Development of pH- and temperature-sensitive microgel particles: synthesis monitoring, characterisation and application as potential oral carriers.

Souza, E. F.

doi:10.11606/t.3.2019.tde-18072019-075603

Cited by 1 publication

(11 citation statements)

References 58 publications

(80 reference statements)

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“…35 A recent study from our group on the monitoring of acetic anhydride hydrolysis 30 needed no NIR spectra pretreatments; on the other hand, more complexes systems, such as miniemulsion and emulsion polymerization, required preprocessing. [4][5][6][7][8]12,14,16,17 ■ CONCLUSIONS NIR spectroscopy is an efficient method to monitor the chemical and physical properties of processes. Calibration models can be constructed to monitor properties with fast dynamics and be extended to monitor other systems with fast kinetics.…”

Section: Industrial and Engineeringmentioning

confidence: 99%

“…High energy transitions, such as overtones, are less likely to occur, resulting in low intensity signals . Despite the low resolution and weak signal intensity, NIR spectroscopy can be combined with fiber optic coupled with immersion probes to monitor chemical processes, such as polymerization reactions. − …”

Section: Introductionmentioning

confidence: 99%

“…Thus, NIR chemometric models require a multivariate calibration. The statistical technique most applied to spectra data treatment is partial least squares (PLS). − ,− ,, In order to construct a calibration model, a training set with known concentration (or conversion, diameter, or any property of interest) is necessary. This property should be analyzed using well-established analytical methods.…”

Section: Introductionmentioning

confidence: 99%

“…Santos et al made an extensive review of the monitoring and control of polymerization reactors by NIR spectroscopy. Both homogeneous , (bulk and solution) and heterogeneous − (suspension, emulsion, miniemulsion, and precipitation) polymerization systems were monitored.…”

Section: Introductionmentioning

confidence: 99%

“…The most common absorption bands in the NIR spectral region to predict polymer conversion of polymerization reactions are between 6200 and 5700 cm –1 , − ,− corresponding to the C–H stretch absorption bands of terminal double bonds present in the residual monomer. Despite the band selection methods available in the literature, the visual band selection method has been the most applied one.…”

Section: Introductionmentioning

confidence: 99%

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Stabilizer-Free Dispersion Copolymerization Monitoring by In-Line NIR Spectroscopy

Giudici

2020

Ind. Eng. Chem. Res.

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Stabilizer-free dispersion copolymerization is a one-step technique to produce uniform polymer particles. Due to its fast kinetics and nucleation, assessing polymer conversion and particle size via off-line sampling can be a challenge. In addition, off-line analyses, e.g., gravimetry and dynamic light scattering, are time-consuming and can be sample-dependent. Near-infrared (NIR) spectroscopy is a fast and non-destructive technique to monitor polymerization reactions in-line. Stabilizer-free dispersion copolymerization between styrene and maleic anhydride was carried out via free-radical polymerization using isobutyl acetate and isopentyl acetate as solvents. Spectra data were collected in parallel with off-line analysis. Multivariate partial least squares calibration models were constructed to predict global conversion and particle size over time. The external validation shows good agreement between the models and experimental data. NIR can be extended to monitor systems with fast kinetics and to avoid destructive and time-consuming analytical methods.

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