Effect of Surface Segregation of Ionic End Groups on Polystyrene Latex Early-Time Interdiffusion

Kim, S. D.; Boczar, E M.; Klein, A.; Sperling, L. H.

doi:10.1021/la990709n

Cited by 7 publications

(8 citation statements)

References 31 publications

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“…Diffusion Model for Polystyrene with Ionic Groups at Interfaces. The model below is designed to answer two questions: (1) why the present SANS results show lower D for one sulfonate end while the previous DET study 43 shows higher D for one sulfate end; (2) why the D values of one sulfonate end and two sulfonate end are similar while the D of H ends is much higher than those with sulfonate ends.…”

Section: Discussionmentioning

confidence: 87%

“…DET Experiments. Since a previous study by DET experiments 43 shows that polystyrene of M n ) 100 000 with H ends has a lower diffusion coefficient than polystyrene with one sulfate end group, a comparison between DET and SANS was performed. The purpose of the DET experiment in this study was to compare SANS and DET to ensure that neither method produces instrumental artifacts.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, the discrepancy of the previous study by DET and the present SANS study should originate from factors other than the instrumental artifacts. Possible sources of the discrepancy are the difference in the nature of end groups (sulfonate vs sulfate), 43 the molecular weight or its polydispersity, and/or the aggregate structure described in the next section.…”

Section: Resultsmentioning

confidence: 99%

“…The diffusion process starting at the polymer latex interface may be controlled by two opposing factors, namely surface segregation of end groups and aggregation of the end groups. The surface segregation of end groups increases the initial diffusion coefficient of a polymer chain 43 while the aggregation of end groups decreases it. The ionic end groups are preferentially located at the latex surface in the dispersion and surface segregation of end groups probably continues to exist in the film at the outset of interdiffusion.…”

Section: Discussionmentioning

confidence: 99%

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SANS Study of Sulfonate End Group Effect on Polystyrene Self-Diffusion

et al. 2000

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Film formation from a latex involves interdiffusion of polymer chains. The interdiffusion behavior of polystyrene with H ends, one sulfonate end, and two sulfonate ends are compared via smallangle neutron scattering (SANS) and a direct nonradiative energy transfer technique (DET) at short times. High molecular weight (M n = 300 000) anionically synthesized polystyrenes were confined in latex particles utilizing an artificial miniemulsification technique. Interdiffusion of the polystyrenes in a latex film was carried out at temperatures of 125-145 °C. The diffusion coefficients of polystyrene with H ends were five times and 10 times higher than that of polystyrene with one sulfonate end and two sulfonate ends, respectively. The probable cause is end-to-end aggregation of the chains, supported by the ratio R g/M 1/2 remaining substantially constant.

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Section: Discussionmentioning

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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SANS Study of Sulfonate End Group Effect on Polystyrene Self-Diffusion

et al. 2000

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“…1a) [16][17][18]. Styrene monomer (20 g), divinyl benzene as a cross-linker, surfactant sodium dodecyl sulfate (360 mg) and sodium tetraborate (0.85%, w/v) as a pH controller were added to 250 mL of distilled water in a 500 mL three-necked round-bottom flask that was heated to 70 • C. The pH of the solution was controlled by sodium tetraborate (Na 2 B 4 O 7 ) to maintain a basic condition.…”

Section: Preparation Of Polystyrene Nanoparticlesmentioning

confidence: 99%

ZnO nanosphere fabrication using the functionalized polystyrene nanoparticles for dye-sensitized solar cells

Jung

Yun

Kim

et al. 2010

Electrochimica Acta

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Review of polystyrene diffusion studies in latex particles by small‐angle neutron scattering

Kim¹,

Klein²,

Sperling³

2002

Polymers for Advanced Techs

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This paper reviews small‐angle neutron scattering (SANS) and some results from direct nonradiative energy transfer (DET), for the observation of the diffusion coefficients of polystyrene chains at latex interfaces. To compare SANS with DET, doubly labeled polystyrene with deuterium and fluorescence groups were synthesized, showing that while SANS and DET produce comparable data in terms of diffusion coefficients, both results differ in detail, each having their own advantages. Chain confinement, ionic end groups, and short branch effects on interdiffusion were studied. Large polymer chains confined in small particles have non‐Gaussian shapes that store rubber elastic energy. Rapid, non‐diffusion relaxation is inhibited because the density would be required to become less than normal. Hence confinement effects on the diffusion rate are not significant. Using the DET method, ionic end‐groups were found to increase the early‐time apparent interdiffusion coefficients during film formation. The early‐time apparent diffusion coefficients of polystyrene with varying end‐groups were found to increase as follows: The higher apparent diffusion coefficients of the chains with ionic groups are presumably due to a surface segregation of the end‐groups caused by the polar, aqueous environment during latex synthesis. The interdiffusion behavior of sulfite‐ended polystyrene (Mn ≅ 300 000 g/mol) with H‐ends, one sulfite end, and two sulfite ends were compared via SANS and DET. The diffusion coefficients of polystyrene with one or two sulfite end groups were five times and ten times lower than that of polystyrene, respectively. The ionic end group effects on the reduced diffusion coefficients are interpreted as the competition between enhancement by the surface segregation of end groups and reduction by end group aggregation. Noting that sulfate end groups diffused faster, while sulfite end groups diffused slower, the effect is complex, and not yet fully resolved. Diffusion coefficients of polystyrene with branches were studied by DET. Short branches work to decrease the Tg and hence increase the diffusion coefficients. However, after the experimental temperature, T, is converted to a normalized temperature, T‐Tg, the diffusion coefficients are found to be almost independent upon the number of branches and the length of branches. The branch length ranged from one‐carbon to 40 carbons. Side chains of entanglement molecular weight or longer may be required to significantly reduce the diffusion coefficient. Copyright © 2002 John Wiley & Sons, Ltd.

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Effect of Surface Segregation of Ionic End Groups on Polystyrene Latex Early-Time Interdiffusion

Cited by 7 publications

References 31 publications

SANS Study of Sulfonate End Group Effect on Polystyrene Self-Diffusion

SANS Study of Sulfonate End Group Effect on Polystyrene Self-Diffusion

ZnO nanosphere fabrication using the functionalized polystyrene nanoparticles for dye-sensitized solar cells

Review of polystyrene diffusion studies in latex particles by small‐angle neutron scattering

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