Publications by authors named "Tijs Nabuurs"

4 Publications

  • Page 1 of 1

Analysis of charged acrylic particles by on-line comprehensive two-dimensional liquid chromatography and automated data-processing.

Anal Chim Acta 2019 Apr 9;1054:184-192. Epub 2019 Jan 9.

University of Amsterdam, van 't Hoff Institute for Molecular Sciences, Analytical-Chemistry Group, Science Park 904, 1098 XH, Amsterdam, the Netherlands.

A thorough understanding of particle formation and polymer growth during emulsion polymerization is indispensable for the development of particles and products with very specific properties. This has created a demand for the detailed characterization of various properties and property distributions - and the relation between these. A method is described that enables comprehensive, simultaneous determination of the size distribution of nanoparticles and the molecular-weight distribution of the constituting polymers as a function of the particle size. The result is a complete two-dimensional distribution that details the interdependence of the two parameters. The approach comprehensively combines hydrodynamic chromatography with size-exclusion chromatography. An automated band-broadening filter has been developed to improve the accuracy of the measured distributions. The algorithm utilizes automated curve-fitting approaches to describe detected particle distributions for each horizontal slice of the 2D-LC chromatogram, and filters band broadening using calibration curves. The method has been applied to samples of complex nanoparticles comprising hydrophobic, hydrophilic and charged moieties, viz. stabilized dispersions of poly[(methyl methacrylate)-co-(butyl acrylate)-co-(methacrylic acid)]-nanoparticles in water. We consistently found that, within a single population of particles, the weight-average molecular weight increases with particle size.
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http://dx.doi.org/10.1016/j.aca.2018.12.059DOI Listing
April 2019

A fluorescence approach to investigate repartitioning of coalescing agents in acrylic polymer emulsions.

Colloid Polym Sci 2012 Apr 27;290(6):541-552. Epub 2011 Dec 27.

Repartitioning of co-solvents between particles of latex emulsions was investigated by means of a fluorescence method based on the detection of the amount of co-solvent via the solvatochromic shift of the emission maximum of a fluorescent probe, copolymerized at a low concentration. Complete repartitioning of co-solvents between particles of latex materials with a low T(g) (ca. 25 °C) occurred within minutes. For a hydrophilic latex with a T(g) of 68 °C, equilibration was achieved within an hour. Repartitioning was faster for more hydrophobic co-solvents. For a hydrophobic latex of similar T(g), co-solvent repartitioning took place on the same time scale, but complete equilibration was not reached. Possibly, there is an additional slow component in the repartitioning, or the prolonged presence of co-solvent causes a structural change in the latex particles that affects the outcome of the experiment.
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http://dx.doi.org/10.1007/s00396-011-2575-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3326236PMC
April 2012

Detection of coalescing agents in water-borne latex emulsions using an environment sensitive fluorescent probe.

Photochem Photobiol Sci 2010 Jul 4;9(7):975-84. Epub 2010 May 4.

Nieuwe Achtergracht 129, 1018, WS, Amsterdam, The Netherlands.

In this paper we report the determination of partitioning of coalescing agents (organic co-solvents) in water-borne latex emulsions by means of a fluorescence method. An environment-sensitive fluorescent probe was copolymerized via emulsion polymerization. The presence of organic co-solvents inside the polymer particles is revealed by the photophysical properties of the probe. In particular, the position of the fluorescence emission maximum of co-polymerized can be used to measure the amount of coalescing agent present in the polymer particles. The spectral shifts are shown to be due to the softening of the matrix, rather than to solvation of the probe by the added co-solvent.
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http://dx.doi.org/10.1039/c0pp00065eDOI Listing
July 2010

Probing of cosolvents in polymer latex materials by using solvatochromic fluorescence.

Ann N Y Acad Sci 2008 ;1130:157-63

Universiteit van Amsterdam, Van 't Hoff Institute for Molecular Sciences, Nieuwe Achtergracht 129, 1018 WS Amsterdam, the Netherlands.

The process of film formation is of great importance for the application of organic coatings. In waterborne coatings, organic cosolvents are still indispensable, but regulations force the industry to reduce their amounts. Here we describe a method that uses the solvatochromic fluorescence of a probe molecule copolymerized in an emulsion polymerization process with different monomers to shed light on the partitioning of cosolvents in polymer latex materials. The formulation of the latex with organic cosolvents that are not very water soluble leads to a quantifiable redshift of the emission of the probe. The transfer of the cosolvent upon mixing of cosolvent-containing and cosolvent-free compartments can also be monitored.
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http://dx.doi.org/10.1196/annals.1430.014DOI Listing
July 2008
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