Related Experiment Video
Updated: Jul 28, 2026

Diffuse Reflectance Infrared Spectroscopic Identification of Dispersant/Particle Bonding Mechanisms in Functional Inks
Published on: May 8, 2015
Removal of solvent effect from Raman and NIR spectra for real-time monitoring of dissolved polypropylene content
Sofiane Ferchichi1, Nida Sheibat-Othman2, Maud Rey-Bayle3
1IFP Energies Nouvelles, Rond-Point de l'échangeur de Solaize, Solaize, 69360, France; Universite Claude Bernard Lyon 1, LAGEPP, UMR 5007 CNRS, Villeurbanne, 69622, France; Universite Claude Bernard Lyon 1, CP2M, UMR 5128, CNRS, Villeurbanne, 69616, France.
Abstract:
A methodology is developed for real-time monitoring the dissolved polypropylene concentration during the polypropylene dissolution recycling process across several solvents. The selection of the most appropriate solvents is based on the thermodynamic dissolution properties of polypropylene and the solvents. In-situ Raman and near infrared (NIR) spectroscopy are employed for in-situ monitoring. First, partial least square (PLS) regression is used to develop several single-solvent models to predict the dissolved polymer concentration in the solvent. Then, based on the same data, a generalized multi-solvent model is developed to operate across several predefined solvents, mixture of solvents or new comparable solvents. To do so, an external parameter orthogonalization (EPO) approach is employed to eliminate the influence of the solvent on the spectra. The method allows to monitor in-situ the concentration of polypropylene dissolved in several types of solvents, not used during the model development.
More Related Videos
Related Concept Videos
¹H NMR Signal Integration: Overview
High-Performance Liquid Chromatography: Types of Detectors
Raman Spectroscopy Instrumentation: Overview
The monochromatic laser source, typically using visible or near-infrared radiation, generates a highly focused beam of light. This light interacts with the molecules of the sample, scattering some of the light. Liquid and gaseous samples are usually tested in ordinary glass capillaries, while solids can be analyzed as powders packed in capillaries or as potassium...

