In Situ Near-Infrared Spectroscopy for Simultaneous Monitoring of Multiple Process Variables in Emulsion Copolymerization

Reis, Marlon M.; Araújo, Pedro Henrique Hermes de; Sayer, Cláudia; Giudici, Reinaldo

doi:10.1021/ie034277u

Cited by 39 publications

(38 citation statements)

References 24 publications

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“…These observations could be explained by the insight provided by taking a closer look at the bulk absorption coefficient given by (4). Although µ a is free from nonlinear photon pathlength variations, it still has some variation not related to chemical information.…”

Section: Simulationmentioning

confidence: 99%

“…1 The effective solution to this problem is of tremendous practical importance since it is encountered in many areas such as monitoring polymerization [2][3][4][5] and fermentation 6,7 processes and in medical diagnostics 8 . Spectroscopic measurements have the potential for providing such information and would be preferable, because they are fast, cheap, compatible with fibre optics and multifunctional.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Extraction of Chemical Information of Suspensions Using Radiative Transfer Theory to Remove Multiple Scattering Effects: Application to a Model Two-Component System

Steponavičius

Thennadil

2009

Anal. Chem.

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This version is available at https://strathprints.strath.ac.uk/13703/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Extraction of Chemical Information of Suspensions RECEIVED DATE (to be automatically inserted after your manuscript is accepted if requiredaccording to the journal that you are submitting your paper to) ABSTRACTAn approach for removing multiple light scattering effects using the radiative transfer theory (RTE) in order to improve the performance of multivariate calibration models is proposed. This approach is then applied to the problem of building calibration models for predicting the concentration of a scattering (particulate) component. Application of this approach to a simulated four component system showed 1 that it will lead to calibration models which perform appreciably better than when empirically scatter corrected measurements of diffuse transmittance (T d ) or reflectance (R d ) are used. The validity of the method was also tested experimentally using a two-component (Polystyrene-water) system. While the proposed method led to a model that performed better than that built using R d , its performance was worse compared to when T d measurements were used. Analysis indicates that this is because the model built using T d benefits from the strong secondary correlation between particle concentration and pathlength travelled by the photons which occurs due to the system containing only two components.On the other hand, the model arising from the proposed methodology uses essentially only the chemical (polystyrene) signal. Thus this approach can be expected to work better in multi-component systems where the pathlength correlation would not exist.

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Section: Simulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Extraction of Chemical Information of Suspensions Using Radiative Transfer Theory to Remove Multiple Scattering Effects: Application to a Model Two-Component System

Steponavičius

Thennadil

2009

Anal. Chem.

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“…[30,31] The calibration was based on the off-line data of conversion (measured by gravimetry) and average particle size (measured by dynamic light scattering, DLS). For each variable considered, the data are split in two sets.…”

Section: Nir Spectroscopymentioning

confidence: 99%

Miniemulsion Polymerization Monitoring Using Off‐Line Raman Spectroscopy and In‐Line NIR Spectroscopy

Ambrogi

Colmán

Giudici

2016

Macro Reaction Engineering

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by water-borne latex, increasing the importance of conventional emulsion and miniemulsion polymerization.In comparison with conventional emulsion polymerization processes, miniemulsion polymerization presents clear advantages because polymerization takes place inside the monomer droplets, which allows using monomers and other highly hydrophobic components in the formulation. Therefore, these components do not need to diffuse in the aqueous medium as in emulsion polymerization. [1][2][3][4] The miniemulsion polymerization process starts with the preparation of the monomer miniemulsion and, after that, the addition of an initiator starts the polymerization. A standard miniemulsion formulation uses water as continuous phase, monomer as disperse phase, surfactant to stabilize the particles droplets, costabilizer to avoid diffusional degradation (Oswald Ripening), and buffer to stabilize the pH of the medium. [5] Constant particle size, use of costabilizers, use of surfactant below the critical micellar concentration, and inexistence of mass transport through the aqueous phase are Miniemulsion polymerization has been extensively studied in the last decade due to its advantages when compared with conventional emulsion polymerization. In this work, monomer conversion and particle size are monitored during miniemulsion polymerization of styrene using in-line near-infrared (NIR) spectroscopy and at-line Raman spectroscopy. Gravimetric analysis and dynamic light scattering have been used as off-line reference measurements. Good agreement has been found between off-line data and the values predicted by NIR and Raman spectroscopy for conversion. The values of average particle size are well predicted from the NIR spectra with the respective calibration model, but the predictions from Raman spectra present some slight discrepancies for particle size. The results show a decrease of the average particle size during the initial period of the polymerization, indicating the occurrence of nucleation mechanisms other than the classical droplet nucleation. These results indicate that insightful information can be obtained by monitoring miniemulsion polymerizations with the use of spectroscopic techniques.

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“…The results showed that the control of copolymer composition and average molecular weights were achieved simultaneously. The semi-continuous styrene/butyl acrylate emulsion copolymerization reactions were monitored by NIR spectroscopy (Reis et al, 2004). A transflection probe was immersed in the reaction medium.…”

Section: Emulsion Polymerizationmentioning

confidence: 99%

“…Obviously, the prediction of average particle sizes in emulsions systems from NIR spectra is a very controversial issue. Reis et al think that there is a correlation between the average polymer particle size and NIR spectra, but it is not fully understood how the polymer particle size affects NIR spectra (Reis et al, 2004).…”

Section: Emulsion Polymerizationmentioning

confidence: 99%

Process Monitoring of Polymer Systems by using Near-Infrared Spectroscopy

Li¹

2011

Applications and Experiences of Quality Control

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In Situ Near-Infrared Spectroscopy for Simultaneous Monitoring of Multiple Process Variables in Emulsion Copolymerization

Cited by 39 publications

References 24 publications

Extraction of Chemical Information of Suspensions Using Radiative Transfer Theory to Remove Multiple Scattering Effects: Application to a Model Two-Component System

Extraction of Chemical Information of Suspensions Using Radiative Transfer Theory to Remove Multiple Scattering Effects: Application to a Model Two-Component System

Miniemulsion Polymerization Monitoring Using Off‐Line Raman Spectroscopy and In‐Line NIR Spectroscopy

Process Monitoring of Polymer Systems by using Near-Infrared Spectroscopy

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