Publications associées à Stöber process

Silica aerogel as rear reflector in silicon heterojunction solar cells for improved infrared response

Silicon (Si), with its indirect bandgap, is a non-ideal absorber. Thus, various strategies to boost silicon solar cells' efficiency, including advanced texturing, multilayer anti-reflecting coating, and rear reflectors are utilized. Dielectrics, deposited ...

ELSEVIER2023

Fractal Analysis of Four Xerogels Based on TEGylated Phenothiazine and Chitosan

Maria-Alexandra Paun

The present article describes novel massive materials (in the solid phase) based on TEGylated phenothiazine and chitosan that possess great capability to recover mercury ions from constituent aqueous solutions. These were produced by chitosan hydrogelation ...

MDPI2023

Functionalization of polymer optical fibers for medical application

Jialuo Luo

The increasing challenges caused by the growing and aging population and the fast pace of life are calling for a change of our current medical care system towards being rapid, easy, and on-demand self-care. Empowerment with the self-caring components such ...

EPFL2022

Synthesis of heterogeneous catalysts with metal oxide overcoat for renewable catalysis applications

Yuan-Peng Du

Metal oxide deposition is an emerging synthetic technique for designing heterogeneous catalysts. Depositing a nanoscale overcoat of metal oxide on heterogeneous catalysts can modify their structural and chemical characteristics. Many deposition approaches, ...

EPFL2020

Polyphenols as Morphogenetic Agents for the Controlled Synthesis of Mesoporous Silica Nanoparticles

Fabien Sorin, Jialuo Luo, René M. Rossi, Alina Osypova

Non-surfactant-induced synthesis of mesoporous silica nanoparticles (MSNPs) is gaining increasing interest because of their low toxicity and simple purification compared to conventional surfactant-based methods. Tannic acid (TA), considered as a glucose-de ...

AMER CHEMICAL SOC2019

Post-synthesis deposition of mesoporous niobic acid with improved thermal stability by kinetically controlled sol–gel overcoating

Jeremy Luterbacher, Florent Emmanuel Héroguel, Yuan-Peng Du

Niobia is a well-known solid acid catalyst owing to its intrinsic Brønsted and Lewis acidity. However, catalyst development with this oxide has been limited by our ability to control its pore structure and thermal stability. Here we report a novel post-syn ...

Royal Society of Chemistry2019

Evolution of critical buckling conditions in imperfect bilayer shells through residual swelling

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla, Dong Yan, Anna Lee

We propose and investigate a minimal mechanism that makes use of differential swelling to modify the critical buckling conditions of elastic bilayer shells, as measured by the knockdown factor. Our shells contain an engineered defect at the north pole and ...

ROYAL SOC CHEMISTRY2019

Effect of surface modification of colloidal silica nanoparticles on the rigid amorphous fraction and mechanical properties of amorphous polyurethane-urea-silica nanocomposites

John Christopher Plummer, Nicolas Candau, Oguzhan Oguz, Stéphane Henri Florian Bernhard

Colloidal silica nanoparticles (NPs) modified with eight different silane coupling agents were incorporated into an amorphous poly(tetramethylene oxide)-based polyurethane-urea copolymer matrix at a concentration of 10 wt % (4.4 vol %) in order to investig ...

2019

Slowing the Kinetics of Alumina Sol-Gel Chemistry for Controlled Catalyst Overcoating and Improved Catalyst Stability and Selectivity

Jeremy Luterbacher, Yuan-Peng Du, Florent Emmanuel Héroguel

Catalyst overcoating is an emerging approach to engineer surface functionalities on supported metal catalyst and improve catalyst selectivity and durability. Alumina deposition on high surface area material by sol–gel chemistry is traditionally difficult t ...

2018

Reducing Humidity Response of Gas Sensors for Medical Applications: Use of Spark Discharge Synthesis of Metal Oxide Nanoparticles

Thomas Maeder

The application of gas sensors in breath analysis is an important trend in the early diagnostics of different diseases including lung cancer, ulcers, and enteric infection. However, traditional methods of synthesis of metal oxide gas-sensing materials for ...

MDPI2018

Morphological Characterization of ALD and Doping Effects on Mesoporous SnO2 Aerogels by XPS and Quantitative SEM Image Analysis

Juan-Pablo Correa-Baena

Atomic layer deposition (ALD) is unsurpassed in its ability to create thin conformal coatings over very rough and/or porous materials. Yet although the coating thickness on flat surfaces can be measured by ellipsometry, characterization of these coatings o ...

Amer Chemical Soc2016

Innovative optical lactate biosensing through the design of nanostructured materials

Oswaldo Javier Pérez Anguiano

The scope of this thesis is the synthesis of nanostructured materials, their functionalization and use for optical lactate biosensing applications. Rapid detection of L-lactate is important in many applications in the clinical sector, in the food industry, ...

EPFL2015

Confinement of a tris-aqua Gd(III) complex in silica nanoparticles leads to high stability and high relaxivity and supresses anion binding

Marinella Mazzanti

The water soluble tris-aqua complex Gd(dhqN-SO3)(H2O)(3) based on a hexadentate hydroxyquinoline ligand shows high thermodynamic stability and high relaxivity (12.54 mM(-1) s(-1) at 1.2 T). Its non-covalent confinement in 25 nm silica nanoparticles p ...

Royal Society of Chemistry2015

Isolation and Characterization of Monodisperse Core Shell Nanoparticle Fractions

Francesco Stellacci, Randy Patrick Carney, Raffaele Mezzenga

Monodispersity is a key property to control the self-assembly of colloidal particles, and is typically reached after fine-tuning of the synthesis conditions. Monodisperse particle fractions can also be separated from polydisperse suspensions via ultracentr ...

American Chemical Society2015

Optimization of Gold Nanoparticle Photoluminescence by Alkanethiolation

Giorgio Margaritondo, Ying Chen

Surface thiolation was recently found to affect two important properties of gold nanoparticles: their size and the presence of visible luminescence under UV stimulation. We explored these phenomena by systematically analysing alkanethiolate coatings with d ...

Royal Society of Chemistry2015

Energy dissipation in concentrated monodisperse colloidal suspensions of silica particles in polyethylene glycol

Véronique Michaud, Mathieu Soutrenon

Highly concentrated colloidal suspensions exhibit a discontinuous shear-thickening behaviour. The transition from a low to a high viscosity state is associated to a large energy dissipation. This effect could find applications in structural damping while t ...

Springer2014

Mesoporous Silica Nanoparticles Loaded with Surfactant: Low Temperature Magic Angle Spinning C-13 and Si-29 NMR Enhanced by Dynamic Nuclear Polarization

Geoffrey Bodenhausen, Diego Carnevale

We show that dynamic nuclear polarization (DNP) can be used to enhance NMR signals of C-13 and Si-29 nuclei located in mesoporous organic/inorganic hybrid materials, at several hundreds of nanometers from stable radicals (TOTAPOL) trapped in the surroundin ...

American Chemical Society2013

Enhancing the open circuit voltage of dye sensitized solar cells by surface engineering of silica particles in a gel electrolyte

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Lioz Etgar, Guillaume Schuchardt

We prepared a quasi-solid electrolyte for dye-sensitized solar cells (DSSCs) that consist of ionic liquid and modified silica particles. Commercial bare silica F5 particles and modified silica F5 by NH2 and NH3+ groups were prepared, and fully characterize ...

Royal Society of Chemistry2013

A silica sol-gel design strategy for nanostructured metallic materials

Michael Graetzel, Scott Charles Warren

Batteries, fuel cells and solar cells, among many other high-current-density devices, could benefit from the precise meso-to macroscopic structure control afforded by the silica sol-gel process. The porous materials made by silica sol-gel chemistry are typ ...

Nature Publishing Group2012

Laser-Heating-Induced Displacement of Surfactants on the Water Surface

Sylvie Roke

We report a combined vibrational sum-frequency generation (SFG) spectroscopy, Brewster angle microscopy (BAM), and ellipsometry study of different surfactants on water as a function of surfactant density. Vibrational SFG spectra of surfactants on the water ...

2012