Analysis of Flocculated Latex Particles using Multi-Detector Hydrodynamic Chromatography Amandaa K. Brewer ARKEMA Inc., Analytical and Systems Research, King of Prussia, PA, USA Latex Particles Colloids or polymers with a molar mass > 106 g/mol. Particle size and shape play a role in: − Development of new materials − Shelf-life of materials − Control of material processing − Quality control of colloids − End-use properties Provder, T.; Texter, J., Eds. Particle Sizing and Characterization; ACS Symposium Series 881; American Chemical Society: Washington, DC, 2004. 2 | Latex Particles Colloids or polymers with a molar mass > 106 g/mol. Particle size and shape play a role in: − Development of new materials − Shelf-life of materials − Control of material processing − Quality control of colloids − End-use properties Methodology − Sieving − Sedimentation − Microscopy − Laser Diffraction Limitations − Cost, speed, complexity, accuracy, resolution, etc. Provder, T.; Texter, J., Eds. Particle Sizing and Characterization; ACS Symposium Series 881; American Chemical Society: Washington, DC, 2004. 3 | Flocculated Latex Particles System of interests: • A fluoropolymer/acrylic hybrid latex particle with surfactant package Properties of interest: • Particle size/particle size distribution is speculated to effect the end-use properties of the latex such as thickening response. • Morphology of the fluoropolymer/acrylic hybrid latex particle may influence the end-use properties of the particle. • Effects of pH and heat aging on the particle size/shape and their distributions (latex flocculation). • Shelf-life of the fluoropolymer/acrylic hybrid latex particle (time frame for flocculation.) 4 | Hydrodynamic Chromatography • A solution-based separation method • Open tube • Packed (Non-porous beads) • Separation is due to parabolic (Poiseuille) flow profile in an open tube channel. 5 | Hydrodynamic Chromatography • Analytes are sampled in a size-dependent manner 6 | Hydrodynamic Chromatography • Analytes are sampled in a size-dependent manner • Small particles sample region close to the walls, where the flow is stagnant • Large particles remain nearer to center where the flow is faster 7 | Multi-Detector Hydrodynamic Chromatography Multi-Angle Light Scattering (MALS) HDC Columns 8 | Multi-Detector Hydrodynamic Chromatography Multi-Angle Light Scattering (MALS) HDC Columns Quasi-Elastic Light Scattering (QELS) 9 | Multi-Detector Hydrodynamic Chromatography Multi-Angle Light Scattering (MALS) HDC Columns Quasi-Elastic Light Scattering (QELS) Differential Refractometry (DRI) 10 | Multi-Detector Hydrodynamic Chromatography Multi-Angle Light Scattering (MALS) MALS RG QELS RH DRI + MALS M HDC Columns Quasi-Elastic Light Scattering (QELS) Differential Refractometry (DRI) 11 | Non-Flocculated Latex Particle 9 9 9 Polymer Mn (× 10 g/mol) Mw (× 10 g/mol) Mz (× 10 g/mol) Mw/Mn Original Fluoropolymer/Acrylic Particle 1.74 ± 0.20 2.10 ± 0.32 3.03 ± 0.26 1.16 ± 0.1 12 | Non-Flocculated Latex Particle 9 9 9 Polymer Mn (× 10 g/mol) Mw (× 10 g/mol) Mz (× 10 g/mol) Mw/Mn Original Fluoropolymer/Acrylic Particle 1.74 ± 0.20 2.10 ± 0.32 3.03 ± 0.26 1.16 ± 0.1 Original Fluoropolymer/Acrylic Particle 1.0 1010 0.5 SLS (V) o 90 Molar Mass (g/mol)Molar Mass 109 0.0 11.5 12.0 12.5 13.0 13.5 13 | Retention time (minutes) Polymeric Radii MALS RG Root mean square distance of an array of atoms from their common center of mass n = number of bond in polymer backbone ri = location of an individual atom or group of atoms Rcm=the location of the center of mass 14 | Non-Flocculated Latex Particle Polymer RG,n (nm) RG,w (nm) RG,z (nm) Original Fluoropolymer/Acrylic Particle 82 ± 1 95 ± 1 127 ± 1 15 | Non-Flocculated Latex Particle Polymer RG,n (nm) RG,w (nm) RG,z (nm) Original Fluoropolymer/Acrylic Particle 82 ± 1 95 ± 1 127 ± 1 Original Fluoropolymer/Acrylic Particle 200 1.0 150 0.5 SLS (V) o 100 90 Radius (nm) 50 0.0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 16 | Polymeric Radii R MALS RG QELS H Root mean square distance of an array Radius of an equivalent hard sphere of atoms from their common center of that has the same translational mass diffusion coefficient (DT) as a macromolecule. n = number of bond in polymer backbone kB = Boltzman’s Constant ri = location of an individual atom or group of atoms ηs = Viscosity of the solvent Rcm=the location of the center of mass DT=Translational Diffusion Coefficient 17 | Non-Flocculated Latex Particle Polymer RG,n (nm) RG,w (nm) RG,z (nm) RH,n (nm) RH,w (nm) RH,z (nm) Original Fluoropolymer/Acrylic Particle 82 ± 1 95 ± 1 127 ± 1 22 ± 1 22 ± 1 23 ± 1 18 | Non-Flocculated Latex Particle Polymer RG,n (nm) RG,w (nm) RG,z (nm) RH,n (nm) RH,w (nm) RH,z (nm) Original Fluoropolymer/Acrylic Particle 82 ± 1 95 ± 1 127 ± 1 22 ± 1 22 ± 1 23 ± 1 Original Fluoropolymer/Acrylic Particle 50 1.0 45 40 35 30 0.5 25 SLS (V) o 20 Radius (nm) 90 15 10 5 0.0 0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 19 | Non-Flocculated Latex Particle Particle Morphology MALS/QELS: ρ ≡ RG,z / RH,z 20 | Non-Flocculated Latex Particle Particle Morphology MALS/QELS: ρ ≡ RG,z / RH,z ρ Structure 1.36-2.24 Prolate Ellipsoid 2.0-3.5 Non-overlapping particles 21 | Non-Flocculated Latex Particle Particle Morphology MALS/QELS: ρ ≡ R / R Original Fluoropolymer/Acrylic Polymer G,z H,z 10 1.0 ρ Structure 8 1.36-2.24 Prolate Ellipsoid 6 0.5 ρ ~2.7-4.0 Sample SLS (V) ~ 4 o 4 90 2.0-3.5 Non-overlapping particles ~ 2.7 2 0.0 0 11.0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 22 | Heat-Aging Latex Particles Original Particle 1.0 0.5 SLS (V) o 90 0.0 12.0 12.5 13.0 Retention time (minutes) 23 | Heat-Aging Latex Particles Original Particle o Original Particle Heat Aged at 40 C 1.0 0.5 SLS (V) o 90 0.0 12.0 12.5 13.0 Retention time (minutes) 24 | Heat-Aging Latex Particles Original Particle o Original Particle Heat Aged at 40 C o Original Particle Heat Aged at 50 C 1.0 0.5 SLS (V) o 90 0.0 12.0 12.5 13.0 Retention time (minutes) 25 | Heat-Aging Latex Particles Original Particle o Original Particle Heat Aged at 40 C o Original Particle Heat Aged at 50 C 300 1.0 250 200 0.5 150 SLS (V) o 90 100 50 0.0 0 12.0 12.5 13.0 Retention time (minutes) 26 | pH Manipulated Latex Particles pH 8 1.0 0.5 S S ( ) 90 0.0 12.0 12.5 13.0 Retention time (minutes) 27 | pH Manipulated Latex Particles pH 8 pH 7.5 1.0 pH 7 0.5 ( ) 0.0 12.0 12.5 13.0 Retention time (minutes) 28 | pH Manipulated Latex Particles Polymer RG,n (nm) RG,w (nm) RG,z (nm) RH,n (nm) RH,w (nm) RH,z (nm) pH 8 84 ± 1 96 ± 1 128 ± 1 25 ± 1 26 ± 1 29 ± 1 pH 7.5 88 ± 1 109 ± 1 170 ± 1 26 ± 1 27 ± 1 30 ± 1 pH 7 71 ± 1 71± 1 76 ± 1 25 ± 1 25 ± 1 26 ± 1 pH 8 pH 7.5 1.0 pH 7 0.5 SLS (V) o 90 0.0 12.0 12.5 13.0 Retention time (minutes) 29 | pH Manipulated Latex Particles Polymer RG,n (nm) RG,w (nm) RG,z (nm) RH,n (nm) RH,w (nm) RH,z (nm) pH 8 84 ± 1 96 ± 1 128 ± 1 25 ± 1 26 ± 1 29 ± 1 pH 7.5 88 ± 1 109 ± 1 170 ± 1 26 ± 1 27 ± 1 30 ± 1 pH 7 71 ± 1 71± 1 76 ± 1 25 ± 1 25 ± 1 26 ± 1 pH 8 pH 7.5 1.0 pH 7 0.5 SLS (V) o 90 0.0 12.0 12.5 13.0 Retention time (minutes) 30 | HDC pH Results compared to Microscopy AFM and HDC both show that the particles at pH=7 are more monodisperse and uniform than those at the other pHs. pH = 7 pH = 7.5 pH appears to play a role in particle flocculation of the fluoropolymer/acrylic hybrid particle pH = 8 31 | Time Aged Latex Particles Original Particle 1.0 0.5 SLS (V) o 90 0.0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 32 | Time Aged Latex Particles Original Particle 1.0 2 month old original particle 0.5 SLS (V) o 90 0.0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 33 | Time Aged Latex Particles Flocculation Original Particle 1.0 2 month old original particle Size 5 month old original particle 0.5 SLS (V) o 90 0.0 11.5 12.0 12.5 13.0 13.5 Retention time (minutes) 34 | HDC Time Aged Results Compared to Rheology Original Particle A decrease in viscosity 100 1 month old original particle was observed by 5 month old original particle rheology as the fluoropolymer/acrylic latex particle ages was, indicating an increase in flocculation. Both HDC and rheology show an increase in Viscosity (poise) -1 flocculated particles as 10 the fluoropolymer/acrylic particle ages. 10-1 100 101 102 103 104 Shear rate (1/s) 35 | Conclusions Multi-detector hydrodynamic chromatography (HDC) was successfully used to analyze the particle size, shape, and their distributions of a fluoropolymer/acrylic hybrid latex particle. HDC provided a tool for monitoring the flocculation of a fluoropolymer/acrylic hybrid latex particle as a function of pH, heat aging and time aging.