Documents disponibles écrits par cet auteur

Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner / Jeroen Cornel in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10740–10745 Titre : Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner Type de document : texte imprimé Auteurs : Jeroen Cornel, Auteur ; Mazzotti, Marco, Auteur Année de publication : 2010 Article en page(s) : pp. 10740–10745 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Estimating--Crystal--Growth--Rates--Using--situ  ATR-FTIR--Raman--Spectroscopy--  Calibration-Free  Manner Résumé : Seeded batch desupersaturation experiments of paracetamol in water were monitored using in situ ATR-FTIR and in situ Raman spectroscopy. On the basis of the linear relationship between the measured signal and the concentrations of the involved components, in situ ATR-FTIR and Raman spectroscopy could be used quantitatively in a calibration-free manner to estimate the crystal growth rate of paracetamol. Using a population balance model and a nonlinear least-squares optimization routine, it was shown that by fitting the measured time-resolved ATR-FTIR spectra directly and by fitting the desupersaturation profiles obtained from these spectra combined with a previously developed calibration model, essentially the same growth rate parameters can be estimated. Very similar growth rate parameters could be obtained by fitting the measured time-resolved Raman spectra using the same population balance model. These results show that crystal growth rates can be estimated in a calibration-free manner using both in situ spectroscopic techniques, thereby avoiding lengthy calibration procedures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008138 [article] Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner [texte imprimé] / Jeroen Cornel, Auteur ; Mazzotti, Marco, Auteur . - 2010 . - pp. 10740–10745. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10740–10745 Mots-clés : Estimating--Crystal--Growth--Rates--Using--situ  ATR-FTIR--Raman--Spectroscopy--  Calibration-Free  Manner Résumé : Seeded batch desupersaturation experiments of paracetamol in water were monitored using in situ ATR-FTIR and in situ Raman spectroscopy. On the basis of the linear relationship between the measured signal and the concentrations of the involved components, in situ ATR-FTIR and Raman spectroscopy could be used quantitatively in a calibration-free manner to estimate the crystal growth rate of paracetamol. Using a population balance model and a nonlinear least-squares optimization routine, it was shown that by fitting the measured time-resolved ATR-FTIR spectra directly and by fitting the desupersaturation profiles obtained from these spectra combined with a previously developed calibration model, essentially the same growth rate parameters can be estimated. Very similar growth rate parameters could be obtained by fitting the measured time-resolved Raman spectra using the same population balance model. These results show that crystal growth rates can be estimated in a calibration-free manner using both in situ spectroscopic techniques, thereby avoiding lengthy calibration procedures. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008138

Nonclassical composition fronts in nonlinear chromatography / Mazzotti, Marco in Industrial & engineering chemistry research, Vol. 48 N° 16 (Août 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7733–7752 Titre : Nonclassical composition fronts in nonlinear chromatography : delta-shock Type de document : texte imprimé Auteurs : Mazzotti, Marco, Auteur Année de publication : 2009 Article en page(s) : pp. 7733–7752 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Nonlinear  chromatography  Binary  systems Résumé : The local equilibrium theory of chromatography is applied to study binary systems subject to the mixed generalized Langmuir isotherm, ni = Hici/(1 − K1c1 + K2c2) (i = 1, 2), where components 1 and 2 are anti-Langmuir-like and Langmuir-like, respectively. Riemann problems, where a stream of a given composition is fed to a column initially saturated at a different composition, are analyzed. Within the hyperbolic region of the hodograph plane close to the origin, it is shown that such Riemann problems admit not only classical solutions, consisting of constant states separated by simple wave and shock wave transitions, but also nonclassical solutions, namely including a continuous nonsimple wave transition and a delta-shock. The latter can be viewed as a traveling spike of growing strength superimposed to the discontinuity separating the initial and the feed states. Exact conditions for the occurrence of classical and nonclassical solutions are derived. Thus, this work adds two new types of composition fronts to the classical ones already known in nonlinear chromatography. In the case of the delta-shock, the most striking new transition, it is possible to derive exact relationships for its properties, including the slope of its image in the physical plane, i.e. the reciprocal of its propagation speed, dt/dz = {1/W}{1 + ν((H1K2[n2] − H2K1[n1])/(H1K2[c2] − H2K1[c2]))}, where the symbol [·] denotes the jump across the discontinuity of the quantity enclosed. These analytical expressions match the results obtained through numerical simulations. The physical legitimacy of the model considered in this work is demonstrated theoretically and is further supported by the experimental evidence of the existence of delta-shocks that has been recently provided [Mazzotti et al. J. Chromatogr., submitted]. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9001537 [article] Nonclassical composition fronts in nonlinear chromatography : delta-shock [texte imprimé] / Mazzotti, Marco, Auteur . - 2009 . - pp. 7733–7752. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 16 (Août 2009) . - pp. 7733–7752 Mots-clés : Nonlinear  chromatography  Binary  systems Résumé : The local equilibrium theory of chromatography is applied to study binary systems subject to the mixed generalized Langmuir isotherm, ni = Hici/(1 − K1c1 + K2c2) (i = 1, 2), where components 1 and 2 are anti-Langmuir-like and Langmuir-like, respectively. Riemann problems, where a stream of a given composition is fed to a column initially saturated at a different composition, are analyzed. Within the hyperbolic region of the hodograph plane close to the origin, it is shown that such Riemann problems admit not only classical solutions, consisting of constant states separated by simple wave and shock wave transitions, but also nonclassical solutions, namely including a continuous nonsimple wave transition and a delta-shock. The latter can be viewed as a traveling spike of growing strength superimposed to the discontinuity separating the initial and the feed states. Exact conditions for the occurrence of classical and nonclassical solutions are derived. Thus, this work adds two new types of composition fronts to the classical ones already known in nonlinear chromatography. In the case of the delta-shock, the most striking new transition, it is possible to derive exact relationships for its properties, including the slope of its image in the physical plane, i.e. the reciprocal of its propagation speed, dt/dz = {1/W}{1 + ν((H1K2[n2] − H2K1[n1])/(H1K2[c2] − H2K1[c2]))}, where the symbol [·] denotes the jump across the discontinuity of the quantity enclosed. These analytical expressions match the results obtained through numerical simulations. The physical legitimacy of the model considered in this work is demonstrated theoretically and is further supported by the experimental evidence of the existence of delta-shocks that has been recently provided [Mazzotti et al. J. Chromatogr., submitted]. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9001537

Precipitation and transformation of the three polymorphs of d-mannitol / Jeroen Cornel in Industrial & engineering chemistry research, Vol. 49 N° 12 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5854–5862 Titre : Precipitation and transformation of the three polymorphs of d-mannitol Type de document : texte imprimé Auteurs : Jeroen Cornel, Auteur ; Piran Kidambi, Auteur ; Mazzotti, Marco, Auteur Année de publication : 2010 Article en page(s) : pp. 5854–5862 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : d-mannitol’s  three  polymorphs  Thermodynamic  aspects  kinetic  aspects  Solid-state  forms Résumé : In this work, the thermodynamic and kinetic aspects of d-mannitol’s three polymorphs and their transformations are addressed. Scalable and reproducible syntheses of the solid-state forms are presented, and a mathematical model to describe a three-polymorph transformation is discussed in detail. It is shown that, for certain initial solute concentrations, the α polymorph nucleates first and then transforms through the β form to the γ form. Moreover, a supersaturation threshold to nucleate the α form has been observed, and below this threshold value, the γ form nucleates. A theoretical analysis demonstrates that this behavior can be predicted and that this experimental observation is physically sound. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019616 [article] Precipitation and transformation of the three polymorphs of d-mannitol [texte imprimé] / Jeroen Cornel, Auteur ; Piran Kidambi, Auteur ; Mazzotti, Marco, Auteur . - 2010 . - pp. 5854–5862. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5854–5862 Mots-clés : d-mannitol’s  three  polymorphs  Thermodynamic  aspects  kinetic  aspects  Solid-state  forms Résumé : In this work, the thermodynamic and kinetic aspects of d-mannitol’s three polymorphs and their transformations are addressed. Scalable and reproducible syntheses of the solid-state forms are presented, and a mathematical model to describe a three-polymorph transformation is discussed in detail. It is shown that, for certain initial solute concentrations, the α polymorph nucleates first and then transforms through the β form to the γ form. Moreover, a supersaturation threshold to nucleate the α form has been observed, and below this threshold value, the γ form nucleates. A theoretical analysis demonstrates that this behavior can be predicted and that this experimental observation is physically sound. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9019616

Quantitative application of in situ ATR-FTIR and Raman spectroscopy in crystallization processes / Jeroen Cornel in Industrial & engineering chemistry research, Vol. 47 n°14 (Juillet 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4870–4882 Titre : Quantitative application of in situ ATR-FTIR and Raman spectroscopy in crystallization processes Type de document : texte imprimé Auteurs : Jeroen Cornel, Auteur ; Christian Lindenberg, Auteur ; Mazzotti, Marco, Auteur Année de publication : 2008 Article en page(s) : p. 4870–4882 Langues : Anglais (eng) Mots-clés : Fourier  transform  infrared;  Raman  spectroscopy;  Crystallization  processe Résumé : In this work, different process analytical technologies based on vibrational spectroscopy, i.e., attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectroscopy, were applied by means of multivariate data analysis techniques. Wide applicability has been demonstrated by in situ monitoring of various crystallization processes, e.g., solubility curve measurement, cooling crystallization, and solvent-mediated polymorph transformation. A calibration strategy has been proposed to obtain accurate and robust estimations of the solute concentration by ATR-FTIR monitoring. Different calibration models and preprocessing techniques were applied and compared. It was shown that these methods allow for solute concentration monitoring of nonisothermal processes even for sparingly soluble substances such as l-glutamic acid in an aqueous environment. An extensive study has been performed to identify the underlying process parameters that influence the Raman signal, i.e., solid composition, solute concentration, suspension density, particle size and shape, and temperature. It is demonstrated that principal component analysis provides qualitative information for seeded and unseeded polymorphic transformations and enables end-point determination of a solid-state transformation process using l-glutamic acid. The multivariate calibration approach described in this work allows for quantitative application of Raman spectroscopy to a multiphase multicomponent dynamic process such as a solvent-mediated polymorphic transformation. Additionally, it was shown that multivariate analysis of Raman data allows for solute concentration estimation despite the fact that solute signals are weak and completely overlapping with signals related to the solid phase. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800236v [article] Quantitative application of in situ ATR-FTIR and Raman spectroscopy in crystallization processes [texte imprimé] / Jeroen Cornel, Auteur ; Christian Lindenberg, Auteur ; Mazzotti, Marco, Auteur . - 2008 . - p. 4870–4882. Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°14 (Juillet 2008) . - p. 4870–4882 Mots-clés : Fourier  transform  infrared;  Raman  spectroscopy;  Crystallization  processe Résumé : In this work, different process analytical technologies based on vibrational spectroscopy, i.e., attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectroscopy, were applied by means of multivariate data analysis techniques. Wide applicability has been demonstrated by in situ monitoring of various crystallization processes, e.g., solubility curve measurement, cooling crystallization, and solvent-mediated polymorph transformation. A calibration strategy has been proposed to obtain accurate and robust estimations of the solute concentration by ATR-FTIR monitoring. Different calibration models and preprocessing techniques were applied and compared. It was shown that these methods allow for solute concentration monitoring of nonisothermal processes even for sparingly soluble substances such as l-glutamic acid in an aqueous environment. An extensive study has been performed to identify the underlying process parameters that influence the Raman signal, i.e., solid composition, solute concentration, suspension density, particle size and shape, and temperature. It is demonstrated that principal component analysis provides qualitative information for seeded and unseeded polymorphic transformations and enables end-point determination of a solid-state transformation process using l-glutamic acid. The multivariate calibration approach described in this work allows for quantitative application of Raman spectroscopy to a multiphase multicomponent dynamic process such as a solvent-mediated polymorphic transformation. Additionally, it was shown that multivariate analysis of Raman data allows for solute concentration estimation despite the fact that solute signals are weak and completely overlapping with signals related to the solid phase. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800236v

Shortcut Experimental Method for Designing Chiral SMB Separations / Miglioritini, Cristiano in Aiche journal, Vol. 48 N°1 (Janvier 2002) 

Public ISBD [article]  in Aiche journal > Vol. 48 N°1 (Janvier 2002) . - 69-77 p. Titre : Shortcut Experimental Method for Designing Chiral SMB Separations Titre original : Méthode Expérimentale de Raccourci pour Concevoir des Séparations Chirales de SMB Type de document : texte imprimé Auteurs : Miglioritini, Cristiano, Auteur ; Mazzotti, Marco, Auteur ; Zenoni, Giammarco ; Massimo Morbidelli Article en page(s) : 69-77 p. Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Séparation  Chromatographie  mobile  Ethanol  Micro-cristalline  Triacétate  Colonne  Prévision  Transfert  de  masse  SMB  Méthode  de  racourci Index. décimale : 660.627.3 Résumé : The simulated moving-bed (SMB) chromatographic separation of the Tröger's base enantiomers with ethanol as eluent on microcrystalline triacetate cellulose was studied. An experimental technique to design nonlinear SMB separations with few column experiments is presented. This shortcut technique allows the rigorous solution of the Equilibrium Theory model to be approximated without knowing the adsorption equilibria, and therefore can be useful in developing new separations. The predictions of the shortcut method are compared with the experimental results of the SMB separation. The effect of the feed concentration and of the nonideal contributions, such as mass-transfer resistance and extracolumn band broadening, are elucidated. La séparation chromatographique mobile simulée du lit (SMB) des énantiomères bas du Tröger avec de l'éthanol comme éluant sur la cellulose micro-cristalline de triacétate a été étudiée. Une technique expérimentale pour concevoir des séparations non linéaires de SMB avec peu d'expériences de colonne est présentée. Cette technique de raccourci permet à la solution rigoureuse du modèle de théorie d'équilibre d'être rapprochée sans savoir les équilibres d'adsorption, et peut donc être utile en développant de nouvelles séparations. Les prévisions de la méthode de raccourci sont comparées aux résultats expérimentaux de la séparation de SMB. L'effet de la concentration en alimentation et des contributions non idéales, telles que la résistance de transfert de masse et la bande supplémentaire de colonne élargissant, sont élucidés. DEWEY : 660.627.3 ISSN : 0001-1541 En ligne : www.aiche.org [article] Shortcut Experimental Method for Designing Chiral SMB Separations = Méthode Expérimentale de Raccourci pour Concevoir des Séparations Chirales de SMB [texte imprimé] / Miglioritini, Cristiano, Auteur ; Mazzotti, Marco, Auteur ; Zenoni, Giammarco ; Massimo Morbidelli . - 69-77 p. Génie Chimique Langues : Anglais (eng) in Aiche journal > Vol. 48 N°1 (Janvier 2002) . - 69-77 p. Mots-clés : Séparation  Chromatographie  mobile  Ethanol  Micro-cristalline  Triacétate  Colonne  Prévision  Transfert  de  masse  SMB  Méthode  de  racourci Index. décimale : 660.627.3 Résumé : The simulated moving-bed (SMB) chromatographic separation of the Tröger's base enantiomers with ethanol as eluent on microcrystalline triacetate cellulose was studied. An experimental technique to design nonlinear SMB separations with few column experiments is presented. This shortcut technique allows the rigorous solution of the Equilibrium Theory model to be approximated without knowing the adsorption equilibria, and therefore can be useful in developing new separations. The predictions of the shortcut method are compared with the experimental results of the SMB separation. The effect of the feed concentration and of the nonideal contributions, such as mass-transfer resistance and extracolumn band broadening, are elucidated. La séparation chromatographique mobile simulée du lit (SMB) des énantiomères bas du Tröger avec de l'éthanol comme éluant sur la cellulose micro-cristalline de triacétate a été étudiée. Une technique expérimentale pour concevoir des séparations non linéaires de SMB avec peu d'expériences de colonne est présentée. Cette technique de raccourci permet à la solution rigoureuse du modèle de théorie d'équilibre d'être rapprochée sans savoir les équilibres d'adsorption, et peut donc être utile en développant de nouvelles séparations. Les prévisions de la méthode de raccourci sont comparées aux résultats expérimentaux de la séparation de SMB. L'effet de la concentration en alimentation et des contributions non idéales, telles que la résistance de transfert de masse et la bande supplémentaire de colonne élargissant, sont élucidés. DEWEY : 660.627.3 ISSN : 0001-1541 En ligne : www.aiche.org