Abstract:
Dataset supporting the publication "Competitive Adsorption Between PEO-Containing Block Copolymers and Homopolymers at Silica" that appears in Journal of Dispersion Science and Technology 2014, http://dx.doi.org/10.1080/01932691.2014.880847. The ability to manipulate polymer adsorption is useful for applications involving colloidal stabilization, e.g., paints, cosmetics, lubricants, and mineral and waste-water treatment. We have an on-going interest on the use of organic molecules for modulating the aqueous solution and adsorption properties of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers. In the present study, the influence of low molecular weight PEO homopolymer on the adsorption of a representative PEO-PPO-PEO block copolymer (Pluronic P105: EO37-PO56-EO37) at the surface of protonated silica nanoparticles dispersed in water is investigated. Pluronic P105 forms hydrophobic domains on the surface of protonated silica at a critical surface micelle concentration, csmc, of 0.02 wt% in the presence 0.1 wt% silica nanoparticles in water, well below the cmc of Pluronic P105 in water (0.6 wt%). Dye solubilization experiments reveal an increase in the PEO-PPO-PEO block copolymer critical surface micelle concentration with increasing amounts of added PEO homopolymer. The resulting critical displacer concentration, cdc, for PEO homopolymer of molecular weights 200 and 600 Da was measured to be 0.1 wt% and 0.07 wt%, respectively, in the presence of 0.1 wt% silica nanoparticles. Capillary viscometry measurements indicate a decrease in the adsorbed layer thickness at the protonated silica surface with increasing PEO homopolymer concentration. The data presented herein are consistent with a physical model which considers “patches” of PEO-PPO-PEO block copolymer and PEO homopolymer adsorbed at the silica surface.
Purpose:
The adsorption of polymers at particles is of practical importance to numerous industrial and natural settings, including mineral processing, paper-making, and various foodstuffs. The manipulation of adsorption is thus an important undertaking. We have evaluated the use of PEO homopolymers as potential displacer agents which could control interfacial and bulk solution properties of PEO-PPO-PEO block copolymers.
Data Parameters and Units:
Data for Figure 1-- Pyrene fluorescence emmision intensity (I1/I3) ratio vs. Pluronic P105 concentration in the presence of 0 (top panels) and 0.1 wt% (bottom panels) protonated silica nanoparticles and varying amounts of PEO homopolymer: PEO 200 (left column); PEO 600 (right column). Pyrene Fluorescence spectra for Pluronic P105 in water: [0 wt%, 0.01 wt%, 0.1 wt%, 0.1 wt%, 0] silica nanoparticles, [none, 0.005 wt%,0.01wt%, 0.05 wt%, 0.1 wt%, 1.0 wt%] PEO [200, 600] homopolymer at pH = 3, [0 wt%, 0.005 wt%, 0.01 wt%, 0.05 wt%, 0.08 wt%, 0.1 wt%, 0.3 wt%, 05. wt%, 0.8 wt%, 1.0 wt%, 5.0 wt%, 10.0 wt%] Pluronic P105, wavelength (nm), Intensity. Data for Figure 3-- Adsorbed layer thickness observed for Pluronic P105-stabilized silica dispersions in the presence of PEO 200 or PEO 600, plotted versus the logarithm of added PEO homopolymer concentration (wt%). Adsorbed Layer thicknesses are calculated from the slope relative viscosity versus nanoparticle volume fraction: Kinematic Viscosity of Aqueous Dispersion of 10.6 nm silica nanoparticle (SM) in the presence of 2.0 wt% Pluronic P105 and [0 wt%, 0.002 wt%, 0.01 wt%, 1.0 wt%, 5 wt%] PEO [600, 200] at 20 oC and pH ~ 3, Sample number, SM NP concentration (wt%), NP (g), Total (g), SM-30 Dispersion required (g), P105 required (g), Water required (g), P105 added (g), SM-30 added (g), Water added (g), Total actual (g), Pluronic Concentration actual (wtT), NP Concentration actual (wt%), Nanoparticle Volume Fraction, Bath Temperature (degrees Celsius), Beaker Temperature (degrees Celsius), Viscometer Size/ID, Viscometer Constant, Efflux time-Trial 1 (seconds), Efflux time-Trial 2 (seconds), Average efflux time (seconds), Kinematic Viscosity (cst), Relative viscosity.
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