Easy orientation of diblock copolymers on self-assembled monolayers using UV irradiation

A simple method based on UV/ozone treatment is proposed to control the surface energy of dense grafted silane layers for orientating block copolymer mesophases. Our method allows one to tune the surface energy down to a fraction of a mN/m. We show that related to the surface, perpendicular orientation of a lamellar phase of a PS-PMMA diblock copolymer (neutral surface) is obtained for a critical surface energy of 23.9-25.7 mN/m. Perpendicular cylinders are obtained for 24.6 mN/m and parallel cylinders for 26.8 mN/m.Comment: 3 figures, 1 tabl

Surface Tension Drives the Orientation of Crystals at the Air−Water Interface

International audienceThe fabrication of oriented crystalline thin films is essential for a range of applications ranging from semiconductors to optical components, sensors, and catalysis. Here we show by depositing micrometric crystal particles on a liquid interface from an aerosol phase that the surface tension of the liquid alone can drive the crystallographic orientation of initially randomly oriented particles. The X-ray diffraction patterns of the particles at the interface are identical to those of a monocrystalline sample cleaved along the {104} (CaCO 3) or {111} (CaF 2) face. We show how this orientation effect can be used to produce thin coatings of oriented crystals on a solid substrate. These results also have important implications for our understanding of heterogeneous crystal growth beneath amphiphile monolayers and for 2D self-assembly processes at the air−liquid interface. T he first crystals to grow from a supersaturated aqueous solution often nucleate at the air−water interface. This can happen for a variety of reasons. When crystallization is induced by cooling of a hot, saturated salt solution, for example, faster cooling at the air−water interface makes the super-saturation highest at this location. CaCO 3 nucleation from hard water occurs first at the interface because gaseous CO 2 resulting from the reaction Ca 2+ + 2 HCO 3

107 Care management of heart failure in elderly patients in France. Results from the DEVENIR study

RationaleThe part of elderly patients (pts) in heart failure (HF) population is growing. They might pose specific problems due to the greater proportion of HF with preserved LVEF, more frequent comorbidities or contra-indications to recommended HF treatment.Objectivesto describe the care management of pts > 80-year treated for HF in France.MethodsCross sectional observational survey with retrospective collection of data at hospital discharge. Pts must have been diagnosed with CHF and have been hospitalised for CHF within the previous 18 months. Pts are classified according to the LVEF at hospital discharge.Results412 French outhospital cardiologists entered 1 452 pts meeting the inclusion criteria. FEVG at hospital discharge was known for 1408 pts. 355 (25%) were more than 80-year-old. Management care at hospital discharge according to age and LVEF is detailed below.LVEF < 40%LVEF 40-50%LVEF > 50%TotalAge>80ACEI/ARB84%81%80%82%*BB71%67%40%†,‡62%*Loop diuretics92%85%85%88%Spironolactone/eplerenone26%20%18%22%*Digoxin20%15%29%21%*Calcium antagonists10%14%37%†,‡18%Anticoagulants49%45%51%49%*Age≤80ACEI/ARB93%93%85%†,‡92%BB79%78%76%79%Loop diuretics90%82%79%†,§86%Spironolactone/eplerenone35%21%25%†,§30%Digoxin16%15%16%15%Calcium antagonists9%19%21%†,§13%Anticoagulants42%39%39%41%†p<0.05 for comparisons between LVEF > 50% and LVEF<40%;‡p<0.05 for comparisons between LVEF>50% and LVEF between 40% and 50%;§: p<0.05 for comparisons between LVEF<40% and LVEF between 40% and 50%;*p<0.05 for comparisons between > 80 and ≤ 80 years old adjusted for LVEF.ConclusionBB, ACEI/ARB, spironolactone/eplerenone are less often prescribed in elderly patients contrasting with digoxin and anticoagulants prescription. These differences persist after adjustment on LVEF

088 Prescription of beta blockers at hospital discharge and beyond, in patients with heart failure. Results from the DEVENIR study

RationaleBeta blockers are a corner stone treatment of heart failure (HF) in patients with altered systolic function (LVEF<40%). Guidelines are less clear for HF patients with preserved systolic function (LVEF>50%) or for patients belonging to the “grey zone” (LVEF 40-50%).Objectivesto describe the prescription rate of beta-blockers in HF patients.MethodsCross sectional observational survey with retrospective collection of data at hospital discharge. Patients must have been diagnosed with CHF and have been hospitalised for CHF within the previous 18 months. Patients are classified according to the LVEF at hospital discharge.Results1 452 patients were included by 412 French outhospital cardiologists. 1137 with known LVEF at hospital discharge have had at least one visit by the cardiologist between hospital discharge (mean delay 5.76±4.51 months). In a multivariate model, BB prescription was more frequent in HF from ischemic origin (OR=1.39) or with dilated cardiomyopathy (OR=1.44) and less frequent in older patients (OR=0.97 per year) and in case of asthma/COPD (OR=0.31 and if FEVG was >50% (OR=0.62).LVEF < 40% N=661LVEF 40-50% N=282LVEF > 50% N=194Total N=1137At hospital discharge/at entry in the surveyBB78%/83%78%/85%62%/70%76%/82%Recommended BB†75%/77%72%/74%54%/62%71%/74%Reaching the target dose8%/16%7%/16%7%/13%7%/15%Changes since dischargeBB added*28%34%25%28%BB stopped**1%1%2%1%BB dose increased*27%27%17%25%BB dose decreased4%1%3%3%†metoprolol, nebivolol, bisoprolol, carvedilol ;*percentage calculated in patients without BB at hospital discharge (N=278);**percentage calculated in patients with BB at hospital discharge (N=859).ConclusionRate of betablockers prescription is high at hospital discharge. Outhospital cardiologists not only pursue but also amplify the care strategies defined during hospitalisation increasing the proportion of patients receiving BB and the percentage reaching the target dose

Organization of Block Copolymers using NanoImprint Lithography: Comparison of Theory and Experiments

We present NanoImprint lithography experiments and modeling of thin films of block copolymers (BCP). The NanoImprint lithography is used to align perpendicularly lamellar phases, over distances much larger than the natural lamellar periodicity. The modeling relies on self-consistent field calculations done in two- and three-dimensions. We get a good agreement with the NanoImprint lithography setups. We find that, at thermodynamical equilibrium, the ordered BCP lamellae are much better aligned than when the films are deposited on uniform planar surfaces

Phase separation of water-soluble polymer solutions: application to membrane formation

International audienc

Ordered block copolymer films at interfaces: from thin films to thick ones

International audienc

Auto-assemblage de peptides amyloïdes (développement d'une interface modèle pour la biominéralisation)

Nous avons étudié l organisation à une interface eau/air d un peptide amyloïde de 12 acides aminés. La construction de films peptidiques structurés en feuillets Beta répond à la nécessité de développer des surfaces organiques modèles pour étudier la biominéralisation. Par ailleurs, l organisation in vitro de peptides amyloïdes courts à une interface simple permet une première modélisation pertinente des comportements interfaciaux in vivo de ces protéines, pathologiques dans les maladies neuro-dégénératives ou fonctionnelles chez certains micro-organismes. L association de techniques d analyse structurale à différentes échelles spatiales a permis une caractérisation complète de la monocouche peptidique. Les expériences de spectroscopie infrarouge (IRRAS) montrent que les peptides forment à l interface des feuillets Beta pratiquement parallèles à la surface de l eau. Les observations par microscopie à force atomique (AFM) mettent en évidence la formation de structures hiérarchiques dirigée par l interface. A l échelle moléculaire, ces structures présentent un ordre cristallin, caractérisé par diffraction de rayons X sous incidence rasante. Cet ordre, supposé bidimensionnel, est induit par le réseau de liaisons hydrogène entre brins Beta (ordre transversal) et par d autres interactions, comme les interactions hydrophobes, menant à l empilement des brins (ordre longitudinal). Sous l effet de la compression, la monocouche subit des transformations structurales détectées grâce aux isothermes de Langmuir et observées par microscopie à angle de Brewster et AFM, avec notamment une transition de phase du premier ordre mettant en jeu un accroissement de l ordre cristallin longitudinal.PARIS-BIUSJ-Physique recherche (751052113) / SudocSudocFranceF