky polar polyamines were used for the selective colorimetric detection of formaldehyde. The reaction of thiols groups in the nanoparticles surface with a squaraine dye resulted in loss of the pi-conjugation of the chromophores, and the subsequent bleaching of the solution. However, when formaldehyde was present in the suspension, the thiol-squaraine reaction was inhibited and a chromogenic response was observed. A selective response to formaldehyde was observed only when the thiol and polyamine groups were anchored to the silica surface. The observed selective response was ascribed to the fact that bulky polyamines generat…

MODIFICA SUPERFICIALE DI FILM DI POLY(ETILENE-co-ACIDO ACRILICO) CON NANOPARTICELLE DI SILICE ATTIVATA

2009

Photoactive Hybrid Materials based on Conjugated Porous Polymers and Inorganic Nanoparticles

2021

This review explores the current state‐of‐the‐art for functional photoactive hybrids containing inorganic nanoparticles (magnetic and metal) and conjugated organic porous polymers (CPPs). Albeit new in the field, with the first hybrid material of this kind reported in 2012, those materials have gained increasing interest in applications such as sensing, heterogeneous catalysis, photocatalysis, and lithium‐ion batteries (LIBs). This review describes the two main synthetic strategies for those materials, namely, 1) using the chemical and morphological features (e.g., porosity and complexation sites) of CPPs to in situ form nanoparticles and 2) fabricating the nanoparticle for templating CPPs.…

Polyamines : études et applications

2008

International audience

Single crystal X-ray diffraction studies on [(CH3)nNH4–n]3[Sb2Cl9] (2,3) chloroantimonates(III) in their low-temperature ferroelectric phases—structu…

2005

The structures of two ferroic chloroantimonates(III): [(CH3)2NH2]3[Sb2Cl9] (DMACA) and [(CH3)3NH]3[Sb2Cl9] (TMACA) were determined in their low-temperature phases. The structure of DMACA was investigated at 100 and 15 K, and TMACA at 15 K. The structures consist of two-dimensional inorganic layers and organic cations bound together by the N(C)–H⋯Cl hydrogen bonds. All of the organic cations in both compounds at all studied temperatures are ordered. There is no indication of the structural phase transition in the structure of DMACA below 242 K. The geometry and distortions of the [SbCl6]3– octahedra in both compounds is discussed.

Hybrid materials based on conductive polymers for energy harvesting

2022

Uno de los objetivos de la Organización de las Naciones Unidas (ONU) para el Desarrollo Sostenible 2030 es obtener energía asequible y no contaminante. Por este motivo, se recomiendan encarecidamente las mejoras en la eficiencia energética y las fuentes de energía verde como soluciones óptimas para reducir las emisiones de dióxido de carbono y, por tanto, reducir la huella de carbono de nuestra sociedad. Las emisiones de carbono se han cuadriplicado desde 1950 y actualmente contribuyen en torno al 80 % de las emisiones de gases de efecto invernadero. Como resultado de este cambio, el clima global sufre cambios en las tendencias globales de lluvia y una reducción en los casquetes polares. Co…

Supported Poly(Ionic Liquid)-Heteropolyacid Based Materials for Heterogeneous Catalytic Fructose Dehydration in Aqueous Medium

2022

Two sets of four different supported catalyst materials were prepared. One set was obtained by polymerization of a bis-vinylimidazolium salt, which formed a poly(ionic liquid) coating on SiO2, TiO2, boron nitride BN, and carbon nitride C3N4. The other set was, instead, obtained by immobilizing Keggin heteropolyacid H3PW12O40 onto poly-imidazolium functionalized materials. All the catalysts, including the bare supports, were subjected to physical and chemical characterization by XRD, SEM, Specific Surface Area and pore size measurements, TGA, FTIR, and acidity-basicity measurements. The catalytic activity of the materials was tested versus the fructose dehydration in water solution at two di…

Surface modification of poly(ethylene-co-acrylic acid) with amino-functionalized silica nanoparticles

2011

In this work we studied the possibility to achieve a hybrid-surface through the modification, via a facile wet chemical process, of the surface of films of poly(ethylene-co-acrylic acid) (EAA) with amino-modified silica nanoparticles. Films of EAA were preliminarily activated by the introduction of -COCl groups on their surface. Silica nanoparticles were thereafter covalently bound on the polymeric surface as confirmed by FTIR, ATR-FTIR, XPS, NMR and SEM determinations. The nanoparticles formed a multilayer on the film surface and covered almost uniformly the whole film surface. Direct measurements of superficial amino groups by titration allowed us to detect a concentration of about 18 nmo…