Time filter

Source Type

Paris, France

Chimie ParisTech , also known as ENSCP or Chimie Paris) is an elite chemical science and engineering college founded in 1896, located in the 5th arrondissement of Paris. It is one of the founding members of ParisTech , and Paris science et Lettres – Quartier latin. The students enter the school after highly competitive exams known as the Concours Communs Polytechniques, following at least two years of classes préparatoires. The school is known as France's most selective chemical engineering collegeThe school is a research center hosting nine laboratories which conduct high level research in various fields of chemistry. Wikipedia.

Recent years have seen a large increase of the research effort focused on framework materials, including the nowadays-ubiquitous metal-organic frameworks but also dense coordination polymers, covalent organic frameworks, and molecular frameworks. With the quickly increasing number of structures synthesized and characterized, one pattern emerging is the common occurrence of flexibility. More specifically, an important number of framework materials are stimuli-responsive: their structure can undergo changes of large amplitude in response to physical or chemical stimulation. They can display transformations induced by temperature, mechanical pressure, guest adsorption or evacuation, light absorption, etc. and are sometimes referred to as smart materials, soft crystals, or dynamic materials. This Perspective highlights recent progress in this field, showcasing some of the most novel and unusual responses to stimuli, as well as advances in the fundamental understanding of flexible framework materials. © 2015 American Chemical Society. Source

While the energetic stability of the large number of possible SiO 2 polymorphs has been widely addressed by both experimental and theoretical studies, there is a real dearth of information on their mechanical properties. We performed a systematic study of the elastic properties of 121 pure silica zeolites, including both experimentally synthesized and hypothetical structures, by means of density-functional theory calculations. We found that most frameworks exhibit high elastic anisotropy, and the experimentally synthesized structures are among the most mechanically stable ones. We propose to extend the feasibility criterion proposed in earlier literature to include elastic anisotropy, allowing to further reduce the number of possible targets for synthesis of SiO2 polymorphs. We also predict that a small number of hypothetical pure silica zeolites present large negative linear compressibility (NLC), which we link to the wine-rack motif of their framework. © 2013 The Owner Societies. Source

Adamo C.,Chimie Paristech | Adamo C.,Institut Universitaire de France | Jacquemin D.,Institut Universitaire de France | Jacquemin D.,University of Nantes
Chemical Society Reviews | Year: 2013

In this tutorial review, we show how Time-Dependent Density Functional Theory (TD-DFT) has become a popular tool for computing the signatures of electronically excited states, and more specifically, the properties directly related to the optical (absorption and emission) spectra of molecules. We discuss the properties that can be obtained with widely available programs as well as how to account for the environmental effects (solvent and surfaces) and present recent applications in these fields. We next expose the transformation of the TD-DFT results into chemically intuitive parameters (colours as well as charge-transfer distances). Eventually, the non-specialised reader will find a series of advices and warnings necessary to perform her/his first TD-DFT calculations. © 2013 The Royal Society of Chemistry. Source

Coudert F.-X.,Chimie Paristech
Physical Chemistry Chemical Physics | Year: 2010

Predictive analytical methods are crucial tools in the design of adsorptive gas separation processes. While they are widely used for rigid nanoporous solids, there is a lack of flexible materials, including the very topical and promising dynamic metal-organic frameworks (MOFs), which display such eye-catching phenomena as gate opening and breathing. We present here the osmotic framework adsorbed solution theory (OFAST), which predicts the evolution of structural transitions and selectivity upon adsorption of fluid mixtures in flexible nanoporous solids, using as a sole input experimental pure component isotherms. © 2010 the Owner Societies. Source

Thomas C.M.,Chimie Paristech | Lutz J.-F.,Charles Sadron Institute
Angewandte Chemie - International Edition | Year: 2011

Its all in the sequence: The primary structure of poly(lactic-co-glycolic acid) (PLGA), a member of the most widely used class of biodegradable polymers employed in biomedical applications, is demonstrated to strongly influence its degradation properties. Experimental studies evidenced the beneficial effect of ordered monomer sequences on the material properties (see picture). © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Discover hidden collaborations