Direct measurement of electrostatic interactions between poly(methyl methacrylate) microspheres with optical laser tweezers

Kyu Hwan Choi, Dong Woo Kang, Kyung Hak Kim, Jiwon Kim, Youngbok Lee, Sang Hyuk Im, Bum Jun Park

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

In this study, we measured the force of electrostatic interactions between poly(methyl methacrylate) (PMMA) particles dispersed in organic solvent mixtures of cyclohexyl bromide (CHB) and n-decane. Optical laser tweezers were employed to directly measure interactive forces between paired PMMA particles in a CHB medium that contained n-decane in various volume ratios. CHB, having a moderate dielectric constant, provided an environment with a high charge storage capacity. The addition of n-decane lowered the effective refractive index of the medium, which increased the optical trapping efficiency. We also fabricated microscope flow cells with a commonly used UV-curable adhesive and quantified the effects of dissolved adhesive compounds through interactive force measurements and nuclear magnetic resonance analysis. In addition, we studied the impact of CHB dissociation into H+ and Br- ions, which could screen electrostatic interactions.

Original languageEnglish
Pages (from-to)8051-8058
Number of pages8
JournalSoft Matter
Volume15
Issue number40
DOIs
Publication statusPublished - 2019 Jan 1

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics

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