利用動態散射光研究磺酸鈉聚苯乙烯(NaPSS)的濃度和分子量其微流變性質的影響

The Effect of Concentration and Molecular Weight on the Microrheology of Sodium Polystyrene Sulfonate Solutioins Studied by Dynamic Light Scattering

陳胤全 ； 鄭宸語 ； 蔣佳君 ； 魏名佐 ； 余翊禾 ； 黃郁喬 ； 黃怡惠 ； Olivier Lavastre ； Husson Guillaume ； Darsy Guillaume ； 邱爾德

《光學工程》 112期 (2010/09) Pp. 52-62

https://doi.org/10.30011/OE.201009.0006

摘要

微流變學因具有低樣品量需求、高靈敏度，且可量測非均勻材料內部微米尺度的局部黏彈性等優點，適合於研究細胞、生物組織液、化學聚合物的動態黏彈性及探討樣品的結構變異時其黏彈性係數的變化，如：分子濃度、分子重量或結構排列對黏彈性係數的影響。我們利用動態散射光(Dynamic light scattering, DLS)方法量測磺酸鈉聚苯乙烯(Sodium Polystyrene Sulfonate, NaPSS)的微流變性質，包括NaPSS在不同濃度(10^(-4)M-10^(-3)M)下的動態黏彈性模數和鬆弛時間(relaxation time)以及不同分子重(70KDa & 200KDa)的NaPSS在同濃度下其黏彈性模數的差異。

關鍵字

微流變 ； 動態散射光 ； 磺酸鈉聚苯乙烯 ； 黏彈性模數 ； 鬆弛時間 ； 均方位移值 ； 布朗運動

並列摘要

Microrheology has proven to be a very useful technique for the determination of the viscoelastic properties of biological samples such as living cells, bio-fluids, and polymer solutions due to the following unique features: (1) require only extremely small amount of sample (~ micro-liter); (2) capable of probing local viscoelastic properties of an heterogeneous medium with micron scale spatial resolution; (3) capable of monitoring the temporal change of the sample viscoelastic properties; (4) fairly high sensitivity. Microrheology can be accomplished by different methods such as active vs. passive, single vs. multiple particle tracking, and with vs. without optical trapping. in this paper, we report our study of the viscoelastic properties of sodium polystyrene sulfonate (NaPSS) solution with different concentration (in the range of 10^(-4)M to 10^(-3)M) and with different molecular weight (70KDa vs. 200KDa) via (multiple-particle) dynamic light scattering (DLS) method. The viscoelastic properties of the sample solutions are characterized in terms of the dynamic complex shear modulus G(superscript *) (consisting of the storage modulus G' and the loss modulus G”) as a function of frequency (f); in addition, the effect of polymer concentration and molecular weight on G' and G”, and on the relaxation time are presented.

並列關鍵字

Microrheology ； Dynamic light scattering ； Sodium Polystyrene Sulfonate ； Complex Shear Modulus ； Relaxation Time ； Mean Square Displacement ； Brownian motion