Article
  • Studies on Depletion Layer of Probe Particles in the System of Poly(vinyl acetate)/Dimethyl Sulfoxide by Dynamic Light Scattering
  • Jeon GJ, Jang J, Park IH
  • 폴리(비닐 아세테이트)/디메틸설폭사이드 계에서 동적 광산란법에 의한 탐침입자의 배제층 연구
  • 전국진, 장진호, 박일현
Abstract
In the system of poly(vinyl alcohol) (PVA)/dimethyl sulfoxide, the refractive index of polymer was very well matched to that of solvent and thus its scattered intensity could be minimized. After adding small amount of polystyrene latex particle (nominal diameter 200 nm), diffusion behavior of only probe particle was investigated against the concentration of polymer matrix by means of dynamic light scattering. The polymer concentration dependence of its reduced diffusion coefficient was able to be analysed with the stretched exponential function of the reduced concentration C[η]. In very dilute concentration regime, the depletion layer kept constant but at the early semi-dilute regime of 1≤C[η]≤2.5, the concentration-dependent exponent of depletion layer δ was appeared to be -0.8 which was very close to theoretical one of -0.85. However it was also observed at the higher concentration that its layer thickness decreased more abruptly than theoretical expectation and this phenomenon was ascribed to Oosawa type attractive interaction between adjacent latex particles.

고분자와 용매의 굴절률이 서로 일치되어 자체 산란광의 세기가 극소화된 시스템인 폴리(비닐 아세테이트) (PVAc)/디메틸설폭사이드(DMSO) 계에 폴리스티렌 라텍스 탐침입자(표시 직경 200 nm)를 소량 첨가한 뒤 동적 광 산란법으로 용액의 PVAc 농도에 대한 입자의 확산 거동을 정밀하게 조사하였다. 구형 입자의 환산확산계수의 농도 의존성은 환산농도 C[η]의 신장지수함수로 분석할 수 있었고, 묽은 농도에서는 배제층의 두께가 일정하게 유지되었 으나 초기 준희박 농도인 1≤C[η]≤2.5 범위에서는 배제층의 사슬농도 의존지수가 -0.8로써 이론적 계산치 -0.85와 일치하였다. 그러나 보다 높은 농도에서는 배제층의 두께가 이론적 예측보다 급속히 감소하는 현상 또한 관찰되었 으며, 그 원인은 인접한 탐침 입자들 사이에 존재하는 Oosawa 인력 때문인 것으로 설명할 수 있었다.

Keywords: light scattering; refractive-index matching; depletion layer; semi-dilute; Oosawa interaction

  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2022 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2015; 39(3): 370-381

    Published online May 25, 2015

  • 10.7317/pk.2015.39.3.370
  • Received on Jun 20, 2014
  • Revised on Nov 30, -0001
  • Accepted on Oct 1, 2014

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