Particle dynamics and relaxation in bimodal suspensions during drying using multispeckle diffusing wave spectroscopy

Gwi Jeong Oh, Ji Won Hwang, Ki Wan Bong, Hyun Wook Jung, Seong Jae Lee

Research output: Contribution to journalArticle

5 Citations (Scopus)


The motion of polystyrene particles in a bimodal suspension drop during drying was characterized via multispeckle diffusing wave spectroscopy. The fast and slow dynamics of bimodal particles, which were expressed in terms of autocorrelation function data from two kinds of cameras, were well connected in short and long lag time regimes. Characteristic time of β-relaxation, representing the rapid movement of bimodal particles, became lower in the short lag time region as the portion of small particles increased, reflecting their fast Brownian motion. The difference in the relaxation features between bimodal suspension with large and small particles and unimodal suspension with only large particles became more evident as the size ratio between particles was high. Drying temperature could encourage the particle movement at the early stages of drying, leading to lower relaxation time, and inversely retard the relaxation behavior when drying time further elapsed, due to the structural rearrangement of particles.

Original languageEnglish
Pages (from-to)1114-1121
Number of pages8
JournalAICHE Journal
Issue number3
Publication statusPublished - 2017 Mar 1



  • autocorrelation function
  • bimodal PS particles
  • characteristic relaxation time
  • multispeckle diffusing wave spectroscopy
  • suspension drying
  • α-relaxation
  • β-relaxation

ASJC Scopus subject areas

  • Biotechnology
  • Environmental Engineering
  • Chemical Engineering(all)

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