Nicolas Sbirrazzuoli | Université Nice Sophia Antipolis (original) (raw)

Papers by Nicolas Sbirrazzuoli

nano Online, Mar 29, 2018

Thermochimica Acta, Mar 1, 2021

Abstract Four complex mechanisms of two parallel independent reactions were simulated under vario... more Abstract Four complex mechanisms of two parallel independent reactions were simulated under various isothermal and nonisothermal conditions. Equations to perform isothermal predictions and nonisothermal simulations at a different temperature program are presented, based on the isoconversional methods of Vyazovkin and Friedman. Isoconversional kinetic parameters were used to simulate the reaction progress under different isothermal and nonisothermal conditions. It was shown that accurate simulations can be performed in a model-free way, i.e. without knowledge of the reaction mechanism. A higher accuracy was obtained for mechanism involving more separated individual steps. The methods proposed are applicable to both DSC and TG data.

HAL (Le Centre pour la Communication Scientifique Directe), Aug 1, 2013

HAL (Le Centre pour la Communication Scientifique Directe), Jun 15, 2014

Thermochimica Acta

In this study, thermogravimetry (TG) coupled with differential thermal analysis (DTA) was perform... more In this study, thermogravimetry (TG) coupled with differential thermal analysis (DTA) was performed to examine the thermal behavior of a straight-run distillation bitumen utilized in a variety of applications, including the conditioning of nuclear waste. The non-isothermal characterization of this bitumen was carried out from 30 to 900°C with heating rates of 1, 2, 5, 10 and 25°C/min, in nitrogen and air atmospheres. TG and DTA results showed that under nitrogen atmosphere, pure bitumen shows a single thermal event, which is attributed to its pyrolysis. While under air, it undergoes two exothermic low temperature oxidation stages, one endothermic fuel deposition stage, and one exothermic high temperature oxidation. Kinetic parameters were determined using Kissinger, Friedman and advanced non-linear (NLN) methods to assess activation energy for each event, from the non-isothermal experimental data. Good agreement between kinetic modeling was found for bitumen under nitrogen and air.

Polymers, 2019

Humins is a biomass-derived material, co-product of the acid-catalyzed conversion of cellulose an... more Humins is a biomass-derived material, co-product of the acid-catalyzed conversion of cellulose and hemicellulose to platform chemicals. This work presents a thorough study concerning the crosslinking kinetics of humins by chemorheological analysis and model-free kinetics under isothermal and non-isothermal curing. Humins can auto-crosslink under the effect of temperature, and the reaction can be fastener when adding an acidic initiator. Thus, the effect of P-Toluenesulfonic acid monohydrate (pTSA) on the crosslinking kinetics was also studied. The dependencies of the effective activation energy (Eα-dependencies) were determined by an advanced isoconversional method and correlated with the variation of complex viscosity during curing. It is shown that humins curing involves multi-step complex reactions and that the use of an acidic initiator allows faster crosslinking at lower temperatures, involving lower Eα. The shift from chemical to diffusion control was also estimated.

Bioconjugate Chemistry, Oct 27, 2001

There is a need for the development of nonviral gene transfer systems with improved and original ... more There is a need for the development of nonviral gene transfer systems with improved and original properties. "Fluorinated" lipoplexes are such candidates, as supported by the remarkably higher in vitro and in vivo transfection potency found for such fluorinated lipoplexes as compared with conventional ones or even with PEI-based polyplexes (Boussif, O., Gaucheron, J., Boulanger, C., Santaella, C., Kolbe, H. V. J., Vierling, P. (2001) Enhanced in vitro and in vivo cationic lipid-mediated gene delivery with a fluorinated glycerophosphoethanolamine helper lipid. J. Gene Med. 3, 109-114). Here, we describe the synthesis of fluorinated glycerophosphoethanolamines (F-PEs), close analogues of dioleoylphosphatidylethanolamine (DOPE), and report on their lipid helper properties vs that of DOPE, as in vitro gene transfer components of fluorinated lipoplexes based on pcTG90, DOGS (Transfectam), or DOTAP. To evaluate the contribution of the F-PEs to in vitro lipoplex-mediated gene transfer, we examined the effect of including the F-PEs in lipoplexes formulated with these cationic lipids (CL) for various CL:DOPE:F-PE molar ratios [1:(1 - x):x with x = 0, 0.5 and 1; 1:(2 - y):y with y = 0, 1, 1.5, and 2], and various N/P ratios (from 10 to 0.8, N = number of CL amines, P = number of DNA phosphates). Irrespective of the F-PE chemical structure, of the colipid F-PE:DOPE composition, and of the N/P ratio, comparable transfection levels to those of their respective control DOPE lipoplexes were most frequently obtained when using one of the F-PEs as colipid of DOGS, pcTG90, or DOTAP in place of part of or of all DOPE. However, a large proportion of DOGS-based lipoplexes were found to display a higher transfection efficiency when formulated with the F-PEs rather than with DOPE alone while the opposite tendency was evidenced for the DOTAP-based lipoplexes. The present work indicates that "fluorinated" lipoplexes formulated with fluorinated helper lipids and conventional cationic lipids are very attractive candidates for gene delivery. It confirms further that lipophobicity and restricted miscibility of the lipoplex lipids with the endogenous lipids does not preclude efficient gene transfer and expression. Their transfection potency is rather attributable to their unique lipophobic and hydrophobic character (resulting from the formulation of DNA with fluorinated lipids), thus preventing to some extent DNA from interactions with lipophilic and hydrophilic biocompounds, and from degradation.

HAL (Le Centre pour la Communication Scientifique Directe), 2015

Poly(decylene-2,5-furandicarboxylate), a new bio-based polyester, was successfully synthesized fr... more Poly(decylene-2,5-furandicarboxylate), a new bio-based polyester, was successfully synthesized from 2,5-furan dicarboxylic acid and 1,10-decanediol. It has mechanical properties and melting point similar to those of linear low density polyethylene.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 28, 2021

Thermochimica Acta, Jun 1, 2002

... The applications are illustrated by simulations as well as by epoxy-anhydride andepoxy-amine ... more ... The applications are illustrated by simulations as well as by epoxy-anhydride andepoxy-amine cures. ... 2. Experimental. An epoxy-anhydride system was a mixture of DGEBA of MW 348 g mol −1 with hexahydro-4-methylphthalic anhydride (HHMPA). ...

HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2013

International audienc

Reactive & Functional Polymers, Apr 1, 2023

Macromolecular Materials and Engineering, Jan 28, 2015

Poly(ethylene 2,5-furandicarboxylate) (PEF) is a polyester from ethylene glycol and 2,5-Furandica... more Poly(ethylene 2,5-furandicarboxylate) (PEF) is a polyester from ethylene glycol and 2,5-Furandicarboxylic acid which has gained increasing interest due to its excellent properties compared to chemically similar PET. This paper presents an estimation of the crystallization enthalpy, the crystalline and amorphous density and the crystallization kinetics of PEF. Using Avrami and the Hoffman-Lauritzen theory, Hoffman-Lauritzen parameters are proposed that relate crystal growth rate of catalyst-free PEF to temperature and molecular weight. Characteristic is a higher activation energy for chain diffusion (U*) for PEF compared PET, which can be attributed to more restricted chain conformational changes. Finally, the crystallization rate of PEF is shown to be significantly affected by catalyst type.

HAL (Le Centre pour la Communication Scientifique Directe), 2019

Abstract Cardanol is a bio-phenol used in the field of polybenzoxazine (polyBZ) due to its abunda... more Abstract Cardanol is a bio-phenol used in the field of polybenzoxazine (polyBZ) due to its abundance, low cost, effectiveness, and ease of reaction. Its impact on the polymerization kinetic of benzoxazine as well as on the thermal stability has been hereby investigated. To this aim, three di-functional benzoxazine monomers (BZ) are synthesized by bridging with ethylene diamine either two phenols (di-phenol), one phenol and one cardanol (asymmetric card-phenol), or two cardanol moieties (di-cardanol). FT-IR measurements show that the presence of the cardanol aliphatic chain modifies the formation of hydrogen bonding network. These differences are highlighted in the chemorheology of polymerization, where the di-phenol BZ monomer shows an early vitrification explained by the formation of a high degree of H-bonding interactions during curing. An important feature of benzoxazines reactions, highlighted in this study, is that vitrification does not stop the polymerization process. Cardanol long alkyl side chain can cause a plasticizing effect and induces a lower degree of polymerization. This is observed through the decrease of the glass transition temperature (Tg) and the apparition of a β relaxation for cardanol-based polymers. Interestingly, the thermal stability is significantly improved for cardanol-based polyBZ, which can be the result of H-bonds reorganization in the system due to the cardanol aliphatic chains.

Thermochimica Acta, Jun 1, 1992

Abstract Following our research on organic phase-change materials, we tested the different kineti... more Abstract Following our research on organic phase-change materials, we tested the different kinetic methods, described in previously established software, on the solid-plastic transition of pentaerythritol using criteria based on the minimization, of the difference between experimental and calculated thermograms obtained by differential scanning calorimetry. The good modelling of the Achar-Brindley-Sharp method, which does not require long calculation times, led to its selection from other differential methods. The Freeman-Carroll and Ellerstein methods are not appropriate for modelling the transition.

Physical Chemistry Chemical Physics, 2014